TY  - JOUR
AU  - LHCb Collaboration (Aaij, R. et al
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
AU  - Ruiz Valls, P.
AU  - Sanchez Mayordomo, C.
PY  - 2015
DA  - 2015//
TI  - Measurement of the exclusive gamma production cross-section in pp collisions at root s=7 TeV and 8 TeV
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 084
EP  - 20pp
VL  - 09
IS  - 9
PB  - Springer
KW  - Diffraction
KW  - Hadron-Hadron Scattering
KW  - Forward physics
KW  - Particle and resonance production
KW  - Heavy quark production
AB  - A study is presented of central exclusive production of gamma(n S) states, where the gamma (n S) resonances decay to the mu(+) mu(-) final state, using p p collision data recorded by the LHCb experiment. The cross-section is measured in the rapidity range 2 < y (gamma) < 4.5 where the muons are reconstructed in the pseudorapidity range 2 < eta (mu(+/-)) < 4.5. The data sample corresponds to an integrated luminosity of 2.9 fb(-1) and was collected at centreof- mass energies of 7TeV and 8TeV. The measured gamma(1 S) and gamma(2 S) production crosssections are sigma(pp -> p gamma(1S)p) = 9.0 +/- 1.7 pb and sigma(pp -> p gamma(2S)p) = 1.3 +/- 0.3 pb, where the first uncertainties are statistical and the second are systematic. The gamma (1S) cross-section is also measured as a function of rapidity and is found to be in good agreement with Standard Model predictions. An upper limit is set at 3.4 pb at the 95% confidence level for the exclusive gamma(3 S) production cross-section, including possible contamination from chi b (3P) -> gamma (3S)gamma decays.
SN  - 1029-8479
UR  - http://arxiv.org/abs/1505.08139
UR  - https://doi.org/10.1007/JHEP09(2015)084
DO  - 10.1007/JHEP09(2015)084
LA  - English
N1  - WOS:000361555400002
ID  - LHCbCollaborationAaij_etal2015
ER  -