Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userPrecision radiative corrections to the muon polarization in the semileptonic decay of a charged kaon
82
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
An expression for the Dalitz plot of the semileptonic decay of a charged kaon, including radiative corrections to order O[alpha pi)(q/M_1)], where q is the four-momentum transfer and M_1 is the mass of the decaying kaon, is obtained. Contributions of both the three- and four-body regions are accounted for. Besides, the emitted muon is considered to be polarized so the analysis is also focused on evaluating the radiative corrections to the longitudinal, transverse, and normal polarization components of the muon. The final formulas, with the triple integration of the bremsstrahlung photon variables ready to be performed numerically, are general enough to be used in model-independent experimental analyses whether or not the real photon is discriminated. With the numerical values of the weak form factors and slope parameters of the process, the radiative corrections to the components of the muon polarization are found to be very small compared to their respective uncorrected values.
rate research
Read More
We discuss the theoretical framework required for the computation of radiative corrections to semileptonic decay rates in lattice simulations, and in particular to those for $K_{ell3}$ decays. This is an extension of the framework we have developed and successfully implemented for leptonic decays. New issues which arise for semileptonic decays, include the presence of unphysical terms which grow exponentially with the time separation between the insertion of the weak Hamiltonian and the sink for the final-state meson-lepton pair. Such terms must be identified and subtracted. We discuss the cancellation of infrared divergences and show that, with the QED$_mathrm{,L}$ treatment of the zero mode in the photon propagator, the $O(1/L)$ finite-volume corrections are universal. These corrections however, depend not only on the semileptonic form factors $f^pm(q^2)$ but also on their derivatives $df^pm/dq^2$. (Here $q$ is the momentum transfer between the initial and final state mesons.) We explain the perturbative calculation which would need to be performed to subtract the $O(1/L)$ finite-volume effects.
Radiative muon decay in the kinematics similar to the neutrinoless decay $muto egamma$ is considered. Radiative corrections due to 1-loop virtual photons and emission of additional soft or hard photons are taken into account. Analytical expressions and numerical estimations are presented.
We review some recent progress in the theory of electroweak radiative corrections in semileptonic decay processes. The resurrection of the so-called Sirlins representation based on current algebra relations permits a clear separation between the perturbatively-calculable and incalculable pieces in the $mathcal{O}(G_Falpha)$ radiative corrections. The latter are expressed as compact hadronic matrix elements that allow systematic non-perturbative analysis such as dispersion relation and lattice QCD. This brings substantial improvements to the precision of the electroweak radiative corrections in semileptonic decays of pion, kaon, free neutron and $J^P=0^+$ nuclei that are important theory inputs in precision tests of the Standard Model. Unresolved issues and future prospects are discussed.
This paper is devoted to the measurement of the fully inclusive absolute branching ratios of the charged kaon semileptonic decays, $K^{pm}topi^0e^pm u(gamma)$ and $K^pm to pi^0mu^pm u(gamma)$. The measurements have been done using a tag technique, employing the two-body decays, $K^pm to mu^pm u$ and $K^pm to pi^pmpi^0$, and using a sample of about 410 pb$^{-1}$ collected during the 2001 and 2002 data taking of the KLOE experiment at Daphne, the Frascati $phi$-factory. The results obtained are BR(K$^pm_{e3}$) = $0.04965 (38)_{Stat} (37)_{Syst}$ and BR(K$^pm_{mu3}$) = $0.03233 (29)_{Stat} (26)_{Syst}$.
The order - alpha radiative corrections to the differential decay rate of polarized orthopositronium are obtained. Their influences on the three photons coincidence rate as a function of positronium polarization is considered.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
