E-resources
PDF-
Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Baechler, J.; Barrera, C. Baldenegro; Berardi, V.; Berretti, M.; Bossini, E.; Bottigli, U.; Bozzo, M.; Bruce, R.; Burkhardt, H.; Cafagna, F. S.; Catanesi, M. G.; Csanád, M.; Csörgő, T.; Deile, M.; De Leonardis, F.; D’Orazio, A.; Doubek, M.; Druzhkin, D.; Eggert, K.; Eremin, V.; Ferro, F.; Fiergolski, A.; Garcia, F.; Morales, H. Garcia; Georgiev, V.; Giani, S.; Grzanka, L.; Hammerbauer, J.; Heino, J.; Helander, P.; Isidori, T.; Ivanchenko, V.; Janda, M.; Karev, A.; Kašpar, J.; Kopal, J.; Kundrát, V.; Lami, S.; Latino, G.; Lauhakangas, R.; Linhart, R.; Lindsey, C.; Lokajíček, M. V.; Losurdo, L.; Lo Vetere, M.; Rodríguez, F. Lucas; Macrí, M.; Malawski, M.; Mereghetti, A.; Minafra, N.; Minutoli, S.; Mirarchi, D.; Naaranoja, T.; Nemes, F.; Niewiadomski, H.; Novák, T.; Oliveri, E.; Oljemark, F.; Oriunno, M.; Österberg, K.; Palazzi, P.; Passaro, V.; Peroutka, Z.; Procházka, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Redaelli, S.; Robutti, E.; Royon, C.; Ruggiero, G.; Saarikko, H.; Salvachua, B.; Scribano, A.; Siroky, J.; Smajek, J.; Snoeys, W.; Stefanovitch, R.; Sziklai, J.; Taylor, C.; Tcherniaev, E.; Turini, N.; Vacek, V.; Valentino, G.; Welti, J.; Wenninger, J.; Williams, J.; Wyszkowski, P.; Zich, J.; Zielinski, K.
The European physical journal. C, Particles and fields, 09/2019, Volume: 79, Issue: 9Journal Article
The TOTEM experiment at the LHC has performed the first measurement at s = 13 TeV of the ρ parameter, the real to imaginary ratio of the nuclear elastic scattering amplitude at t = 0 , obtaining the following results: ρ = 0.09 ± 0.01 and ρ = 0.10 ± 0.01 , depending on different physics assumptions and mathematical modelling. The unprecedented precision of the ρ measurement, combined with the TOTEM total cross-section measurements in an energy range larger than 10 TeV (from 2.76 to 13 TeV ), has implied the exclusion of all the models classified and published by COMPETE. The ρ results obtained by TOTEM are compatible with the predictions, from other theoretical models both in the Regge-like framework and in the QCD framework, of a crossing-odd colourless 3-gluon compound state exchange in the t -channel of the proton–proton elastic scattering. On the contrary, if shown that the crossing-odd 3-gluon compound state t -channel exchange is not of importance for the description of elastic scattering, the ρ value determined by TOTEM would represent a first evidence of a slowing down of the total cross-section growth at higher energies. The very low-| t | reach allowed also to determine the absolute normalisation using the Coulomb amplitude for the first time at the LHC and obtain a new total proton–proton cross-section measurement σ tot = ( 110.3 ± 3.5 ) mb , completely independent from the previous TOTEM determination. Combining the two TOTEM results yields σ tot = ( 110.5 ± 2.4 ) mb .
