Related papers: B-> K photon photon via intermediate eta'
Within the frameworks of the light-front quark model (LFQM) and chiral perturbation theory (ChPT) of $O(p^6)$, we reevaluate the form factors of the $K^+ \to \gamma$ transition. We use these form factors to study the decay of $K^+ \to e^+…
We present a systematic study of exclusive charmless nonleptonic two-body B decays including axial-vector mesons in the final state. We calculate branching ratios of B\to PA, VA and AA decays, where A, V and P denote an axial-vector, a…
We report measurements for two-body charmless B decays with an eta' meson in the final state. Using 11.1X10^6 BBbar pairs collected with the Belle detector, we find BF(B^+ ->eta'K^+)=(79^+12_-11 +-9)x10^-6 and BF(B^0 -> eta'K^0)=(55^+19_-16…
It has been argued long ago that eta(b) could be observed through the eta(b) => J/psi(=> mu+ mu-) J/psi(=> mu+ mu-) decay chain. Recent calculations indicate that the width of eta(b) into two J/psi is almost three order of magnitude smaller…
In this work, we calculate the branching ratios for the $\eta(\eta')\rightarrow\bar{\ell}\ell$ decays, where $\ell = e,\mu$. These processes have tiny rates in the standard model due to spin flip, loop, and electromagnetic suppression, for…
The charm content in $\eta'$ is estimated using the QCD U(1) axial anomaly applied to $b\to s g g \to \eta' s$. We find $f_{\eta'}^{(c)} \approx - 3.1$ MeV for $m_c = 1.3$ GeV. Our estimate agrees with other independent methods by Feldmann…
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 have computed the branching ratios of the exclusive pseudoscalar (vector) + tensor modes that are allowed in the decays of the B_c meson. The dominant spectator and annihilation contributions in those decays are evaluated using the…
We evaluate the rare radiative kaon decays K_{L,S} -> 3 gamma. Applying the requirements of gauge invariance and Bose symmetry, we derive a general form of the decay amplitude, including both parity-conserving and parity-violating…
The $B^+ \rightarrow J/\psi \eta^{\prime} K^+$ decay is observed for the first time using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8, and 13TeV, corresponding to a total integrated…
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 study the indication of large different branching ratios between $B^{-}\to D^{(*)0} K^{-} {K}^{0}$ and $\bar{B}_{d}\to D^{(*)+} K^{-} {K}^{0}$ observed by Belle. Interestingly, the same situation is not found in the decays $B\to D^{(*)}…
Results of a study of the $K^+ \rightarrow \pi^{0} e^{+} \nu \gamma $ decay at OKA setup are presented. More than 32000 events of this decay are observed. The differential spectra over the photon energy and the photon-electron opening angle…
Exclusive semileptonic B decays to radially excited charmed mesons and rare radiative B decay to the orbitally excited tensor K_2^*(1430) meson are investigated in the framework of the relativistic quark model based on the quasipotential…
I present new results for the Standard-Model predictions of the differential decay rates for $H\to \ell^{+} \ell^{-} \gamma$, where $\ell=e, \mu$, and the forward-backward asymmetries defined in terms of the flight direction of the photon…
In this paper we study the angular distribution of the rare B decay $B \to K^*_2 (\to K \pi) l^+ l^-$, which is expected to be observed soon. We use the standard effective Hamiltonian approach, and use the form factors that have already…
We estimate the density matrix element for the pi^0, eta and eta' production from the vacuum in the large-N_c limit. As a consequence, we find that the QCD axial anomaly leads to highly non-trivial corrections to the usual flavour SU(3)…
We report an observation of the $B^{\pm} \to J/\psi \eta K^{\pm}$ and $B^0 \to J/\psi \eta K^0_S$ decays using 772$\times 10^{6}$ $B\bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB…
The exotic $\beta$-delayed proton emission is calculated in $^{11}$Be from first principles using chiral two- and three-nucleon forces. To investigate the unexpectedly-large branching ratio measured in [PRL 123, 082501 (2019)] we calculate…
The paper deals with a next-to-leading order analysis of the radiative $B \to K^* \gamma$ decay. Working in a PQCD approach, we compute the correction to the essential form factor, coming from a single gluon exchange with the spectator. We…