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Abstract |
The first observation of the decay B+ -> p (Lambda) over bar is presented using proton-proton collision data collected by the LHCb experiment between 2016 and 2018 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb(-1). The signal significance exceeds seven standard deviations. Using the B+ -> K-S(0)pi(+) decay as a normalization channel, the branching fraction is measured and combined with previous LHCb results based on data collected at 7 and 8 TeV in 2011 and 2012, yielding B(B+ -> p (Lambda) over bar) = (1.24 +/- 0.17 +/- 0.05 +/- 0.03) x 10(-7); where the first uncertainty is statistical, the second is systematic, and the third comes from the uncertainty on the branching fraction of the normalization channel. The B+ -> p (Lambda) over bar weak decay parameter is measured to be alpha(B) = 0.87(-0.29)(+0.26) +/- 0.09, indicating the presence of comparable S-wave and P-wave decay amplitudes. |
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Address |
[Bonacci, R. B.; Dekkers, S.; Egede, U.; Hadavizadeh, T.; Harris, T. H.; Henderson, R. D. L.; Lane, J. J.; Liu, F. L.; Lobo, I.; Song, R.; Walton, E. J.; Ward, J. A.] Monash Univ, Sch Phys & Astron, Melbourne, Vic, Australia |
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