Related papers: Subleading Light-cone distributions functions in t…
A solution is presented for the spectrum of high-energy gamma-ray burst photons confined to a quasi-thermal baryonic photosphere. The solution is valid in the steady-state limit assuming the region under consideration is optically thick to…
The short distance QCD corrections to $b\to s\gamma \gamma$ are calculated in the leading logarithmic approximation. The equivalence of operator basis reduction for S-matrix elements by using the equations of motion or by proving a low…
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…
Using soft-collinear effective theory we describe at leading order in 1/m_b all the semi-inclusive hadronic B -> XM decays near the endpoint, where an energetic light meson M recoils against an inclusive jet X. We also include the decays…
High energy photon colliders (gamma-gamma, gamma-electron) based on backward Compton scattering of laser light is a very natural addition to e+e- linear colliders. In this report we consider mainly this option for the TESLA project. Recent…
The shape of the lepton spectrum in inclusive semileptonic $B\to X\,\ell\,\bar\nu_\ell$ decay is sensitive to matrix elements of the heavy quark effective theory, $\bar\Lambda$ and $\lambda_1$. From CLEO data we extract…
The weak decays of doubly heavy $\Xi_{QQ}$ baryon induced by flavor changing $b \to d$ and $ c \to u$ flavor changing neutral current within the light cone sum rules are studied. Using the parallel components of the light cone distribution…
The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang…
The Light-cone distribution amplitudes (LCDAs) of the $\Sigma^\pm$ baryons up to twist six are investigated on the basis of QCD conformal partial wave expansion approach. The calculations are carried out to the next-to-leading order of…
We show that the B \to X(s) gamma photon energy (E_gamma) spectrum can be reliably computed by resummed perturbation theory. Our calculation is based on Dressed Gluon Exponentiation (DGE) incorporating Sudakov and renormalon resummation. It…
We perform a comprehensive analysis of the rare "Lambda_b -> Lambda l+ l-" decay in the framework of family non-universal Z' model. It is shown that Z' gives considerable contribution to the decay width. Zero positions of the…
We present a theoretical prediction for the photon spectrum in radiative Upsilon decay including the effects of resumming the endpoint region, E_\gamma -> M_\Upsilon/2. Our approach is based on NRQCD and the soft collinear effective theory.…
We give a general parameterization of the Lambda_b --> Lambda(1520) gamma decay amplitude, applicable to any strange isosinglet spin-3/2 baryon, and calculate the branching fraction and helicity amplitudes. Large-energy form factor…
We investigate the leading power corrections to the decay rates and distributions in the decay $B \rightarrow X_s \ell^+ \ell^- $ in the standard model (SM) using heavy quark expansion (HQE) in $(1/m_b)$ and a phenomenological model…
It is by now well known that, at subleading power in scale ratios, factorization theorems for high-energy cross sections and decay amplitudes contain endpoint-divergent convolution integrals. The presence of these divergences hints at a…
We compute the weak lensing convergence power spectrum, $C^{\kappa\kappa}(\theta)$, in a dust-filled universe using fully non-linear general relativistic simulations. The spectrum is then compared to more standard, approximate calculations…
Relating the forward light-by-light scattering to energy weighted integrals of the \gamma* \gamma -fusion cross sections, with one real photon (\gamma) and one virtual photon (\gamma*), we find two new exact super-convergence relations.…
Double-lepton polarization asymmetries in the (B -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian including all possible forms of the interaction. The dependencies of the…
We evaluate the O(alpha_em/alpha_s) correction to the rate of B -> X_s gamma decay, i.e. we resum all the 0[ alpha_em ln M_W^2/m_b^2 x (alpha_s ln M_W^2/m_b^2)^n ] corrections for n=0,1,2,... Our calculation differs from the previously…
We analyze the factorization to subleading power in the flavor changing neutral current process $\bar B\to X_s \ell^+ \ell^-$. In particular, we compute the so-called resolved contributions and explore the numerical impact on observables.…