Related papers: Backgrounds in the search for Second Class Current…

The decays $\tau^-\to K^-\eta\nu_\tau$ and $K^-\eta^\prime\nu_\tau$ are studied in the context of Chiral Perturbation Theory supplemented with the explicit inclusion of resonances. For the required vector-form factors we have explored three…

Performance of nuclear threat detection systems based on gamma-ray spectrometry often strongly depends on the ability to identify the part of measured signal that can be attributed to background radiation. We have successfully applied a…

In this paper we show that the baryon-to-photon ratio $\eta$ is in general not conserved before decoupling in non-minimally coupled theories of gravity. We use big-bang nucleosynthesis and cosmic microwave background limits on the…

A search for the invisible decays of $\omega$ and $\phi$ mesons in $J/\psi\to \omega (\phi)\eta$ transitions has been performed by the BESIII Collaboration very recently. Inspired by this experimental study, we compute the lowest order…

The radiative decay b to s gamma is examined in the Standard Model and in nine classes of models which contain physics beyond the Standard Model. The constraints which may be placed on these models from the recent results of the CLEO…

The DONUT collaboration has observed four events in a hybrid emulsion spectrometer consistent with tau neutrino charged-current interactions. The resulting tau lepton is identified by its decay into a single charged particle. The expected…

We consider the bremsstrahlung and model-dependent contributions to the radiative decay $\tau^- \to \pi^-\pi^0\nu_{\tau}\gamma$ in the context of a meson dominance model. We focus on several observables related to this decay, including the…

The secondary $\gamma$ rays emitted following a nuclear reaction are often relatively straightforward to detect experimentally. Despite the large volume of such data, a practical formalism for describing these $\gamma$ rays in terms of…

Rare radiative decays based on b->s+gamma transitions are among the most prominent examples of flavor-changing neutral current processes. They benefit from good theoretical control and experimental accessibility, large sensitivity to…

Searching for neutrinoless double beta decays ($\beta\beta0\nu$) is the only practical way to establish if the neutrinos are their own antiparticles. Due to the smallness of neutrino masses, the lifetime of $\beta\beta0\nu$ is expected to…

We propose a new method to probe the magnetic and electric dipole moments of the $\tau$ lepton using precise measurements of the differential rates of radiative leptonic $\tau$ decays at high-luminosity $B$ factories. Possible deviations of…

We present a calculation of $P\to \gamma^{(\ast)}\gamma^{(\ast)}$ processes, where $P=\pi^0,\ \eta,\ \eta'$, at the one-loop level up to and including next-to-next-to-leading order (NNLO) in large-$N_c$ chiral perturbation theory. The…

We present measurements of the branching fractions of 3-prong and 5-prong tau decay modes using a sample of 430 million tau lepton pairs, corresponding to an integrated luminosity of 468 fb-1, collected with the BaBar detector at the PEP-II…

Solar neutrinos can interact with the source isotope in neutrinoless double beta decay experiments through charged current and neutral current interactions. The charged-current product nucleus will then beta decay with a Q-value larger than…

We use a set of Monte Carlo simulations to follow the cascade produced by a primary electron of energy E_in in the intergalactic medium. We choose E_in=3-10 keV as expected from the decay of one of the most popular Warm Dark Matter (WDM)…

The background induced by radioactive impurities of $^{208}\rm Tl$ and $^{214}\rm Bi$ in the source of the double beta experiment NEMO-3 has been investigated. New methods of data analysis which decrease the background from the above…

We present a search for the decay B+ -->tau+ nu using 467.8 x 10^6 B B pairs collected at the Y(4S) resonance with the BaBar detector at the SLAC PEP-II B-Factory. We select a sample of events with one completely reconstructed B- in the…

We examine in detail the semi-leptonic decay $\Lambda_b \to \Lambda_c \tau{\bar \nu}_{\tau}$, which may confirm previous hints, from the analogous $B$ decay, of a new physics beyond the standard model. First of all, starting from rather…

We perform a theoretical analysis of the semileptonic decays $\eta^{(\prime)} \to \pi^0 \ell^+ \ell^-$ and $\eta' \to \eta \ell^+ \ell^-$, where $\ell = e, \mu$, via a charge-conjugation-conserving two-photon mechanism. The underlying form…

The KATRIN experiment is designed to measure the absolute neutrino mass scale with a sensitivity of 200 meV at 90% C.L. by high resolution tritium beta-spectroscopy. A low background level of 10 mHz at the beta-decay endpoint is required in…