Publication
Coherent $J/\psi$ photoproduction in ultra-peripheral PbPb collisions at $\sqrt {s_{NN}} =$ 2.76 TeV with the CMS experiment
| dc.contributor.author | CMS collaboration (2289 authors) | |
| dc.contributor.author | Calpas, Betty | |
| dc.contributor.author | Nayak, Aruna | |
| dc.contributor.author | Bargassa, Pedrame | |
| dc.contributor.author | Beirão Da Cruz E Silva, Cristóvão | |
| dc.contributor.author | Di Francesco, Agostino | |
| dc.contributor.author | Faccioli, Pietro | |
| dc.contributor.author | Ferreira Parracho, Pedro Guilherme | |
| dc.contributor.author | Gallinaro, Michele | |
| dc.contributor.author | Hollar, Jonathan | |
| dc.contributor.author | Leonardo, Nuno | |
| dc.contributor.author | Lloret Iglesias, Lara | |
| dc.contributor.author | Nguyen, Federico | |
| dc.contributor.author | Rodrigues Antunes, Joao | |
| dc.contributor.author | Seixas, Joao | |
| dc.contributor.author | Toldaiev, Oleksii | |
| dc.contributor.author | Vadruccio, Daniele | |
| dc.contributor.author | Varela, Joao | |
| dc.contributor.author | Vischia, Pietro | |
| dc.contributor.author | David Tinoco Mendes, Andre | |
| dc.contributor.author | Silva, Pedro | |
| dc.contributor.author | Musella, Pasquale | |
| dc.contributor.author | Pela, Joao | |
| dc.date.accessioned | 2019-02-04T10:03:50Z | |
| dc.date.available | 2019-02-04T10:03:50Z | |
| dc.date.issued | 2017-09-10 | |
| dc.date.updated | 2019-02-04T10:03:50Z | |
| dc.description.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=2.76 TeV . The analysis is based on a data sample corresponding to an integrated luminosity of 159 μb−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 dσXn0ncoh/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. | |
| dc.description.version | Peer Reviewed | |
| dc.identifier | Phys.Lett. B772 (2017) 489-511; DOI 10.1016/j.physletb.2017.07.001 | |
| dc.identifier.uri | http://dx.doi.org/10.1016/j.physletb.2017.07.001 | |
| dc.identifier.uri | http://hdl.handle.net/10400.26/27092 | |
| dc.language.iso | eng | |
| dc.title | Coherent $J/\psi$ photoproduction in ultra-peripheral PbPb collisions at $\sqrt {s_{NN}} =$ 2.76 TeV with the CMS experiment | |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | pt |
| rcaap.type | article |