An observation of the Λb 0→ψ(2S)Λ0 decay and a comparison of its branching fraction with that of the Λb 0→J/ψΛ0 decay has been made with the ATLAS detector in proton-proton collisions at s=8 TeV at the LHC using an integrated luminosity of 20.6 fb-1. The J/ψ and ψ(2S) mesons are reconstructed in their decays to a muon pair, while the Λ0→ pπ- decay is exploited for the Λ0 baryon reconstruction. The Λb 0 baryons are reconstructed with transverse momentum pT>10 GeV and pseudorapidity |η|<2.1. The measured branching ratio of the Λb 0→ψ(2S)Λ0 and Λb 0J/ψΛ0 decays is Gcyrillic(Λb 0→ψ(2S)Λ0/Gcyrillic(Λb 0J/ψΛ0)=0.501$\pm$0.033(stat)$\pm$0.019(syst), lower than the expectation from the covariant quark model. \copyright 2015 The Authors.
Measurement of the branching ratio Gcyrillic(Λb 0→ψ(2S)Λ0)/G(Λb 0→J/ψΛ0) with the ATLAS detector / Aad, G; Aloisio, Alberto; Alviggi, Mariagrazia; Canale, Vincenzo; DELLA PIETRA, Massimo; DELLA VOLPE, Domenico; Merola, Leonardo; Conventi, Francesco; Rossi, Elvira; Cirotto, Francesco; Perrella, Sabrina; SANCHEZ PINEDA, ARTURO RODOLFO; Carlino, Gianpaolo; DE ASMUNDIS, Riccardo; DI DONATO, Camilla; Doria, Alessandra; Iengo, Paolo; Izzo, Vincenzo; Sekhniaidze, Givi; Et, A. l.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 751:(2015), pp. 63-80. [10.1016/j.physletb.2015.10.009]
Measurement of the branching ratio Gcyrillic(Λb 0→ψ(2S)Λ0)/G(Λb 0→J/ψΛ0) with the ATLAS detector
ALOISIO, ALBERTO;ALVIGGI, MARIAGRAZIA;CANALE, VINCENZO;DELLA PIETRA, MASSIMO;DELLA VOLPE, DOMENICO;MEROLA, LEONARDO;CONVENTI, FRANCESCO;ROSSI, ELVIRA;CIROTTO, FRANCESCO;PERRELLA, SABRINA;SANCHEZ PINEDA, ARTURO RODOLFO;CARLINO, GIANPAOLO;DE ASMUNDIS, Riccardo;DI DONATO, CAMILLA;IENGO, PAOLO;IZZO, VINCENZO;
2015
Abstract
An observation of the Λb 0→ψ(2S)Λ0 decay and a comparison of its branching fraction with that of the Λb 0→J/ψΛ0 decay has been made with the ATLAS detector in proton-proton collisions at s=8 TeV at the LHC using an integrated luminosity of 20.6 fb-1. The J/ψ and ψ(2S) mesons are reconstructed in their decays to a muon pair, while the Λ0→ pπ- decay is exploited for the Λ0 baryon reconstruction. The Λb 0 baryons are reconstructed with transverse momentum pT>10 GeV and pseudorapidity |η|<2.1. The measured branching ratio of the Λb 0→ψ(2S)Λ0 and Λb 0J/ψΛ0 decays is Gcyrillic(Λb 0→ψ(2S)Λ0/Gcyrillic(Λb 0J/ψΛ0)=0.501$\pm$0.033(stat)$\pm$0.019(syst), lower than the expectation from the covariant quark model. \copyright 2015 The Authors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
