arXiv subjects

Yigang Cao

Publications and source records attributed to Yigang Cao.

4 recordsLinked to original sources

arXiv1997

TC corrections to the single-top-quark production at the Fermilab Tevatron

We calculate one-loop corrections to the single-top-quark production via $q\overline{q}' \to t\overline b$ at the Fermilab Tevatron from the Pseudo-Goldstone bosons ( PGBs ) in the framework of one generation technicolor model. The maximum correction to the total cross section for the single-top-quark production is found to reach -2.4% relative to the tree-level cross section, which may be observable at a high-luminosity Tevatron.

hep-ph↗

arXiv1996

Multiscale Technicolor and $b \to s γ$

Correction to the $b\rightarrow sγ$ branching ratio in the multiscale walking technicolor model (MWTCM) is examined. For the original MWTCM, the correction is too large to explain the recent CLEO data. We show that if topcolor is further introduced, the branching ratio in the topcolor assisted MWTCM can be in agreement with the CLEO data for a certain range of the parameters.

hep-ph↗

arXiv1996

A study on the rare radiative decay $B_c \to D_s^*γ$ in technicolor with scalars

Applying the perturbative QCD (PQCD), we study the process $B_c\rightarrow D_s^*γ$ 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 $B_c\rightarrow D_s^* γ$ process. One proceeds through the short distance $b\rightarrow s γ$ 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 $B_c\rightarrow D_s^*γ$ from $π_p$ (the physical pions in this model) is small for the allowed mass of $π_p$.

hep-ph↗

arXiv1996

Study on the rare radiative decay $B_c \to D_s^*γ$ in the standard model and multiscale walking technicolor model

Applying the perturbative QCD ( PQCD ) method, we study the decay $B_c\rightarrow D_s^*γ$ in the standard model and multiscale walking technicolor model. In the SM, we find that the contribution of weak annihilation is more important than that of the electromagnetic penguin. The presence of Pseudo-Goldstone-Bosons in the MWTCM leads to a large enhancement in the rate of $B_c\rightarrow D_s^*γ$, but this model is in conflict with the branching ratio of $Z\rightarrow b\overline b$ ( $R_b$ ) and the CLEO data on the branching ratio BR ( $b\rightarrow sγ$ ). If topcolor is further introduced, the calculated results in the topcolor assisted MWTCM can be suppressed and be in agreement with the CLEO data for a certain range of the parameters.

hep-ph↗