A search for the rare decays Bs0âμ+μ- and B0âμ+μ- is performed at the LHCb experiment using data collected in pp collisions corresponding to a total integrated luminosity of 4.4 fb-1. An excess of Bs0âμ+μ- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0âμ+μ-)=(3.0±0.6-0.2+0.3)Ã10-9, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0âμ+μ- effective lifetime, Ï(Bs0âμ+μ-)=2.04±0.44±0.05 ps, is reported. No significant excess of B0âμ+μ- decays is found, and a 95% confidence level upper limit, B(B0âμ+μ-)<3.4Ã10-10, is determined. All results are in agreement with the standard model expectations.
Measurement of the Bs0 -> mu(+) mu(-) Branching Fraction and Effective Lifetime and Search for B0 -> mu(+) mu(-) Decays
De Serio, M.;Pappagallo, M.;Simone, S.;
2017-01-01
Abstract
A search for the rare decays Bs0âμ+μ- and B0âμ+μ- is performed at the LHCb experiment using data collected in pp collisions corresponding to a total integrated luminosity of 4.4 fb-1. An excess of Bs0âμ+μ- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0âμ+μ-)=(3.0±0.6-0.2+0.3)Ã10-9, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0âμ+μ- effective lifetime, Ï(Bs0âμ+μ-)=2.04±0.44±0.05 ps, is reported. No significant excess of B0âμ+μ- decays is found, and a 95% confidence level upper limit, B(B0âμ+μ-)<3.4Ã10-10, is determined. All results are in agreement with the standard model expectations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.