Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/171232
Title: Measurement of the mass and production rate of Xi(-)(b)( )baryons
Author: Alfonso Albero, Alejandro
Calvo Gómez, Míriam
Camboni, Alessandro
Coquereau, Samuel
Garrido Beltrán, Lluís
Gascón Fora, David
Gironella Gironell, Pere
Graciani Díaz, Ricardo
Graugés Pous, Eugeni
Vilasis-Cardona, Xavier
LHCb Collaboration
Keywords: Barions
Quarks
Gran Col·lisionador d'Hadrons
Baryons
Quarks
Large Hadron Collider (France and Switzerland)
Issue Date: 22-Mar-2019
Publisher: American Physical Society
Abstract: The first measurement of the production rate of Ξ − b baryons in p p collisions relative to that of Λ 0 b 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 p T < 20     GeV / c , we measure f Ξ − b f Λ 0 b B ( Ξ − b → J / ψ Ξ − ) B ( Λ 0 b → J / ψ Λ ) = ( 10.8 ± 0.9 ± 0.8 ) × 10 − 2 [ √ s = 7 , 8     TeV ], f Ξ − b f Λ 0 b B ( Ξ − b → J / ψ Ξ − ) B ( Λ 0 b → J / ψ Λ ) = ( 13.1 ± 1.1 ± 1.0 ) × 10 − 2 [ √ s = 13     TeV ], where f Ξ − b and f Λ 0 b are the fragmentation fractions of b quarks into Ξ − b and Λ 0 b baryons, respectively; B represents branching fractions; and the uncertainties are due to statistical and experimental systematic sources. The values of f Ξ − b / f Λ 0 b are obtained by invoking SU(3) symmetry in the Ξ − b → J / ψ Ξ − and Λ 0 b → J / ψ Λ decays. Production asymmetries between Ξ − b and ¯ Ξ + b baryons are also reported. The mass of the Ξ − b baryon is also measured relative to that of the Λ 0 b baryon, from which it is found that m ( Ξ − b ) = 5796.70 ± 0.39 ± 0.15 ± 0.17     MeV / c 2 , where the last uncertainty is due to the precision on the known Λ 0 b mass. This result represents the most precise determination of the Ξ − b mass.
Note: Reproducció del document publicat a: https://doi.org/10.1103/PhysRevD.99.052006
It is part of: Physical Review D, 2019, vol. 99, num. 5, p. 052006
URI: http://hdl.handle.net/2445/171232
Related resource: https://doi.org/10.1103/PhysRevD.99.052006
ISSN: 2470-0010
Appears in Collections:Articles publicats en revistes (Física Quàntica i Astrofísica)

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