Rare decay in the relativistic quark model

R. N. Faustov; V. O. Galkin

doi:10.1140/epjc/s10052-018-6010-y

EPJ

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2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2018) 78: 527
https://doi.org/10.1140/epjc/s10052-018-6010-y

Regular Article - Theoretical Physics

Rare $\Lambda _c\rightarrow p \ell ^+\ell ^-$ decay in the relativistic quark model

R. N. Faustov and V. O. Galkin^*

Institute of Cybernetics and Informatics in Education, FRC CSC RAS, Vavilov Street 40, 119333, Moscow, Russia

^* e-mail: galkin@ccas.ru

Received: 7 May 2018
Accepted: 18 June 2018
Published online: 27 June 2018

Abstract

The relativistic quark model based on the quasipotential approach with the QCD-motivate potential is employed for the calculation of the form factors of the $\Lambda _c\rightarrow p$ rare weak transitions. Their momentum dependence is explicitly determined without additional assumptions and extrapolations in the whole kinematical range of the momentum transfer squared $$q^2$$ . The differential $\Lambda _c\rightarrow p l^+l^-$ decay branching fractions and angular distributions are calculated on the basis of these form factors. Both the perturbative and effective Wilson coefficients, which include contributions of vector meson resonances, are used. The calculated branching fraction of the $\Lambda _c\rightarrow p \mu ^+\mu ^-$ rare decay is well consistent with the experimental upper limit very recently set by the LHCb Collaboration.