An azimuthal asymmetry in the pion from tau decays in specific neutrino-hyperon processes provides a CP-odd signal for beyond-Standard-Model physics encoded in dimension-six operators.
Covariant Light-Front Approach for $B_c$ transition form factors
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
In the covariant light-front quark model, we investigate the form factors of $B_c$ decays into $D, D^*, D_s, D_s^*, \eta_c, J/\psi, B, B^*, B_s, B_s^*$ mesons. The form factors in the spacelike region $q^2<0$ are directly evaluated. To extrapolate the form factors to the full kinematic region, we fit the form factors by adopting a three-parameter form from the spacelike region. $b\to u,d,s$ transition form factors at maximally recoiling point ($q^2=0$) are smaller than $b\to c$ and $c\to d,s$ transition form factors, while the $b\to d,s,c$ form factors at zero recoiling point are close to each other. In the fitting procedure, we find the parameters for the form factors $A_2(B_c\to B^*)$ and $A_2(B_c\to B^*_s)$ strongly depend on the decay constants of $B^*$ and $B_s^*$ mesons. Fortunately, the semileptonic and nonleptonic $B_c$ decays are not sensitive to these form factors. With the form factors, we also investigate the branching fractions, polarizations of the semileptonic $B_c\to Ml\nu$ decays. Semileptonic $B_c\to (\eta_c,J/\psi)l\nu$ and $B_c\to (B_s,B_s^*)l\nu$ decays have much larger branching fractions than $B_c\to (D,D^*,B,B^*)l\nu$. In the three kinds of $B_c\to Vl\nu$ decays, contributions from the longitudinal polarized vector is comparable with those from the transversely polarized vector. These predictions will be tested at the ongoing and forthcoming hadron colliders.
fields
hep-ph 2representative citing papers
Computes pQCD form factors for B_c to D(*) transitions via lattice inputs and heavy quark symmetry, then predicts branching fractions and angular observables for semileptonic and rare dilepton decays.
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Probing New Physics and CP Violation in $\nu_\tau n \to \Lambda_c \tau^- (\pi^- \nu_\tau)$ and $\bar\nu_\tau p \to \Lambda \tau^+ (\pi^+ \bar\nu_\tau)$
An azimuthal asymmetry in the pion from tau decays in specific neutrino-hyperon processes provides a CP-odd signal for beyond-Standard-Model physics encoded in dimension-six operators.
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Study of Form Factors and Observables in $B_c^- \rightarrow \bar{D}^{(*)0}\ell^-\bar{\nu}_{\ell}$ and $B_c^- \rightarrow D^{(*)-}\ell^+\ell^-$ decays
Computes pQCD form factors for B_c to D(*) transitions via lattice inputs and heavy quark symmetry, then predicts branching fractions and angular observables for semileptonic and rare dilepton decays.