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