%0 Journal Article
%T Measurement of the exclusive gamma production cross-section in pp collisions at root s=7 TeV and 8 TeV
%A LHCb Collaboration (Aaij, R. et al
%A Martinez-Vidal, F.
%A Oyanguren, A.
%A Ruiz Valls, P.
%A Sanchez Mayordomo, C.
%J Journal of High Energy Physics
%D 2015
%V 09
%N 9
%I Springer
%@ 1029-8479
%G English
%F LHCbCollaborationAaij_etal2015
%O WOS:000361555400002
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=2395), last updated on Fri, 16 Oct 2015 10:24:01 +0000
%X 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.
%K Diffraction
%K Hadron-Hadron Scattering
%K Forward physics
%K Particle and resonance production
%K Heavy quark production
%R 10.1007/JHEP09(2015)084
%U http://arxiv.org/abs/1505.08139
%U https://doi.org/10.1007/JHEP09(2015)084
%P 084-20pp