相关论文: Muon lifetime and muon capture
We report on our progress toward the computation of the $\pi^0$, $\eta$ and $\eta^{\prime}$ transition form factors using staggered quarks on $N_f=2+1+1$ gauge ensembles generated by the Budapest-Marseille-Wuppertal collaboration. These…
We scrutinize recent findings on the charged-pion elastic form factor and the form factors entering in neutral-meson-to-photons transition amplitudes within the framework of QCD sum rules.
The Muon g-2 Experiment at Fermi National Accelerator Laboratory (FNAL) has measured the muon anomalous precession frequency $\omega_a$ to an uncertainty of 434 parts per billion (ppb), statistical, and 56 ppb, systematic, with data…
A significant challenge in zero-field muSR experiments arises from the uncertainty in the muon site. It is possible to calculate the dipole field (and hence precession frequency nu) at any particular site given the magnetic moment mu and…
Having calculated the light-cone wave function of the pseudoscalar meson by using two equivalent and fully covariant methods, we generalize such methods to the valence Fock states of the vector meson in the light-cone formalism. We…
The aim of the FAMU experiment is to realize the first measurement of the hyperfine splitting (hfs) in the 1S state of muonic hydrogen $\Delta E^{hfs}_{1S}$, by using the RIKEN-RAL intense pulsed muon beam and a high-energy mid-infrared…
From the famous experiments of Stern and Gerlach to the present, measurements of magnetic dipole moments, and searches for electric dipole moments of ``elementary'' particles have played a major role in our understanding of sub-atomic…
Due to improvements in computer performance and algorithms, the rapidly increasing cost for unquenched Wilson-type fermions with lighter quarks has been ameliorated and new simulations are now possible. Here we present results using two…
In the framework of a dynamical gluon mass model recently developed, we investigate the effects of two essential parameters in the description of elastic $pp$ and $\bar{p}p$ data at high energies: the soft Pomeron intercept and the…
Given the eventuality of neutrino and muon factories in the foreseeable future, all possible 2-to-2 processes involving two neutrinos, whether Dirac or Majorana ones, and two charged fermions are considered on the basis of the most general…
The Muon g-2 Experiment (E989) at Fermilab is seeking to measure the anomalous magnetic moment of muon ($a_{\mu}$) with a precision of 140 parts-per-billion (ppb) and aiming to resolve the discrepancy between the E821 measurement and the…
Weak $B^-\rightarrow D^0, \pi^0$ and $D^-\rightarrow {K}^0, \pi^0$ transition form factors are described in both the space- and time-like momentum transfer regions, within a constituent-quark model. Neutrino-meson scattering and…
The Muon g-2 Experiment at Fermilab will measure the anomalous magnetic moment of the muon to a precision of 140 parts per billion, which is a factor of four improvement over the previous E821 measurement at Brookhaven. The experiment will…
In a recent preprint Cheon and Cheoun have derived from a chiral model an additional term, not usually appearing in the standard matrix element for radiative muon capture. Using that term they generate a large correction to the RMC spectrum…
I discuss the history of the muon $(g-2)$ measurements, beginning with the Columbia-Nevis measurement that observed parity violation in muon decay, and also measured the muon $g$-factor for the first time, finding $g_\mu=2$. The theoretical…
This paper elucidates the anomalous decay of the muon ascribed to extended waves. Due to a large overlap of the parent and daughters, the transition amplitude and probability for the neutrinos are modified from the standard formula. A…
I report on the progress of two new muon anomalous magnetic moment experiments, which are in advanced design and construction phases. The goal of Fermilab E989 is to reduce the experimental uncertainty of $a_\mu$ from Brookhaven E821 by a…
We perform a calculation of the $\tau^- \to \nu_{\tau} M_1 M_2$, with $M_1, M_2$ either pseudoscalar or vector mesons using the basic weak interaction and angular momentum algebra to relate the different processes. The formalism also leads…
One of the main goals of the COMPASS experiment at CERN is the determination of the gluon contribution to the nucleon spin. To achieve this goal COMPASS uses a naturally polarised muon beam with an energy of 160 GeV and a fixed polarised…
Using simulated data, obtained with the FLUKA code, we derive empirical regularities about the propagation and stopping of low-energy negative muons in hydrogen and selected solid materials. The results are intended to help the preliminary…