Mullier, Geoffrey; Haug, Sigve; Weber, Michael; Meloni, Federico; Cervelli, Alberto; Beck, Hans Peter; Stucci, Stefania; Ereditato, Antonio (2016). Study of the Bc⁺ → J/ψ Ds⁺ and Bc⁺ → J/ψ Ds*⁺ decays with the ATLAS detector. European physical journal. C  particles and fields, 76(1) EDP Sciences 10.1140/epjc/s1005201537438

Text
1507.07099.pdf  Accepted Version Available under License Creative Commons: Attribution (CCBY). Download (828kB)  Preview 


Text
10.1140_epjc_s1005201537438.pdf  Published Version Available under License Creative Commons: Attribution (CCBY). Download (2MB)  Preview 
The decays B⁺c →J/ψD⁺s and B⁺c → J/ψD∗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 centreofmass energies s√ = 7 TeV and 8 TeV, respectively. Signal candidates are identified through J/ψ→μ⁺μ⁻ and Ds(∗)⁺ → ϕπ⁺ (γ/π⁰) decays. With a twodimensional likelihood fit involving the B + c reconstructed invariant mass and an angle between the μ⁺ and Ds⁺ candidate momenta in the muon pair rest frame, the yields of B⁺c →J/ψD + s and Bc⁺ → J/ψD∗s⁺, and the transverse polarisation fraction in Bc⁺ → J/ψD ∗+ s decay are measured. The transverse polarisation fraction is determined to be Γ ±± (B⁺c →J/ψD ∗s⁺)/Γ(Bc⁺ → J/ψD∗s⁺) = 0.38±0.23±0.07 , and the derived ratio of the branching fractions of the two modes is B B⁺c →J/ψD∗s⁺ /B B⁺c →J/ψD⁺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/ψπ⁺ decays is used to derive the ratios of branching fractions B B⁺c → J/ψDs⁺ /B B⁺c →J/ψπ⁺ =3.8±1.1±0.4±0.2 and B B⁺c → J/ψD∗s⁺/B B⁺c → J/ψπ⁺ =10.4±3.1±1.5±0.6, where the third error corresponds to the uncertainty of the branching fraction of D⁺s →ϕ(K⁺ K⁻)π⁺ decay. The available theoretical predictions are generally consistent with the measurement.
Item Type: 
Journal Article (Original Article) 

Division/Institute: 
08 Faculty of Science > Physics Institute > Laboratory for High Energy Physics (LHEP) 
UniBE Contributor: 
Haug, Sigve; Weber, Michael and Beck, Hans Peter 
Subjects: 
500 Science > 530 Physics 500 Science > 510 Mathematics 
ISSN: 
14346044 
Publisher: 
EDP Sciences 
Language: 
English 
Submitter: 
Annette KrebsWegenast 
Date Deposited: 
26 Jul 2017 13:03 
Last Modified: 
30 Jul 2017 02:16 
Publisher DOI: 
10.1140/epjc/s1005201537438 
Additional Information: 
Kollaboration  Es sind nur die Berner Autoren namentlich erwähnt. 
BORIS DOI: 
10.7892/boris.100032 
URI: 
https://boris.unibe.ch/id/eprint/100032 