0470661 - FZÚ 2017 RIV US eng J - Článek v odborném periodiku
Aad, G. - Abbott, B. - Abdallah, J. - Chudoba, Jiří - Havránek, Miroslav - Hejbal, Jiří - Jakoubek, Tomáš - Kepka, Oldřich - Kupčo, Alexander - Kůs, Vlastimil - Lokajíček, Miloš - Lysák, Roman - Marčišovský, Michal - Mikeštíková, Marcela - Němeček, Stanislav - Šícho, Petr - Staroba, Pavel - Svatoš, Michal - Taševský, Marek - Vrba, Václav … celkem 2828 autorů
Study of the B+c→J/ψD+s and B+c→J/ψD∗+s decays with the ATLAS detector.
European Physical Journal C. Roč. 76, č. 1 (2016), s. 1-17, č. článku 4. ISSN 1434-6044. E-ISSN 1434-6052
Institucionální podpora: RVO:68378271
Klíčová slova: ATLAS * CERN LHC Coll * experimental results
Kód oboru RIV: BF - Elementární částice a fyzika vys. energií
Impakt faktor: 5.297, rok: 2016 ; AIS: 1.673, rok: 2016
DOI: https://doi.org/10.1140/epjc/s10052-015-3743-8

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 and 20.6 fb−1 of pp collisions collected at centre-of-mass energies s√=7 TeV and 8 TeV, respectively. Signal candidates are identified through J/ψ→μ+μ− and D(∗)+s→ϕπ+(γ/π0) 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/ψD+s and B+c→J/ψD∗+s , and the transverse polarisation fraction in B+c→J/ψD∗+s decay are measured. The transverse polarisation fraction is determined to be Γ±±(B+c→J/ψD∗+s)/Γ(B+c→J/ψD∗+s)=0.38±0.23±0.07 , and the derived ratio of the branching fractions of the two modes is BB+c→J/ψD∗+s/BB+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 BB+c→J/ψD+s/BB+c→J/ψπ+=3.8±1.1±0.4±0.2 and BB+c→J/ψD∗+s/BB+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.
Trvalý link: http://hdl.handle.net/11104/0268234