相关论文: On The Dimensional Methods in Rare b Decays
We give a more complete calculation of $b \to s\gamma $ decay in 2-Higgs doublet model, including leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. The inclusive decay rate in the first…
Theoretical predictions for the branching ratios of the $B \rightarrow X_s\,\gamma$ and $B \rightarrow K^*\,\gamma$ decays are calculated in the Standard Model and in the (type II) two-Higgs-doublet model. Both the complete leading and the…
We give a more complete calculation of $b \to s\gamma $ decay, including leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. We have included the full set of dimension-6 operators and…
In a wide class of models -- including the standard model -- flavor-changing neutral currents are suppressed by an approximate chiral symmetry of the low-energy lagrangian. This symmetry allows the derivation of general relations among…
We calculate next to leading order QCD corrections to the direct decays b -> J/Psi + X and b -> eta_c + X. The strong renormalization scale dependence is seen to persist also in this order and in fact the rate is driven to an unphysical…
The method of QCD sum rules in the presence of the external electromagnetic $F_{\mu\nu}$ field is used to analyze radiative decays of charmed or bottomed mesons such as $D^{\ast}\to D\gamma$ and $B^{\ast}\to B\gamma$, with the…
Recent results in radiative B decays from the Belle and BaBar collaborations are discussed. New measurements of the decay rate and CP asymmetries in b -> s gamma and b -> d gamma decays are presented, together with measurements of the…
We summarize the different features which show that QCD spectral sum rule analyses of the scalar two- and three-point functions do not favour the $\bar uu+\bar dd$ interpretation of the broad and low mass $\sigma (0.6)$ and emphasize that a…
We estimate the beyond the Standard Model (SM) contribution to the B_{s,d} \to \gamma\gamma double radiative decay in the framework of the model with one universal extra dimension. This contribution gives a \sim 3 (6)% enhancement of the…
This paper is dedicated to the Oldroyd-B model with fractional dissipation $(-\Delta)^{\alpha}\tau$ for any $\alpha>0$. We establish the global smooth solutions to the Oldroyd-B model in the corotational case with arbitrarily small…
Numerous approaches to quantum gravity report a reduction in the number of spacetime dimensions at the Planck scale. However, accepting the reality of dimensional reduction also means accepting its consequences, including a variable speed…
In this talk some of the theoretical aspects of $b \to s \gamma$ transitions are discussed. The focus is on inclusive decays, since these can be computed more reliably. Topics covered are (1) perturbative QCD corrections, (2)…
We study model-independently the implications of non-standard scalar and pseudoscalar interactions for the decays b ->s gamma, b -> s g, b -> s l^+l^- (l=e,mu) and B_s -> mu^+ mu^-. We find sizeable renormalization effects from scalar and…
In this work we compute the leading logarithmic corrections to the b -> s gamma decay in a dimensional scheme which does not require any definition of the gamma5 matrix. The scheme does not exhibit unconsistencies and it is therefore a…
A substantial enhancement is found of the $b \to c\,{\overline c}\, s$ decay rate due to the QCD interaction within the $\overline c s$ pair, which enhancement may amount to 30\%, or more. Some general features of calculation of the QCD…
The contribution to the decay $b\to s \gamma$ in the Minimal Supersymmetric Standard Model with radiative electroweak breaking is presented. The impact of a detection of this inclusive decay at the SM level is discussed. Results for other…
The differential decay spectrum $d\Gamma/dE_e dq^2$ for the semileptonic decay of an unpolarized hadron containing a b-quark, and the decay spectrum $d\Gamma/dE_e dq^2 d\!\cos\theta$ for polarized $\Lambda_b$ decay are computed to second…
We estimate the renormalon corrections to the inclusive decay rate of heavy hadrons. We assume the gluon mass term $\lambda^2 \gg `^2$ to imitate the short distance nonperturbative effects. It is found that the the inclusive decay rates are…
Rare b decays provide a unique opportunity to measure Standard Model parameters and probe beyond the Standard Model. We review here the experimentalprogress made in measuring these decays, and the importance of future measurements,…
We estimate contributions from Kaluza-Klein excitations of third generation quarks and gauge bosons to the branching ratio of $B\rightarrow X_s\gamma$ decay process in 5-Dimensional Universal Extra Dimensional scenario with non-vanishing…