A search for the rare decays B0s → μ+ μ− and B0 → μ+ μ− is performed at the LHCb experiment. The data analyzed correspond to an integrated luminosity of 1 fb^−1 of pp collisions at a center-of-mass energy of 7 TeV and 2 fb^−1 at 8 TeV. An excess of B0s → μ+ μ− signal candidates with respect to the background expectation is seen with a significance of 4.0 standard deviations. A time-integrated branching fraction of B(B0s → μ+ μ−) = (2.9_{−1.0}^{+1.1}) x 10^−9 is obtained and an upper limit of B(B0 → μ+ μ−) < 7.4 x 10^−10 at 95% confidence level is set. These results are consistent with the standard model expectations.
R. Aaij, B. Adeva, M. Adinolfi, C. Adrover, A. Affolder, Z. Ajaltouni, et al. (2013). Measurement of the B0s → μ+ μ− Branching Fraction and Search for B0 → μ+ μ− Decays at the LHCb Experiment. PHYSICAL REVIEW LETTERS, 111(10), 1-9 [10.1103/PhysRevLett.111.101805].
Measurement of the B0s → μ+ μ− Branching Fraction and Search for B0 → μ+ μ− Decays at the LHCb Experiment
CARBONE, ANGELO;GALLI, DOMENICO;PATRIGNANI, CLAUDIA;PERAZZINI, STEFANO;VAGNONI, VINCENZO MARIA;ZANGOLI, MARIA;
2013
Abstract
A search for the rare decays B0s → μ+ μ− and B0 → μ+ μ− is performed at the LHCb experiment. The data analyzed correspond to an integrated luminosity of 1 fb^−1 of pp collisions at a center-of-mass energy of 7 TeV and 2 fb^−1 at 8 TeV. An excess of B0s → μ+ μ− signal candidates with respect to the background expectation is seen with a significance of 4.0 standard deviations. A time-integrated branching fraction of B(B0s → μ+ μ−) = (2.9_{−1.0}^{+1.1}) x 10^−9 is obtained and an upper limit of B(B0 → μ+ μ−) < 7.4 x 10^−10 at 95% confidence level is set. These results are consistent with the standard model expectations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.