相关论文: On the Muon Decay Parameters
We analyse the sensitivity of all experimentally observable asymmetries and energy distributions for the neutron beta-decay with a polarised neutron and unpolarised decay proton and electron and the lifetime of the neutron to contributions…
In this paper we study the noncommutative effects to the lepton spectrum from the decay of a polarized top quark. It is shown that the lowest contribution comes from the quadratic terms of the noncommutative parameter. The deviations from…
An equation for the reduced density matrix which describes a free particle, that is interacting with a linearly dissipative medium, is derived using the total Hamiltonian, and without resorting to any artificial model. A Master equation is…
Double-lepton polarization asymmetries in the (B -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian including all possible forms of the interaction. The dependencies of the…
We discuss polarization characteristics of the deuteron disintegration near the threshold energy. Due to the small relative energy of the outgoing $np$ pair, the dominant amplitude for this process is a 1+ -> 0^+ transition. Relativistic…
A cartoon is drawn how and why to define and extract the energy dependence of the nucleon polarisabilities from low energy Compton scattering on the nucleon. The information dynamical polarisabilities contain about the low energy degrees of…
We give a pedagogical introduction to the rich phenomenology of hadronic tau decays. These decays provide a unique window into the interplay of electroweak and strong interactions at low energies, as they occur primarily via $W$ exchange…
The amplitude for ordinary muon capture on the proton is evaluated, through the first four orders in the expansion parameter, in a manifestly Lorentz invariant form of baryon chiral perturbation theory. Expressions for the low energy…
One of the key assumptions of the Standard Model of fundamental particles is that the interactions of the charged leptons, namely electrons, muons, and taus, differ only because of their different masses. While precision tests comparing…
Transport properties of degenerate relativistic electrons along quantizing magnetic fields in neutron star crusts are considered. A kinetic equation is derived for the spin polarization density matrix of electrons. Its solution does not…
Radiative muon and tau lepton decays are described within the model-independent approach with the help of generalized Michel parameters. The exact dependence on charged lepton masses is taken into account. The results are relevant for…
The electromagnetic interactions of electrons and muons can be described to very high accuracy within the framework of standard theory, in particular within the hydrogen-like muonium atom. Therefore precision measurements allow to test…
An alternative method to the density matrix formalism for the derivation of general expressions of the interaction of polarized atoms with polarized photons and electrons is presented. The expression for the cross-section describing the…
The spectrum of very fast electrons in five-lepton decay $\mu^+\to e^-e^+e^+\nu\bar\nu,$ that is the main background decay at the study of the muonium-antimuonium conversion in vacuum, is considered. The essential decrease of the spectral…
A model-independent expression for the Dalitz plot of the semileptonic decays of a neutral kaon $K_{\mu 3}^0$, including radiative corrections to order $\mathcal{O}[(\alpha / \pi )(q/M_1)]$, where $q$ is the four-momentum transfer and $M_1$…
The usage of channelling radiation arising from a high energy electron beam traversing a crystal for the production of an intense low emittance muon beam is investigated. The optimal energy and divergence of the electron beam are computed…
Dipolar interaction between the magnetic moments of electrons is studied as a source for electron spin decay in quantum dots or arrays of quantum dots. This magnetic interaction will govern spin decay, after other sources, such as the…
The relative immunity of muons to synchrotron radiation suggests that they might be used in place of electrons as probes in fundamental high-energy physics experiments. Muons are commonly produced indirectly through pion decay by…
A positive muon is a spin-1/2 particle. Beams of muons with all their spins polarized can be prepared and subsequently implanted in various types of condensed matter. The subsequent precession and relaxation of their spins can then be used…
We do the spectral analysis of the Hamiltonian for the weak leptonic decay of the gauge bosons W+/-. Using Mourre theory, it is shown that the spectrum between the unique ground state and the first threshold is purely absolutely continuous.…