Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userStudy on pure annihilation type B to V gamma decays
56
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We investigate the pure annihilation type radiative $B$ meson decays $B^0 to phi gamma$ and $B_s to rho^0(omega)gamma$ in the soft-collinear effective theory. We consider three types of contributions to the decay amplitudes, including the direct annihilation topology, the contribution from the electro-magnetic penguin operator and the contribution of the neutral vector meson mixings. The numerical analysis shows that the decay amplitudes are dominated by the $omega-phi$ mixing effect in the $B^0 to phigamma$ and $B_s to omegagamma$ modes. The corresponding decay branching ratios are enhanced about three orders of magnitudes relative to the pure annihilation type contribution in these two decay channels. The decay rate of $B_s to rho^0gamma$ is much smaller than that of $B_s to omegagamma$ because of the smaller $rho^0-phi$ mixing. The predicted branching ratios $B(B^{0}rightarrowphigamma)=(3.99^{+1.67}_{-1.46} )times10^{-9},,B(B_srightarrowomegagamma)=(2.01^{+0.81}_{-0.71} )times10^{-7}$ are to be tested by the Belle-II and LHC-b experiments.
rate research
Read More
Pure leptonic radiative decays of heavy-light mesons are calculated using a very simple non-relativistic model. Dominant contribution originates from photon emission from light initial quark. We find $BR(B^pmtoell ugamma)sim3.5times10^{-6}$ and $BR(D_sto ell ugamma)sim1.7 times10^{-4}$. The importance of these reactions to clarify the dynamics of the annihilation graph is emphasized.
We study a set of exclusive decay modes of the Standard Model Higgs boson into a vector meson and a dilepton pair: $hto V ell^+ ell^-$, with $V=Upsilon, J/psi,phi$, and $ell=mu, tau$, determining the decay rates, the dilepton mass spectra and the $V$ longitudinal helicity fraction distributions. In the same framework, we analyze the exclusive modes into neutrino pairs $hto V u bar u$. We also discuss the implications of the recent CMS and ATLAS results for the lepton flavor-changing process $hto tau^+ mu^-$ on the $hto V tau^+ mu^-$ decay modes.
We give a summary of the discussions in Working Group V of the CKM2010 workshop dealing with determinations of the angle gamma of the unitarity triangle of the Cabibbo-Kobayashi-Maskawa matrix from B-meson decays into charmed final states.
Some years ago, a method was proposed for measuring the CP-violating phase gamma using pairs of two-body decays that are related by U-spin reflection (d <-> s). In this paper we adapt this method to charmless B -> PPP decays. Time-dependent Dalitz-plot analyses of these three-body decays are required for the measurement of the mixing-induced CP asymmetries. However, isobar analyses of the decay amplitudes are not necessary. A potential advantage of using three-body decays is that the effects of U-spin breaking may be reduced by averaging over the Dalitz plot. This can be tested independently using the measurements of direct CP asymmetries and branching ratios in three-body charged B decays.
It has been pointed out by Gronau and Rosner that the angle gamma of the unitarity triangle could be determined by combining future results on B_s and B_d decays to K pi. Here we show that it is important to include in the analysis the information on the phase beta which will be determined in the near future. Omitting this information could lead to an error as large as 8 degrees in gamma.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
