The TOTEM experiment at the LHC has performed the first measurement at s=13TeV 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 10TeV (from 2.76 to 13TeV), 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 σtot=(110.3±3.5)mb, completely independent from the previous TOTEM determination. Combining the two TOTEM results yields σtot=(110.5±2.4)mb.

First determination of the ρ parameter at √s=13 TeV: probing the existence of a colourless C-odd three-gluon compound state: TOTEM Collaboration / Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Baechler, J.; Barrera, C. B.; Berardi, V.; Berretti, M.; Bossini, E.; Bottigli, U.; Bozzo, M.; Bruce, R.; Burkhardt, H.; Cafagna, F. S.; Catanesi, M. G.; Csanad, M.; Csorgo, 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. G.; Georgiev, V.; Giani, S.; Grzanka, L.; Hammerbauer, J.; Heino, J.; Helander, P.; Isidori, T.; Ivanchenko, V.; Janda, M.; Karev, A.; Kaspar, J.; Kopal, J.; Kundrat, V.; Lami, S.; Latino, G.; Lauhakangas, R.; Linhart, R.; Lindsey, C.; Lokajicek, M. V.; Losurdo, L.; Lo Vetere, M.; Rodriguez, F. L.; Macri, M.; Malawski, M.; Mereghetti, A.; Minafra, N.; Minutoli, S.; Mirarchi, D.; Naaranoja, T.; Nemes, F.; Niewiadomski, H.; Novak, T.; Oliveri, E.; Oljemark, F.; Oriunno, M.; Osterberg, K.; Palazzi, P.; Passaro, V.; Peroutka, Z.; Prochazka, 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.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - STAMPA. - 79:9(2019). [10.1140/epjc/s10052-019-7223-4]

First determination of the ρ parameter at √s=13 TeV: probing the existence of a colourless C-odd three-gluon compound state: TOTEM Collaboration

Berardi V.;De Leonardis F.;D'Orazio A.;Passaro V.;
2019-01-01

Abstract

The TOTEM experiment at the LHC has performed the first measurement at s=13TeV 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 10TeV (from 2.76 to 13TeV), 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 σtot=(110.3±3.5)mb, completely independent from the previous TOTEM determination. Combining the two TOTEM results yields σtot=(110.5±2.4)mb.
2019
First determination of the ρ parameter at √s=13 TeV: probing the existence of a colourless C-odd three-gluon compound state: TOTEM Collaboration / Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Baechler, J.; Barrera, C. B.; Berardi, V.; Berretti, M.; Bossini, E.; Bottigli, U.; Bozzo, M.; Bruce, R.; Burkhardt, H.; Cafagna, F. S.; Catanesi, M. G.; Csanad, M.; Csorgo, 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. G.; Georgiev, V.; Giani, S.; Grzanka, L.; Hammerbauer, J.; Heino, J.; Helander, P.; Isidori, T.; Ivanchenko, V.; Janda, M.; Karev, A.; Kaspar, J.; Kopal, J.; Kundrat, V.; Lami, S.; Latino, G.; Lauhakangas, R.; Linhart, R.; Lindsey, C.; Lokajicek, M. V.; Losurdo, L.; Lo Vetere, M.; Rodriguez, F. L.; Macri, M.; Malawski, M.; Mereghetti, A.; Minafra, N.; Minutoli, S.; Mirarchi, D.; Naaranoja, T.; Nemes, F.; Niewiadomski, H.; Novak, T.; Oliveri, E.; Oljemark, F.; Oriunno, M.; Osterberg, K.; Palazzi, P.; Passaro, V.; Peroutka, Z.; Prochazka, 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.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - STAMPA. - 79:9(2019). [10.1140/epjc/s10052-019-7223-4]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11589/188583
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