Related papers: $K^0 $ Decays into Three Photons

It is shown that, for a nontrivial radiative decay channel of the 17-keV neutrino, the photons would distort the microwave background radiation through ionization of the universe. The constraint on the branching ratio of such decays from…

The $K_{S}^{0}-K_{L}^{0}$ asymmetries in the $D$ meson decays, induced by the interference between the Cabibbo-favored and the doubly Cabibbo-suppressed amplitudes, can help to understand the dynamics of charm decays. All possible processes…

We report the first measurements of the absolute branching fractions of $D^0\to K_L^0\phi$, $D^0\to K_L^0\eta$, $D^0\to K_L^0\omega$, and $D^0\to K_L^0\eta^{\prime}$, obtained by analyzing $2.93\,\rm fb^{-1}$ of $e^+e^-$ collision data…

Landau Yang theorem is well known for the past several decades. It prohibits the decay of a massive spin 1 particle to two photons. This emerges simply from the representation theory of the Poincare group and Bose Statistics. It does not…

The ATLAS and CMS Collaborations reported that the observed number of Higgs boson decays into a $Z$ boson and a photon is $\mu = 2.2 \pm 0.7$ times higher than predicted by the Standard Model. Initially, this discrepancy was attributed to a…

The K^+ \to \pi^0 \mu^+ \nu \gamma ($K_{\mu 3 \gamma}$) decay has been measured with stopped positive kaons at the KEK 12 GeV proton synchrotron. A $K_{\mu 3 \gamma}$ sample containing 125 events was obtained. The partial branching ratio…

We calculate the momentum dependent form factors of $P \to \gamma^* \gamma^*$($P=\pi^{0}, \eta$) within the light-front quark model. Using the form factors, we examine the decays of $P \to l^+ l^-$, $P \to l^+ l^- \gamma$ and $P \to l^+ l^-…

The first observation of the $B^0_s \to D_s^{*\mp} K^{\pm}$ decay is reported using 3.0$fb^{-1}$ of proton-proton collision data collected by the LHCb experiment. The $D_s^{*\mp}$ mesons are reconstructed through the decay chain $D_s^{*\mp}…

Measurements of the branching fractions of $B^0_s \to K^{*\pm}K^\mp$ and $B^0_s \to K^{*\pm}\pi^\mp$ decays are performed using a data sample corresponding to $1.0 \ {\rm fb}^{-1}$ of proton-proton collision data collected with the LHCb…

Form factors parameterizing radiative leptonic decays of heavy mesons $% (B^{+}\to \gamma l^{+}\nu_{l}) $ for photon energy are computed in the language of dispersion relation. The contributing states to the absorptive part in the…

The radiative decays $V\to S\gamma$ and $S\to V\gamma$ with $V=\rho, \omega, \phi$ and $S=a_0, \sigma, f_0$ are calculated within the framework of the Linear Sigma Model. Current experimental data on the $\phi\to f_0\gamma$ and…

We present the result for the three-loop singlet QCD corrections to the decay of a Higgs boson into two photons and improve the calculation for the non-singlet case. With the new result presented, the decay width Gamma(H -> \gamma \gamma)…

The photon energy spectrum in inclusive weak radiative B -> X_s gamma decay is computed to order alpha_s^2 beta_0. This result is used to extract a value for the HQET parameter $\bar\Lambda$ from the average <1-2E_\gamma/m_B>, and a value…

The $K^{+} \to \pi^{+}\pi^{0}\pi^{0}\gamma$ decay is observed by the OKA collaboration. The branching ratio is measured to be $(4.1 \pm 0.9(stat) \pm 0.4(syst))\times 10^{-6}$. The branching ratio and $\gamma$ energy spectrum are consistent…

The decays of the CP-even ($h,\,H$) and the CP-odd ($A$) Higgs bosons $h,\,H,\,A\to Z\gamma\gamma$ are calculated in the context of the minimal supersymmetric standard model (MSSM), where they are induced at the one-loop level via box and…

We present a complete calculation of the K_{l3} decays K^+ --> pi^0 l^+ nu_l and K^0 --> pi^- l^+ nu_l to O(p^4, (m_d-m_u) p^2, e^2 p^2) in chiral perturbation theory with virtual photons and leptons. We introduce the concept of generalized…

We examine our previous conjecture that the eta' intermediate resonance has the dominant role in the long distance contributions to B decay into two photons and a strange final state hadron. We calculate the branching ratio of the exclusive…

Future precision measurements of Higgs boson decays will determine the branching fraction for the decay into two photons with a precision at the one percent level. To fully exploit such measurements, equally precise theoretical predictions…

Existing predictions for the branching ratio for $\phi\rightarrow K\bar{K}\gamma$ {\it via} $\phi\rightarrow S\gamma$ (where $S$ denotes one of the scalar mesons $f_0$(975) and $a_0$(980)) vary by several orders of magnitude. Given the…

We report an observation of the decay B^\pm -> \phi \phi K^\pm and evidence for B^0 -> \phi \phi K^0. These results are based on a 414 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider…