Related papers: Uncertainties from Long Range Effects in $B \to K^…
The factorization properties of the radiative decays B->V gamma are analyzed at leading order in 1/m_b using the soft-collinear effective theory. It is shown that the decay amplitudes can be expressed in terms of a B->V form factor…
The dominant long-distance contributions to the exclusive radiative decays $B \to \rho (\omega) + \gamma$ involve photon emission from the light quarks at large distances, which cannot be treated perturbatively. We point out that this…
We study the effect of supersymmetric contributions to the effective quark transition $b\to s\gamma\gamma$, including leading order QCD effects. We apply the discussion to the decay $B_s\to\gamma\gamma$. Even though one-particle irreducible…
The extraction of right-handed currents, beyond the Standard Model, faces theoretical challenges from long-distance contributions. We show that these effects can be controlled by combining, for example, studies of $B \to V(1^-) \gamma$ and…
Exclusive radiative B decays, B to K* gamma, K_1(1270) gamma, K_1(1400) gamma and K*_2(1430) gamma, are studied in the framework of a covariant light-front quark model. The tensor form factor T_1(q^2) at q^2=0, which is relevant to the…
We discuss a novel approach to systematically determine the long-distance contribution to $B\to K^*\ell\ell$ decays in the kinematic region where the dilepton invariant mass is below the open charm threshold. This approach provides the most…
We apply the perturbative QCD factorization theorem developed recently for nonleptonic heavy meson decays to the radiative decay $B\to K^*\gamma$. In this formalism the evolution of the Wilson coefficients from the $W$ boson mass down to…
Electromagnetic interactions are introduced in the effective chiral Lagrangian for heavy mesons which includes light vector particles. A suitable notion of vector meson dominance is formulated. The constraints on the heavy meson -light…
A representation of the amplitude $\gamma^*(q^2)\to\gamma\pi\pi$ is proposed which combines large $N_c$ chiral resonance Lagrangian modelling with general unitarity and analyticity properties. The amplitude is constrained from…
A new phase for the measurements of radiative decay modes in $b \to s$ transitions has started with new measurements of exclusive modes by LHCb and with Belle-II showing distinctive promises in both inclusive and exclusive channels. After…
We revisit the calculation of the long-distance contribution to the muon-polarization asymmetry \Delta_{LR}, which arises, in K^+\to\pi^+\mu^+\mu^-, from the two-photon intermediate state. The parity-violating amplitude of this process,…
This Letter presents a study of the flavor-changing neutral current radiative $B^{\pm} \to K^{\pm}\pi^{\mp}\pi^{\pm}\gamma$ decays performed using data collected in proton-proton collisions with the LHCb detector at $7$ and $8\,$TeV…
We evaluate the impact of radiative corrections in the ratios $\Gamma[B\to M \mu^+\mu^-]/\Gamma[B\to M e^+e^-]$ when the meson $M$ is a $K$ or a $K^*$. Employing the cuts on $m^2_{\ell\ell}$ and the reconstructed $B$-meson mass presently…
Recent data for B decays to two light vector mesons show that the longitudinal amplitude dominates in $B^0 \to \rho^+ \rho^-$, $B^+ \to \rho^+ \rho^0$, $\rho^0 K^{*+}$ decays and not in $B^0 \to \phi K^{*0}$, $B^+ \to \phi K^{*+}$. We…
We explore the theoretical feasibility of extracting V_ub from two ratios built from B meson inclusive partial decays, R_1 = Gamma(b-> u cbar s)/3Gamma(b -> c l nu), and R_2 = [Gamma(b -> c X) - Gamma(b -> cbar X)]/Gamma(b -> c ubar d). We…
We describe a calculation of the two-photon decays of heavy vector-mesons, $B^*\to B\gamma\gamma$ and $D^*\to D\gamma\gamma$, by using the ``heavy meson chiral Lagrangian''. The decay amplitudes are expressed in terms of the strong coupling…
We present a phenomenological study of the $\gamma\gamma^*\to K\bar{K}^*(892)$ process by including the $s$-channel production of the $\eta(1475)$ and $f_1(1420)$ resonances. The non-resonant channel via $K$- and $K^*$-exchanges is…
We present the results of a numerical calculation of the $B\to K^* \gamma$ form factors. The results have been obtained by studying the relevant correlation functions at $\beta=6.0$, on an $18^3 \times 64$ lattice, using the ${\rm…
Relativistic bending in the vicinity of a massive body is characterized only by the post-Newtonian parameter $\gamma$ within the standard parameterized post-Newtonian formalism, which is unity in General Relativity. Aiming at estimating…
A method is proposed to measure the photon polarisation parameter $\lambda_\gamma$ in $b\to s\gamma$ transitions using an amplitude analysis of $B\to K\pi\pi\gamma$ decays. Simplified models of the $K\pi\pi$ i system are used to simulate…