Differential cross sections are presented for the prompt and non-prompt production of the hidden-charm states X(3872) and Ï(2S), in the decay mode J/ÏÏ+Ïâ, measured using 11.4 fbâ1 of pp collisions at s=8 TeV by the ATLAS detector at the LHC. The ratio of cross-sections X(3872)/Ï(2S) is also given, separately for prompt and non-prompt components, as well as the non-prompt fractions of X(3872) and Ï(2S). Assuming independent single effective lifetimes for non-prompt X(3872) and Ï(2S) production gives RB=â¬(BâX(3872)+any)â¬(X(3872)âJ/ÏÏ+Ïâ)/â¬(BâÏ(2S)+any)â¬(Ï(2S)âJ/ÏÏ+Ïâ)=(3.95±0.32(stat)±0.08(sys))Ã10â2 separating short- and long-lived contributions, assuming that the short-lived component is due to Bc decays, gives RB = (3.57 ± 0.33(stat) ± 0.11(sys)) à 10â2, with the fraction of non-prompt X(3872) produced via Bc decays for pT(X(3872)) > 10 GeV being (25 ± 13(stat) ± 2(sys) ± 5(spin))%. The distributions of the dipion invariant mass in the X(3872) and Ï(2S) decays are also measured and compared to theoretical predictions.[Figure not available: see fulltext.]
Measurements of Ï(2S) and X(3872) â J/ÏÏ + Ï â production in pp collisions at âs=8 TeV with the ATLAS detector
BARBERIS, DARIO;FAVARETO, ANDREA;FERRETTO PARODI, ANDREA;GAGLIARDI, GUIDO;GAUDIELLO, ANDREA;GUIDO, ELISA;MIGLIORANZI, SILVIA;OSCULATI, BIANCA MARIA;PARODI, FABRIZIO;SANNINO, MARIO;SCHIAVI, CARLO;Sforza, F.;
2017-01-01
Abstract
Differential cross sections are presented for the prompt and non-prompt production of the hidden-charm states X(3872) and Ï(2S), in the decay mode J/ÏÏ+Ïâ, measured using 11.4 fbâ1 of pp collisions at s=8 TeV by the ATLAS detector at the LHC. The ratio of cross-sections X(3872)/Ï(2S) is also given, separately for prompt and non-prompt components, as well as the non-prompt fractions of X(3872) and Ï(2S). Assuming independent single effective lifetimes for non-prompt X(3872) and Ï(2S) production gives RB=â¬(BâX(3872)+any)â¬(X(3872)âJ/ÏÏ+Ïâ)/â¬(BâÏ(2S)+any)â¬(Ï(2S)âJ/ÏÏ+Ïâ)=(3.95±0.32(stat)±0.08(sys))Ã10â2 separating short- and long-lived contributions, assuming that the short-lived component is due to Bc decays, gives RB = (3.57 ± 0.33(stat) ± 0.11(sys)) à 10â2, with the fraction of non-prompt X(3872) produced via Bc decays for pT(X(3872)) > 10 GeV being (25 ± 13(stat) ± 2(sys) ± 5(spin))%. The distributions of the dipion invariant mass in the X(3872) and Ï(2S) decays are also measured and compared to theoretical predictions.[Figure not available: see fulltext.]I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.