Evidence for the decay X(3872) ψ(2S)γ

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ScienceDirect

Nuclear Physics B 886 (2014) 665–680

www.elsevier.com/locate/nuclphysb

Evidence

for

the

decay

X(3872)

→ ψ(2S)γ

.

LHCb

Collaboration

Received 2April2014;receivedinrevisedform 9June2014;accepted 11June2014 Availableonline 16June2014

Editor: NuclearPhysicsB,EditorialOffice

Abstract

EvidenceforthedecaymodeX(3872)→ ψ(2S)γ inB+→ X(3872)K+decaysisfound witha sig-nificanceof4.4standarddeviations.Theanalysisisbasedona datasampleofproton–protoncollisions, correspondingtoanintegratedluminosityof 3 fb−1,collectedwiththeLHCbdetector,atcentre-of-mass energiesof7 and 8 TeV.TheratioofthebranchingfractionoftheX(3872)→ ψ(2S)γ decaytothatofthe X(3872)→ J/ψγ decayismeasuredtobe

B(X(3872) → ψ(2S)γ)

B(X(3872) → J/ψγ) = 2.46 ± 0.64 ± 0.29,

wherethefirstuncertaintyisstatisticalandthesecondissystematic.Themeasuredvaluedoesnotsupport a pure D ¯D∗molecularinterpretationoftheX(3872) state.

1. Introduction

The X(3872) state was discovered in 2003 by the Belle Collaboration[1]. Subsequently, it has been studied by several other experiments [2–6]. Several properties of the X(3872) state have been determined, including the precise value of its mass [5,7]and the dipion mass spectrum in the decay X(3872) → J/ψπ+_π−_[1,6,8]_{. Recently, its quantum numbers were determined to}

be JP C= 1++by combination of the measurements performed by the CDF [9]and the LHCb

[10]Collaborations.

Despite a large amount of experimental information, the nature of X(3872) state and other similar states is still uncertain [11,12]. In particular for the X(3872) state, interpretation as a D ¯D∗ molecule [13], tetraquark [14], ccg hybrid meson [15], vector glueball [16]or mixed state [17,18]

are proposed. Radiative decays of the X(3872) provide a valuable opportunity to understand its

http://dx.doi.org/10.1016/j.nuclphysb.2014.06.011

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nature. Studies of the decay modes X(3872) → J/ψγ resulted in the determination of its C-parity

[19,20]. Evidence for the X(3872) → ψ(2S)γ decay and the branching fraction ratio,

R_ψγ≡B(X(3872) → ψ(2S)γ)

B(X(3872) → J/ψγ) = 3.4 ± 1.4,

were reported by the BaBar Collaboration[21]. In contrast, no significant signal was found for the X(3872)→ ψ(2S)γ decay by the Belle Collaboration, therefore only an upper limit for R_ψγ <

2.1 (at 90% confidence level) was reported [20]. The ratio R_ψγ is predicted to be in the range

(3–4) × 10−3 for a D ¯D∗ molecule [22–24], 1.2–15 for a pure charmonium state [25–32] and 0.5–5 for a molecule-charmonium mixture [29,33].

In this paper, evidence for the decay X(3872) → ψ(2S)γ and a measurement of the ratio

R_ψγ using B+→ X(3872)K+decays are presented.1The analysis is based on a data sample of proton–proton (pp) collisions, corresponding to an integrated luminosity of 1 fb−1at a centre-of-mass energy of 7 TeV and 2 fb−1at 8 TeV, collected with the LHCb detector.

2. Detector and software

The LHCb detector [34]is a single-arm forward spectrometer covering the pseudorapidity range 2 <η < 5, designed for the study of particles containing b or c quarks. The detector includes a high-precision tracking system consisting of a silicon-strip vertex detector surrounding the pp interaction region, a large-area silicon-strip detector located upstream of a dipole magnet with a bending power of about 4 Tm, and three stations of silicon-strip detectors and straw drift tubes placed downstream. The combined tracking system provides a momentum measurement with relative uncertainty that varies from 0.4% at 5 GeV/c to 0.6% at 100 GeV/c, and impact parameter resolution of 20 µm for tracks with high transverse momentum. Charged hadrons are identified using two ring-imaging Cherenkov detectors [35]. The calorimeter system consists of a scintillating pad detector (SPD) and a pre-shower system (PS), followed by electromagnetic (ECAL) and hadron calorimeters. The SPD and PS are designed to distinguish between signals from photons and electrons. Muons are identified by a system composed of alternating layers of iron and multiwire proportional chambers [36].

The trigger [37]consists of a hardware stage, based on information from the calorimeter and muon systems, followed by a software stage where a full event reconstruction is applied. This analysis uses events collected by triggers that select the μ+_μ−_{pair from J/ψ and ψ(2S) decays}

with high efficiency. At the hardware stage either one or two muon candidates are required to trigger the event. For single muon triggers, the transverse momentum of the muon candidate,

pT, is required to be greater than 1.48 GeV/c. For dimuon candidates, the product of the pTof

the muon candidates is required to satisfy pT(μ+)× pT(μ−) >1.3 GeV/c. At the subsequent

software trigger stage, two muons are selected with an invariant mass larger than 2.5 GeV/c2 and consistent with originating from a common vertex. The common vertex is required to be significantly displaced from the pp collision vertices by requiring the decay length significance to be greater than 3.

The analysis technique reported below has been validated using simulated events. The pp collisions are generated using PYTHIA [38]with a specific LHCb configuration described in Ref.[39]. Decays of hadronic particles are described by EVTGEN[40]in which final state radi-ation is generated using PHOTOSpackage [41]. The interaction of the generated particles with

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the detector and its response are implemented using the GEANT4 toolkit [42,43]as described in Ref.[44].

3. Event selection

Candidate B+→ X(3872)K+decays, followed by X(3872) → ψγ, where ψ denotes a J/ψ or ψ(2S) meson, are reconstructed using the ψ → μ+_μ−_{channel. The ψ(2S) → J/ψπ}+_π−_decay

mode is not used due to low reconstruction efficiency. Most selection criteria are common for the two channels, except where directly related to the photon kinematics, due to the difference in the energy release in these two channels. The selection criteria follow those used in Refs.[45–47].

The track quality of reconstructed charged particles is ensured by requiring that the χ2 per degree of freedom, χ2/ndf, is less than 3. Well-identified muons are selected by requiring that the difference in the logarithms of the muon hypothesis likelihood with respect to the pion hypothesis likelihood, logLμ/π [48], is larger than zero. To select kaons, the corresponding difference in the logarithms of likelihoods of the kaon and pion hypotheses [35]is required to satisfy logLK/π>0.

To ensure that the muons and kaons do not originate from a pp interaction vertex, the impact parameter χ2, defined as the difference between the χ2of a given PV formed with and without the considered track, is required to be When more than one PV is reconstructed, the smallest value of χ_IP2 is chosen.

Pairs of oppositely charged tracks identified as muons, each having pT>0.55 GeV/c, are

combined to form ψ → μ+μ−candidates. The fit of the common two-prong vertex is required to satisfy χ2/ndf < 20. The vertex is required to be well separated from the reconstructed PV by selecting candidates with decay length significance greater than 3. The invariant mass of the dimuon combination is required to be between 3.020 and 3.135 GeV/c2for the J/ψ candidates and between 3.597 and 3.730 GeV/c2for the ψ(2S) candidates. The selected ψ candidates are required to match the dimuon candidates used to trigger the event.

Photons are reconstructed using the electromagnetic calorimeter and identified using a likelihood-based estimator, constructed from variables that rely on calorimeter and tracking information [49]. Candidate photon clusters must not be matched to the trajectory of a track extrapolated from the tracking system to the cluster position in the calorimeter. Further photon quality refinement is done using information from the PS and SPD detectors. The photon trans-verse momentum is required to be greater than 1 GeV/c or 0.6 GeV/c for the J/ψ or ψ(2S) in the final state, respectively. To suppress the large combinatorial background from π0_{→ γγ}

de-cays, a pion veto is applied [46]. The photons that, when combined with another photon, form a π0_{→ γγ candidate with invariant mass within 25 MeV/c}2_{of the π}0_{mass, corresponding to ±3}

times the mass resolution [46,50], are not used in the reconstruction.

To form X(3872) candidates, the selected ψ candidates are combined with a reconstructed photon. To be considered as a X(3872) candidate, the J/ψγ or ψ(2S)γ combination must have an invariant mass in the range 3.7–4.1 GeV/c2or 3.75–4.05 GeV/c2, respectively, to account for the different available phase space.

The X(3872) candidates are combined with selected kaons to create B+meson candidates. The kaons are required to have transverse momentum larger than 0.8 GeV/c. The quality of the B+vertex is ensured by requiring the χ2/ndf of the vertex fit to be less than 25/3. In addition, the decay time of the B+is required to be larger than 150 µm/c to reduce the large combinatorial background from particles produced at the PV.

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To improve the invariant mass resolution of the X(3872) candidate, a kinematic fit [51]is per-formed. In this fit, the invariant mass of the ψ candidate is constrained to its nominal value [52], the decay products of the B+candidate are required to originate from a common vertex, and the momentum vector of the B+candidate is required to point back to the PV. The χ2/ndf for this fit is required to be less than 5. To improve the resolution on the B+candidate invariant mass, and reduce its correlation with the reconstructed X(3872) candidate mass, the B+mass is determined from a similar kinematic fit with an additional constraint applied to the mass of the X(3872) reso-nance [52]. The B+candidates are required to have invariant mass in the range 5.0–5.5 GeV/c2. To reject possible contributions from B+→ ψK+ decays with an additional random soft pho-ton, the invariant mass of the ψK+_{combination is required to be outside a}_{±40 MeV/c}2_mass

window around the known B+mass [52]. 4. Signal yields

To determine the signal yield of the B+→ X(3872)K+decays followed by X(3872) → ψγ, an unbinned extended maximum likelihood two-dimensional fit in ψγK+ and ψγ invariant masses is performed. The probability density function used in the fit consists of three compo-nents to describe the mass spectrum: signal, background from other B decays that peaks in the ψγK+_{and ψγ invariant mass distributions (henceforth called “peaking background”) and pure}

combinatorial background.

The signal component is modelled as a product of a Gaussian function in the ψγK+

invari-ant mass and a Crystal Ball function [53]in the ψγ invariant mass. The mass resolution and tail parameters of the Crystal Ball function are fixed to those determined from simulated signal events.

The peaking background is studied using simulation. The sources of the peaking background are different in the J/ψ and ψ(2S) channels due to differences in the photon spectra and in the photon selection requirements in these two channels. The main source of the peaking background in the J/ψ channel is the partially reconstructed B+→ J/ψK∗+ decays followed by K∗+→ K+π0 where one photon from the π0decay is not detected. In the ψ(2S) channel the peaking background arises from partially reconstructed B → ψ(2S)K+_{Y decays combined with a random}

photon, where B denotes a b hadron and Y denotes additional particles of the B decay, that escape detection. These background contributions are modelled in the fit using non-parametric kernel probability density functions [54], obtained from simulation of B decays to final states containing a J/ψ or ψ(2S) meson.

Pure combinatorial background is modelled as the product of an exponential function of the ψγK+_{invariant mass and a second-order polynomial function of the J/ψγ invariant mass or a}

third-order polynomial function of the ψ(2S)γ invariant mass. For the latter case, the polyno-mial function is constrained to account for the small available phase space, allowing only two polynomial degrees of freedom to vary in the fit.

The significance of the observed signal in the ψ(2S) channel is determined by simulating a large number of background-only experiments, taking into account all uncertainties in the shape of the background distribution. The probability for the background to fluctuate to at least the number of observed events is found to be 1.2 × 10−5, corresponding to a significance of 4.4 standard deviations for the B+→ X(3872)K+decay followed by X(3872) → ψ(2S)γ.

The fit results for the position of the B+and X(3872) mass peaks, mB+ and mX(3872),

re-spectively, and the signal yields N_ψare listed in Table 1. Projections of the fit on ψγK+and ψγ

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Table 1

Parametersofthesignalfunctionsofthefitstothetwo-dimensionalmassdistributionsofthe B+→ X(3872)K+decaysfollowedbyX(3872)→ ψγ.Uncertaintiesarestatisticalonly.

Parameter Decay mode

X(3872)→ J/ψγ X(3872)→ ψ(2S)γ

m_B+[MeV/c2] 5277.7± 0.8 5281.9± 2.4

mX(3872)[MeV/c2] 3873.4± 3.4 3869.5± 3.4

Nψ 591± 48 36.4± 9.0

Fig. 1.a)DistributionoftheJ/ψγK+invariantmasswithfitprojectionoverlaid,restrictedtothosecandidateswithJ/ψγ invariantmasswithin±3σ fromtheX(3872) peakposition.b) DistributionoftheJ/ψγ invariantmasswithfitprojection overlaid,restrictedtothosecandidateswithJ/ψγK+invariantmasswithin±3σ fromtheB+peakposition.Thetotal fit(thicksolidblue)togetherwiththesignal(thinsolidgreen)andbackgroundcomponents(dash-dottedorangeforthe purecombinatorial,dashedmagentaforthepeakingcomponentandlongdashedbluefortheirsum)areshown.(For interpretationofthereferencestocolorinthisfigurelegend,thereaderisreferredtothewebversionofthisarticle.) 5. Efficiencies and systematic uncertainties

The ratio of the X(3872) → ψ(2S)γ and X(3872) → J/ψγ branching fractions is calculated using the formula

R_ψγ=Nψ(2S) NJ/ψ × εJ/ψ ε_ψ(2S) × B(J/ψ → μ+_μ−₎ B(ψ(2S) → μ+_μ−₎, (1)

where NJ/ψand Nψ(2S)are the measured yields listed in Table 1, and εJ/ψand εψ(2S)are the total

efficiencies. For the ratio of the ψ → μ+μ−branching fractions, lepton universality is assumed and a ratio of dielectron branching fractions equal to 7.60 ± 0.18[52]is used. The uncertainty is treated as a systematic uncertainty.

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Fig. 2.a) Distributionoftheψ(2S)γK+invariantmasswithfitprojectionoverlaid,restrictedtothosecandidateswith ψ(2S)γ invariantmasswithin±3σ fromtheX(3872) peakposition(theinsetshowsa zoomoftheψ(2S)γK+mass region).b) Distributionoftheψ(2S)γ invariantmasswithfitprojectionoverlaid,restrictedtothosecandidateswith ψ(2S)γK+_invariant_mass_within_{±3σ from}_the_B+_peak_position._The_total_fit_(thick_solid_blue)_together_with_the_signal

(thinsolidgreen)andbackgroundcomponents(dash-dottedorangeforthepurecombinatorial,dashedmagentaforthe peakingcomponentandlongdashedbluefortheirsum)areshown.(Forinterpretationofthereferencestocolorinthis figurelegend,thereaderisreferredtothewebversionofthisarticle.)

The total efficiency is the product of the geometrical acceptance, the detection, reconstruction, selection and trigger efficiencies. The efficiencies are estimated using simulated events that have been corrected to reproduce the observed kinematics of B+mesons using the high-yield decay B+→ χc1K+ with χc1→ J/ψγ, which has a topology and kinematics similar to those of the

decays under study. The ratio of the efficiencies is found to be εJ/ψ/εψ(2S)= 5.25 ± 0.04, where

the uncertainty is due to finite size of the simulated samples. The ratio of efficiencies is different from unity mainly because of the different photon spectra in the decays with J/ψ and ψ(2S) in the final state.

Most sources of systematic uncertainty cancel in the ratio, in particular those related to the kaon, muon and ψ reconstruction and identification. The remaining systematic uncertainties are summarized in Table 2and discussed in turn in the following.

Systematic uncertainties related to the signal yield determination are considered in four cate-gories: signal, peaking background, combinatorial background and intervals used in the fit. For each category individual uncertainties are estimated using a number of alternative fit models. The maximum deviations from the baseline values of the yields are taken as individual systematic un-certainties, which are then added in quadrature. The systematic uncertainties on the event yields

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Table 2

Relativesystematicuncertaintiesontheratioofbranchingfractions(R_ψγ).

Source Uncertainty [%] X(3872)→ J/ψγ yield determination 6 X(3872)→ ψ(2S)γ yield determination 7 Photon reconstruction 6 B+kinematics 3 Selection criteria 2 Trigger 1 B(J/ψ → e+_e−_)/_{B(ψ(2S) → e}+_e−₎ ₂

Simulation sample size 1

Sum in quadrature 12

are dominated by uncertainties in the description of backgrounds and are 6% and 7% in the J/ψ and ψ(2S) channels, respectively.

Another important source of systematic uncertainty arises from the potential disagreement between data and simulation in the estimation of efficiencies. This includes the photon re-construction efficiency, the imperfect knowledge of B+ kinematics and the description of the selection criteria efficiencies. The photon reconstruction efficiency is studied using a large sam-ple of B+→ J/ψK∗+decays, followed by K∗+→ K+π0and π0→ γγ decays. The relative yields of B+→ J/ψK∗+and B+→ J/ψK+decays are compared in data and simulation. For photons with transverse momentum greater than 0.6 GeV/c, the agreement between data and simulation is within 6%, which is assigned as the systematic uncertainty due to the photon reconstruction.

The systematic uncertainty related to the knowledge of the B+production properties is esti-mated by comparing the ratio of efficiencies determined without making corrections to the B+ transverse momentum and rapidity spectra to the default ratio of efficiencies determined after the corrections. The relative difference between the two methods is found to be 3% and is conserva-tively assigned as the systematic uncertainty from this source.

To study the uncertainty due to selection criteria, the high-yield decay B+→ χc1K+, followed

by χc1→ J/ψγ, which has a similar topology to the decays studied in this analysis, is used.

The selection criteria for the photon and kaon transverse momentum, the π0_{→ γγ veto and the}

χ2/ndf of the kinematic fit are studied. The selection criteria are varied in ranges corresponding to as much as a 30% change in the signal yields and the ratios of the selection and reconstruction efficiencies are compared between data and simulation. The largest difference of 2% is assigned as the corresponding systematic uncertainty.

The systematic uncertainty related to the trigger efficiency is obtained by comparing the trig-ger efficiency ratios in data and simulation for the high yield decay modes B+→ J/ψK+and B+→ ψ(2S)K+, which have similar kinematics and the same trigger requirements as the chan-nels under study in this analysis [55]. An agreement within 1% is found, which is assigned as the corresponding systematic uncertainty.

6. Results and summary

Using a sample of pp collisions at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1, evidence for the decay X(3872) → ψ(2S)γ in B+→ X(3872)K+decays is found with a significance of 4.4 standard deviations. Its branching fraction, normalized to that of the X(3872) → J/ψγ decay mode is measured to be

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R_ψγ=B(X(3872) → ψ(2S)γ)

B(X(3872) → J/ψγ) = 2.46 ± 0.64 ± 0.29,

where the first uncertainty is statistical and the second is systematic. This result is compati-ble with, but more precise than, previous measurements [20,21]. The measured value of R_ψγ does not support a pure D ¯D∗molecular interpretation [22–24]of the X(3872) state, whereas it agrees with expectations for a pure charmonium interpretation of the X(3872) state [25–32]and a molecular-charmonium mixture interpretations [29,33].

Acknowledgements

We express our gratitude to our colleagues in the CERN accelerator departments for the ex-cellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); NSFC (China); CNRS/IN2P3 and Region Auvergne (France); BMBF, DFG, HGF and MPG (Germany); SFI (Ireland); INFN (Italy); FOM and NWO (The Netherlands); SCSR (Poland); MEN/IFA (Romania); MinES, Rosatom, RFBR and NRC “Kur-chatov Institute” (Russia); MinECo, XuntaGal and GENCAT (Spain); SNSF and SER (Switzer-land); NASU (Ukraine); STFC and the Royal Society (United Kingdom); NSF (USA). We also acknowledge the support received from EPLANET, Marie Curie Actions and the ERC under FP7. The Tier1 computing centres are supported by IN2P3 (France), KIT and BMBF (Germany), INFN (Italy), NWO and SURF (The Netherlands), PIC (Spain), GridPP (United Kingdom). We are indebted to the communities behind the multiple open source software packages on which we depend. We are also thankful for the computing resources and the access to software R&D tools provided by Yandex LLC (Russia).

References

[1]Belle Collaboration, S.-K. Choi, etal., Observation ofa narrowcharmonium-like state in exclusive B+→ K+π+π−J/ψ decays,Phys.Rev.Lett.91(2003)262001,arXiv:hep-ex/0309032.

[2]CDF_√ Collaboration,D.Acosta,etal.,ObservationofthenarrowstateX(3872)→ J/ψπ+π−inpp collisionsat s= 1.96 TeV,Phys.Rev.Lett.93(2004)072001,arXiv:hep-ex/0312021.

[3]D0Collaboration,V.M.Abazov,etal.,ObservationandpropertiesoftheX(3872) decayingtoJ/ψπ+π−inpp collisionsat√s= 1.96 TeV,Phys.Rev.Lett.93(2004)162002,arXiv:hep-ex/0405004.

[4]BaBarCollaboration,B.Aubert,etal.,StudyoftheB−→ J/ψK−π+π−decayandmeasurementoftheB−→ X(3872)K−branchingfraction,Phys.Rev.D71(2005)071103,arXiv:hep-ex/0406022.

[5]LHCbCollaboration,R.Aaij,etal.,ObservationofX(3872) productioninpp collisionsat√s= 7 TeV,Eur.Phys. J.C72(2012)1972,arXiv:1112.5310.

[6]CMSCollaboration,S.Chatrchyan,etal.,MeasurementoftheX(3872) productioncrosssectionviadecaysto J/ψπ+π−inpp collisionsat√s= 7 TeV,J.HighEnergyPhys.04(2013)154,arXiv:1302.3968.

[7]CDFCollaboration,T.Aaltonen,etal.,PrecisionmeasurementoftheX(3872) massinJ/ψπ+π−decays,Phys. Rev.Lett.103(2009)152001,arXiv:0906.5218.

[8]CDFCollaboration,A.Abulencia,etal.,MeasurementofthedipionmassspectruminX(3872)→ J/ψπ+π− de-cays,Phys.Rev.Lett.96(2006)102002,arXiv:hep-ex/0512074.

[9]CDFCollaboration,A.Abulencia,etal.,AnalysisofthequantumnumbersJP CoftheX(3872) particle,Phys.Rev. Lett.98(2007)132002,arXiv:hep-ex/0612053.

[10]LHCbCollaboration,R.Aaij,etal.,DeterminationoftheX(3872) quantumnumbers,Phys.Rev.Lett.110(2013) 222001,arXiv:1302.6269.

[11]S.Godfrey,S.L.Olsen,TheexoticXYZ charmonium-likemesons,Annu.Rev.Nucl.Part.Sci.58(2008)51, arXiv:0801.3867.

[12]S.-L.Zhu,etal.,XYZ states,PoSHadron2013(2013)005,arXiv:1311.3763.

(9)

[14]L.Maiani,F.Piccinini,A.D.Polosa,V.Riquer,Diquark–antidiquarkstateswithhiddenoropencharmandthe natureofX(3872),Phys.Rev.D71(2005)014028,arXiv:hep-ph/0412098.

[15]B.A.Li,IsX(3872) apossiblecandidateasahybridmeson?,Phys.Lett.B605(2005)306,arXiv:hep-ph/0410264.

[16]K.K.Seth,AnalternativeinterpretationofX(3872),Phys.Lett.B612(2005)1,arXiv:hep-ph/0411122.

[17]R.D.Matheus,F.S.Navarra,M.Nielsen,C.M.Zanetti,QCDsumrulesfortheX(3872) asamixed molecule-char-monium state,Phys.Rev.D80(2009)056002,arXiv:0907.2683.

[18]W.Chen,etal.,QCDsum-ruleinterpretationofX(3872) withJP C= 1++mixturesofhybridcharmoniumand ¯DD∗_molecular_currents,_Phys._Rev._D₈₈₍₂₀₁₃₎_045027,_{arXiv:1305.0244.}

[19]BaBarCollaboration,B.Aubert,etal.,SearchforB+→ X(3872)K+,X(3872)→ J/ψγ,Phys.Rev.D74(2006) 071101,arXiv:hep-ex/0607050.

[20]BelleCollaboration,V.Bhardwaj,etal.,ObservationofX(3872)→ J/ψγ andsearchforX(3872)→ ψγ inB decays,Phys.Rev.Lett.107(2011)091803,arXiv:1105.0177.

[21]BaBarCollaboration,B.Aubert,etal.,EvidenceforX(3872)→ ψ(2S)γ inB±→ X(3872)K±decays,andastudy ofB→ ccγK,Phys.Rev.Lett.102(2009)132001,arXiv:0809.0042.

[22]E.S.Swanson,MolecularinterpretationoftheX(3872),Phys.Lett.B588(2004)189,arXiv:hep-ph/0410284.

[23]Y.Dong,A.Faessler,T.Gutsche,V.E.Lyubovitskij,J/ψγ andψ(2S)γ decaymodesoftheX(3872),J.Phys.G38 (2011)015001,arXiv:0909.0380.

[24]J.Ferretti,G.Galata,QuarkstructureoftheX(3872) andχb(3P) resonances,arXiv:1401.4431.

[25]T.Barnes,S.Godfrey,E.S.Swanson,Highercharmonia,Phys.Rev.D72(2005)054026,arXiv:hep-ph/0505002.

[26]T. Barnes, S. Godfrey,Charmonium options for theX(3872), Phys. Rev. D69 (2004) 054008, arXiv:hep-ph/0311162.

[27]B.-Q.Li,K.-T.Chao,HighercharmoniaandX,Y,Z stateswithscreenedpotential,Phys.Rev.D79(2009)094004, arXiv:0903.5506.

[28]T.A.Lahde,Exchangecurrentoperatorsandelectromagneticdipoletransitionsinheavyquarkonia,Nucl.Phys.A 714(2003)183,arXiv:hep-ph/0208110.

[29]A.M.Badalin,V.D.Orlovsky,Y.A.Simonov,B.L.G.Bakker,TheratioofdecaywidthsofX(3872) toψγ andJ/ψγ asatestoftheX(3872) dynamicalstructure,Phys.Rev.D85(2012)114002,arXiv:1202.4882[hep-ph].

[30]T.Mehen,R.Springer,RadiativedecaysX(3872)→ ψ(2S)+ γ andψ(4040)→ X(3872)+ γ ineffectivefield theory,Phys.Rev.D83(2011)094009,arXiv:1101.5175.

[31]T.M.Wang,G.L.Wang,RadiativeE1decaysofX(3872),Phys.Lett.B697(2011)3,arXiv:1006.3363.

[32]F.DeFazio,Radiativetransitionsofheavyquarkoniumstates,Phys.Rev.D79(2009)054015;

F.DeFazio,Erratum:Radiativetransitionsofheavyquarkoniumstates[Phys.Rev.D79,054015(2009)],Phys. Rev.D83(2011)099901.

[33]E.J.Eichten,K.Lane,C.Quigg,Newstatesabovecharmthreshold,Phys.Rev.D73(2006)014014, arXiv:hep-ph/0511179.

[34]LHCbCollaboration,A.A.AlvesJr.,etal.,TheLHCbdetectorattheLHC,J.Instrum.3(2008)S08005.

[35]M.Adinolfi, etal.,Performance oftheLHCb RICHdetector attheLHC, Eur.Phys.J. C73 (2013)2431, arXiv:1211.6759.

[36]A.A.AlvesJr.,etal.,PerformanceoftheLHCbmuonsystem,J.Instrum.8(2013)P02022,arXiv:1211.1346.

[37]R.Aaij,etal.,TheLHCbtriggeranditsperformancein2011,J.Instrum.8(2013)P04022,arXiv:1211.3055.

[38]T.Sjöstrand,S.Mrenna,P.Skands, PYTHIA6.4physicsandmanual,J.HighEnergyPhys.05(2006)026, arXiv:hep-ph/0603175;

T.Sjöstrand,S.Mrenna,P.Skands,AbriefintroductiontoPYTHIA8.1,Comput.Phys.Commun.178(2008)852, arXiv:0710.3820.

[39]I.Belyaev,etal.,Handlingofthegenerationofprimaryeventsin GAUSS,theLHCbsimulationframework,in: NuclearScienceSymposiumConferenceRecord(NSS/MIC),IEEE,2010,p. 1155.

[40]D.J.Lange,The EVTGENparticledecaysimulationpackage,Nucl.Instrum.MethodsA462(2001)152.

[41]P.Golonka,Z.Was, PHOTOSMonteCarlo:aprecisiontoolforQEDcorrectionsinZ andW decays,Eur.Phys.J. C45(2006)97,arXiv:hep-ph/0506026.

[42]Geant4Collaboration,S.Agostinelli,etal., GEANT4:asimulationtoolkit,Nucl.Instrum.MethodsA506(2003) 250.

[43]Geant4Collaboration,J.Allison,etal., GEANT4developmentsandapplications,IEEETrans.Nucl.Sci.53(2006) 270.

[44]M.Clemencic,etal.,TheLHCbsimulationapplication, GAUSS:design,evolutionandexperience,J.Phys.Conf. Ser.331(2011)032023.

[45]LHCbCollaboration,R.Aaij,etal.,ObservationofB0_s→ χc1φ decayandstudyofB0→ χc1,2K∗0decays,Nucl.

(10)

[46]LHCbCollaboration,R.Aaij,etal.,EvidenceforthedecayB→ J/ψω andmeasurementoftherelativebranching fractionsofB0_smesondecaystoJ/ψη andJ/ψη,Nucl.Phys.B867(2013)547,arXiv:1210.2631.

[47]LHCbCollaboration,R.Aaij,etal.,ObservationsofB0_s→ ψ(2S)η andB0(s)→ ψ(2S)π+π−decays,Nucl.Phys.

B871(2013)403,arXiv:1302.6354.

[48]F.Archilli,etal.,PerformanceofthemuonidentificationatLHCb,J.Instrum.8(2013)P10020,arXiv:1306.0249.

[49]LHCb_√ Collaboration,R.Aaij,etal.,MeasurementoftheratioofpromptχctoJ/ψ productioninpp collisionsat

s= 7 TeV,Phys.Lett.B718(2012)431,arXiv:1204.1462.

[50]D.Savrina,MeasurementofthebranchingfractionsoftheB_s0→ J/ψη,B0_s→ J/ψηandB0→ J/ψω0decays intheLHCbexperiment,PhDthesis,InstituteforTheoreticalandExperimentalPhysics,Moscow,2013, CERN-THESIS-2013-229.

[51]W.D.Hulsbergen,DecaychainfittingwithaKalmanfilter,Nucl.Instrum.MethodsA552(2005)566,arXiv: physics/0503191.

[52]ParticleDataGroup,J.Beringer,etal.,Reviewofparticlephysics,Phys.Rev.D86(2012)010001,and2013partial updateforthe2014edition.

[53]T.Skwarnicki,Astudyoftheradiativecascadetransitionsbetweentheϒandϒresonances,PhDthesis,Institute ofNuclearPhysics,Krakow,1986,DESY-F31-86-02.

[54]K.S.Cranmer,Kernelestimationinhigh-energyphysics,Comput.Phys.Commun.136(2001)198, arXiv:hep-ex/0011057.

[55]LHCbCollaboration,R.Aaij,etal.,MeasurementofrelativebranchingfractionsofB decaystoψ(2S) andJ/ψ mesons,Eur.Phys.J.C72(2012)2118,arXiv:1205.0918.

LHCb Collaboration

R. Aaij

41

_,

_{B. Adeva}

37

_,

_{M. Adinolfi}

46

_,

_{A. Affolder}

52

_,

_{Z. Ajaltouni}

5

_,

J. Albrecht

9

_,

_{F. Alessio}

38

_,

_{M. Alexander}

51

_,

_{S. Ali}

41

_,

_{G. Alkhazov}

30

_,

P. Alvarez Cartelle

37

_,

_{A.A. Alves Jr}

25,38

_,

_{S. Amato}

2

_,

_{S. Amerio}

22

_,

Y. Amhis

7

_,

_{L. An}

3

_,

_{L. Anderlini}

17,g

_,

_{J. Anderson}

40

_,

_{R. Andreassen}

57

_,

M. Andreotti

16,f

_,

_{J.E. Andrews}

58

_,

_{R.B. Appleby}

54

_,

O. Aquines Gutierrez

10

_,

_{F. Archilli}

38

_,

_{A. Artamonov}

35

_,

_{M. Artuso}

59

_,

E. Aslanides

6

_,

_{G. Auriemma}

25,n

_,

_{M. Baalouch}

5

_,

_{S. Bachmann}

11

_,

J.J. Back

48

_,

_{A. Badalov}

36

_,

_{V. Balagura}

31

_,

_{W. Baldini}

16

_,

_{R.J. Barlow}

54

_,

C. Barschel

38

_,

_{S. Barsuk}

7

_,

_{W. Barter}

47

_,

_{V. Batozskaya}

28

_,

_{Th. Bauer}

41

_,

A. Bay

39

_,

_{J. Beddow}

51

_,

_{F. Bedeschi}

23

_,

_{I. Bediaga}

1

_,

_{S. Belogurov}

31

_,

K. Belous

35

_,

_{I. Belyaev}

31,∗

_,

_{E. Ben-Haim}

8

_,

_{G. Bencivenni}

18

_,

S. Benson

50

_,

_{J. Benton}

46

_,

_{A. Berezhnoy}

32

_,

_{R. Bernet}

40

_,

_{M.-O. Bettler}

47

_,

M. van Beuzekom

41

_,

_{A. Bien}

11

_,

_{S. Bifani}

45

_,

_{T. Bird}

54

_,

_{A. Bizzeti}

17,i

_,

P.M. Bjørnstad

54

_,

_{T. Blake}

48

_,

_{F. Blanc}

39

_,

_{J. Blouw}

10

_,

_{S. Blusk}

59

_,

V. Bocci

25

_,

_{A. Bondar}

34

_,

_{N. Bondar}

30,38

_,

_{W. Bonivento}

15,38

_,

_{S. Borghi}

54

_,

A. Borgia

59

_,

_{M. Borsato}

7

_,

_{T.J.V. Bowcock}

52

_,

_{E. Bowen}

40

_,

_{C. Bozzi}

16

_,

T. Brambach

9

_,

_{J. van den Brand}

42

_,

_{J. Bressieux}

39

_,

_{D. Brett}

54

_,

M. Britsch

10

_,

_{T. Britton}

59

_,

_{N.H. Brook}

46

_,

_{H. Brown}

52

_,

_{A. Bursche}

40

_,

G. Busetto

22,q

_,

_{J. Buytaert}

38

_,

_{S. Cadeddu}

15

_,

_{R. Calabrese}

16,f

_,

_{O. Callot}

7

_,

M. Calvi

20,k

_,

_{M. Calvo Gomez}

36,o

_,

_{A. Camboni}

36

_,

_{P. Campana}

18,38

_,

D. Campora Perez

38

_,

_{A. Carbone}

14,d

_,

_{G. Carboni}

24,l

_,

_{R. Cardinale}

19,38,j

_,

(11)

G. Casse

52

_,

_{L. Cassina}

20

_,

_{L. Castillo Garcia}

38

_,

_{M. Cattaneo}

38

_,

Ch. Cauet

9

_,

_{R. Cenci}

58

_,

_{M. Charles}

8

_,

_{Ph. Charpentier}

38

_,

_{S.-F. Cheung}

55

_,

N. Chiapolini

40

_,

_{M. Chrzaszcz}

40,26

_,

_{K. Ciba}

38

_,

_{X. Cid Vidal}

38

_,

G. Ciezarek

53

_,

_{P.E.L. Clarke}

50

_,

_{M. Clemencic}

38

_,

_{H.V. Cliff}

47

_,

J. Closier

38

_,

_{C. Coca}

29

_,

_{V. Coco}

38

_,

_{J. Cogan}

6

_,

_{E. Cogneras}

5

_,

_{P. Collins}

38

_,

A. Comerma-Montells

11

_,

_{A. Contu}

15,38

_,

_{A. Cook}

46

_,

_{M. Coombes}

46

_,

S. Coquereau

8

_,

_{G. Corti}

38

_,

_{M. Corvo}

16,f

_,

_{I. Counts}

56

_,

_{B. Couturier}

38

_,

G.A. Cowan

50

_,

_{D.C. Craik}

48

_,

_{M. Cruz Torres}

60

_,

_{S. Cunliffe}

53

_,

R. Currie

50

_,

_{C. D’Ambrosio}

38

_,

_{J. Dalseno}

46

_,

_{P. David}

8

_,

_{P.N.Y. David}

41

_,

A. Davis

57

_,

_{K. De Bruyn}

41

_,

_{S. De Capua}

54

_,

_{M. De Cian}

11

_,

J.M. De Miranda

1

_,

_{L. De Paula}

2

_,

_{W. De Silva}

57

_,

_{P. De Simone}

18

_,

D. Decamp

4

_,

_{M. Deckenhoff}

9

_,

_{L. Del Buono}

8

_,

_{N. Déléage}

4

_,

D. Derkach

55

_,

_{O. Deschamps}

5

_,

_{F. Dettori}

42

_,

_{A. Di Canto}

38

_,

H. Dijkstra

38

_,

_{S. Donleavy}

52

_,

_{F. Dordei}

11

_,

_{M. Dorigo}

39

_,

A. Dosil Suárez

37

_,

_{D. Dossett}

48

_,

_{A. Dovbnya}

43

_,

_{F. Dupertuis}

39

_,

P. Durante

38

_,

_{R. Dzhelyadin}

35

_,

_{A. Dziurda}

26

_,

_{A. Dzyuba}

30

_,

_{S. Easo}

49

_,

U. Egede

53

_,

_{V. Egorychev}

31

_,

_{S. Eidelman}

34

_,

_{S. Eisenhardt}

50

_,

U. Eitschberger

9

_,

_{R. Ekelhof}

9

_,

_{L. Eklund}

51,38

_,

_{I. El Rifai}

5

_,

Ch. Elsasser

40

_,

_{S. Esen}

11

_,

_{T. Evans}

55

_,

_{A. Falabella}

16,f

_,

_{C. Färber}

11

_,

C. Farinelli

41

_,

_{S. Farry}

52

_,

_{D. Ferguson}

50

_,

_{V. Fernandez Albor}

37

_,

F. Ferreira Rodrigues

1

_,

_{M. Ferro-Luzzi}

38

_,

_{S. Filippov}

33

_,

_{M. Fiore}

16,f

_,

M. Fiorini

16,f

_,

_{M. Firlej}

27

_,

_{C. Fitzpatrick}

38

_,

_{T. Fiutowski}

27

_,

M. Fontana

10

_,

_{F. Fontanelli}

19,j

_,

_{R. Forty}

38

_,

_{O. Francisco}

2

_,

_{M. Frank}

38

_,

C. Frei

38

_,

_{M. Frosini}

17,38,g

_,

_{J. Fu}

21,38

_,

_{E. Furfaro}

24,l

_,

_{A. Gallas Torreira}

37

_,

D. Galli

14,d

_,

_{S. Gallorini}

22

_,

_{S. Gambetta}

19,j

_,

_{M. Gandelman}

2

_,

P. Gandini

59

_,

_{Y. Gao}

3

_,

_{J. Garofoli}

59

_,

_{J. Garra Tico}

47

_,

_{L. Garrido}

36

_,

C. Gaspar

38

_,

_{R. Gauld}

55

_,

_{L. Gavardi}

9

_,

_{E. Gersabeck}

11

_,

_{M. Gersabeck}

54

_,

T. Gershon

48

_,

_{Ph. Ghez}

4

_,

_{A. Gianelle}

22

_,

_{S. Giani’}

39

_,

_{V. Gibson}

47

_,

L. Giubega

29

_,

_{V.V. Gligorov}

38

_,

_{C. Göbel}

60

_,

_{D. Golubkov}

31

_,

A. Golutvin

53,31,38

_,

_{A. Gomes}

1,a

_,

_{H. Gordon}

38

_,

_{C. Gotti}

20

_,

M. Grabalosa Gándara

5

_,

_{R. Graciani Diaz}

36

_,

_{L.A. Granado Cardoso}

38

_,

E. Graugés

36

_,

_{G. Graziani}

17

_,

_{A. Grecu}

29

_,

_{E. Greening}

55

_,

_{S. Gregson}

47

_,

P. Griffith

45

_,

_{L. Grillo}

11

_,

_{O. Grünberg}

62

_,

_{B. Gui}

59

_,

_{E. Gushchin}

33

_,

Yu. Guz

35,38

_,

_{T. Gys}

38

_,

_{C. Hadjivasiliou}

59

_,

_{G. Haefeli}

39

_,

_{C. Haen}

38

_,

S.C. Haines

47

_,

_{S. Hall}

53

_,

_{B. Hamilton}

58

_,

_{T. Hampson}

46

_,

_{X. Han}

11

_,

S. Hansmann-Menzemer

11

_,

_{N. Harnew}

55

_,

_{S.T. Harnew}

46

_,

_{J. Harrison}

54

_,

(12)

P. Henrard

5

_,

_{L. Henry}

8

_,

_{J.A. Hernando Morata}

37

_,

_{E. van Herwijnen}

38

_,

M. Heß

62

_,

_{A. Hicheur}

1

_,

_{D. Hill}

55

_,

_{M. Hoballah}

5

_,

_{C. Hombach}

54

_,

W. Hulsbergen

41

_,

_{P. Hunt}

55

_,

_{N. Hussain}

55

_,

_{D. Hutchcroft}

52

_,

_{D. Hynds}

51

_,

M. Idzik

27

_,

_{P. Ilten}

56

_,

_{R. Jacobsson}

38

_,

_{A. Jaeger}

11

_,

_{J. Jalocha}

55

_,

E. Jans

41

_,

_{P. Jaton}

39

_,

_{A. Jawahery}

58

_,

_{M. Jezabek}

26

_,

_{F. Jing}

3

_,

_{M. John}

55

_,

D. Johnson

55

_,

_{C.R. Jones}

47

_,

_{C. Joram}

38

_,

_{B. Jost}

38

_,

_{N. Jurik}

59

_,

M. Kaballo

9

_,

_{S. Kandybei}

43

_,

_{W. Kanso}

6

_,

_{M. Karacson}

38

_,

T.M. Karbach

38

_,

_{M. Kelsey}

59

_,

_{I.R. Kenyon}

45

_,

_{T. Ketel}

42

_,

_{B. Khanji}

20

_,

C. Khurewathanakul

39

_,

_{S. Klaver}

54

_,

_{O. Kochebina}

7

_,

_{M. Kolpin}

11

_,

I. Komarov

39

_,

_{R.F. Koopman}

42

_,

_{P. Koppenburg}

41,38

_,

_{M. Korolev}

32

_,

A. Kozlinskiy

41

_,

_{L. Kravchuk}

33

_,

_{K. Kreplin}

11

_,

_{M. Kreps}

48

_,

_{G. Krocker}

11

_,

P. Krokovny

34

_,

_{F. Kruse}

9

_,

_{M. Kucharczyk}

20,26,38,k

_,

_{V. Kudryavtsev}

34

_,

K. Kurek

28

_,

_{T. Kvaratskheliya}

31

_,

_{V.N. La Thi}

39

_,

_{D. Lacarrere}

38

_,

G. Lafferty

54

_,

_{A. Lai}

15

_,

_{D. Lambert}

50

_,

_{R.W. Lambert}

42

_,

_{E. Lanciotti}

38

_,

G. Lanfranchi

18

_,

_{C. Langenbruch}

38

_,

_{B. Langhans}

38

_,

_{T. Latham}

48

_,

C. Lazzeroni

45

_,

_{R. Le Gac}

6

_,

_{J. van Leerdam}

41

_,

_{J.-P. Lees}

4

_,

_{R. Lefèvre}

5

_,

A. Leflat

32

_,

_{J. Lefrançois}

7

_,

_{S. Leo}

23

_,

_{O. Leroy}

6

_,

_{T. Lesiak}

26

_,

B. Leverington

11

_,

_{Y. Li}

3

_,

_{M. Liles}

52

_,

_{R. Lindner}

38

_,

_{C. Linn}

38

_,

F. Lionetto

40

_,

_{B. Liu}

15

_,

_{G. Liu}

38

_,

_{S. Lohn}

38

_,

_{I. Longstaff}

51

_,

_{J.H. Lopes}

2

_,

N. Lopez-March

39

_,

_{P. Lowdon}

40

_,

_{H. Lu}

3

_,

_{D. Lucchesi}

22,q

_,

_{H. Luo}

50

_,

A. Lupato

22

_,

_{E. Luppi}

16,f

_,

_{O. Lupton}

55

_,

_{F. Machefert}

7

_,

I.V. Machikhiliyan

31

_,

_{F. Maciuc}

29

_,

_{O. Maev}

30

_,

_{S. Malde}

55

_,

_{G. Manca}

15,e

_,

G. Mancinelli

6

_,

_{M. Manzali}

16,f

_,

_{J. Maratas}

5

_,

_{J.F. Marchand}

4

_,

U. Marconi

14

_,

_{C. Marin Benito}

36

_,

_{P. Marino}

23,s

_,

_{R. Märki}

39

_,

_{J. Marks}

11

_,

G. Martellotti

25

_,

_{A. Martens}

8

_,

_{A. Martín Sánchez}

7

_,

_{M. Martinelli}

41

_,

D. Martinez Santos

42

_,

_{F. Martinez Vidal}

64

_,

_{D. Martins Tostes}

2

_,

A. Massafferri

1

_,

_{R. Matev}

38

_,

_{Z. Mathe}

38

_,

_{C. Matteuzzi}

20

_,

A. Mazurov

16,f

_,

_{M. McCann}

53

_,

_{J. McCarthy}

45

_,

_{A. McNab}

54

_,

R. McNulty

12

_,

_{B. McSkelly}

52

_,

_{B. Meadows}

57,55

_,

_{F. Meier}

9

_,

M. Meissner

11

_,

_{M. Merk}

41

_,

_{D.A. Milanes}

8

_,

_{M.-N. Minard}

4

_,

J. Molina Rodriguez

60

_,

_{S. Monteil}

5

_,

_{D. Moran}

54

_,

_{M. Morandin}

22

_,

P. Morawski

26

_,

_{A. Mordà}

6

_,

_{M.J. Morello}

23,s

_,

_{J. Moron}

27

_,

_{R. Mountain}

59

_,

F. Muheim

50

_,

_{K. Müller}

40

_,

_{R. Muresan}

29

_,

_{B. Muster}

39

_,

_{P. Naik}

46

_,

T. Nakada

39

_,

_{R. Nandakumar}

49

_,

_{I. Nasteva}

2

_,

_{M. Needham}

50

_,

_{N. Neri}

21

_,

S. Neubert

38

_,

_{N. Neufeld}

38

_,

_{M. Neuner}

11

_,

_{A.D. Nguyen}

39

_,

T.D. Nguyen

39

_,

_{C. Nguyen-Mau}

39,p

_,

_{M. Nicol}

7

_,

_{V. Niess}

5

_,

_{R. Niet}

9

_,

(13)

V. Obraztsov

35

_,

_{S. Oggero}

41

_,

_{S. Ogilvy}

51

_,

_{O. Okhrimenko}

44

_,

R. Oldeman

15,e

_,

_{G. Onderwater}

65

_,

_{M. Orlandea}

29

_,

J.M. Otalora Goicochea

2

_,

_{P. Owen}

53

_,

_{A. Oyanguren}

64

_,

_{B.K. Pal}

59

_,

A. Palano

13,c

_,

_{F. Palombo}

21,t

_,

_{M. Palutan}

18

_,

_{J. Panman}

38

_,

A. Papanestis

49,38

_,

_{M. Pappagallo}

51

_,

_{C. Parkes}

54

_,

_{C.J. Parkinson}

9

_,

G. Passaleva

17

_,

_{G.D. Patel}

52

_,

_{M. Patel}

53

_,

_{C. Patrignani}

19,j

_,

A. Pazos Alvarez

37

_,

_{A. Pearce}

54

_,

_{A. Pellegrino}

41

_,

_{M. Pepe Altarelli}

38

_,

S. Perazzini

14,d

_,

_{E. Perez Trigo}

37

_,

_{P. Perret}

5

_,

_{M. Perrin-Terrin}

6

_,

L. Pescatore

45

_,

_{E. Pesen}

66

_,

_{K. Petridis}

53

_,

_{A. Petrolini}

19,j

_,

E. Picatoste Olloqui

36

_,

_{B. Pietrzyk}

4

_,

_{T. Pilaˇr}

48

_,

_{D. Pinci}

25

_,

_{A. Pistone}

19

_,

S. Playfer

50

_,

_{M. Plo Casasus}

37

_,

_{F. Polci}

8

_,

_{A. Poluektov}

48,34

_,

I. Polyakov

31

_,

_{E. Polycarpo}

2

_,

_{A. Popov}

35

_,

_{D. Popov}

10

_,

_{B. Popovici}

29

_,

C. Potterat

2

_,

_{A. Powell}

55

_,

_{J. Prisciandaro}

39

_,

_{A. Pritchard}

52

_,

_{C. Prouve}

46

_,

V. Pugatch

44

_,

_{A. Puig Navarro}

39

_,

_{G. Punzi}

23,r

_,

_{W. Qian}

4

_,

_{B. Rachwal}

26

_,

J.H. Rademacker

46

_,

_{B. Rakotomiaramanana}

39

_,

_{M. Rama}

18

_,

M.S. Rangel

2

_,

_{I. Raniuk}

43

_,

_{N. Rauschmayr}

38

_,

_{G. Raven}

42

_,

_{S. Reichert}

54

_,

M.M. Reid

48

_,

_{A.C. dos Reis}

1

_,

_{S. Ricciardi}

49

_,

_{A. Richards}

53

_,

K. Rinnert

52

_,

_{V. Rives Molina}

36

_,

_{D.A. Roa Romero}

5

_,

_{P. Robbe}

7

_,

A.B. Rodrigues

1

_,

_{E. Rodrigues}

54

_,

_{P. Rodriguez Perez}

54

_,

_{S. Roiser}

38

_,

V. Romanovsky

35

_,

_{A. Romero Vidal}

37

_,

_{M. Rotondo}

22

_,

_{J. Rouvinet}

39

_,

T. Ruf

38

_,

_{F. Ruffini}

23

_,

_{H. Ruiz}

36

_,

_{P. Ruiz Valls}

64

_,

_{G. Sabatino}

25,l

_,

J.J. Saborido Silva

37

_,

_{N. Sagidova}

30

_,

_{P. Sail}

51

_,

_{B. Saitta}

15,e

_,

V. Salustino Guimaraes

2

_,

_{C. Sanchez Mayordomo}

64

_,

B. Sanmartin Sedes

37

_,

_{R. Santacesaria}

25

_,

_{C. Santamarina Rios}

37

_,

E. Santovetti

24,l

_,

_{M. Sapunov}

6

_,

_{A. Sarti}

18,m

_,

_{C. Satriano}

25,n

_,

_{A. Satta}

24

_,

M. Savrie

16,f

_,

_{D. Savrina}

31,32

_,

_{M. Schiller}

42

_,

_{H. Schindler}

38

_,

M. Schlupp

9

_,

_{M. Schmelling}

10

_,

_{B. Schmidt}

38

_,

_{O. Schneider}

39

_,

A. Schopper

38

_,

_{M.-H. Schune}

7

_,

_{R. Schwemmer}

38

_,

_{B. Sciascia}

18

_,

A. Sciubba

25

_,

_{M. Seco}

37

_,

_{A. Semennikov}

31

_,

_{K. Senderowska}

27

_,

I. Sepp

53

_,

_{N. Serra}

40

_,

_{J. Serrano}

6

_,

_{L. Sestini}

22

_,

_{P. Seyfert}

11

_,

M. Shapkin

35

_,

_{I. Shapoval}

16,43,f

_,

_{Y. Shcheglov}

30

_,

_{T. Shears}

52

_,

L. Shekhtman

34

_,

_{V. Shevchenko}

63

_,

_{A. Shires}

9

_,

_{R. Silva Coutinho}

48

_,

G. Simi

22

_,

_{M. Sirendi}

47

_,

_{N. Skidmore}

46

_,

_{T. Skwarnicki}

59

_,

_{N.A. Smith}

52

_,

E. Smith

55,49

_,

_{E. Smith}

53

_,

_{J. Smith}

47

_,

_{M. Smith}

54

_,

_{H. Snoek}

41

_,

M.D. Sokoloff

57

_,

_{F.J.P. Soler}

51

_,

_{F. Soomro}

39

_,

_{D. Souza}

46

_,

B. Souza De Paula

2

_,

_{B. Spaan}

9

_,

_{A. Sparkes}

50

_,

_{F. Spinella}

23

_,

(14)

S. Stevenson

55

_,

_{S. Stoica}

29

_,

_{S. Stone}

59

_,

_{B. Storaci}

40

_,

_{S. Stracka}

23,38

_,

M. Straticiuc

29

_,

_{U. Straumann}

40

_,

_{R. Stroili}

22

_,

_{V.K. Subbiah}

38

_,

_{L. Sun}

57

_,

W. Sutcliffe

53

_,

_{K. Swientek}

27

_,

_{S. Swientek}

9

_,

_{V. Syropoulos}

42

_,

M. Szczekowski

28

_,

_{P. Szczypka}

39,38

_,

_{D. Szilard}

2

_,

_{T. Szumlak}

27

_,

S. T’Jampens

4

_,

_{M. Teklishyn}

7

_,

_{G. Tellarini}

16,f

_,

_{E. Teodorescu}

29

_,

F. Teubert

38

_,

_{C. Thomas}

55

_,

_{E. Thomas}

38

_,

_{J. van Tilburg}

41

_,

_{V. Tisserand}

4

_,

M. Tobin

39

_,

_{S. Tolk}

42

_,

_{L. Tomassetti}

16,f

_,

_{D. Tonelli}

38

_,

S. Topp-Joergensen

55

_,

_{N. Torr}

55

_,

_{E. Tournefier}

4

_,

_{S. Tourneur}

39

_,

M.T. Tran

39

_,

_{M. Tresch}

40

_,

_{A. Tsaregorodtsev}

6

_,

_{P. Tsopelas}

41

_,

N. Tuning

41

_,

_{M. Ubeda Garcia}

38

_,

_{A. Ukleja}

28

_,

_{A. Ustyuzhanin}

63

_,

U. Uwer

11

_,

_{V. Vagnoni}

14

_,

_{G. Valenti}

14

_,

_{A. Vallier}

7

_,

_{R. Vazquez Gomez}

18

_,

P. Vazquez Regueiro

37

_,

_{C. Vázquez Sierra}

37

_,

_{S. Vecchi}

16

_,

_{J.J. Velthuis}

46

_,

M. Veltri

17,h

_,

_{G. Veneziano}

39

_,

_{M. Vesterinen}

11

_,

_{B. Viaud}

7

_,

_{D. Vieira}

2

_,

M. Vieites Diaz

37

_,

_{X. Vilasis-Cardona}

36,o

_,

_{A. Vollhardt}

40

_,

D. Volyanskyy

10

_,

_{D. Voong}

46

_,

_{A. Vorobyev}

30

_,

_{V. Vorobyev}

34

_,

_{C. Voß}

62

_,

H. Voss

10

_,

_{J.A. de Vries}

41

_,

_{R. Waldi}

62

_,

_{C. Wallace}

48

_,

_{R. Wallace}

12

_,

J. Walsh

23

_,

_{S. Wandernoth}

11

_,

_{J. Wang}

59

_,

_{D.R. Ward}

47

_,

_{N.K. Watson}

45

_,

A.D. Webber

54

_,

_{D. Websdale}

53

_,

_{M. Whitehead}

48

_,

_{J. Wicht}

38

_,

D. Wiedner

11

_,

_{G. Wilkinson}

55

_,

_{M.P. Williams}

45

_,

_{M. Williams}

56

_,

F.F. Wilson

49

_,

_{J. Wimberley}

58

_,

_{J. Wishahi}

9

_,

_{W. Wislicki}

28

_,

_{M. Witek}

26

_,

G. Wormser

7

_,

_{S.A. Wotton}

47

_,

_{S. Wright}

47

_,

_{S. Wu}

3

_,

_{K. Wyllie}

38

_,

Y. Xie

61

_,

_{Z. Xing}

59

_,

_{Z. Xu}

39

_,

_{Z. Yang}

3

_,

_{X. Yuan}

3

_,

_{O. Yushchenko}

35

_,

M. Zangoli

14

_,

_{M. Zavertyaev}

10,b

_,

_{F. Zhang}

3

_,

_{L. Zhang}

59

_,

_{W.C. Zhang}

12

_,

Y. Zhang

3

_,

_{A. Zhelezov}

11

_,

_{A. Zhokhov}

31

_,

_{L. Zhong}

3

_,

_{A. Zvyagin}

38 1_Centro_Brasileiro_de_Pesquisas_Físicas_(CBPF),_Rio_de_Janeiro,_Brazil

2_Universidade_Federal_do_Rio_de_Janeiro_(UFRJ),_Rio_de_Janeiro,_Brazil 3_Center_for_High_Energy_Physics,_Tsinghua_University,_Beijing,_China 4_LAPP,_Université_de_Savoie,_CNRS/IN2P3,_{Annecy-Le-Vieux,}_France

5_Clermont_Université,_Université_Blaise_Pascal,_CNRS/IN2P3,_LPC,_{Clermont-Ferrand,}_France 6_CPPM,_{Aix-Marseille}_Université,_CNRS/IN2P3,_Marseille,_France

7_LAL,_Université_Paris-Sud,_CNRS/IN2P3,_Orsay,_France

8_LPNHE,_Université_Pierre_et_Marie_Curie,_Université_Paris_Diderot,_CNRS/IN2P3,_Paris,_France 9_Fakultät_Physik,_Technische_Universität_Dortmund,_Dortmund,_Germany

10_{Max-Planck-Institut}_für_Kernphysik_(MPIK),_Heidelberg,_Germany

11_{Physikalisches}_Institut,_{Ruprecht-Karls-Universität}_Heidelberg,_Heidelberg,_Germany 12_School_of_Physics,_University_College_Dublin,_Dublin,_Ireland

13_Sezione_INFN_di_Bari,_Bari,_Italy 14_Sezione_INFN_di_Bologna,_Bologna,_Italy 15_Sezione_INFN_di_Cagliari,_Cagliari,_Italy 16_Sezione_INFN_di_Ferrara,_Ferrara,_Italy 17_Sezione_INFN_di_Firenze,_Firenze,_Italy

18_Laboratori_Nazionali_dell’INFN_di_Frascati,_Frascati,_Italy 19_Sezione_INFN_di_Genova,_Genova,_Italy