Measurement of the forward charged-particle pseudorapidity density in pp collisions at √s = 7 TeV with the TOTEM experiment

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

doi:10.1209/0295-5075/98/31002

The TOTEM experiment has measured the charged-particle pseudorapidity density dN ch/dη in pp collisions at for 5.3<|η|<6.4 in events with at least one charged particle with transverse momentum above 40 MeV/c in this pseudorapidity range. This extends the analogous measurement performed by the other LHC experiments to the previously unexplored forward η region. The measurement refers to more than 99% of non-diffractive processes and to single and double diffractive processes with diffractive masses above ∼3.4 GeV/c 2, corresponding to about 95% of the total inelastic cross-section. The dN ch/dη has been found to decrease with |η|, from 3.84 ± 0.01(stat) ± 0.37(syst) at |η|=5.375 to 2.38±0.01(stat)±0.21(syst) at |η|=6.375. Several MC generators have been compared to data; none of them has been found to fully describe the measurement.

Measurement of the forward charged-particle pseudorapidity density in pp collisions at √s = 7 TeV with the TOTEM experiment / Antchev, G; Aspell, P; Atanassov, I; Avati, V; Baechler, J; Berardi, Vincenzo; Berretti, M.; Bossini, E.; Bozzo, M.; Brogi, P.; Brücken, E.; Buzzo, A.; Cafagna, F. S.; Calicchio, M.; Catanesi, M. G.; Covault, C.; Csanád, M.; Csörg, T.; Deile, M.; Eggert, K.; Eremin, V.; Ferretti, R.; Ferro, F.; Fiergolski, A.; Garcia, F.; Giani, S.; Greco, V.; Grzanka, L.; Heino, J.; Hilden, T.; Intonti, M. R.; Kašpar, J.; Kopal, J.; Kundrát, V.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Leszko, T.; Lippmaa, E.; Lokajíček, M.; Lo, Vetere; Lucas, Rodríguez; F., Macrí; M., Magaletti; L., Mäki; T., Mercadante; A., Minafra; N., Minutoli; S., Nemes; F., Niewiadomski; H., Oliveri; E., Oljemark; F., Orava; R., Oriunno; M., Österberg; K., Palazzi; P., Procházka; J., Quinto; M., Radermacher; E., Radicioni; E., Ravotti; F., Robutti; E., Ropelewski; L., Ruggiero; G., Saarikko; H., Santroni; A., Scribano; A., Snoeys; W., Sziklai; J., Taylor; C., Turini; N., Vacek; V., Vitek; M., Welti; J., Whitmore. - In: EUROPHYSICS LETTERS. - ISSN 0295-5075. - 98:3(2012). [10.1209/0295-5075/98/31002]