TY - JOUR
T1 - Measurement of the mass and production rate of Ξb- baryons
AU - (LHCb Collaboration)
AU - Aaij, R.
AU - Abellán Beteta, C.
AU - Adeva, B.
AU - Adinolfi, M.
AU - Aidala, C. A.
AU - Ajaltouni, Z.
AU - Akar, S.
AU - Albicocco, P.
AU - Albrecht, J.
AU - Alessio, F.
AU - Alexander, M.
AU - Alfonso Albero, A.
AU - Alkhazov, G.
AU - Alvarez Cartelle, P.
AU - Alves, A. A.
AU - Amato, S.
AU - Amerio, S.
AU - Amhis, Y.
AU - An, L.
AU - Anderlini, L.
AU - Andreassi, G.
AU - Andreotti, M.
AU - Andrews, J. E.
AU - Archilli, F.
AU - D'Argent, P.
AU - Arnau Romeu, J.
AU - Artamonov, A.
AU - Artuso, M.
AU - Arzymatov, K.
AU - Aslanides, E.
AU - Atzeni, M.
AU - Audurier, B.
AU - Bachmann, S.
AU - Back, J. J.
AU - Baker, S.
AU - Balagura, V.
AU - Baldini, W.
AU - Baranov, A.
AU - Barlow, R. J.
AU - Barrand, G. C.
AU - Barsuk, S.
AU - Barter, W.
AU - Bartolini, M.
AU - Baryshnikov, F.
AU - Batozskaya, V.
AU - Batsukh, B.
AU - Battig, A.
AU - Battista, V.
AU - Petrov, A.
AU - Strokov, S.
PY - 2019/3/1
Y1 - 2019/3/1
N2 - The first measurement of the production rate of Ξb- baryons in pp collisions relative to that of Λb0 baryons is reported, using data samples collected by the LHCb experiment, and corresponding to integrated luminosities of 1, 2 and 1.6 fb-1 at s=7, 8 and 13 TeV, respectively. In the kinematic region 2<η<6 and pT<20 GeV/c, we measure fΞb-fΛb0B(Ξb-→J/ψΞ-)B(Λb0→J/ψΛ)=(10.8±0.9±0.8)×10-2 [s=7,8 TeV], fΞb-fΛb0B(Ξb-→J/ψΞ-)B(Λb0→J/ψΛ)=(13.1±1.1±1.0)×10-2 [s=13 TeV], where fΞb- and fΛb0 are the fragmentation fractions of b quarks into Ξb- and Λb0 baryons, respectively; B represents branching fractions; and the uncertainties are due to statistical and experimental systematic sources. The values of fΞb-/fΛb0 are obtained by invoking SU(3) symmetry in the Ξb-→J/ψΞ- and Λb0→J/ψΛ decays. Production asymmetries between Ξb- and Ξb+ baryons are also reported. The mass of the Ξb- baryon is also measured relative to that of the Λb0 baryon, from which it is found that m(Ξb-)=5796.70±0.39±0.15±0.17 MeV/c2, where the last uncertainty is due to the precision on the known Λb0 mass. This result represents the most precise determination of the Ξb- mass.
AB - The first measurement of the production rate of Ξb- baryons in pp collisions relative to that of Λb0 baryons is reported, using data samples collected by the LHCb experiment, and corresponding to integrated luminosities of 1, 2 and 1.6 fb-1 at s=7, 8 and 13 TeV, respectively. In the kinematic region 2<η<6 and pT<20 GeV/c, we measure fΞb-fΛb0B(Ξb-→J/ψΞ-)B(Λb0→J/ψΛ)=(10.8±0.9±0.8)×10-2 [s=7,8 TeV], fΞb-fΛb0B(Ξb-→J/ψΞ-)B(Λb0→J/ψΛ)=(13.1±1.1±1.0)×10-2 [s=13 TeV], where fΞb- and fΛb0 are the fragmentation fractions of b quarks into Ξb- and Λb0 baryons, respectively; B represents branching fractions; and the uncertainties are due to statistical and experimental systematic sources. The values of fΞb-/fΛb0 are obtained by invoking SU(3) symmetry in the Ξb-→J/ψΞ- and Λb0→J/ψΛ decays. Production asymmetries between Ξb- and Ξb+ baryons are also reported. The mass of the Ξb- baryon is also measured relative to that of the Λb0 baryon, from which it is found that m(Ξb-)=5796.70±0.39±0.15±0.17 MeV/c2, where the last uncertainty is due to the precision on the known Λb0 mass. This result represents the most precise determination of the Ξb- mass.
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U2 - 10.1103/PhysRevD.99.052006
DO - 10.1103/PhysRevD.99.052006
M3 - Article
AN - SCOPUS:85064410812
VL - 99
JO - Physical Review D
JF - Physical Review D
SN - 2470-0010
IS - 5
M1 - 052006
ER -