Related papers: A General Lower Bound for Radiative B Decay
The recent observation by the CLEO Collaboration of the inclusive decay $b\to s\gamma$ with a branching fraction consistent with the expectations of the Standard Model is used to constrain the parameter space of the Left-Right Symmetric…
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…
The rare Hyperon decay $\Sigma^+ \to p \ell^+ \ell^-$ is an $s \to d$ flavour changing neutral current process, which is highly suppressed within the Standard Model, and is therefore sensitive to new physics. Due to recent improvements in…
Deviations from the standard model prediction have been observed in several leptonic and semileptonic $B$ meson decays to $\tau\nu$ final states mediated via $b \to u$ and $b \to c$ charged current interactions. The measured value of ratio…
The weak decays Xi_b -> Lambda_b pi and Xi_c -> Lambda_c pi, in which the heavy quark is not destroyed, are discussed. The branching fractions for these decays, corresponding to an absolute rate of order 0.01 ps^{-1}, should be at a one…
We discuss the constraints on the supersymmetric parameter space from the decay mode b -> s \gamma for large values of tan\beta. We improve the theoretical prediction for the decay rate by summing very large radiative corrections to all…
Decay rates of the B-meson are studied through charmless and strangless transitions into pi, rho, omega and gamma systems. The important features of these modes are their clean signatures. The CLEO II collaboration has recently reported the…
We describe two recent theoretical calculations of the $B \to K^* \gamma$ decay. The first method is based on an effective lagrangian incorporating chiral symmetry for the light degrees of freedom and the heavy quark spin-flavor symmetries…
The flavor changing neutral current processes $K_L \to \pi^0 e^+ e^-$, $B \to X_s e^+ e^-$ and $B \to X_s \mu^+ \mu^-$ are studied within the minimal supersymmetric extension of the Standard Model. We first examine the rates for these decay…
In the Standard Model, the photon emitted in b->s\gamma decays is predicted to be left-handed polarized. We discuss the types of New Physics which can produce a deviation from this prediction, focusing on the Minimal Supersymmetric Standard…
Main theoretical approaches to weak radiative hyperon decays are briefly reviewed. It is emphasized that only approaches with great predictive power should be seriously considered when seeking a resolution of the puzzle presented by…
We review the theoretical status of the predictions for the decay rate differences in the neutral B-system. We find (Delta Gamma/Gamma) Bs = (12 pm 5) 10^(-2) and (Delta Gamma/Gamma) Bd = (3 pm 1.2) 10^(-3).
I discuss the theoretical and empirical status of $b \to s \gamma$, $b \to s \ell^+ \ell^-$ decays, as well as their future prospects. I emphasize those observables in rare $b$-decays which can potentially establish new physics and…
We present an estimate of certain higher order corrections to the contribution of the charm triangle loop in the inclusive B -> X_s gamma decay rate, recently discussed by Voloshin. We find that these corrections are minute and hence the…
Popular extensions of the standard model of particle physics feature new fields and symmetries which could, for example, dynamically generate neutrino masses from $B-L$ spontaneous symmetry breaking. If a new light scalar that decays into…
The propagation and decay of neutral B-mesons can be described in terms of quantum dynamical semigroups; they provide generalized time-evolutions that take into account possible non-standard effects leading to loss of phase coherence and…
We analyze the inclusive $b(c) \to s(u) \mu^+ \mu^-$ and the exclusive $B(D^+) \to K(\pi^+) \mu^+ \mu^-$ flavour changing neutral current decays in the light of HyperCP boson $X^0$ of mass 214 MeV recently observed in the hyperon decay…
We investigate the potential effects of the scalar flavour changing neutral currents that are generated e.g. in supersymmetry with $\tan\beta\gg1$ in the $b\to sl^+l^-$ transitions. Using the experimental upper limit on…
I review the NLO QCD calculations of the branching ratio for B--> X_s gamma in the SM. Including the leading electromagnetic corrections, one obtaines BR(B-> X_s gamma)=(3.32 +- 0.30)*10^{-4}. Confronting theory with the newest data, an…
We present standard model (SM) estimates for exclusive $c \to u \gamma$ processes in heavy quark and hybrid frameworks. Measured branching ratios ${\cal{B}}(D^0 \to (\phi, \bar K^{*0}) \gamma)$ are at or somewhat exceeding the upper range…