Model independent New Physics analysis in ${\Lambda }_b\to \Lambda {\mu }^{+}{\mu }^{-}$ decay

Abstract

We study the rare ${\Lambda }_b\to \Lambda {\mu }^{+}{\mu }^{-}$ decay in the Standard Model and beyond. Beyond the Standard Model we include new vector and axial-vector operators, scalar and pseudo-scalar operators, and tensor operators in the effective Hamiltonian. Working in the helicity basis and using appropriate parametrization of the ${\Lambda }_b\to \Lambda$ hadronic matrix elements, we give expressions of hadronic and leptonic helicity amplitudes and derive expression of double differential branching ratio with respect to dilepton invariant mass squared and cosine of lepton angle. Appropriately integrating the differential branching ratio over the lepton angle, we obtain the longitudinal polarization fraction and the leptonic forward-backward asymmetry and sequentially study the observables in the presence of the new couplings. To analyze the implications of the new vector and axial-vector couplings, we follow the current global fits to $b\to s{\mu }^{+}{\mu }^{-}$ data. While the impacts of scalar couplings can be significant, exclusive $\bar{B}\to X_s{\mu }^{+}{\mu }^{-}$ data imply stringent constraints on the tensor couplings and hence the effects on ${\Lambda }_b\to \Lambda {\mu }^{+}{\mu }^{-}$ are negligible.

24 pages, 5 captioned figures, 1 table, matches published version in Eur. Phys. J. C, typos corrected

References in corpus (10)

• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• On the B to D* tau nu Sensitivity to New Physics
• $R_K$ and future $b\to s\ell \ell$ BSM opportunities
• Rare baryon decays Lambda_b -> Lambda l+ l- (l=e, mu, tau) and Lambda_b -> Lambda gamma : Differential and total rates, lepton- and hadron-side forward-backward asymmetries
• Lambda_b -> Lambda l+ l- form factors and differential branching fraction from lattice QCD
• Exclusive semileptonic decays of ${\Lambda }_b\to \Lambda l^{+}{l}^{-}$ in supersymmetric theories
• Angular distribution of polarised ${\Lambda }_b$ baryons decaying to $\Lambda {\ell }^{+}{\ell }^{-}$
• Effects of scalar leptoquark on semileptonic ${\Lambda }_b$ decays
• Integrability of the evolution equations for heavy-light baryon distribution amplitudes
• Lepton mass effects and angular observables in ${\Lambda }_b\to \Lambda (\to p\pi ){\ell }^{+}{\ell }^{-}$

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