相关论文: The D coefficient in neutron beta decay in effecti…
The traditional Fermi function ansatz for nuclear beta decay describes enhanced perturbative effects in the limit of large nuclear charge $Z$ and/or small electron velocity $\beta$. We define and compute the quantum field theory object that…
The angular correlation of the electrons in the neutrinoless double beta decay ($0\nu2\beta$) is calculated taking into account the nucleon recoil, the $S$ and $P$-waves for the electrons and the electron mass using a general Lorentz…
We calculate higher order corrections for the three-nucleon system up to next-to-next-to-leading within an effective field theory with contact interactions alone. We employ a subtraction formalism previously developed and for which it has…
We describe two recent developments of the radiative correction theory in semileptonic beta decays. For neutron, a novel dispersive analysis of the $\gamma W$-box diagram making use of neutrino scattering data leads to an improved precision…
In this paper we study in detail the neutrinoless double beta decay in left-right symmetric models with right-handed gauge bosons at TeV scale which is within the presently accessible reach of colliders. We discuss the different diagrams…
We present complete formulas of the allowed and first-forbidden transitions of the nuclear beta decay taking into account the recoil-order and induced currents up to the next-to-leading order (NLO). The longitudinal part of the vector…
We analyze the decays $K\to\pi\ell\nu$ and $P\to\ell\nu$ ($P=K,\pi$, $\ell=e,\,\mu$) using a low-energy Effective-Field-Theory approach to parametrize New Physics and study the complementarity with baryon $\beta$ decays. We then provide a…
Baryon number violating (BNV) nucleon decays into three leptons provide a unique probe of BNV interactions beyond the conventional two-body modes involving a single lepton and a light meson. In a previous work [Nucleon decays into three…
Radiative corrections are essential for an accurate determination of $V_{ud}$ from superallowed $\beta$ decays. In view of recent progress in the single-nucleon sector, the uncertainty is dominated by the theoretical description of…
The neutrinoless double beta decay is analyzed using a general Lorentz invariant effective Lagrangian for various decaying nuclei of current experimental interest: $^{76}$Ge, $^{82}$Se, $^{100}$Mo, $^{130}$Te, and $^{136}$Xe. We work out…
In the framework of the Standard Model (SM) a theoretical description of the neutron beta decay is given at the level of 10^{-5}. The neutron lifetime and correlation coefficients of the neutron beta decay for a polarized neutron, a…
We consider tritium beta decay with additional emission of light pseudoscalar or vector bosons coupling to electrons or neutrinos. The electron energy spectrum for all cases is evaluated and shown to be well estimated by approximated…
The cross section of neutron-deuteron radiative capture $n d\to {^3H}\gamma$ is calculated at energies relevant to Big-Bang nucleosynthesis ($ 20 \leq E \leq 200 $ Kev) with pionless Effective Field Theory. At these energies, magnetic…
We compute the $\bar d - \bar u$ asymmetry in the proton in chiral effective theory, including both nucleon and $\Delta$ degrees of freedom, within both the relativistic and heavy baryon frameworks. In addition to the distribution at $x>0$,…
We calculate the contributions of weak magnetism and proton recoil of order O(E^2_e/m^2_N)~10^{-5}, i.e. to next-to-next-to-leading order in the large nucleon mass expansion, to the neutron lifetime and correlation coefficients of the…
Limits from neutron beta decay on parameters describing physics beyond the Standard Model are presented. New Physics is described by the most general Lorentz invariant effective Hamiltonian involving vector, scalar and tensor operators and…
We reanalyse hyperon beta decay data to extract the corresponding F and D values. We show that flavour symmetry breaking effects lead naturally to a reduction of the $F/D$ ratio. For proton and neutron our analyses suggests $F/D = 0.49 \pm…
A method for the general analysis of the sensitivities of neutron beta-decay experiments to manifestations of possible deviations from the Standard model is proposed. In a consistent fashion, we take into account all known (radiative and…
We propose the transverse velocity ($\beta_T$) dependence of the anti-deuteron to deuteron ratio as a new observable to search for the QCD critical point in heavy-ion collisions. The QCD critical point can attract the system evolution…
The amplitude for the neutrinoless double $\beta$ ($0\nu\beta\beta$) decay of the two-neutron system, $nn\to ppe^-e^-$, constitutes a key building block for nuclear-structure calculations of heavy nuclei employed in large-scale…