@article{4989c208bc4f4c9b909f342bd253ad18,

title = "Coherent J/ψ photoproduction in ultra-peripheral PbPb collisions at sNN=2.76TeV with the CMS experiment",

abstract = "The cross section for coherent J/ψ photoproduction accompanied by at least one neutron on one side of the interaction point and no neutron activity on the other side, Xn0n, is measured with the CMS experiment in ultra-peripheral PbPb collisions at sNN=2.76TeV. The analysis is based on a data sample corresponding to an integrated luminosity of 159μb−1, collected during the 2011 PbPb run. The J/ψ mesons are reconstructed in the dimuon decay channel, while neutrons are detected using zero degree calorimeters. The measured cross section is dσXn0n coh/dy(J/ψ)=0.36±0.04(stat)±0.04(syst) mb in the rapidity interval 1.8<|y|<2.3. Using a model for the relative rate of coherent photoproduction processes, this Xn0n measurement gives a total coherent photoproduction cross section of dσcoh/dy(J/ψ)=1.82±0.22(stat)±0.20(syst)±0.19(theo) mb. The data strongly disfavor the impulse approximation model prediction, indicating that nuclear effects are needed to describe coherent J/ψ photoproduction in γ+Pb interactions. The data are found to be consistent with the leading twist approximation, which includes nuclear gluon shadowing.",

keywords = "CMS, Heavy ion collisions, J/Psi, Physics, UPC, Ultra-peripheral collisions",

author = "{The CMS collaboration} and V. Khachatryan and Sirunyan, {A. M.} and A. Tumasyan and W. Adam and E. Asilar and T. Bergauer and J. Brandstetter and E. Brondolin and M. Dragicevic and J. Er{\"o} and M. Flechl and M. Friedl and R. Fr{\"u}hwirth and Ghete, {V. M.} and C. Hartl and N. H{\"o}rmann and J. Hrubec and M. Jeitler and A. K{\"o}nig and M. Krammer and I. Kr{\"a}tschmer and D. Liko and T. Matsushita and I. Mikulec and D. Rabady and N. Rad and B. Rahbaran and H. Rohringer and J. Schieck and R. Sch{\"o}fbeck and J. Strauss and W. Treberer-Treberspurg and W. Waltenberger and Wulz, {C. E.} and V. Mossolov and N. Shumeiko and {Suarez Gonzalez}, J. and S. Alderweireldt and T. Cornelis and {De Wolf}, {E. A.} and X. Janssen and A. Knutsson and J. Lauwers and S. Luyckx and {Van De Klundert}, M. and {Van Haevermaet}, H. and {Van Mechelen}, P. and {Van Remortel}, N. and {Van Spilbeeck}, A. and {Abu Zeid}, S. and F. Blekman and J. D'Hondt and N. Daci and {De Bruyn}, I. and K. Deroover and N. Heracleous and J. Keaveney and S. Lowette and S. Moortgat and L. Moreels and A. Olbrechts and Q. Python and D. Strom and S. Tavernier and {Van Doninck}, W. and {Van Mulders}, P. and {Van Onsem}, {G. P.} and {Van Parijs}, I. and H. Brun and C. Caillol and B. Clerbaux and {De Lentdecker}, G. and G. Fasanella and L. Favart and R. Goldouzian and A. Grebenyuk and Andrew Whitbeck and Nural Akchurin and Shuichi Kunori and Sungwon Lee and Igor Volobouev",

year = "2017",

month = sep,

day = "10",

doi = "10.1016/j.physletb.2017.07.001",

language = "English",

volume = "772",

pages = "489--511",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

}