相关论文: Decays of Positronium

We consider the decay of positronium to a neutrino-antineutrino accompanied by a single photon. Since the neutrino pair go undetected, this appears as a single photon decay of positronium. These decay channel are mediated through the…

The manuscript by Berezhiani (arXiv:1812.11089) proposes a model that has the neutron decaying into a mirror neutron with a branching fraction of 1%, alleviating the tension between neutron lifetime measurements in beam vs bottle…

We revisit the neutron lifetime puzzle, a discrepancy between beam and bottle measurements of the weak neutron decay. Since both types of measurements are realized at different times after the nuclear production of free neutrons, we argue…

Recently, the O(alpha) and O(alpha^3 ln(alpha)) radiative corrections to the orthopositronium lifetime have been presented in closed analytical form, in terms of basic irrational numbers that can be evaluated numerically to arbitrary…

I present a grand view of some of the main particle physics challenges from a neutrino perspective. After a brief review of the current status of neutrino physics, I illustrate the possible role neutrinos can play in the elucidation of…

Theoretical positron lifetime values have been calculated systematically for most of the elements of the Periodic Table. Self-consistent and non-self-consistent schemes have been used for the calculation of the electronic structure in the…

If massive sterile neutrinos exist, their decays into photons and/or electron-positron pairs may give rise to observable consequences. We consider the possibility that MeV sterile neutrino decays lead to the diffuse positron annihilation…

We investigate a scenario in which neutrinos are coupled to a pseudoscalar degree of freedom $\ph$ and where decays $\nu_1 \to \nu_2+\ph$ and inverse decays are the responsible mechanism for obtaining equilibrium. In this context we discuss…

Para positronium composed by an electron-antielectron pair is an unstable system decaying into two high energetic gamma photons via self annihilation process, due to the conservation of the charge conjugation parity in electromagnetically…

Positronium atoms (Ps) are widely used as a probe to characterize voids or vacancies in non-metallic materials, where Ps annihilation lifetime is strongly modified by pickoff, depending on the size of the trapping cavity and on the…

Using simple physical reasoning we have estimated the wavelengths and line-widths of spectral lines arising from the decays of massive neutrinos. We have, also, to some extent, discussed the possible consequences of these decays in…

Recent proposals have suggested that a previously unknown decay mode of the neutron into a dark matter particle could solve the long lasting measurement problem of the neutron decay width. We show that, if the dark particle in neutron decay…

The decay of the para-positronium into two photons is studied in the framework of a composite Quantum Field Theoretical approach. This amounts to the evaluation of the electron-positron dressing together with the Weinberg compositeness…

Many models of dark matter contain more than one new particle beyond those in the Standard Model. Often heavier particles decay into the lightest dark matter particle as the Universe evolves. Here we explore the possibilities that arise if…

We give an personal overview of some of the unsolved problems related to hyperon decays. We cover nonleptonic decays, radiative decays and magnetic moments. Some of the theoretical issues are also touched upon.

Possible explanations of solar neutrino and atmospheric neutrino anomalies are summarized and future tests discussed.

Positronium, the electron-positron bound state, is described to a good approximation by pure QED. The states of positronium have definite values of C and P. Consequently, positronium is an attractive system for the investigation of possible…

We review the discovery of the neutrino and outline the history of neutrino physics. Many interesting phenomena involving the neutrino are exhibited. We also discuss the long-standing solar neutrino puzzle and the properties of the neutrino…

Experimental measurement of the probability of direct decay of a pion into a positron allows searching for interactions beyond the Standard Model: test of the hypothesis about the universality of the charged current,search for new…

We investigate different neutrino signals from the decay of dark matter particles to determine the prospects for their detection, and more specifically if any spectral signature can be disentangled from the background in present and future…