Probing effects of new physics in $\Lambda^0_{b}\to\Lambda^+_{c}\mu^{-}\bar{\nu}_{\mu}$ decays

Abstract

We present, for the first time, the six-fold differential decay density expression for $\Lambda^0_b\to\Lambda^+_{c} l^- \bar{\nu}_{l}$, taking into account the polarisation of the $\Lambda^0_b$ baryon and a complete basis of new physics operators. Using the expected yield in the current dataset collected at the LHCb experiment, we present sensitivity studies to determine the experimental precision on the Wilson coefficients of the new physics operators with $\Lambda^0_{b}\to\Lambda^+_{c}\mu^{-}\bar{\nu}_{\mu}$ decays in two scenarios. In the first case, unpolarised $\Lambda^0_{b}\to\Lambda^+_{c}\mu^{-}\bar{\nu}_{\mu}$ decays with $\Lambda^+_c\to p K^+ \pi^-$ are considered, whereas polarised $\Lambda^0_{b}\to\Lambda^+_{c}\mu^{-}\bar{\nu}_{\mu}$ decays with $\Lambda^+_c \to p K^0_S$ are studied in the second. For the latter scenario, the experimental precision that can be achieved on the determination of $\Lambda^0_b$ polarisation and $\Lambda^+_c$ weak decay asymmetry parameter is also presented.