Rare $$\Lambda _c\rightarrow p \ell ^+\ell ^-$$ Λ c → p ℓ + ℓ -

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 c → 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 c → pl + 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 c → pμ + μ − rare decay is well consistent with the experimental upper limit very recently set by the LHCb Collaboration.

Semileptonic Decays of Heavy Baryons in the Relativistic Quark Model

“…From Table 6 we also see that predictions for the rare Λ b → Λτ + τ − decay vary significantly. Our results [5][6][7] are close to those from quark models Refs. [13][14][15]37].…”

“…Here we review our study of the bottom and charm baryon decays in the framework of the relativistic quark model based on the quark-diquark picture and the quasipotential approach [1][2][3][4][5][6][7]. Heavy baryons are considered to be the heavy-quark-light-diquark bound states.…”

Probing for new physics with rare charm baryon (Λc, Ξc, Ωc) decays

“…In particular, the four-momenta of the decaying hadron, the final hadron, and the dilepton system, q µ , are proportional to each other at zero recoil, allowing for fewer Lorentz structures, hence relations between helicity amplitudes. At the maximum hadronic recoil endpoint, we also obtain F L (4m 2 ) = 1/3, in agreement with [10]. 2 This is no coincidence, as at maximum recoil the four-momenta of the leptons are the same, causing also here the angular distribution (2.9) to become flat, dΓ/d cos θ = const.…”

“…We study Λ c → p + − , = e, µ decays, and null test processes with charged lepton flavor violation (cLFV) Λ c → pe ± µ ∓ , and into dineutrinos Λ c → pνν. Hadronic transition vector and tensor form factors for Λ c → p decays are available from lattice QCD [9], and quark models [10], and in Light cone sum rules for Ξ c → Σ [11]. We also present null test results for the related, spin 1/2 → 1/2 + decays Ξ c → Σ , Ξ c → Λ and Ω c → Ξ , also induced by |∆c| = |∆u| = 1 quark transitions, with more strange spectator quarks.…”

Null test searches for BSM physics with rare charm decays

“…The experimental and theoretical status of rare charm decays is presented in Ref. [5] and increasing and ongoing research interest [1,2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] manifests the importance of progress in the field.…”