A search for the B-0 -> K+K- decay is performed using pp-collision data collected by LHCb. The data set corresponds to integrated luminosities of 1.0, 2.0 fb(-1) at center-of-mass energies of 7, 8 TeV, respectively. This decay is observed for the first time with a significance of more than 5 standard deviations. The analysis also results in an improved measurement of the branching fraction for the B-s(0) -> pi(+)pi(-) decay. The measured branching fractions are B(B-0 -> K+K-) = (7.80 +/- 1.27 +/- 0.81 +/- 0.21) x 10(-8), B(B-s(0) -> pi(+)p(-)) = (6.91 +/- 0.54 +/- 0.63 +/- 0.19 +/- 0.40) x 10(-7). The first uncertainty is statistical the second is systematic the third is due to the uncertainty on the B-0 -> K+pi(-) branching fraction used as a normalization. For the B-s(0) mode the fourth accounts for the uncertainty on the ratio of the probabilities for b quarks to hadronize into B-s(0), B-0 mesons.

Observation of the Annihilation Decay Mode B-0 -> K+K-

Dettori F.;Lai A.;Manca G.;Oldeman R.;Saitta B.;
2017-01-01

Abstract

A search for the B-0 -> K+K- decay is performed using pp-collision data collected by LHCb. The data set corresponds to integrated luminosities of 1.0, 2.0 fb(-1) at center-of-mass energies of 7, 8 TeV, respectively. This decay is observed for the first time with a significance of more than 5 standard deviations. The analysis also results in an improved measurement of the branching fraction for the B-s(0) -> pi(+)pi(-) decay. The measured branching fractions are B(B-0 -> K+K-) = (7.80 +/- 1.27 +/- 0.81 +/- 0.21) x 10(-8), B(B-s(0) -> pi(+)p(-)) = (6.91 +/- 0.54 +/- 0.63 +/- 0.19 +/- 0.40) x 10(-7). The first uncertainty is statistical the second is systematic the third is due to the uncertainty on the B-0 -> K+pi(-) branching fraction used as a normalization. For the B-s(0) mode the fourth accounts for the uncertainty on the ratio of the probabilities for b quarks to hadronize into B-s(0), B-0 mesons.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/240333
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