Related papers: New Physics effects on decay $B_s \to \gamma\gamma…
The complete calculation of the lowest order short-distance contributions to the $B_{s}\to\gamma\gamma$ decay in the SM are presented. The amplitude and branching ratio are calculated.
Recent experimental results for the ratio of the branching fractions of $\bar B\to D^{(*)}\tau\bar \nu_\tau$ and $\bar B\to D^{(*)}\mu\bar \nu_\mu$ decays came as a surprise and lead to a discussion of possibility to constraining New…
We investigate the production and the decays of pseudo-Goldstone bosons (PGBs) predicted by technicolor theories with the GIM mechanism (TC-GIM). The TC-GIM models contain exotic fermion families that do not interact under weak $SU(2)$, but…
Inspired by the recently observed tensions between the experimental data and the theoretical predictions, based on QCD factorisation, for several colour-allowed non-leptonic $B$-meson decays, we study the potential size of new physics (NP)…
We reanalyze the $B\to M$ tensor form factors in a covariant light-front quark model, where $M$ represents a vector meson $V$, an axial-vector meson $A$, or a tensor meson $T$. The treatment of masses and mixing angles in the $K_{1A,1B}$…
We investigate the differential branching ratio, branching ratio, differential forward-backward asymmetry, the forward-backward asymmetry of the lepton pair and the lepton polarization asymmetry of the exclusive $B\to \tau^+ \tau^- \gamma$…
We re-visit the problem of New Physics (NP) contribution to the branching ratio of the $B_s \to \mu^+ \mu^-$ decay in light of the recent observation of this decay by LHCb. We consider R-parity violating (RPV) supersymmetric models as a…
We review and update the effects of physics beyond the standard model on CP asymmetries in B decays. These asymmetries can be significantly altered if there are important new-physics contributions to \bqbqbar mixing. This same new physics…
Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios $R_K$ and $R_{K^*}$. The currently observed values align with the predictions of the standard model. In light of these recent updates, our…
We examine, in a number of Standard Model extensions, whether the decays $A \to WW/ZZ$ of a neutral pseudoscalar (Higgs) resonance can have branching ratios at the percent level and we determine the possible size of $B(A \to WW/ZZ)$…
The B_s to mu+ mu- decay plays an outstanding role in tests of the Standard Model and physics beyond it. The LHCb collaboration has recently reported the first evidence for this decay at the 3.5 sigma level, with a branching ratio in the…
We present a detailed study of $B\to K_1(1270) \gamma$ and $B\to K_1(1400) \gamma$ decays. Using the light-cone sum rule technique, we calculate the $B\to K_{1A} (1^3P_1)$ and $B\to K_{1B} (1^1P_1)$ tensor form factors, $T_1^{K_{1A}}(0)$…
We suppose that there is new physics (NP) in b -> s transitions, and examine its effect on the angular distribution of B_q^0 -> V_1 V_2 (q=d,s), where V_{1,2} are vector mesons. We find that, in the presence of such NP, the formulae…
The two $B$-factories, Belle and BaBar, has been played major roles in the B decays study. Their wonderful design and excellent operation enables their fruitful analysis results. Also recently the Tevatron experiments, CDF and DO, join the…
The decays of a Higgs boson to the $\gamma\gamma$ and $Z\gamma$ final states are purely quantum mechanical phenomena that are closely related to each other. We study the effects of an extended Higgs sector on the decay rates of the two…
Motivated by the $\sim 2\sigma$ discrepancy between the experimental value for $R_b$ and the theoretical prediction of the Standard Model, we examine the effect of new physics on the $Z$-$b$-$\overline{b}$ vertex. Using general results for…
The significance of new physics appearing in the loop-induced decays of neutral Higgs bosons into pairs of dibosons $\gamma\gamma$ and $Z\gamma$ will be discussed in the framework of the 3-3-1 models based on a recent…
We extend the Standard Model with the general effective Hamiltonian for the quark level transition $c \to s \ell \nu$ with a complete set of four fermion operators including right-handed neutrinos. The current experimental measurements in…
The $B_s$-meson system is a key element in the $B$-physics programme of hadron colliders, offering various avenues to explore CP violation and to search for new physics. One of the most prominent decays is $B_s\to J/\psi\phi$, the…
By employing the QCD factorization approach for the exclusive $B \to V \gamma$ decays, we calculated the new physics contributions to the branching ratios, CP asymmetries, isospin and U-spin symmetry breaking of $B \to K^*\gamma$ and $B \to…