Measurement of the $\Lambda^0_b\rightarrow J/\psi\Lambda$ angular distribution and the $\Lambda^0_b$ polarisation in $pp$ collisions

Aaij, Roel; Abellán Beteta, Carlos; Ackernley, Thomas; Adeva, Bernardo; Adinolfi, Marco; Afsharnia, Hossein; Aidala, Christine Angela; Aiola, Salvatore; Ajaltouni, Ziad; Akar, Simon

doi:10.1007/JHEP06(2020)110

Measurement of the $\Lambda^0_b\rightarrow J/\psi\Lambda$ angular distribution and the $\Lambda^0_b$ polarisation in $pp$ collisions

LHCb

Collaboration

Apr 22, 2020

30 pages

Published in:

JHEP 06 (2020) 110

Published: Jun 17, 2020

e-Print:

2004.10563 [hep-ex]

DOI:

10.1007/JHEP06(2020)110

PDG: \alpha _{−} FOR

{{\mathit \Lambda}}

\rightarrow

{{\mathit p}}{{\mathit \pi}^{-}}

Report number:

LHCb-PAPER-2020-005,
CERN-EP-2020-051

Experiments:

CERN-LHC-LHCb

View in:

reference search45 citations

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Abstract: (Springer)

This paper presents an analysis of the

{\Lambda}_b^0

→ J/ψΛ angular distribution and the transverse production polarisation of

{\Lambda}_b^0

baryons in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The measurements are performed using data corresponding to an integrated luminosity of 4.9 fb

^{−1}

, collected with the LHCb experiment. The polarisation is determined in a fiducial region of

{\Lambda}_b^0

transverse momentum and pseudorapidity of 1 < p

_{T}

< 20 GeV/c and 2 < η < 5, respectively. The data are consistent with

{\Lambda}_b^0

baryons being produced unpolarised in this region. The parity-violating asymmetry parameter of the Λ → pπ

^{−}

decay is also determined from the data and its value is found to be consistent with a recent measurement by the BES III collaboration.[graphic not available: see fulltext]

Note:

All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-005.html (LHCb public pages)

B physics
Flavor physics
Hadron-Hadron scattering (experiments)
Heavy quark production
Polarization
p p: scattering
p p: colliding beams
Lambda/b0: hadronic decay
polarization: transverse
decay: angular distribution

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