Abstract
In the semileptonic decays of heavy mesons and baryons, the lepton-mass dependence factors out in the quadratic coefficient of the differential distribution. We call the corresponding normalized coefficient the convexity parameter. This observation opens the path to a test of lepton universality in semileptonic heavy meson and baryon decays that is independent of form-factor effects. By projecting out the quadratic rate coefficient, dividing out the lepton-mass-dependent factor, and restricting the phase space integration to the lepton phase space, one can define optimized partial rates which, in the Standard Model, are the same for all three modes in a given semileptonic decay process. We discuss how the identity is spoiled by new physics effects. We discuss semileptonic heavy meson decays such as and and semileptonic heavy baryon decays such as for each , , .
- Received 25 February 2021
- Accepted 4 April 2021
DOI:https://doi.org/10.1103/PhysRevD.103.093001
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society