相关论文: Radiative Corrections and the Universality of the …
Two loop electroweak corrections to b --> s gamma decays are computed. Fermion and photonic loop effects are found to reduce R = BR(b --> s gamma)/BR(b --> c e nu) by 8+-2% and lead to the standard model prediction BR(B --> X_s gamma)=(3.28…
Using the general connection between the upper limit on the neutrino mass and the upper limits on certain types of non-Standard Model interaction that can generate loop corrections to the neutrino mass, we derive constraints on some…
We investigate the radiative process of the $\Lambda_b\rightarrow \Lambda \gamma$ in the standard model as well as models with one or two compact universal extra dimensions. Using the form factors entered to the low energy matrix elements,…
In co-annihilation scenarios, the weakly interacting dark matter particle (WIMP) is close in mass to another particle that can decay into the WIMP. As a result, both particles freeze out at roughly the same time in the early universe, and…
Ultracold neutrons are great experimental tools to explore the gravitational interaction in the regime of quantized states. From a theoretical perspective, starting from a Dirac equation in curved spacetime, we applied a perturbative scheme…
There is a well known anomaly between the value of the Fermi decay constant extracted from super-allowed Fermi beta-decay of nuclear isotriplets and that required by unitarity of the Cabibbo-Kobayashi-Maskawa matrix. This discrepancy…
Radiative corrections are crucial for modern high-precision physics experiments, and are an area of active research in the experimental and theoretical community. Here we provide an overview of the state of the field of radiative…
This report is dedicated to the investigation of radiative neutron decay. The theoretical spectrum of radiative gamma quanta, calculated within the framework of the standard electroweak interaction model, is compared with our experimental…
We present a nonrelativistic transition potential for the weak strangeness-changing reaction $\Lambda N \to NN$. The potential is based on a one meson exchange model (OME), where, in addition to the long-ranged pion, the exchange of the…
Nuclear beta decays between (J^pi,T) = (0^+,1) analog states yield the best value for the Vud element of the Cabibbo-Kobayashi-Maskawa matrix. Current world data establish the corrected Ft values of 14 separate superallowed transitions to a…
We discuss the complete virtual and soft-photonic O(alpha) corrections to AA -> W+W- within the electroweak Standard Model for arbitrary polarized photons. In the on-shell renormalization scheme for fixed M_W no leading corrections…
Recently Barbieri, et al. have introduced a formalism to express the deviations of electroweak interactions from their standard model forms in "universal" theories, i.e. theories in which the corrections due to new physics can be expressed…
At temperatures below the critical temperature of superfluid phase transition baryonic matter emits neutrinos by breaking and recombination of Cooper pairs formed in the condensate. The strong interactions in the nuclear medium modify the…
The contribution of the weak interaction to the hyperfine splitting of the ground state of muonium is investigated. The amplitudes of the one- and two-quantum exchange determined by the Z and W bosons are calculated. One-loop corrections in…
A coarse-grained description of the restricted primitive model is considered in terms of the local charge- and number-density fields. Exact reduction to a one-field theory is derived, and exact expressions for the number-density correlation…
We present here the update of the Unitarity Triangle (UT) analysis performed by the UTfit Collaboration within the Standard Model (SM) and beyond. Continuously updated flavour results contribute to improving the precision of several…
In a wide class of models -- including the standard model -- flavor-changing neutral currents are suppressed by an approximate chiral symmetry of the low-energy lagrangian. This symmetry allows the derivation of general relations among…
The theoretical status of NNLO QCD corrections to the inclusive radiative anti-B -> X_s gamma decay in the standard model is briefly overviewed. Emphasis is put on recent results for three-loop fermionic corrections to matrix elements of…
We derive a relativistic expression for neutrino energy losses caused by the direct Urca processes in degenerate baryon matter of neutron stars. We use two different ways to calculate the emissivity caused by the reactions to our interest.…
The explicit energy dependence of the single particle self-energy (dispersive effects), due to short range correlations, is included in the treatment of neutron matter superfluidity. The method can be applied in general to strong…