First measurement of the total proton-proton cross section at the LHC energy of {\surd} s =7 TeV

G. Antchev, P. Aspell, I. Atanassov, V. Avati, J. Baechler, V. Berardi, M. Berretti, E. Bossini, M. Bozzo, P. Brogi, E. Brücken, A. Buzzo, F. Cafagna, M. Calicchio, M. G. Catanesi, C. Covault, T. Csörgö, M. Deile, K. Eggert, V. Eremin, R. Ferretti, F. Ferro, A. Fiergolski, F. Garcia, S. Giani, V. Greco, L. Grzanka, J. Heino, T. Hilden, M. R. Intonti, J. Kašpar, J. Kopal, V. Kundrát, K. Kurvinen, S. Lami, G. Latino, R. Lauhakangas, T. Leszko, E. Lippmaa, M. Lokajíček, M. Lo Vetere, F. Lucas Rodríguez, M. Macrí, L. Magaletti, A. Mercadante, S. Minutoli, F. Nemes, H. Niewiadomski, E. Oliveri, F. Oljemark, R. Orava, M. Oriunno, K. Österberg, P. Palazzi, J. Procházka, M. Quinto, E. Radermacher, E. Radicioni, F. Ravotti, E. Robutti, L. Ropelewski, G. Ruggiero, H. Saarikko, G. Sanguinetti, A. Santroni, A. Scribano, W. Snoeys, J. Sziklai, C. Taylor, N. Turini, V. Vacek, M. Vítek, J. Welti, J. Whitmore

Published 2011-10-06Version 1

TOTEM has measured the differential cross-section for elastic proton-proton scattering at the LHC energy of {\srud}s = 7TeV analysing data from a short run with dedicated large {\beta} * optics. A single exponential fit with a slope B = (20:1{\pm}0:2stat {\pm}0:3syst)GeV-2 describes the range of the four-momentum transfer squared |t| from 0.02 to 0.33 GeV2. After the extrapolation to |t| = 0, a total elastic scattering cross-section of (24:8{\pm}0:2stat {\pm}1:2syst) mb was obtained. Applying the optical theorem and using the luminosity measurement from CMS, a total proton-proton cross-section of (98:3{\pm}0:2stat {\pm}2:8syst) mb was deduced which is in good agreement with the expectation from the overall fit of previously measured data over a large range of center-of-mass energies. From the total and elastic pp cross-section measurements, an inelastic pp cross-section of (73:5{\pm}0:6stat +1:8 -1:3 syst) mb was inferred. PACS 13.60.Hb: Total and inclusive cross sections