11 de setembro de 2018 | Altas Energias, Publicações
D.A.Fagundes, M.J.Menon, P.V.R.G.Silva
Nuclear Physics A, vol. 996, p. 185-196, October 2017
08/07/2017
Abstract
Recent measurements of the proton–proton total cross section at 7 and 8 TeV by the TOTEM and ATLAS Collaborations are characterized by some discrepant values: the TOTEM data suggest a rise of the cross section with the energy faster than the ATLAS data. Attempting to quantify these different behaviors, we develop new analytical fits to and ρ data from pp and scattering in the energy region 5 GeV–8 TeV. The dataset comprises all the accelerator data below 7 TeV and we consider three ensembles by adding: either only the TOTEM data (T), or only the ATLAS data (A), or both sets (T + A). For the purposes, we use our previous RRPLγ parametrization for , consisting of two Reggeons (RR), one critical Pomeron (P) and a leading log-raised-to-gamma (Lγ) contribution (with γ as a free fit parameter), analytically connected to through singly-subtracted derivative dispersion relations and energy scale fixed at the physical threshold. The data reductions with ensembles T and A present good agreement with the experimental data analyzed and cannot be distinguished on statistical grounds. The quality of the fit is not as good with ensemble T + A. The fit results provide (T), (A), (), with (T), 1.09 (A), 1.14 (T + A), suggesting extrema bounds for γ given by 1.9 and 2.4. Fits with (fixed) are also developed and discussed.