Abstract

The decays B+c -> J/psi D+s and B+c -> J/psi D*+s are studied with the ATLAS detector at the LHC using a dataset corresponding to integrated luminosities of 4.9 fb-1 and 20.6 fb-1 of pp collisions collected at centre-of-mass energies sqrt(s) = 7 TeV and 8 TeV, respectively. Signal candidates are identified through J/??µ+µ- and D(*)+s??p+(?/p0) decays. With a two-dimensional likelihood fit involving the B+c reconstructed invariant mass and an angle between the µ+ and D+s candidate momenta in the muon pair rest frame, the yields of B+c?J/?D+s and B+c?J/?D*+s, and the transverse polarisation fraction in B+c?J/?D*+s decay are measured. The transverse polarisation fraction is determined to be G±±(B+c?J/?D*+s)/G(B+c?J/?D*+s)=0.38±0.23±0.07, and the derived ratio of the branching fractions of the two modes is BB+c?J/?D*+s/BB+c?J/?D+s=2.8+1.2-0.8±0.3, where the first error is statistical and the second is systematic. Finally, a sample of B+c?J/?p+ decays is used to derive the ratios of branching fractions BB+c?J/?D+s/BB+c?J/?p+=3.8±1.1±0.4±0.2 and BB+c?J/?D*+s/BB+c?J/?p+=10.4±3.1±1.5±0.6, where the third error corresponds to the uncertainty of the branching fraction of D+s??(K+K-)p+ decay. The available theoretical predictions are generally consistent with the measurement.

Autore Pugliese

• Gorini Edoardo , Ventura Andrea , Spagnolo Stefania Antonia

Tutti gli autori

• G. AAD , G. CHIODINI , E. GORINI , M. PRIMAVERA , S. SPAGNOLO , A. VENTURA

Titolo volume/Rivista

THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS

Anno di pubblicazione

2016

ISSN

1434-6044

ISBN

Non Disponibile

Numero di citazioni Wos

3

Ultimo Aggiornamento Citazioni

28/04/2018

Numero di citazioni Scopus

3

Ultimo Aggiornamento Citazioni

28/04/2018

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile