Related papers: Backgrounds in the search for Second Class Current…
Yang's theorem states that an initial J=1 state cannot decay into two photons. Because of this result some reactions relating to elementary particles or atomic transitions can be ruled out. The theorem is not valid in the presence of…
The scalar and vector meson exchange contributions to the doubly radiative decays $\eta^{(\prime)}\to\pi^0\gamma\gamma$ and $\eta^\prime\to\eta\gamma\gamma$ are analysed within the Linear Sigma Model and Vector Meson Dominance frameworks,…
We use experimental data on $e^+e^- \to \eta (\eta^{\prime})\pi^+\pi^-$ and conservation of vector current to estimate the branching fractions of $\tau^-$ decay to $\eta (\eta^{\prime})\pi^-\pi^0\nu_{\tau}$. The obtained values are compared…
The possible anomalous New Physics contributions to electric and magnetic dipole moments of the $\tau$ lepton has brought renewed interest in development of new charge-parity violating signatures in the $\tau$-pair production at Belle II…
We calculate the decay rate B-> X_s photon photon via intermediate psuedoscalar charmonium eta_c. This process is thought to be the main long-distance contribution which dominates the corresponding inclusive rare B decay. We point out that…
In this second part of a series we attempt to construct an empirical model that can mimick all experimental observations made regarding the role of an alternative interleaved scan pattern in STEM imaging on the beam damage in a specific…
In this paper, we study gamma ray spectra for various scenarios of dark matter annihilation and decay. We focus on processes which generate only high-energy photons or leptons and photons, but no proton-antiproton pairs, to be compatible…
The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double-beta ($0\nu\beta\beta$) decay of $^{76}$Ge. The technological challenge of GERDA is to operate in a…
At the present time, there are a number of measurements of $B$-decay observables that disagree with the predictions of the standard model. These discrepancies have been seen in processes governed by two types of decay: (i) $b \to s \mu^+…
The rare decays $\eta^{(\prime)}\to\ell^+\ell^-$, $\ell\in\{e,\mu\}$, are highly suppressed in the Standard Model, both by their chirality structure and the required loop attaching the lepton line to the $\eta^{(\prime)}\to\gamma^*\gamma^*$…
Ground-state two-proton (2p) radioactivity is a decay mode found in isotopes of elements with even atomic numbers located beyond the two-proton drip line. So far, this exotic process has been experimentally observed in a few light and…
We present in this talk recent investigations on the nucleon-like resonance N*(1675) newly found in eta photoproduction by the GRAAL, Tohoku LNS-gamma and CB-ELSA collaborations. We focus on the production mechanism of the N*(1675),…
The Advanced Mo-based Rare process Experiment (AMoRE)-Pilot experiment is an initial phase of the AMoRE search for neutrinoless double beta decay of $^{100}$Mo, with the purpose of investigating the level and sources of backgrounds.…
A number of theories, spanning a wide range of mass scales, predict dark matter candidates that have lifetimes much longer than the age of the universe, yet may produce a significant flux of gamma rays in their decays today. We constrain…
I discuss isospin breaking effects within the standard model. Chiral perturbation theory presents the appropriate theoretical framework for such an investigation in the low--energy range. Recent results on the electromagnetic contributions…
The identification of the intermediate-mass Higgs process $\gamma\gamma\to H \to b \bar b$ will be one of the most important goals of a future photon linear collider. Potentially important backgrounds from the continuum $\gamma\gamma \to c…
We summarize recent work in determining the transition form factor (TFF) of the neutral pion ($\pi^0 \to \gamma^*\gamma^*$), by solving the non-perturbative Dyson-Schwinger and Bethe-Salpeter equations. We first study the transition form…
We present a technique for separating nuclear double beta decay ($\beta\beta$-decay) events from background neutrino interactions due to $^{8}$B decays in the sun. This background becomes dominant in a kiloton-scale liquid-scintillator…
The PandaX-III experiment will search for neutrinoless double beta decay of $^{136}$Xe with high pressure gaseous time projection chambers at the China Jin-Ping underground Laboratory. The tracking feature of gaseous detectors helps…
We study the decays of $\tau^- \to \nu_{\tau} P^-\gamma (P=\pi^-, K^-)$ in the light front quark model. We calculate the form factors and use them to evaluate the decay widths. We find that, in the standard model, the decay widths are…