相关论文: Spin-dependent $\mu \to e$ conversion

The effect of central, tensor and spin-isospin nucleon-nucleon correlations upon semi-exclusive ^{16}O(e,e'p) reactions is studied for Q^2 and Bjorken x values in the range $0.2 \lesssim Q^2 \lesssim 1.1 (GeV/c)^2$ and 0.15 $\lesssim$ x…

Together with the existence of new neutral gauge bosons, models based on extended gauge groups (rank $> 4$) often predict also new charged fermions. A mixing of the known fermions with new states with {\it exotic} weak-isospin assignments…

The symmetrized contribution of E-type spin-rotation interaction to conversion between spin modifications of E- and A_1-types in molecules with C_{3v}-symmetry is considered. Using the high-J descending of collisional broadening for…

We show that the precise determination of the Tau magnetic properties is possible in the next generation accelerators, specially at B/Flavour factories. We define spin correlation observables suitable to extract the real part of the…

The variation of the coherent branching ratio $R_{\mu e}$ (ratio of the $\mu^-\to e^-$ reaction rate divided by the total muon-capture rate) through the periodic table is studied by using exact muon wave functions. It was found that, by…

Using an effective lagrangian description we analyze possible new physics contributions to the most relevant muon number violating processes: $\mu \to e \gamma$ and $\mu$--$e$ conversion in nuclei. We identify a general class of models in…

We prove that the {\em gauge dependent} gluon spin, gluon and quark orbital angular momenta operators have {\em gauge invariant} expectation values on hadron states with {\em definite} momentum and polarization, therefore the conventional…

We investigate the effect of different forms of relativistic spin coupling of constituent quarks in the nucleon electromagnetic form factors. The four-dimensional integrations in the two-loop Feynman diagram are reduced to the null-plane,…

In this article, we study control of electron-nuclear spin dynamics at magnetic field strengths where the Larmor frequency of the nucleus is comparable to the hyperfine coupling strength. The quantization axis for the nuclear spin differs…

We compute the spin-dependent and spin-independent structure functions of the forward virtual-photon Compton tensor of the proton at one loop using heavy baryon effective theory including the Delta particle. We compare with previous results…

Lepton-flavor-violating decays of light pseudoscalars, $P=\pi^0,\eta,\eta'\to\mu e$, are stringently suppressed in the Standard Model up to tiny contributions from neutrino oscillations, so that their observation would be a clear indication…

A theoretical model of nuclear spin conversion in molecules controlled by an external electromagnetic radiation resonant to rotational transition has been developed. It has been shown that one can produce an enrichment of spin isomers and…

The effects of varying the spin-orbit and tensor components of a realistic interaction on $M1$ excitation rates and $B(E2)'s$ are studied on nuclei in the $0p$ and $1s-0d$ shells. Not only the total $M1$ but also the spin and orbital parts…

We report on the first example of quantum coherence between the spins of muons and quadrupolar nuclei. We observe this effect in vanadium intermetallic compounds which adopt the A15 crystal structure, and whose members include all…

In physical experiments, reference frames are standardly modelled through a specific choice of coordinates used to describe the physical systems, but they themselves are not considered as such. However, any reference frame is a physical…

We summarize recent work to develop an effective theory of muon-to-electron conversion, based on a complete set of low-energy effective operators that are developed from a systematic expansion in velocities and momenta. The expansion…

We analyze next-to-leading order (NLO) corrections and uncertainties for coherent $\mu-e$ conversion . The analysis is general but numerical results focus on ${}^{27}\textrm{Al}$, which will be used in the Mu2E experiment. We obtain a…

In a few years, the COMET experiment at J-PARC and the Mu2e experiment at Fermilab will probe the $\mu-e$ conversion rate in the vicinity of $\mathcal{O}(10^{-17})$ for an Al target with high experimental sensitivity. Within the framework…

Electric control of spins has been a longstanding goal in the field of solid state physics due to the potential for increased efficiency in information processing. This efficiency can be optimized by transferring spintronics to the atomic…

In Effective Field Theory, we describe $\mu\leftrightarrow e$ flavour changing transitions using an operator basis motivated by experimental observables. In a six-dimensional subspace probed by $\mu \to e \gamma$, $\mu \to 3e$ and $\mu\to…