TY  - JOUR
AU  - Penalva, N.
AU  - Hernandez, E.
AU  - Nieves, J.
PY  - 2021
DA  - 2021//
TI  - The role of right-handed neutrinos in b -> c tau (pi nu(tau), rho nu(tau), mu(nu)over-bar(mu)nu(tau))(nu)over-bar(tau) from visible final-state kinematics
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 122
EP  - 45pp
VL  - 10
IS  - 10
PB  - Springer
KW  - Beyond Standard Model
KW  - CP violation
AB  - In the context of lepton flavor universality violation (LFUV) studies, we fully derive a general tensor formalism to investigate the role that left- and right-handed neutrino new-physics (NP) terms may have in b -> c tau(nu) over bar (tau) transitions. We present, for several extensions of the Standard Model (SM), numerical results for the Lambda(b) -> Lambda(c)tau(nu) over bar (tau) semileptonic decay, which is expected to be measured with precision at the LHCb. This reaction can be a new source of experimental information that can help to confirm, or maybe rule out, LFUV presently seen in (B) over bar meson decays. The present study analyzes observables that can help in distinguishing between different NP scenarios that otherwise provide very similar results for the branching ratios, which are our currently best hints for LFUV. Since the tau lepton is very short-lived, we consider three subsequent tau-decay modes, two hadronic pi nu(tau) and rho nu(tau) and one leptonic mu(nu) over bar (mu)nu(tau), which have been previously studied for (B) over bar -> D(*) decays. Within the tensor formalism that we have developed in previous works, we re-obtain the expressions for the differential decay width written in terms of visible (experimentally accessible) variables of the massive particle created in the tau decay. There are seven different tau angular and spin asymmetries that are defined in this way and that can be extracted from experiment. Those asymmetries provide observables that can help in constraining possible SM extensions.
SN  - 1029-8479
UR  - https://arxiv.org/abs/2107.13406
UR  - https://doi.org/10.1007/JHEP10(2021)122
DO  - 10.1007/JHEP10(2021)122
LA  - English
N1  - WOS:000708483600004
ID  - Penalva_etal2021
ER  -