Related papers: The $B_c$ decay rate in the Standard Model
Discrepancies have been noted between experimental measurements and Standard Model predictions for various observables related to the $B\to(K, K^*,\phi) ll$ processes. Recently, the Belle-II Collaboration observed a $2.8\sigma$ deviation…
We study the decay constants of pseudoscalar and vector $B$ meson in the framework of light-cone quark model (LCQM). We apply the variational method to the relativistic Hamiltonian with the Gaussian-type trial wave function to obtain the…
The charm quark has unique properties that make it a very important probe of many facets of the Standard Model. New experimental information on charm decays is becoming available from dedicated experiments at charm factories, and through…
Importance of studies of $b$ quark decays and experimental status of various measurements are discussed.
In this work we study the decay constants of $B$ and $B_s$ mesons based on the wave function obtained in the relativistic potential model. Our results are in good agreement with experimental data which enables us to apply this method to the…
Semileptonic decay of the $B_c$ meson is studied in the heavy quark limit. The six possible form factors for $B_c \rightarrow B_s (B^0),B_s^* (B^{*0})$ semileptonic decay are determined by two invariant functions. Only one of these…
We investigate the mass and decay constant of the heavy-heavy pseudoscalar, $B_c$, $\eta_c$ and $\eta_b$ mesons in the framework of finite temperature QCD sum rules. The annihilation and scattering parts of spectral density are calculated…
We review the physics of purely leptonic decays of $\pi^\pm$, $K^\pm$, $D^{\pm}$, $D_s^\pm$, and $B^\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of…
$B_d$ and $B_s$ meson systems play a fundamental role to test and improve our understanding of Standard Model flavor dynamics. The mixing parameters $\Delta m_{d,s}$ represent important constraints in the unitarity triangle analysis. Their…
We study certain exclusive decays of high spin mesons into mesons in models of large N_c Yang-Mills with few flavors at strong coupling using string theory. The rate of the process is calculated by studying the splitting of a macroscopic…
The rare decay $B^0_s \to \mu^+\mu^-$ plays a key role for the testing of the Standard Model. It is pointed out that the sizable decay width difference $\Delta\Gamma_s$ of the $B_s$-meson system affects this channel in a subtle way. As a…
The weak decays of B_{c} --> D_{s}^{*}l^{+}l^{-} (l=mu,tau) are investigated in the Standard Model with fourth generation (SM4). Taking fourth generation quark mass m_{t'} of about 300 to 600 GeV with the CKM matrix elements…
We extend the picture of $B$-meson decay constants obtained in lattice QCD beyond those of the $B$, $B_s$ and $B_c$ to give the first full lattice QCD results for the $B^*$, $B^*_s$ and $B^*_c$. We use improved NonRelativistic QCD for the…
The problem of possible deviations from the Standard Model is considered in the framework of a variant of dynamical electroweak symmetry breaking. It comes clear, that the parameters of the theory, being obtained earlier and describing…
We present a study of various $B_{s}$ meson decays, including hadronic and semileptonic final states with different spins and diagram topologies. The covariant confined quark model is employed to describe hadronic effects, and our analysis…
We apply our Bethe-Salpeter model for mesons to the $B_c$ family with parameters fixed in our previous investigation. We evaluate the mass of the pseudo-scalar $B_c$ meson as 6.356 GeV/$c^2$ and 6.380 GeV/$c^2$ and the lifetime as 0.47 ps…
The comparison between parameterisations of the perturbation results for the decay width of the Standard Model Higgs boson to \bar{b}b-quarks pairs, based on application of \bar{MS}-scheme running quark mass and pole b-quark mass, are…
We give a review and present a comprehensive calculation for the leptonic constant B_{c} of the low-lying pseudoscalar and vector states of B_{c}-meson in the framework of static and QCD-motivated nonrelativistic potential models taking…
Including the recent preliminary results of BaBar and BELLE experiments, we update the currently allowed intervals for various CKM parameters: $\bar\rho$, $\bar\eta$, $\sin2\beta$, $\sin2\alpha$, $\sin^2\gamma$. We also update the SM…
Progress in the theoretical description of B-meson decays, in particular decays to light hadrons, is reviewed. The factorization properties of such decays can be analyzed using the soft-collinear effective theory. Applications of the…