Measurement of the
B
0s!
þBranching Fraction and Search
for
B
0!
þwith the CMS Experiment
S. Chatrchyan et al.* (CMS Collaboration)
(Received 18 July 2013; published 5 September 2013) Results are presented from a search for the rare decays B0
s ! þand B0! þin pp collisions
at pffiffiffis¼ 7 and 8 TeV, with data samples corresponding to integrated luminosities of 5 and 20 fb1, respectively, collected by the CMS experiment at the LHC. An unbinned maximum-likelihood fit to the dimuon invariant mass distribution gives a branching fraction BðB0
s ! þÞ ¼ ð3:0þ1:00:9Þ 109,
where the uncertainty includes both statistical and systematic contributions. An excess of B0
s ! þ
events with respect to background is observed with a significance of 4.3 standard deviations. For the decay B0! þan upper limit ofBðB0! þÞ < 1:1 109at the 95% confidence level is determined. Both results are in agreement with the expectations from the standard model.
DOI:10.1103/PhysRevLett.111.101804 PACS numbers: 13.20.He, 12.15.Mm
In the standard model (SM) of particle physics, tree-level diagrams do not contribute to flavor-changing neutral-current (FCNC) decays. However, FCNC decays may proceed through higher-order loop diagrams, and this opens up the possibility for contributions from non-SM particles. In the SM, the rare FCNC decays B0
s ðB0Þ ! þ have small branching fractions of BðB0
s ! þÞ ¼ ð3:57 0:30Þ 109, corresponding to the decay-time integrated branching fraction, and BðB0 ! þÞ ¼ ð1:07 0:10Þ 1010 [1,2]. Charge conjuga-tion is implied throughout this Letter. Several extensions of the SM, such as supersymmetric models with nonuniversal Higgs boson masses [3], specific models containing lep-toquarks [4], and the minimal supersymmetric standard model with large tan [5,6], predict enhancements to the branching fractions for these rare decays. The decay rates can also be suppressed for specific choices of model parameters [7]. Over the past 30 years, significant progress in sensitivity has been made, with exclusion limits on the branching fractions improving by 5 orders of magnitude. The ARGUS [8], UA1 [9], CLEO [10], Belle [11], BABAR [12], CDF [13], D0 [14], ATLAS [15], CMS [16], and LHCb [17] experiments have all published limits on these decays. The LHCb experiment has subsequently shown evidence, with 3.5 standard deviation significance, for the decay B0
s! þ with BðB0s ! þÞ ¼ ð3:2þ1:5
1:2Þ 109[18].
This Letter reports a measurement ofBðB0
s! þÞ based on a simultaneous search for B0
s ! þ and B0 ! þ decays using a data sample of pp collisions
corresponding to integrated luminosities of 5 fbffiffiffi 1 at s
p
¼ 7 TeV and 20 fb1 at 8 TeV collected by the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). For these data, the peak luminos-ity varied from 3:5 1030 to 7:7 1033 cm2 s1. The average number of interactions per bunch crossing (pileup) was 9 (21) atpffiffiffis¼ 7ð8Þ TeV.
The search for the B ! þ signal, where B denotes B0
s or B0, is performed in the dimuon invariant mass regions around the B0
s and B0 masses. To avoid possible biases, the signal region 5:20<m<5:45GeV was kept blind until all selection criteria were established. For the 7 TeV data, this Letter reports a reanalysis of the data used in the previous result [16], where the data were reblinded. The combinatorial dimuon background, mainly from semileptonic decays of separate B mesons, is evaluated by extrapolating the data in nearby mass sidebands into the signal region. Monte Carlo (MC) simulations are used to account for backgrounds from B and b decays. These background samples consist of B ! h, B ! h, and b! p decays, as well as ‘‘peaking’’ decays of the type B ! hh0, where h, h0 are charged hadrons misidentified as muons, which give a dimuon invariant mass distribu-tion that peaks in the signal region. The MC simuladistribu-tion event samples are generated using PYTHIA (version 6.424 for 7 TeV, version 6.426 for 8 TeV) [19], with the underlying event simulated with the Z2 tune [20], unstable particles decayed via EVTGEN [21], and the detector response simulated with GEANT4 [22]. A normalization sample of Bþ! J=cKþ! þKþ decays is used to minimize uncertainties related to the b b production cross section and the integrated luminos-ity. A control sample of B0
s ! J=c ! þKþK decays is used to validate the MC simulation and to evaluate potential effects from differences in fragmenta-tion between Bþand B0s. The efficiencies of all samples, *Full author list given at the end of the article.
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distri-bution of this work must maintain attridistri-bution to the author(s) and the published article’s title, journal citation, and DOI.
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including detector acceptances, are determined with MC simulation studies.
A detailed description of the CMS apparatus can be found in Ref. [23]. The CMS experiment uses a right-handed coordinate system, with the origin at the nominal interaction point, the x axis pointing to the center of the LHC ring, the y axis pointing up, and the z axis along the counterclockwise-beam direction. The polar angle is measured from the positive z axis and the azimuthal angle is measured in the x-y plane. The main subdetectors used in this analysis are the silicon tracker and the muon detectors. Muons are tracked within the pseudorapidity regionjj < 2:4, where ¼ ln½tanð=2Þ. A transverse momentum (pT) resolution of about 1.5% is obtained for muons in this analysis [24].
The events are selected with a two-level trigger system. The first level requires only two muon candidates in the muon detectors. The high-level trigger (HLT) uses addi-tional information from the silicon tracker to provide es-sentially a full event reconstruction. The dimuon invariant mass was required to satisfy 4:8 < m< 6:0 GeV. For the 7 TeV data set, the HLT selection required two muons, each with pT> 4:0 GeV, and a dimuon pT > 3:9 GeV. For events having at least one muon withjj > 1:5, pT > 5:9 GeV was required. For the 8 TeV data set, the pT criterion on the muon with lower pT was loosened to pT> 3:0 GeV, with pT > 4:9 GeV. For events contain-ing at least one muon withjj > 1:8, the muons were each required to have pT> 4:0 GeV, pT > 7:0 GeV, and the dimuon vertex fit p value >0:5%.
For the normalization and control samples the HLT selec-tion required the following: two muons, each with pT > 4 GeV andjj<2:2; pT >6:9GeV; 2:9<m<3:3GeV; and the dimuon vertex fit p value >15%. Two additional requirements were imposed in the transverse plane: (i) the pointing angle xy between the dimuon momentum and the vector from the average interaction point to the dimuon vertex had to fulfill cosxy> 0:9, and (ii) the flight length significance ‘xy=ð‘xyÞ must be greater than 3, where ‘xyis the two-dimensional distance between the average interac-tion point and the dimuon vertex, and ð‘xyÞ is its uncer-tainty. The signal, normalization, and control triggers required the three-dimensional (3D) distance of closest approach (dca) between the two muons to satisfy dca< 0:5 cm. The average trigger efficiency for events in the signal and normalization samples, as determined from MC simulation and calculated after all other selection criteria are applied, is in the range (39–85)%, depending on the running period and detector region. The uncertainty in the ratio of trigger efficiencies [muon identification efficiencies] for the signal and normalization samples is estimated to be (3–6)% [(1–4)%] by comparing simulation and data.
The B ! þ candidates are constructed from two oppositely charged ‘‘tight’’ muons as described in
Ref. [25]. Both muons must have pT> 4 GeV and be consistent in direction and pT with the muons that trig-gered the event. A boosted decision tree (BDT) constructed within the TMVA framework [26] is trained to further separate genuine muons from those arising from misiden-tified charged hadrons. The variables used in the BDT can be divided into four classes: basic kinematic quantities, silicon-tracker fit information, combined silicon and muon track fit information, and muon detector information. The BDT is trained on MC simulation samples of B-meson decays to kaons and muons. Compared to the tight muons, the BDT working point used to select muons for this analysis reduces the hadron-to-muon misidentification probability by 50% while retaining 90% of true muons. The probability to misidentify a charged hadron as a muon because of decay in flight or detector punchthrough is measured in data from samples of well-identified pions, kaons, and protons. This probability ranges from ð0:5–1:3Þ103,ð0:8–2:2Þ 103, andð0:4–1:5Þ 103, for pions, kaons, and protons, respectively, depending on whether the particle is in the barrel or end cap, the running period, and the momentum. Each of these probabilities is ascribed an uncertainty of 50%, based on differences between data and MC simulation.
Candidates are kept for further analysis if they have 4:9 < m< 5:9 GeV, after constraining the tracks to a common vertex. The B-candidate momentum and vertex position are used to choose a primary vertex based on the distance of closest approach along the beam line. Since the background level and mass resolution depend significantly on , where is the pseudorapidity of the B-meson candidate, the events are separated into two categories: the ‘‘barrel channel’’ with candidates where both muons have jj < 1:4, and the ‘‘end-cap channel’’ containing those where at least one muon has jj > 1:4. The m resolu-tion, as determined from simulated signal events, ranges from 32 MeV for 0 to 75 MeV for jj > 1:8.
Four isolation variables are defined.
(1) I ¼ pT =ðpT þPtrkpTÞ, where P
trkpT is the sum of pT of all tracks, other than muon candidates, satisfying R ¼pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiðÞ2þ ðÞ2< 0:7, with and as the differences in and between a charged track and the direction of the B candidate. The sum includes all tracks with pT > 0:9 GeV that are (i) consistent with originating from the same primary vertex as the B candidate or (ii) have a dcawith respect to the B vertex <0:05 cm and are not associated with any other primary vertex. (2) I is the isolation variable of each muon, calculated as for the B candidate, but with respect to the muon track. A cone size of R ¼ 0:5 around the muon and tracks with pT> 0:5 GeV and dca< 0:1 cm from the muon are used. (3) Nclose
trk is defined as the number of tracks with pT> 0:5 GeV and dca with respect to the B vertex less than <0:03 cm. (4) d0ca is defined as the smallest dca to the B vertex, considering all tracks in the event that are either PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
associated with the same primary vertex as the B candidate or not associated with any primary vertex.
The final selection is performed with BDTs trained to distinguish between signal and background event candi-dates. For the training, B0s ! þ MC simulation samples are used for the signal, and candidates from the data dimuon mass sidebands after a loose preselection for the background. The preselection retains at least 10 000 events dominated by combinatorial background for each BDT. To avoid any selection bias, the data background events are randomly split into three sets, such that the training and testing of the BDT is performed on sets independent of its application. Studies with sideband events and signal MC simulation samples with shifted B mass show that the BDT response is independent of mass. Separate BDTs are trained for each of the four combina-tions of 7 and 8 TeV data and the barrel and end-cap regions of the detector. For each BDT, a number of varia-bles is considered and only those found to be effective are included. Each of the following 12 variables, shown to be independent of pileup, are used in at least one of the BDTs: I; I; Nclosetrk ; d0ca; pT ; ; the B-vertex fit 2per degree of freedom (dof); the dcabetween the two muon tracks; the 3D pointing angle 3D; the 3D flight length significance ‘3D=ð‘3DÞ; the 3D impact parameter 3Dof the B candi-date; and its significance 3D=ð3DÞ, where ð3DÞ is the uncertainty on 3D. The last four variables are computed with respect to the primary vertex. Good agreement between data and MC simulation is observed for these variables. In total, including the division into three sets, 12 BDTs are trained.
The output discriminant b of the BDT is used in two ways for further analysis. (1) In the 1D-BDT method, a minimum requirement on b per channel is used to define the final selection. The requirement on b is optimized for best S=pffiffiffiffiffiffiffiffiffiffiffiffiffiS þ B(where S is the expected signal and B the background) on statistically independent data control samples. The optimization gives b > 0:29 for both barrel and end cap in thepffiffiffis¼ 7 TeV data, and b > 0:36 (0.38) in the barrel (end cap) for the pffiffiffis¼ 8 TeV sample. The
1D-BDT method is used for the determination of the upper limit on BðB0 ! þÞ. The signal efficiencies "
tot for method (1) are provided in Table I, together with the expected number of events (signal and signal plus back-ground) for the B0signal region 5:20 < m < 5:30 GeV and the B0s signal region 5:30 < m < 5:45 GeV. (2) In the categorized-BDT method, the discriminant b is used to define 12 event categories with different signal-to-background ratios. For the pffiffiffis¼ 7 TeV data in the barrel (end-cap) channel, the two categories have boundaries of 0.10, 0.31, 1.00 (0.10, 0.26, 1.00). For the pffiffiffis¼ 8 TeV sample in the barrel (end-cap) channel, the corresponding boundaries for the four categories are 0.10, 0.23, 0.33, 0.44, 1.00 (0.10, 0.22, 0.33, 0.45, 1.00). This binning is chosen to give the same expected signal yield in each bin. The dimuon invariant mass distributions for the 12 categories of events are fitted simultaneously to obtain the final results. Method (2) has higher expected sensitivity and thus provides the main methodology for the extraction of BðB0
s! þÞ.
The Bþ! J=cKþ! þKþ (B0
s ! J=c ! þKþK) selection requires two oppositely charged muons with 3:0 < m< 3:2 GeV and pT > 7 GeV, combined with one or two tracks, assumed to be kaons, fulfilling pT> 0:5 GeV and jj < 2:4 (jj < 2:1 in the 8 TeV data). The distance of closest approach between all pairs among the three (four) tracks is required to be less than 0.1 cm. For B0
s! J=c candidates the two assumed kaon tracks must have invariant mass 0:995 < mKK< 1:045 GeV and R < 0:25. The B vertex is fitted from the three (four) tracks; a candidate is accepted if the resulting invariant mass is in the range 4.8–6.0 GeV. The final selection is achieved using the same BDT as for the signal, with the following modifications: the B-vertex 2=dof is determined from the dimuon vertex fit, and for the calculation of the isolation variables all B-candidate decay tracks are neglected.
The total efficiency to reconstruct with the 1D-BDT method a Bþ ! J=cKþ! þKþ decay, including the detector acceptance, is "Btotþ¼ ð0:98 0:08Þ 103 TABLE I. The signal selection efficiencies "tot, the predicted number of SM signal events
Nexpsignal, the expected number of signal and background events N exp
total, and the number of observed
events Nobs in the barrel and end-cap channels for the 7 and 8 TeV data using the 1D-BDT
method. The event numbers refer to the B0and B0
s signal regions, respectively.
"tot½102 N exp signal N exp total Nobs 7 TeV B0 barrel 0:33 0:03 0:27 0:03 1:3 0:8 3 B0 s barrel 0:30 0:04 2:97 0:44 3:6 0:6 4 B0end cap 0:20 0:02 0:11 0:01 1:5 0:6 1 B0s end cap 0:20 0:02 1:28 0:19 2:6 0:5 4 8 TeV B0 barrel 0:24 0:02 1:00 0:10 7:9 3:0 11 B0 s barrel 0:23 0:03 11:46 1:72 17:9 2:8 16 B0end cap 0:10 0:01 0:30 0:03 2:2 0:8 3 B0 s end cap 0:09 0:01 3:56 0:53 5:1 0:7 4
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andð0:36 0:04Þ 103, respectively, for the barrel and end-cap channels in the 7 TeV analysis, and ð0:82 0:07Þ 103 and ð0:21 0:03Þ 103 for the 8 TeV analysis, where statistical and systematic uncertainties are combined in quadrature. The distributions of b for the normalization and control samples are found to agree well between data and MC simulation, with residual differences used to estimate systematic uncertainties. No dependence of the selection efficiency on pileup is observed. The systematic uncertainty in the acceptance is estimated by comparing the values obtained with different b b production mechanisms (gluon splitting, flavor excitation, and flavor creation). The uncertainty in the event selection efficiency for the Bþ! J=cKþ normalization sample is evaluated from differences between measured and simulated Bþ ! J=cKþ events. The uncertainty in the B0
s ! þ and B0! þ signal efficiencies [(3–10)%, depending on the channel andpffiffiffis] is evaluated using the B0
s! J=c control sample.
The yields for the normalization (control) sample in each category are fitted with a double (single) Gaussian function. The backgrounds under the normalization and control sample peaks are described with an exponential (plus an error function for the normalization sample). Additional functions are included, with shape templates fixed from simulation, to account for backgrounds from Bþ! J=c þ (Gaussian function) for the normalization sample, and B0! J=cK0(Landau function) for the con-trol sample. In the 7 TeV data, the observed number of Bþ! J=cKþcandidates in the barrel isð71:24:1Þ103 and ð21:4 1:1Þ 103 in the end-cap channel. For the 8 TeV sample the corresponding yields areð309 16Þ 103 (barrel) andð69:3 3:5Þ 103 (end cap). The uncer-tainties include a systematic component estimated from simu-lated events by considering alternative fitting functions.
The B0
s! þbranching fraction is measured using BðB0 s ! þÞ ¼ NS NBþ obs fu fs "Bþ tot "tot BðBþÞ; (1) and analogously for the B0! þ case, where NS (NBþ
obs) is the number of reconstructed B0s ! þ(Bþ ! J=cKþ) decays, "tot ("B
þ
tot) is the total signal (Bþ) effi-ciency,BðBþÞ ¼ ð6:0 0:2Þ 105[27] is the branching fraction for Bþ ! J=cKþ! þKþ, and fu=fsis the ratio of the Bþ and B0
s fragmentation fractions. The value fs=fu¼ 0:256 0:020, as measured by LHCb [28], is used and an additional systematic uncertainty of 5% is assigned to account for possible pseudorapidity and pT dependence of this ratio. Studies based on the Bþ ! J=cK and B0s ! J=c control samples reveal no discern-ible pseudorapidity or pT dependence of this ratio in the kinematic region used in the analysis.
An unbinned maximum-likelihood fit to the m distri-bution is used to extract the signal and background yields. Events in the signal window can result from genuine signal,
combinatorial background, background from semileptonic b-hadron decays, and the peaking background. The proba-bility density functions (PDFs) for the signal, semileptonic, and peaking backgrounds are obtained from fits to MC simulation. The B0
s and B0 signal shapes are modeled by Crystal Ball functions [29]. The peaking background is modeled with the sum of Gaussian and Crystal Ball functions (with a common mean). The semileptonic background is modeled with a Gaussian kernels method [30,31]. The PDF for the combinatorial background is modeled with a first-degree polynomial. Since the dimuon mass resolution , determined on an event-by-event basis from the dimuon mass fit, varies significantly, the PDFs described above are combined as a conditional product with the PDF for the per-event mass resolution, such that the Crystal Ball function width correctly reflects the resolution on a per-event basis. To avoid any effect of the correlation between and the can-didate mass, we divide the invariant mass uncertainty by the mass to obtain a ‘‘reduced’’ mass uncertainty, r¼ =m, which is used in the fit.
The dimuon mass distributions for the four channels (barrel and end cap in 7 and 8 TeV data), further divided into categories corresponding to different bins in the BDT parameter b, are fitted simultaneously. The results are illustrated for the most sensitive categories in Fig. 1. The fits for all 12 categories are shown in the Supplemental Material [32] showing additional plots of the mass fits. Pseudoexperiments, done with MC simulated events, con-firm the robustness and accuracy of the fitting procedure.
(GeV) µ µ m 5.3 Events / ( 0.04 GeV ) 0 8 = 8 TeV - Barrel s -1 CMS - L = 20 fb 0.44 < BDT < 1.00 data full PDF -µ + µ → s 0 B -µ + µ → 0 B combinatorial bkg semileptonic bkg peaking bkg (GeV) µ µ m 4.9 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 Events / ( 0.04 GeV ) = 8 TeV - Barrel s -1 CMS - L = 20 fb 0.33 < BDT < 0.44 data full PDF -µ + µ → s 0 B -µ + µ → 0 B combinatorial bkg semileptonic bkg peaking bkg (GeV) µ µ m Events / ( 0.04 GeV ) = 8 TeV - Endcap s -1 CMS - L = 20 fb 0.45 < BDT < 1.00 data full PDF -µ + µ → s 0 B -µ + µ → 0 B combinatorial bkg semileptonic bkg peaking bkg (GeV) µ µ m Events / ( 0.04 GeV ) = 8 TeV - Endcap s -1 CMS - L = 20 fb 0.33 < BDT < 0.45 data full PDF -µ + µ → s 0 B -µ + µ → 0 B combinatorial bkg semileptonic bkg peaking bkg 4.9 5 5.1 5.2 5.4 5.5 5.6 5.7 5.8 5.9 1 2 3 4 5 6 7 -1 0.44 < BDT < 1.00 data full PDF -µ + µ → s 0 B -µ + µ → 0 B combinatorial bkg semileptonic bkg peaking bkg 5.3 0 2 4 6 8 10 12 14
Systematic uncertainties are constrained with Gaussian PDFs with the standard deviations of the constraints set equal to the uncertainties. Sources of systematic uncer-tainty arise from the hadron-to-muon misidentification probability, the branching fraction uncertainties (domi-nated by 100% for b! p), and the normalization of the peaking background. The B ! hh0 and semileptonic backgrounds are estimated by normalizing to the observed Bþ! J=cKþ yield. The peaking background yield is constrained in the fit with log-normal PDFs with rms parameters set to the mean 1-standard-deviation uncertain-ties. The absolute level of peaking background has been studied on an independent data sample, obtained with single-muon triggers, and is found to agree with the exp-ectation described above. The shape parameters for the peaking and the semileptonic backgrounds and for the signals are fixed to the expectation. The mass scale uncer-tainty at the B-meson mass is 6 MeV (7 MeV) for the barrel
(end-cap) channel, as determined with charmonium and bottomium decays to dimuon final states.
An excess of B0
s ! þ decays is observed above the background predictions. The measured decay-time integrated branching fraction from the fit is BðB0
s! þÞ ¼ ð3:0þ1:00:9Þ 109, where the uncertainty includes both the statistical and systematic components, but is dominated by the statistical uncertainties. The observed (expected median) significance of the excess is 4.3 (4.8) standard deviations and is determined by evaluat-ing the ratio of the likelihood value for the hypothesis with no signal, divided by the likelihood withBðB0
s ! þÞ floating. For this determination, BðB0 ! þÞ is allowed to float and is treated as a nuisance parameter in the fit (see the top plot in Fig.2). The measured branching fraction is consistent with the expectation from the SM. With the 1D-BDT method, the observed (expected median) significance is 4.8 (4.7) standard deviations. Figure3shows the combined mass distributions weighted by S=ðS þ BÞ for the categorized-BDT (left) and the 1D-BDT (right) methods. However, these distributions are illustrative only and were not used to obtain the final results.
No significant excess is observed for B0 ! þ, and the upper limitBðB0! þÞ<1:1109(9:2 1010) at 95% (90%) confidence level (C.L.) is determined with the CLSapproach [33,34], based on the observed numbers of events in the signal and sideband regions with the 1D-BDT method as summarized in Table I. The expected 95% C.L. upper limit forBðB0 ! þÞ in the presence of SM signal plus background (background-only) is 6:3 1010 (5:4 1010), where the statistical and systematic uncertainties are considered. The bottom plot in Fig. 2 shows the observed and expected CLS curves versus the assumed BðB0! þÞ. From the fit, the branching fraction for this decay is determined to be ) -µ + µ → s 0 BF(B 0 1 2 3 4 5 6 7 8 9 10 -9 10 × ) -µ + µ → 0 BF(B 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 -9 10 × σ 1 σ 2 σ 3 σ 4 CMS SM CMS -1 =8 TeV, L=20 fb s -1 =7 TeV, L=5 fb s ) -µ + µ → s 0 BF(B 0 1 2 3 4 5 -9 10 × lnL∆ 2 0 2 4 6 8 10 12 14 16 18 20 σ 1 σ 2 σ 3 σ 4 -9 10 × ) -0.9 +1.0 (3.0 )= -µ + µ → s 0 BF(B σ 4.3 SM ) -µ + µ → 0 BF(B 0 0.2 0.4 0.6 0.8 1 -9 10 × lnL∆ 2 0 2 4 6 8 10 12 14 16 18 20 σ 1 σ 2 σ 3 σ 4 -10 10 × ) -1.8 +2.1 (3.5 )= -µ + µ → 0 BF(B σ 2.0 SM ) -µ + µ → 0 BF(B 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 -9 10 × s CL 0 0.2 0.4 0.6 0.8 1 CLs observed σ 2 ± s Expected SM CL σ 1 ± s Expected SM CL median s Expected SM CL CMS L = 5fb-1 (7TeV) + 20fb-1 (8TeV)
FIG. 2 (color online). Top, scan of the ratio of the joint like-lihood forBðB0s ! þÞ and BðB0! þÞ. As insets, the
likelihood ratio scan for each of the branching fractions when the other is profiled together with other nuisance parameters; the significance at which the background-only hypothesis is rejected is also shown. Bottom, observed and expected CLS for B0! þas a function of the assumed branching fraction.
(GeV)
µ µ
m
4.9 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9
S/(S+B) Weighted Events / ( 0.04 GeV)
0 10 20 30 40 50 = 8 TeV s -1 = 7 TeV, L = 20 fb s -1 CMS - L = 5 fb data full PDF -µ + µ → s 0 B -µ + µ → 0 B combinatorial bkg semileptonic bkg peaking bkg (GeV) µ µ m 4.9 5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9
S/(S+B) Weighted Events / ( 0.04 GeV)
0 2 4 6 8 10 12 14 = 8 TeV s -1 = 7 TeV, L = 20 fb s -1 CMS - L = 5 fb data full PDF -µ + µ → s 0 B -µ + µ → 0 B combinatorial bkg semileptonic bkg peaking bkg
FIG. 3 (color online). Plots illustrating the combination of all categories used in the categorized-BDT method (left) and the 1D-BDT method (right). For these plots, the individual catego-ries are weighted with S=ðS þ BÞ, where S (B) is the signal (background) determined at the B0
s peak position. The overall
normalization is set such that the fitted B0
ssignal corresponds to
the total yield of the individual contributions. These distributions are for illustrative purposes only and were not used in obtaining the final results.
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BðB0 ! þÞ ¼ ð3:5þ2:1
1:8Þ 1010. The significance of this measurement is 2.0 standard deviations. The dimuon invariant mass distributions with the 1D-BDT method for the four channels are shown in the Supplemental Material [32].
In summary, a search for the rare decays B0s! þ and B0 ! þ has been performed on a data sample of pp collisions at pffiffiffis¼ 7 and 8 TeV corresponding to integrated luminosities of 5 and 20 fb1, respectively. No significant evidence is observed for B0 ! þ and an upper limit ofBðB0! þÞ < 1:1 109is estab-lished at 95% C.L. For B0
s! þ, an excess of events with a significance of 4.3 standard deviations is observed, and a branching fraction of BðB0
s!þÞ¼ð3:0þ1:00:9Þ 109is determined, in agreement with the standard model expectations.
We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and at other CMS institutes for their contributions to the success of the CMS effort. In addition, we gratefully acknowledge the computing centers and personnel of the Worldwide LHC Computing Grid for delivering so effec-tively the computing infrastructure essential to our analy-ses. Finally, we acknowledge the enduring support for the construction and operation of the LHC and the CMS detector provided by the following funding agencies: BMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and
CNRS/IN2P3 (France); BMBF, DFG, and HGF
(Germany); GSRT (Greece); OTKA and NKTH
(Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Republic of Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR (Russia); MESTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEPCenter, IPST, STAR and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (U.S.).
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S. Chatrchyan,1V. Khachatryan,1A. M. Sirunyan,1A. Tumasyan,1W. Adam,2T. Bergauer,2M. Dragicevic,2J. Ero¨,2 C. Fabjan,2,bM. Friedl,2R. Fru¨hwirth,2,bV. M. Ghete,2N. Ho¨rmann,2J. Hrubec,2M. Jeitler,2,bW. Kiesenhofer,2 PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
V. Knu¨nz,2M. Krammer,2,bI. Kra¨tschmer,2D. Liko,2I. Mikulec,2D. Rabady,2,cB. Rahbaran,2C. Rohringer,2 H. Rohringer,2R. Scho¨fbeck,2J. Strauss,2A. Taurok,2W. Treberer-Treberspurg,2W. Waltenberger,2C.-E. Wulz,2,b
V. Mossolov,3N. Shumeiko,3J. Suarez Gonzalez,3S. Alderweireldt,4M. Bansal,4S. Bansal,4T. Cornelis,4 E. A. De Wolf,4X. Janssen,4A. Knutsson,4S. Luyckx,4L. Mucibello,4S. Ochesanu,4B. Roland,4R. Rougny,4
Z. Staykova,4H. Van Haevermaet,4P. Van Mechelen,4N. Van Remortel,4A. Van Spilbeeck,4F. Blekman,5 S. Blyweert,5J. D’Hondt,5A. Kalogeropoulos,5J. Keaveney,5S. Lowette,5M. Maes,5A. Olbrechts,5S. Tavernier,5
W. Van Doninck,5P. Van Mulders,5G. P. Van Onsem,5I. Villella,5C. Caillol,6B. Clerbaux,6G. De Lentdecker,6 L. Favart,6A. P. R. Gay,6T. Hreus,6A. Le´onard,6P. E. Marage,6A. Mohammadi,6L. Pernie`,6T. Reis,6T. Seva,6
L. Thomas,6C. Vander Velde,6P. Vanlaer,6J. Wang,6V. Adler,7K. Beernaert,7L. Benucci,7A. Cimmino,7 S. Costantini,7S. Dildick,7G. Garcia,7B. Klein,7J. Lellouch,7A. Marinov,7J. Mccartin,7A. A. Ocampo Rios,7
D. Ryckbosch,7M. Sigamani,7N. Strobbe,7F. Thyssen,7M. Tytgat,7S. Walsh,7E. Yazgan,7N. Zaganidis,7 S. Basegmez,8C. Beluffi,8,dG. Bruno,8R. Castello,8A. Caudron,8L. Ceard,8G. G. Da Silveira,8C. Delaere,8 T. du Pree,8D. Favart,8L. Forthomme,8A. Giammanco,8,eJ. Hollar,8P. Jez,8V. Lemaitre,8J. Liao,8O. Militaru,8
C. Nuttens,8D. Pagano,8A. Pin,8K. Piotrzkowski,8A. Popov,8,fM. Selvaggi,8M. Vidal Marono,8 J. M. Vizan Garcia,8N. Beliy,9T. Caebergs,9E. Daubie,9G. H. Hammad,9G. A. Alves,10M. Correa Martins Junior,10
T. Martins,10M. E. Pol,10M. H. G. Souza,10W. L. Alda´ Ju´nior,11W. Carvalho,11J. Chinellato,11,gA. Custo´dio,11 E. M. Da Costa,11D. De Jesus Damiao,11C. De Oliveira Martins,11S. Fonseca De Souza,11H. Malbouisson,11
M. Malek,11D. Matos Figueiredo,11L. Mundim,11H. Nogima,11W. L. Prado Da Silva,11A. Santoro,11 A. Sznajder,11E. J. Tonelli Manganote,11,gA. Vilela Pereira,11C. A. Bernardes,12bF. A. Dias,12a,h T. R. Fernandez Perez Tomei,12aE. M. Gregores,12bC. Lagana,12aP. G. Mercadante,12bS. F. Novaes,12a Sandra S. Padula,12aV. Genchev,13,cP. Iaydjiev,13,cS. Piperov,13M. Rodozov,13G. Sultanov,13M. Vutova,13 A. Dimitrov,14R. Hadjiiska,14V. Kozhuharov,14L. Litov,14B. Pavlov,14P. Petkov,14J. G. Bian,15G. M. Chen,15
H. S. Chen,15C. H. Jiang,15D. Liang,15S. Liang,15X. Meng,15J. Tao,15X. Wang,15Z. Wang,15 C. Asawatangtrakuldee,16Y. Ban,16Y. Guo,16W. Li,16S. Liu,16Y. Mao,16S. J. Qian,16H. Teng,16D. Wang,16
L. Zhang,16W. Zou,16C. Avila,17C. A. Carrillo Montoya,17L. F. Chaparro Sierra,17J. P. Gomez,17 B. Gomez Moreno,17J. C. Sanabria,17N. Godinovic,18D. Lelas,18R. Plestina,18,iD. Polic,18I. Puljak,18 Z. Antunovic,19M. Kovac,19V. Brigljevic,20K. Kadija,20J. Luetic,20D. Mekterovic,20S. Morovic,20L. Tikvica,20
A. Attikis,21G. Mavromanolakis,21J. Mousa,21C. Nicolaou,21F. Ptochos,21P. A. Razis,21M. Finger,22 M. Finger, Jr.,22Y. Assran,23,jS. Elgammal,23,kA. Ellithi Kamel,23,lA. M. Kuotb Awad,23,mM. A. Mahmoud,23,m
A. Radi,23,n,oM. Kadastik,24M. Mu¨ntel,24M. Murumaa,24M. Raidal,24L. Rebane,24A. Tiko,24P. Eerola,25 G. Fedi,25M. Voutilainen,25J. Ha¨rko¨nen,26V. Karima¨ki,26R. Kinnunen,26M. J. Kortelainen,26T. Lampe´n,26
K. Lassila-Perini,26S. Lehti,26T. Linde´n,26P. Luukka,26T. Ma¨enpa¨a¨,26T. Peltola,26E. Tuominen,26 J. Tuominiemi,26E. Tuovinen,26L. Wendland,26T. Tuuva,27M. Besancon,28F. Couderc,28M. Dejardin,28
D. Denegri,28B. Fabbro,28J. L. Faure,28F. Ferri,28S. Ganjour,28A. Givernaud,28P. Gras,28 G. Hamel de Monchenault,28P. Jarry,28E. Locci,28J. Malcles,28L. Millischer,28A. Nayak,28J. Rander,28 A. Rosowsky,28M. Titov,28S. Baffioni,29F. Beaudette,29L. Benhabib,29M. Bluj,29,pP. Busson,29C. Charlot,29
N. Daci,29T. Dahms,29M. Dalchenko,29L. Dobrzynski,29A. Florent,29R. Granier de Cassagnac,29 M. Haguenauer,29P. Mine´,29C. Mironov,29I. N. Naranjo,29M. Nguyen,29C. Ochando,29P. Paganini,29D. Sabes,29
R. Salerno,29Y. Sirois,29C. Veelken,29A. Zabi,29J.-L. Agram,30,qJ. Andrea,30D. Bloch,30J.-M. Brom,30 E. C. Chabert,30C. Collard,30E. Conte,30,qF. Drouhin,30,qJ.-C. Fontaine,30,qD. Gele´,30U. Goerlach,30 C. Goetzmann,30P. Juillot,30A.-C. Le Bihan,30P. Van Hove,30S. Gadrat,31S. Beauceron,32N. Beaupere,32 G. Boudoul,32S. Brochet,32J. Chasserat,32R. Chierici,32D. Contardo,32P. Depasse,32H. El Mamouni,32J. Fan,32
J. Fay,32S. Gascon,32M. Gouzevitch,32B. Ille,32T. Kurca,32M. Lethuillier,32L. Mirabito,32S. Perries,32 L. Sgandurra,32V. Sordini,32M. Vander Donckt,32P. Verdier,32S. Viret,32H. Xiao,32Z. Tsamalaidze,33,r C. Autermann,34S. Beranek,34M. Bontenackels,34B. Calpas,34M. Edelhoff,34L. Feld,34N. Heracleous,34 O. Hindrichs,34K. Klein,34A. Ostapchuk,34A. Perieanu,34F. Raupach,34J. Sammet,34S. Schael,34D. Sprenger,34
H. Weber,34B. Wittmer,34V. Zhukov,34,fM. Ata,35J. Caudron,35E. Dietz-Laursonn,35D. Duchardt,35 M. Erdmann,35R. Fischer,35A. Gu¨th,35T. Hebbeker,35C. Heidemann,35K. Hoepfner,35D. Klingebiel,35 S. Knutzen,35P. Kreuzer,35M. Merschmeyer,35A. Meyer,35M. Olschewski,35K. Padeken,35P. Papacz,35H. Pieta,35
H. Reithler,35S. A. Schmitz,35L. Sonnenschein,35J. Steggemann,35D. Teyssier,35S. Thu¨er,35M. Weber,35 V. Cherepanov,36Y. Erdogan,36G. Flu¨gge,36H. Geenen,36M. Geisler,36W. Haj Ahmad,36F. Hoehle,36B. Kargoll,36 PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
T. Kress,36Y. Kuessel,36J. Lingemann,36,cA. Nowack,36I. M. Nugent,36L. Perchalla,36O. Pooth,36A. Stahl,36 I. Asin,37N. Bartosik,37J. Behr,37W. Behrenhoff,37U. Behrens,37A. J. Bell,37M. Bergholz,37,sA. Bethani,37
K. Borras,37A. Burgmeier,37A. Cakir,37L. Calligaris,37A. Campbell,37S. Choudhury,37F. Costanza,37 C. Diez Pardos,37S. Dooling,37T. Dorland,37G. Eckerlin,37D. Eckstein,37G. Flucke,37A. Geiser,37I. Glushkov,37
A. Grebenyuk,37P. Gunnellini,37S. Habib,37J. Hauk,37G. Hellwig,37D. Horton,37H. Jung,37M. Kasemann,37 P. Katsas,37C. Kleinwort,37H. Kluge,37M. Kra¨mer,37D. Kru¨cker,37E. Kuznetsova,37W. Lange,37J. Leonard,37
K. Lipka,37W. Lohmann,37,sB. Lutz,37R. Mankel,37I. Marfin,37I.-A. Melzer-Pellmann,37A. B. Meyer,37 J. Mnich,37A. Mussgiller,37S. Naumann-Emme,37O. Novgorodova,37F. Nowak,37J. Olzem,37H. Perrey,37
A. Petrukhin,37D. Pitzl,37R. Placakyte,37A. Raspereza,37P. M. Ribeiro Cipriano,37C. Riedl,37E. Ron,37 M. O¨ . Sahin,37J. Salfeld-Nebgen,37R. Schmidt,37,sT. Schoerner-Sadenius,37N. Sen,37M. Stein,37R. Walsh,37 C. Wissing,37M. Aldaya Martin,38V. Blobel,38H. Enderle,38J. Erfle,38E. Garutti,38U. Gebbert,38M. Go¨rner,38 M. Gosselink,38J. Haller,38K. Heine,38R. S. Ho¨ing,38G. Kaussen,38H. Kirschenmann,38R. Klanner,38R. Kogler,38
J. Lange,38I. Marchesini,38T. Peiffer,38N. Pietsch,38D. Rathjens,38C. Sander,38H. Schettler,38P. Schleper,38 E. Schlieckau,38A. Schmidt,38M. Schro¨der,38T. Schum,38M. Seidel,38J. Sibille,38,tV. Sola,38H. Stadie,38 G. Steinbru¨ck,38J. Thomsen,38D. Troendle,38E. Usai,38L. Vanelderen,38C. Barth,39C. Baus,39J. Berger,39 C. Bo¨ser,39E. Butz,39T. Chwalek,39W. De Boer,39A. Descroix,39A. Dierlamm,39M. Feindt,39M. Guthoff,39,c
F. Hartmann,39,cT. Hauth,39,cH. Held,39K. H. Hoffmann,39U. Husemann,39I. Katkov,39,fJ. R. Komaragiri,39 A. Kornmayer,39,cP. Lobelle Pardo,39D. Martschei,39M. U. Mozer,39Th. Mu¨ller,39M. Niegel,39A. Nu¨rnberg,39
O. Oberst,39J. Ott,39G. Quast,39K. Rabbertz,39F. Ratnikov,39S. Ro¨cker,39F.-P. Schilling,39G. Schott,39 H. J. Simonis,39F. M. Stober,39R. Ulrich,39J. Wagner-Kuhr,39S. Wayand,39T. Weiler,39M. Zeise,39 G. Anagnostou,40G. Daskalakis,40T. Geralis,40S. Kesisoglou,40A. Kyriakis,40D. Loukas,40A. Markou,40 C. Markou,40E. Ntomari,40I. Topsis-giotis,40L. Gouskos,41A. Panagiotou,41N. Saoulidou,41E. Stiliaris,41 X. Aslanoglou,42I. Evangelou,42G. Flouris,42C. Foudas,42P. Kokkas,42N. Manthos,42I. Papadopoulos,42 E. Paradas,42G. Bencze,43C. Hajdu,43P. Hidas,43D. Horvath,43,uF. Sikler,43V. Veszpremi,43G. Vesztergombi,43,v
A. J. Zsigmond,43N. Beni,44S. Czellar,44J. Molnar,44J. Palinkas,44Z. Szillasi,44J. Karancsi,45P. Raics,45 Z. L. Trocsanyi,45B. Ujvari,45N. Sahoo,46S. K. Swain,46,wS. B. Beri,47V. Bhatnagar,47N. Dhingra,47R. Gupta,47
M. Kaur,47M. Z. Mehta,47M. Mittal,47N. Nishu,47A. Sharma,47J. B. Singh,47Ashok Kumar,48Arun Kumar,48 S. Ahuja,48A. Bhardwaj,48B. C. Choudhary,48A. Kumar,48S. Malhotra,48M. Naimuddin,48K. Ranjan,48
P. Saxena,48V. Sharma,48R. K. Shivpuri,48S. Banerjee,49S. Bhattacharya,49K. Chatterjee,49S. Dutta,49 B. Gomber,49Sa. Jain,49Sh. Jain,49R. Khurana,49A. Modak,49S. Mukherjee,49D. Roy,49S. Sarkar,49M. Sharan,49
A. P. Singh,49A. Abdulsalam,50D. Dutta,50S. Kailas,50V. Kumar,50A. K. Mohanty,50,cL. M. Pant,50P. Shukla,50 A. Topkar,50T. Aziz,51R. M. Chatterjee,51S. Ganguly,51S. Ghosh,51M. Guchait,51,xA. Gurtu,51,yG. Kole,51
S. Kumar,51M. Maity,51,zG. Majumder,51K. Mazumdar,51G. B. Mohanty,51B. Parida,51K. Sudhakar,51 N. Wickramage,51,aaS. Banerjee,52S. Dugad,52H. Arfaei,53H. Bakhshiansohi,53S. M. Etesami,53,bbA. Fahim,53,cc A. Jafari,53M. Khakzad,53M. Mohammadi Najafabadi,53S. Paktinat Mehdiabadi,53B. Safarzadeh,53,ddM. Zeinali,53
M. Grunewald,54M. Abbrescia,55a,55bL. Barbone,55a,55bC. Calabria,55a,55bS. S. Chhibra,55a,55bA. Colaleo,55a D. Creanza,55a,55cN. De Filippis,55a,55cM. De Palma,55a,55bL. Fiore,55aG. Iaselli,55a,55cG. Maggi,55a,55c M. Maggi,55aB. Marangelli,55a,55bS. My,55a,55cS. Nuzzo,55a,55bN. Pacifico,55aA. Pompili,55a,55bG. Pugliese,55a,55c G. Selvaggi,55a,55bL. Silvestris,55aG. Singh,55a,55bR. Venditti,55a,55bP. Verwilligen,55aG. Zito,55aG. Abbiendi,56a A. C. Benvenuti,56aD. Bonacorsi,56a,56bS. Braibant-Giacomelli,56a,56bL. Brigliadori,56a,56bR. Campanini,56a,56b P. Capiluppi,56a,56bA. Castro,56a,56bF. R. Cavallo,56aG. Codispoti,56a,56bM. Cuffiani,56a,56bG. M. Dallavalle,56a F. Fabbri,56aA. Fanfani,56a,56bD. Fasanella,56a,56bP. Giacomelli,56aC. Grandi,56aL. Guiducci,56a,56bS. Marcellini,56a
G. Masetti,56aM. Meneghelli,56a,56bA. Montanari,56aF. L. Navarria,56a,56bF. Odorici,56aA. Perrotta,56a F. Primavera,56a,56bA. M. Rossi,56a,56bT. Rovelli,56a,56bG. P. Siroli,56a,56bN. Tosi,56a,56bR. Travaglini,56a,56b
S. Albergo,57a,57bG. Cappello,57a,57bM. Chiorboli,57a,57bS. Costa,57a,57bF. Giordano,57a,cR. Potenza,57a,57b A. Tricomi,57a,57bC. Tuve,57a,57bG. Barbagli,58aV. Ciulli,58a,58bC. Civinini,58aR. D’Alessandro,58a,58b E. Focardi,58a,58bS. Frosali,58a,58bE. Gallo,58aS. Gonzi,58a,58bV. Gori,58a,58bP. Lenzi,58a,58bM. Meschini,58a
S. Paoletti,58aG. Sguazzoni,58aA. Tropiano,58a,58bL. Benussi,59S. Bianco,59F. Fabbri,59D. Piccolo,59 P. Fabbricatore,60aR. Ferretti,60a,60bF. Ferro,60aM. Lo Vetere,60a,60bR. Musenich,60aE. Robutti,60aS. Tosi,60a,60b
A. Benaglia,61aM. E. Dinardo,61a,61bS. Fiorendi,61a,61bS. Gennai,61aA. Ghezzi,61a,61bP. Govoni,61a,61b M. T. Lucchini,61a,61b,cS. Malvezzi,61aR. A. Manzoni,61a,61b,cA. Martelli,61a,61b,cD. Menasce,61aL. Moroni,61a PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
M. Paganoni,61a,61bD. Pedrini,61aS. Ragazzi,61a,61bN. Redaelli,61aT. Tabarelli de Fatis,61a,61bS. Buontempo,62a N. Cavallo,62a,62cA. De Cosa,62a,62bF. Fabozzi,62a,62cA. O. M. Iorio,62a,62bL. Lista,62aS. Meola,62a,62d,c M. Merola,62aP. Paolucci,62a,cP. Azzi,63aN. Bacchetta,63aM. Biasotto,63a,eeD. Bisello,63a,63bA. Branca,63a,63b
R. Carlin,63a,63bP. Checchia,63aT. Dorigo,63aU. Dosselli,63aM. Galanti,63a,63b,cF. Gasparini,63a,63b U. Gasparini,63a,63bP. Giubilato,63a,63bA. Gozzelino,63aK. Kanishchev,63a,63cS. Lacaprara,63aI. Lazzizzera,63a,63c M. Margoni,63a,63bA. T. Meneguzzo,63a,63bM. Nespolo,63aJ. Pazzini,63a,63bN. Pozzobon,63a,63bP. Ronchese,63a,63b
F. Simonetto,63a,63bE. Torassa,63aM. Tosi,63a,63bS. Vanini,63a,63bP. Zotto,63a,63bA. Zucchetta,63a,63b G. Zumerle,63a,63bM. Gabusi,64a,64bS. P. Ratti,64a,64bC. Riccardi,64a,64bP. Vitulo,64a,64bM. Biasini,65a,65b
G. M. Bilei,65aL. Fano`,65a,65bP. Lariccia,65a,65bG. Mantovani,65a,65bM. Menichelli,65aA. Nappi,65a,65b,a F. Romeo,65a,65bA. Saha,65aA. Santocchia,65a,65bA. Spiezia,65a,65bK. Androsov,66a,ffP. Azzurri,66aG. Bagliesi,66a
T. Boccali,66aG. Broccolo,66a,66cR. Castaldi,66aM. A. Ciocci,66a,ffR. T. D’Agnolo,66a,66c,cR. Dell’Orso,66a F. Fiori,66a,66cL. Foa`,66a,66cA. Giassi,66aM. T. Grippo,66a,ffA. Kraan,66aF. Ligabue,66a,66cT. Lomtadze,66a L. Martini,66a,ffA. Messineo,66a,66bC. S. Moon,66a,ggF. Palla,66aA. Rizzi,66a,66bA. Savoy-Navarro,66a,hh A. T. Serban,66aP. Spagnolo,66aP. Squillacioti,66a,ffR. Tenchini,66aG. Tonelli,66a,66bA. Venturi,66aP. G. Verdini,66a C. Vernieri,66a,66cL. Barone,67a,67bF. Cavallari,67aD. Del Re,67a,67bM. Diemoz,67aM. Grassi,67a,67bE. Longo,67a,67b F. Margaroli,67a,67bP. Meridiani,67aF. Micheli,67a,67bS. Nourbakhsh,67a,67bG. Organtini,67a,67bR. Paramatti,67a
S. Rahatlou,67a,67bC. Rovelli,67aL. Soffi,67a,67bN. Amapane,68a,68bR. Arcidiacono,68a,68cS. Argiro,68a,68b M. Arneodo,68a,68cR. Bellan,68a,68bC. Biino,68aN. Cartiglia,68aS. Casasso,68a,68bM. Costa,68a,68bA. Degano,68a,68b
N. Demaria,68aC. Mariotti,68aS. Maselli,68aE. Migliore,68a,68bV. Monaco,68a,68bM. Musich,68a M. M. Obertino,68a,68cN. Pastrone,68aM. Pelliccioni,68a,cA. Potenza,68a,68bA. Romero,68a,68bM. Ruspa,68a,68c R. Sacchi,68a,68bA. Solano,68a,68bA. Staiano,68aU. Tamponi,68aS. Belforte,69aV. Candelise,69a,69bM. Casarsa,69a
F. Cossutti,69a,cG. Della Ricca,69a,69bB. Gobbo,69aC. La Licata,69a,69bM. Marone,69a,69bD. Montanino,69a,69b A. Penzo,69aA. Schizzi,69a,69bA. Zanetti,69aS. Chang,70T. Y. Kim,70S. K. Nam,70D. H. Kim,71G. N. Kim,71 J. E. Kim,71D. J. Kong,71S. Lee,71Y. D. Oh,71H. Park,71D. C. Son,71J. Y. Kim,72Zero J. Kim,72S. Song,72 S. Choi,73D. Gyun,73B. Hong,73M. Jo,73H. Kim,73T. J. Kim,73K. S. Lee,73S. K. Park,73Y. Roh,73M. Choi,74 J. H. Kim,74C. Park,74I. C. Park,74S. Park,74G. Ryu,74Y. Choi,75Y. K. Choi,75J. Goh,75M. S. Kim,75E. Kwon,75
B. Lee,75J. Lee,75S. Lee,75H. Seo,75I. Yu,75I. Grigelionis,76A. Juodagalvis,76H. Castilla-Valdez,77 E. De La Cruz-Burelo,77I. Heredia-de La Cruz,77,iiA. Hernandez-Almada,77R. Lopez-Fernandez,77
J. Martı´nez-Ortega,77A. Sanchez-Hernandez,77L. M. Villasenor-Cendejas,77S. Carrillo Moreno,78 F. Vazquez Valencia,78H. A. Salazar Ibarguen,79E. Casimiro Linares,80A. Morelos Pineda,80M. A. Reyes-Santos,80 D. Krofcheck,81P. H. Butler,82R. Doesburg,82S. Reucroft,82H. Silverwood,82M. Ahmad,83M. I. Asghar,83J. Butt,83 H. R. Hoorani,83S. Khalid,83W. A. Khan,83T. Khurshid,83S. Qazi,83M. A. Shah,83M. Shoaib,83H. Bialkowska,84 B. Boimska,84T. Frueboes,84M. Go´rski,84M. Kazana,84K. Nawrocki,84K. Romanowska-Rybinska,84M. Szleper,84
J. P. Ferna´ndez Ramos,95A. Ferrando,95J. Flix,95M. C. Fouz,95P. Garcia-Abia,95O. Gonzalez Lopez,95 S. Goy Lopez,95J. M. Hernandez,95M. I. Josa,95G. Merino,95E. Navarro De Martino,95J. Puerta Pelayo,95 A. Quintario Olmeda,95I. Redondo,95L. Romero,95J. Santaolalla,95M. S. Soares,95C. Willmott,95C. Albajar,96
J. F. de Troco´niz,96H. Brun,97J. Cuevas,97J. Fernandez Menendez,97S. Folgueras,97I. Gonzalez Caballero,97 L. Lloret Iglesias,97J. Piedra Gomez,97J. A. Brochero Cifuentes,98I. J. Cabrillo,98A. Calderon,98S. H. Chuang,98
J. Duarte Campderros,98M. Fernandez,98G. Gomez,98J. Gonzalez Sanchez,98A. Graziano,98C. Jorda,98 A. Lopez Virto,98J. Marco,98R. Marco,98C. Martinez Rivero,98F. Matorras,98F. J. Munoz Sanchez,98T. Rodrigo,98
A. Y. Rodrı´guez-Marrero,98A. Ruiz-Jimeno,98L. Scodellaro,98I. Vila,98R. Vilar Cortabitarte,98D. Abbaneo,99 E. Auffray,99G. Auzinger,99M. Bachtis,99P. Baillon,99A. H. Ball,99D. Barney,99J. Bendavid,99J. F. Benitez,99
C. Bernet,99,iG. Bianchi,99P. Bloch,99A. Bocci,99A. Bonato,99O. Bondu,99C. Botta,99H. Breuker,99 T. Camporesi,99G. Cerminara,99T. Christiansen,99J. A. Coarasa Perez,99S. Colafranceschi,99,kkM. D’Alfonso,99
D. d’Enterria,99A. Dabrowski,99A. David,99F. De Guio,99A. De Roeck,99S. De Visscher,99S. Di Guida,99 M. Dobson,99N. Dupont-Sagorin,99A. Elliott-Peisert,99J. Eugster,99G. Franzoni,99W. Funk,99G. Georgiou,99 M. Giffels,99D. Gigi,99K. Gill,99D. Giordano,99M. Girone,99M. Giunta,99F. Glege,99R. Gomez-Reino Garrido,99
S. Gowdy,99R. Guida,99J. Hammer,99M. Hansen,99P. Harris,99C. Hartl,99A. Hinzmann,99V. Innocente,99 P. Janot,99E. Karavakis,99K. Kousouris,99K. Krajczar,99P. Lecoq,99Y.-J. Lee,99C. Lourenc¸o,99N. Magini,99
L. Malgeri,99M. Mannelli,99L. Masetti,99F. Meijers,99S. Mersi,99E. Meschi,99R. Moser,99M. Mulders,99 P. Musella,99E. Nesvold,99L. Orsini,99E. Palencia Cortezon,99E. Perez,99L. Perrozzi,99A. Petrilli,99A. Pfeiffer,99
M. Pierini,99M. Pimia¨,99D. Piparo,99M. Plagge,99L. Quertenmont,99A. Racz,99W. Reece,99G. Rolandi,99,ll M. Rovere,99H. Sakulin,99F. Santanastasio,99C. Scha¨fer,99C. Schwick,99S. Sekmen,99A. Sharma,99P. Siegrist,99
P. Silva,99M. Simon,99P. Sphicas,99,mmD. Spiga,99B. Stieger,99M. Stoye,99A. Tsirou,99G. I. Veres,99,v J. R. Vlimant,99H. K. Wo¨hri,99S. D. Worm,99,nnW. D. Zeuner,99W. Bertl,100K. Deiters,100W. Erdmann,100 K. Gabathuler,100R. Horisberger,100Q. Ingram,100H. C. Kaestli,100S. Ko¨nig,100D. Kotlinski,100U. Langenegger,100
D. Renker,100T. Rohe,100F. Bachmair,101L. Ba¨ni,101L. Bianchini,101P. Bortignon,101M. A. Buchmann,101 B. Casal,101N. Chanon,101A. Deisher,101G. Dissertori,101M. Dittmar,101M. Donega`,101M. Du¨nser,101P. Eller,101
K. Freudenreich,101C. Grab,101D. Hits,101P. Lecomte,101W. Lustermann,101B. Mangano,101A. C. Marini,101 P. Martinez Ruiz del Arbol,101D. Meister,101N. Mohr,101F. Moortgat,101C. Na¨geli,101,ooP. Nef,101 F. Nessi-Tedaldi,101F. Pandolfi,101L. Pape,101F. Pauss,101M. Peruzzi,101M. Quittnat,101F. J. Ronga,101 M. Rossini,101L. Sala,101A. K. Sanchez,101A. Starodumov,101,ppM. Takahashi,101L. Tauscher,101,aA. Thea,101
K. Theofilatos,101D. Treille,101C. Urscheler,101R. Wallny,101H. A. Weber,101C. Amsler,102,qqV. Chiochia,102 C. Favaro,102M. Ivova Rikova,102B. Kilminster,102B. Millan Mejias,102P. Robmann,102H. Snoek,102S. Taroni,102
M. Verzetti,102Y. Yang,102M. Cardaci,103K. H. Chen,103C. Ferro,103C. M. Kuo,103S. W. Li,103W. Lin,103 Y. J. Lu,103R. Volpe,103S. S. Yu,103P. Bartalini,104P. Chang,104Y. H. Chang,104Y. W. Chang,104Y. Chao,104 K. F. Chen,104C. Dietz,104U. Grundler,104W.-S. Hou,104Y. Hsiung,104K. Y. Kao,104Y. J. Lei,104R.-S. Lu,104
D. Majumder,104E. Petrakou,104X. Shi,104J. G. Shiu,104Y. M. Tzeng,104M. Wang,104B. Asavapibhop,105 N. Suwonjandee,105A. Adiguzel,106M. N. Bakirci,106,rrS. Cerci,106,ssC. Dozen,106I. Dumanoglu,106E. Eskut,106
S. Girgis,106G. Gokbulut,106E. Gurpinar,106I. Hos,106E. E. Kangal,106A. Kayis Topaksu,106G. Onengut,106,tt K. Ozdemir,106S. Ozturk,106,rrA. Polatoz,106K. Sogut,106,uuD. Sunar Cerci,106,ssB. Tali,106,ssH. Topakli,106,rr M. Vergili,106I. V. Akin,107T. Aliev,107B. Bilin,107S. Bilmis,107M. Deniz,107H. Gamsizkan,107A. M. Guler,107
G. Karapinar,107,vvK. Ocalan,107A. Ozpineci,107M. Serin,107R. Sever,107U. E. Surat,107M. Yalvac,107 M. Zeyrek,107E. Gu¨lmez,108B. Isildak,108,wwM. Kaya,108,xxO. Kaya,108,xxS. Ozkorucuklu,108,yyN. Sonmez,108,zz H. Bahtiyar,109,aaaE. Barlas,109K. Cankocak,109Y. O. Gu¨naydin,109,bbbF. I. Vardarl,109M. Yu¨cel,109L. Levchuk,110
P. Sorokin,110J. J. Brooke,111E. Clement,111D. Cussans,111H. Flacher,111R. Frazier,111J. Goldstein,111 M. Grimes,111G. P. Heath,111H. F. Heath,111L. Kreczko,111C. Lucas,111Z. Meng,111S. Metson,111 D. M. Newbold,111,nnK. Nirunpong,111S. Paramesvaran,111A. Poll,111S. Senkin,111V. J. Smith,111T. Williams,111 K. W. Bell,112A. Belyaev,112,cccC. Brew,112R. M. Brown,112D. J. A. Cockerill,112J. A. Coughlan,112K. Harder,112
S. Harper,112J. Ilic,112E. Olaiya,112D. Petyt,112B. C. Radburn-Smith,112C. H. Shepherd-Themistocleous,112 I. R. Tomalin,112W. J. Womersley,112R. Bainbridge,113O. Buchmuller,113D. Burton,113D. Colling,113N. Cripps,113
M. Cutajar,113P. Dauncey,113G. Davies,113M. Della Negra,113W. Ferguson,113J. Fulcher,113D. Futyan,113 A. Gilbert,113A. Guneratne Bryer,113G. Hall,113Z. Hatherell,113J. Hays,113G. Iles,113M. Jarvis,113 G. Karapostoli,113M. Kenzie,113R. Lane,113R. Lucas,113,nnL. Lyons,113A.-M. Magnan,113J. Marrouche,113 PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
B. Mathias,113R. Nandi,113J. Nash,113A. Nikitenko,113,ppJ. Pela,113M. Pesaresi,113K. Petridis,113M. Pioppi,113,ddd D. M. Raymond,113S. Rogerson,113A. Rose,113C. Seez,113P. Sharp,113,aA. Sparrow,113A. Tapper,113 M. Vazquez Acosta,113T. Virdee,113S. Wakefield,113N. Wardle,113M. Chadwick,114J. E. Cole,114P. R. Hobson,114 A. Khan,114P. Kyberd,114D. Leggat,114D. Leslie,114W. Martin,114I. D. Reid,114P. Symonds,114L. Teodorescu,114
M. Turner,114J. Dittmann,115K. Hatakeyama,115A. Kasmi,115H. Liu,115T. Scarborough,115O. Charaf,116 S. I. Cooper,116C. Henderson,116P. Rumerio,116A. Avetisyan,117T. Bose,117C. Fantasia,117A. Heister,117 P. Lawson,117D. Lazic,117J. Rohlf,117D. Sperka,117J. St. John,117L. Sulak,117J. Alimena,118S. Bhattacharya,118
G. Christopher,118D. Cutts,118Z. Demiragli,118A. Ferapontov,118A. Garabedian,118U. Heintz,118S. Jabeen,118 G. Kukartsev,118E. Laird,118G. Landsberg,118M. Luk,118M. Narain,118M. Segala,118T. Sinthuprasith,118 T. Speer,118R. Breedon,119G. Breto,119M. Calderon De La Barca Sanchez,119S. Chauhan,119M. Chertok,119 J. Conway,119R. Conway,119P. T. Cox,119R. Erbacher,119M. Gardner,119R. Houtz,119W. Ko,119A. Kopecky,119
R. Lander,119T. Miceli,119D. Pellett,119J. Pilot,119F. Ricci-Tam,119B. Rutherford,119M. Searle,119J. Smith,119 M. Squires,119M. Tripathi,119S. Wilbur,119R. Yohay,119V. Andreev,120D. Cline,120R. Cousins,120S. Erhan,120 P. Everaerts,120C. Farrell,120M. Felcini,120J. Hauser,120M. Ignatenko,120C. Jarvis,120G. Rakness,120P. Schlein,120,a
E. Takasugi,120P. Traczyk,120V. Valuev,120M. Weber,120J. Babb,121R. Clare,121J. Ellison,121J. W. Gary,121 G. Hanson,121J. Heilman,121P. Jandir,121H. Liu,121O. R. Long,121A. Luthra,121M. Malberti,121H. Nguyen,121 A. Shrinivas,121J. Sturdy,121S. Sumowidagdo,121R. Wilken,121S. Wimpenny,121W. Andrews,122J. G. Branson,122 G. B. Cerati,122S. Cittolin,122D. Evans,122A. Holzner,122R. Kelley,122M. Lebourgeois,122J. Letts,122I. Macneill,122 S. Padhi,122C. Palmer,122G. Petrucciani,122M. Pieri,122M. Sani,122V. Sharma,122S. Simon,122E. Sudano,122 M. Tadel,122Y. Tu,122A. Vartak,122S. Wasserbaech,122,eeeF. Wu¨rthwein,122A. Yagil,122J. Yoo,122D. Barge,123
C. Campagnari,123T. Danielson,123K. Flowers,123P. Geffert,123C. George,123F. Golf,123J. Incandela,123 C. Justus,123D. Kovalskyi,123V. Krutelyov,123R. Magan˜a Villalba,123N. Mccoll,123V. Pavlunin,123J. Richman,123
R. Rossin,123D. Stuart,123W. To,123C. West,123A. Apresyan,124A. Bornheim,124J. Bunn,124Y. Chen,124 E. Di Marco,124J. Duarte,124D. Kcira,124Y. Ma,124A. Mott,124H. B. Newman,124C. Pena,124C. Rogan,124
M. Spiropulu,124V. Timciuc,124J. Veverka,124R. Wilkinson,124S. Xie,124R. Y. Zhu,124V. Azzolini,125 A. Calamba,125R. Carroll,125T. Ferguson,125Y. Iiyama,125D. W. Jang,125Y. F. Liu,125M. Paulini,125J. Russ,125
H. Vogel,125I. Vorobiev,125J. P. Cumalat,126B. R. Drell,126W. T. Ford,126A. Gaz,126E. Luiggi Lopez,126 U. Nauenberg,126J. G. Smith,126K. Stenson,126K. A. Ulmer,126S. R. Wagner,126J. Alexander,127A. Chatterjee,127
N. Eggert,127L. K. Gibbons,127W. Hopkins,127A. Khukhunaishvili,127B. Kreis,127N. Mirman,127 G. Nicolas Kaufman,127J. R. Patterson,127A. Ryd,127E. Salvati,127W. Sun,127W. D. Teo,127J. Thom,127 J. Thompson,127J. Tucker,127Y. Weng,127L. Winstrom,127P. Wittich,127D. Winn,128S. Abdullin,129M. Albrow,129 J. Anderson,129G. Apollinari,129L. A. T. Bauerdick,129A. Beretvas,129J. Berryhill,129P. C. Bhat,129K. Burkett,129
J. N. Butler,129V. Chetluru,129H. W. K. Cheung,129F. Chlebana,129S. Cihangir,129V. D. Elvira,129I. Fisk,129 J. Freeman,129Y. Gao,129E. Gottschalk,129L. Gray,129D. Green,129O. Gutsche,129D. Hare,129R. M. Harris,129
J. Hirschauer,129B. Hooberman,129S. Jindariani,129M. Johnson,129U. Joshi,129K. Kaadze,129B. Klima,129 S. Kunori,129S. Kwan,129J. Linacre,129D. Lincoln,129R. Lipton,129J. Lykken,129K. Maeshima,129 J. M. Marraffino,129V. I. Martinez Outschoorn,129S. Maruyama,129D. Mason,129P. McBride,129K. Mishra,129
S. Mrenna,129Y. Musienko,129,fffC. Newman-Holmes,129V. O’Dell,129O. Prokofyev,129N. Ratnikova,129 E. Sexton-Kennedy,129S. Sharma,129W. J. Spalding,129L. Spiegel,129L. Taylor,129S. Tkaczyk,129N. V. Tran,129 L. Uplegger,129E. W. Vaandering,129R. Vidal,129J. Whitmore,129W. Wu,129F. Yang,129J. C. Yun,129D. Acosta,130
P. Avery,130D. Bourilkov,130M. Chen,130T. Cheng,130S. Das,130M. De Gruttola,130G. P. Di Giovanni,130 D. Dobur,130A. Drozdetskiy,130R. D. Field,130M. Fisher,130Y. Fu,130I. K. Furic,130J. Hugon,130B. Kim,130
J. Konigsberg,130A. Korytov,130A. Kropivnitskaya,130T. Kypreos,130J. F. Low,130K. Matchev,130 P. Milenovic,130,gggG. Mitselmakher,130L. Muniz,130R. Remington,130A. Rinkevicius,130N. Skhirtladze,130 M. Snowball,130J. Yelton,130M. Zakaria,130V. Gaultney,131S. Hewamanage,131S. Linn,131P. Markowitz,131 G. Martinez,131J. L. Rodriguez,131T. Adams,132A. Askew,132J. Bochenek,132J. Chen,132B. Diamond,132J. Haas,132
S. Hagopian,132V. Hagopian,132K. F. Johnson,132H. Prosper,132V. Veeraraghavan,132M. Weinberg,132 M. M. Baarmand,133B. Dorney,133M. Hohlmann,133H. Kalakhety,133F. Yumiceva,133M. R. Adams,134 L. Apanasevich,134V. E. Bazterra,134R. R. Betts,134I. Bucinskaite,134J. Callner,134R. Cavanaugh,134 O. Evdokimov,134L. Gauthier,134C. E. Gerber,134D. J. Hofman,134S. Khalatyan,134P. Kurt,134F. Lacroix,134
D. H. Moon,134C. O’Brien,134C. Silkworth,134D. Strom,134P. Turner,134N. Varelas,134U. Akgun,135 PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
E. A. Albayrak,135,aaaB. Bilki,135,hhhW. Clarida,135K. Dilsiz,135F. Duru,135S. Griffiths,135J.-P. Merlo,135 H. Mermerkaya,135,iiiA. Mestvirishvili,135A. Moeller,135J. Nachtman,135C. R. Newsom,135H. Ogul,135Y. Onel,135
F. Ozok,135,aaaS. Sen,135P. Tan,135E. Tiras,135J. Wetzel,135T. Yetkin,135,jjjK. Yi,135B. A. Barnett,136 B. Blumenfeld,136S. Bolognesi,136G. Giurgiu,136A. V. Gritsan,136G. Hu,136P. Maksimovic,136C. Martin,136
M. Swartz,136A. Whitbeck,136P. Baringer,137A. Bean,137G. Benelli,137R. P. Kenny III,137M. Murray,137 D. Noonan,137S. Sanders,137R. Stringer,137J. S. Wood,137A. F. Barfuss,138I. Chakaberia,138A. Ivanov,138 S. Khalil,138M. Makouski,138Y. Maravin,138L. K. Saini,138S. Shrestha,138I. Svintradze,138J. Gronberg,139 D. Lange,139F. Rebassoo,139D. Wright,139A. Baden,140B. Calvert,140S. C. Eno,140J. A. Gomez,140N. J. Hadley,140
R. G. Kellogg,140T. Kolberg,140Y. Lu,140M. Marionneau,140A. C. Mignerey,140K. Pedro,140A. Peterman,140 A. Skuja,140J. Temple,140M. B. Tonjes,140S. C. Tonwar,140A. Apyan,141G. Bauer,141W. Busza,141I. A. Cali,141
M. Chan,141L. Di Matteo,141V. Dutta,141G. Gomez Ceballos,141M. Goncharov,141D. Gulhan,141Y. Kim,141 M. Klute,141Y. S. Lai,141A. Levin,141P. D. Luckey,141T. Ma,141S. Nahn,141C. Paus,141D. Ralph,141C. Roland,141
G. Roland,141G. S. F. Stephans,141F. Sto¨ckli,141K. Sumorok,141D. Velicanu,141R. Wolf,141B. Wyslouch,141 M. Yang,141Y. Yilmaz,141A. S. Yoon,141M. Zanetti,141V. Zhukova,141B. Dahmes,142A. De Benedetti,142 A. Gude,142J. Haupt,142S. C. Kao,142K. Klapoetke,142Y. Kubota,142J. Mans,142N. Pastika,142R. Rusack,142 M. Sasseville,142A. Singovsky,142N. Tambe,142J. Turkewitz,142J. G. Acosta,143L. M. Cremaldi,143R. Kroeger,143
S. Oliveros,143L. Perera,143R. Rahmat,143D. A. Sanders,143D. Summers,143E. Avdeeva,144K. Bloom,144 S. Bose,144D. R. Claes,144A. Dominguez,144M. Eads,144R. Gonzalez Suarez,144J. Keller,144I. Kravchenko,144
J. Lazo-Flores,144S. Malik,144F. Meier,144G. R. Snow,144J. Dolen,145A. Godshalk,145I. Iashvili,145S. Jain,145 A. Kharchilava,145A. Kumar,145S. Rappoccio,145Z. Wan,145G. Alverson,146E. Barberis,146D. Baumgartel,146 M. Chasco,146J. Haley,146A. Massironi,146D. Nash,146T. Orimoto,146D. Trocino,146D. Wood,146J. Zhang,146
A. Anastassov,147K. A. Hahn,147A. Kubik,147L. Lusito,147N. Mucia,147N. Odell,147B. Pollack,147 A. Pozdnyakov,147M. Schmitt,147S. Stoynev,147K. Sung,147M. Velasco,147S. Won,147D. Berry,148 A. Brinkerhoff,148K. M. Chan,148M. Hildreth,148C. Jessop,148D. J. Karmgard,148J. Kolb,148K. Lannon,148 W. Luo,148S. Lynch,148N. Marinelli,148D. M. Morse,148T. Pearson,148M. Planer,148R. Ruchti,148J. Slaunwhite,148
N. Valls,148M. Wayne,148M. Wolf,148L. Antonelli,149B. Bylsma,149L. S. Durkin,149S. Flowers,149C. Hill,149 R. Hughes,149K. Kotov,149T. Y. Ling,149D. Puigh,149M. Rodenburg,149G. Smith,149C. Vuosalo,149B. L. Winer,149
H. Wolfe,149E. Berry,150P. Elmer,150V. Halyo,150P. Hebda,150J. Hegeman,150A. Hunt,150P. Jindal,150 S. A. Koay,150P. Lujan,150D. Marlow,150T. Medvedeva,150M. Mooney,150J. Olsen,150P. Piroue´,150X. Quan,150 A. Raval,150H. Saka,150D. Stickland,150C. Tully,150J. S. Werner,150S. C. Zenz,150A. Zuranski,150E. Brownson,151
A. Lopez,151H. Mendez,151J. E. Ramirez Vargas,151E. Alagoz,152D. Benedetti,152G. Bolla,152D. Bortoletto,152 M. De Mattia,152A. Everett,152Z. Hu,152M. Jones,152K. Jung,152O. Koybasi,152M. Kress,152N. Leonardo,152 D. Lopes Pegna,152V. Maroussov,152P. Merkel,152D. H. Miller,152N. Neumeister,152I. Shipsey,152D. Silvers,152
A. Svyatkovskiy,152F. Wang,152W. Xie,152L. Xu,152H. D. Yoo,152J. Zablocki,152Y. Zheng,152N. Parashar,153 A. Adair,154B. Akgun,154K. M. Ecklund,154F. J. M. Geurts,154W. Li,154B. Michlin,154B. P. Padley,154 R. Redjimi,154J. Roberts,154J. Zabel,154B. Betchart,155A. Bodek,155R. Covarelli,155P. de Barbaro,155 R. Demina,155Y. Eshaq,155T. Ferbel,155A. Garcia-Bellido,155P. Goldenzweig,155J. Han,155A. Harel,155 D. C. Miner,155G. Petrillo,155D. Vishnevskiy,155M. Zielinski,155A. Bhatti,156R. Ciesielski,156L. Demortier,156
K. Goulianos,156G. Lungu,156S. Malik,156C. Mesropian,156S. Arora,157A. Barker,157J. P. Chou,157 C. Contreras-Campana,157E. Contreras-Campana,157D. Duggan,157D. Ferencek,157Y. Gershtein,157R. Gray,157 E. Halkiadakis,157D. Hidas,157A. Lath,157S. Panwalkar,157M. Park,157R. Patel,157V. Rekovic,157J. Robles,157 S. Salur,157S. Schnetzer,157C. Seitz,157S. Somalwar,157R. Stone,157S. Thomas,157P. Thomassen,157M. Walker,157
G. Cerizza,158M. Hollingsworth,158K. Rose,158S. Spanier,158Z. C. Yang,158A. York,158O. Bouhali,159,kkk R. Eusebi,159W. Flanagan,159J. Gilmore,159T. Kamon,159,lllV. Khotilovich,159R. Montalvo,159I. Osipenkov,159 Y. Pakhotin,159A. Perloff,159J. Roe,159A. Safonov,159T. Sakuma,159I. Suarez,159A. Tatarinov,159D. Toback,159 N. Akchurin,160C. Cowden,160J. Damgov,160C. Dragoiu,160P. R. Dudero,160K. Kovitanggoon,160S. W. Lee,160
T. Libeiro,160I. Volobouev,160E. Appelt,161A. G. Delannoy,161S. Greene,161A. Gurrola,161W. Johns,161 C. Maguire,161Y. Mao,161A. Melo,161M. Sharma,161P. Sheldon,161B. Snook,161S. Tuo,161J. Velkovska,161 M. W. Arenton,162S. Boutle,162B. Cox,162B. Francis,162J. Goodell,162R. Hirosky,162A. Ledovskoy,162C. Lin,162
C. Neu,162J. Wood,162S. Gollapinni,163R. Harr,163P. E. Karchin,163C. Kottachchi Kankanamge Don,163 P. Lamichhane,163A. Sakharov,163D. A. Belknap,164L. Borrello,164D. Carlsmith,164M. Cepeda,164S. Dasu,164 PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
S. Duric,164E. Friis,164M. Grothe,164R. Hall-Wilton,164M. Herndon,164A. Herve´,164P. Klabbers,164J. Klukas,164 A. Lanaro,164R. Loveless,164A. Mohapatra,164I. Ojalvo,164T. Perry,164G. A. Pierro,164G. Polese,164I. Ross,164
T. Sarangi,164A. Savin,164W. H. Smith,164and J. Swanson164 (CMS Collaboration)
1Yerevan Physics Institute, Yerevan, Armenia 2Institut fu¨r Hochenergiephysik der OeAW, Wien, Austria 3National Centre for Particle and High Energy Physics, Minsk, Belarus
4
Universiteit Antwerpen, Antwerpen, Belgium
5Vrije Universiteit Brussel, Brussel, Belgium 6Universite´ Libre de Bruxelles, Bruxelles, Belgium
7Ghent University, Ghent, Belgium
8Universite´ Catholique de Louvain, Louvain-la-Neuve, Belgium 9Universite´ de Mons, Mons, Belgium
10Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil 11Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
12aUniversidade Estadual Paulista, Sa˜o Paulo, Brazil 12b
Universidade Federal do ABC, Sa˜o Paulo, Brazil
13Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria 14University of Sofia, Sofia, Bulgaria
15Institute of High Energy Physics, Beijing, China
16State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China 17Universidad de Los Andes, Bogota, Colombia
18Technical University of Split, Split, Croatia 19University of Split, Split, Croatia 20Institute Rudjer Boskovic, Zagreb, Croatia
21University of Cyprus, Nicosia, Cyprus 22Charles University, Prague, Czech Republic
23Academy of Scientific Research and Technology of the Arab Republic of Egypt,
Egyptian Network of High Energy Physics, Cairo, Egypt
24National Institute of Chemical Physics and Biophysics, Tallinn, Estonia 25Department of Physics, University of Helsinki, Helsinki, Finland
26Helsinki Institute of Physics, Helsinki, Finland 27
Lappeenranta University of Technology, Lappeenranta, Finland
28DSM/IRFU, CEA/Saclay, Gif-sur-Yvette, France
29Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France
30Institut Pluridisciplinaire Hubert Curien, Universite´ de Strasbourg, Universite´ de Haute Alsace Mulhouse,
CNRS/IN2P3, Strasbourg, France
31Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France 32Universite´ de Lyon, Universite´ Claude Bernard Lyon 1, CNRS-IN2P3, Institut de Physique Nucle´aire de Lyon, Villeurbanne, France
33Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi, Georgia 34RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany
35
RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
36RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany 37Deutsches Elektronen-Synchrotron, Hamburg, Germany
38University of Hamburg, Hamburg, Germany 39Institut fu¨r Experimentelle Kernphysik, Karlsruhe, Germany
40Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece 41University of Athens, Athens, Greece
42University of Ioa´nnina, Ioa´nnina, Greece
43KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary 44Institute of Nuclear Research ATOMKI, Debrecen, Hungary
45University of Debrecen, Debrecen, Hungary
46National Institute of Science Education and Research, Bhubaneswar, India 47Panjab University, Chandigarh, India
48University of Delhi, Delhi, India 49Saha Institute of Nuclear Physics, Kolkata, India
50Bhabha Atomic Research Centre, Mumbai, India
PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
51Tata Institute of Fundamental Research-EHEP, Mumbai, India 52Tata Institute of Fundamental Research-HECR, Mumbai, India 53Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
54University College Dublin, Dublin, Ireland 55aINFN Sezione di Bari, Bari, Italy
55bUniversita` di Bari, Bari, Italy 55cPolitecnico di Bari, Bari, Italy 56aINFN Sezione di Bologna, Bologna, Italy
56b
Universita` di Bologna, Bologna, Italy
57aINFN Sezione di Catania, Catania, Italy 57bUniversita` di Catania, Catania, Italy 58aINFN Sezione di Firenze, Firenze, Italy
58bUniversita` di Firenze, Firenze, Italy
59INFN Laboratori Nazionali di Frascati, Frascati, Italy 60aINFN Sezione di Genova, Genova, Italy
60bUniversita` di Genova, Genova, Italy 61aINFN Sezione di Milano-Bicocca, Milano, Italy
61bUniversita` di Milano-Bicocca, Milano, Italy 62aINFN Sezione di Napoli, Napoli, Italy 62bUniversita` di Napoli ‘‘Federico II,’’ Napoli, Italy 62cUniversita` della Basilicata (Potenza), Napoli, Italy
62dUniversita` G. Marconi (Roma), Napoli, Italy 63aINFN Sezione di Padova, Padova, Italy
63bUniversita` di Padova, Padova, Italy 63c
Universita` di Trento (Trento), Padova, Italy
64aINFN Sezione di Pavia, Pavia, Italy 64bUniversita` di Pavia, Pavia, Italy 65aINFN Sezione di Perugia, Perugia, Italy
65bUniversita` di Perugia, Perugia, Italy 66aINFN Sezione di Pisa, Pisa, Italy
66bUniversita` di Pisa, Pisa, Italy 66cScuola Normale Superiore di Pisa, Pisa, Italy
67aINFN Sezione di Roma, Roma, Italy 67bUniversita` di Roma, Roma, Italy 68aINFN Sezione di Torino, Torino, Italy
68bUniversita` di Torino, Torino, Italy
68cUniversita` del Piemonte Orientale (Novara), Torino, Italy 69aINFN Sezione di Trieste, Trieste, Italy
69bUniversita` di Trieste, Trieste, Italy 70Kangwon National University, Chunchon, Korea
71Kyungpook National University, Daegu, Korea
72Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea 73Korea University, Seoul, Korea
74University of Seoul, Seoul, Korea 75Sungkyunkwan University, Suwon, Korea
76Vilnius University, Vilnius, Lithuania
77Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico 78
Universidad Iberoamericana, Mexico City, Mexico
79Benemerita Universidad Autonoma de Puebla, Puebla, Mexico 80Universidad Auto´noma de San Luis Potosı´, San Luis Potosı´, Mexico
81University of Auckland, Auckland, New Zealand 82University of Canterbury, Christchurch, New Zealand
83National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan 84National Centre for Nuclear Research, Swierk, Poland
85Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland 86Laborato´rio de Instrumentac¸a˜o e Fı´sica Experimental de Partı´culas, Lisboa, Portugal
87
Joint Institute for Nuclear Research, Dubna, Russia
88Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia 89Institute for Nuclear Research, Moscow, Russia
90Institute for Theoretical and Experimental Physics, Moscow, Russia 91P.N. Lebedev Physical Institute, Moscow, Russia
PRL 111, 101804 (2013) P H Y S I C A L R E V I E W L E T T E R S 6 SEPTEMBER 2013week ending
