A Dalitz plot analysis of B0→ηc(1S)K+π- decays is performed using data samples of pp collisions collected with the LHCb detector at centre-of-mass energies of s=7,8 and 13TeV, corresponding to a total integrated luminosity of 4.7fb-1. A satisfactory description of the data is obtained when including a contribution representing an exotic ηc(1 S) π- resonant state. The significance of this exotic resonance is more than three standard deviations, while its mass and width are 4096±20-22+18MeV and 152±58-35+60MeV, respectively. The spin-parity assignments JP= 0 + and JP= 1 - are both consistent with the data. In addition, the first measurement of the B0→ηc(1S)K+π- branching fraction is performed and gives B(B0→ηc(1S)K+π-)=(5.73±0.24±0.13±0.66)×10-4,where the first uncertainty is statistical, the second systematic, and the third is due to limited knowledge of external branching fractions.

Evidence for an ηc(1 S) π- resonance in B0→ ηc(1 S) K+π- decays

Cardinale R.;Fontanelli F.;Petrolini A.;Sergi A.;Spadaro Norella E.
2018-01-01

Abstract

A Dalitz plot analysis of B0→ηc(1S)K+π- decays is performed using data samples of pp collisions collected with the LHCb detector at centre-of-mass energies of s=7,8 and 13TeV, corresponding to a total integrated luminosity of 4.7fb-1. A satisfactory description of the data is obtained when including a contribution representing an exotic ηc(1 S) π- resonant state. The significance of this exotic resonance is more than three standard deviations, while its mass and width are 4096±20-22+18MeV and 152±58-35+60MeV, respectively. The spin-parity assignments JP= 0 + and JP= 1 - are both consistent with the data. In addition, the first measurement of the B0→ηc(1S)K+π- branching fraction is performed and gives B(B0→ηc(1S)K+π-)=(5.73±0.24±0.13±0.66)×10-4,where the first uncertainty is statistical, the second systematic, and the third is due to limited knowledge of external branching fractions.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/951788
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