A search for the rare decays B-s(0)->mu(+)mu(-), B-0 -> mu(+)mu(-) 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 B-s(0) -> mu(+)mu- 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(B-s(0) -> mu(+)mu(-)) = (3.0 +/- 0.6(-0.2)(+)(0.3)) x 10(-9) where the first uncertainty is statistical, the second systematic. The first measurement of the B-s(0) -> mu(+)mu(-) effective lifetime tau(B-s(0)-> mu(+) mu(-)) = 2.04 +/- 0.44 +/- 0.05 ps is reported. No significant excess of B-0 -> mu(+)mu(-) decays is found, a 95\% confidence level upper limit B(B-0 -> mu(+)mu(-) ) < 3.4 x 10(-10) is determined. All results are in agreement with the standard model expectations.
Measurement of the B-s(0)-> mu(+) mu(-) Branching Fraction, Effective Lifetime, Search for B-0 ->mu(+) mu(-) Decays
Bonivento W.;Dettori F.;Lai A.;Manca G.;Oldeman R.;Saitta B.;
2017-01-01
Abstract
A search for the rare decays B-s(0)->mu(+)mu(-), B-0 -> mu(+)mu(-) 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 B-s(0) -> mu(+)mu- 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(B-s(0) -> mu(+)mu(-)) = (3.0 +/- 0.6(-0.2)(+)(0.3)) x 10(-9) where the first uncertainty is statistical, the second systematic. The first measurement of the B-s(0) -> mu(+)mu(-) effective lifetime tau(B-s(0)-> mu(+) mu(-)) = 2.04 +/- 0.44 +/- 0.05 ps is reported. No significant excess of B-0 -> mu(+)mu(-) decays is found, a 95\% confidence level upper limit B(B-0 -> mu(+)mu(-) ) < 3.4 x 10(-10) is determined. All results are in agreement with the standard model expectations.File | Dimensione | Formato | |
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PhysRevLett.118.191801.pdf
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