arXiv subjects

T. H. Wu

Publications and source records attributed to T. H. Wu.

3 recordsLinked to original sources

arXiv2004

Axial-vector Form Factors for $K_{\ell 2γ}$ and $π_{\ell 2γ}$ at $O(p^6)$ in Chiral Perturbation Theory

We present two-loop calculations on the axial-vector form factors $F_A$ of semileptonic radiative kaon and pion decays in chiral perturbation theory. The relevant dimension-6 terms of the lagrangian are evaluated from the resonance contribution and the results of the irreducible two-loop graphs of the sunset topology are given in detail. We also explicitly show that the divergent parts in $F_A$ are cancelled exactly as required.

hep-ph↗

arXiv2002

CP Violation in the Decay $η\toπ^+π^-γ$

We study the CP violating effects in the decay of $η\toπ^+π^-γ$. We show that to have CP violation in the decay, one has to consider both linear and circular photon polarizations. In the standard model, the polarizations are vanishingly small. However, model-independently, i.e. using only experimental constraint imposed by the limit on $Br(η\toπ^+π^-)$ it can be up to $O(10%)$. We also explore various possible operators and we find that the tensor type operator, possibly arising from a nonzero CP violating electric dipole moment of the strange quark, can induce a sizable linear photon polarization.

hep-ph↗

arXiv1999

$τ$ polarization asymmetries in $B^+ \to τ^+ν_τγ$ and $B^+_c \to τ^+ν_τγ$

We study the lepton polarization asymmetries in the radiative leptonic B decays of $B^+\to l^+ν_{l}γ$ and $B^+_{c}\to l^+ν_{l}γ$. We concentrate on the transverse component of the $τ$ lepton asymmetries in the tau decay modes due to CP violation in theories beyond the standard model to search T violating effect.

hep-ph↗