Inclusive rare $\hat{I}{›}_b$ decays to photon

Abstract

Inclusive $H_b\to X_s{\hat{I}}^3$ decays, with $H_b$ a beauty baryon, are treated exploiting an expansion up to the third order in the inverse of the $b$ quark mass $m_b$ and to LO in $\hat{I}{\pm }_s$, keeping the dependence on the hadron spin. Double distribution $\frac{d^2\hat{I}“}{dyd\cos \hat{I}{¸}_P}$ is computed for polarized baryons, with $y=2E_{\hat{I}}^3/m_b$, $E_{\hat{I}}^3$ the photon energy and $\hat{I}{¸}_P$ the angle between the baryon spin vector and the photon momentum in the $H_b$ rest-frame. Modifications to the photon polarization asymmetry can probe effects of physics beyond the Standard Model. A systematic method to treat the singular terms in the photon energy spectrum obtained by the OPE is proposed.

Latex, 8 pages, 3 figures. Talk given at QCD@Work2024, Trani 18-21 June 2024