A study on the rare radiative decay $B_c\to D_s^{\ast }\gamma$ in technicolor with scalars

Abstract

Applying the perturbative QCD (PQCD), we study the process $B_c\to D_s^{\ast }\gamma$ in the technicolor with a massless scalar doublet model (TCMLSM) recently presented by C. D. Carone and H. Georgi; and compare the results with that estimated in the standard model (SM). There are two mechanisms which contribute to the $B_c\to D_s^{\ast }\gamma$ process. One proceeds through the short distance $b\to s\gamma$ transition, the other through weak annihilation accompanied by a photon emission. In the SM, these two processes are found to contribute with the same order of magnitude. In the TCMLSM, the modification of $B_c\to D_s^{\ast }\gamma$ from ${\pi }_p$ (the physical pions in this model) is small for the allowed mass of ${\pi }_p$.

Comments: 16 pages, Latex, no macros, 3 figures(in Latex), hard copy is available upon request. to appear in Z. Phys. C