Observation of the decay <i>Λ<sub>b</sub></i><SUP>0</SUP> → <i>pK</i><SUP>-</SUP><i>μ</i><SUP>+</SUP><i>μ</i><SUP>-</SUP> and a search for <i>CP</i> violation



Aaij, R, Adeva, B, Adinolfi, M, Ajaltouni, Z, Akar, S, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G
et al (show 756 more authors) (2017) Observation of the decay <i>Λ<sub>b</sub></i><SUP>0</SUP> → <i>pK</i><SUP>-</SUP><i>μ</i><SUP>+</SUP><i>μ</i><SUP>-</SUP> and a search for <i>CP</i> violation. JOURNAL OF HIGH ENERGY PHYSICS, 06 (6). 108-.

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Abstract

A search for $C\!P$ violation in the decay $\Lambda^0_b \to p K^- \mu^+ \mu^-$ is presented. This decay is mediated by flavour-changing neutral-current transitions in the Standard Model and is potentially sensitive to new sources of $C\!P$ violation. The study is based on a data sample of proton-proton collisions recorded with the LHCb experiment, corresponding to an integrated luminosity of $3$ $\mathrm{fb}^{-1}$. The $\Lambda^0_b \to p K^- \mu^+ \mu^-$ decay is observed for the first time, and two observables that are sensitive to different manifestations of $C\!P$ violation are measured, $\Delta\mathcal{A}_{C\!P} \equiv \mathcal{A}_{C\!P}(\Lambda^0_b \to p K^- \mu^+ \mu^-)-\mathcal{A}_{C\!P}(\Lambda^0_b\to pK^- J/\psi)$ and $a_{C\!P}^{\widehat{T}-odd}$, where the latter is based on asymmetries in the angle between the $\mu^+\mu^-$ and $p K^-$ decay planes. These are measured to be $\Delta\mathcal{A}_{C\!P} = (-3.5 \pm 5.0(stat) \pm 0.2(syst))\times 10^{-2}$, $a_{C\!P}^{\widehat{T}-odd} = (1.2 \pm 5.0(stat) \pm 0.7(syst))\times 10^{-2}$, and no evidence for $C\!P$ violation is found.

Item Type: Article
Additional Information: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-059.html
Uncontrolled Keywords: B physics, CP violation, FCNC Interaction, Hadron-Hadron scattering (experiments)
Depositing User: Symplectic Admin
Date Deposited: 11 Sep 2017 13:38
Last Modified: 17 Oct 2023 18:21
DOI: 10.1007/JHEP06(2017)108
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3009396