Related papers: Muon spin force
We investigate the possibility of explanation for the muon anomalous magnetic moment $g_\mu-2$ in a left-right model with an inverse seesaw mechanism. We emphasize that the observed deviation from the Standard Model predictions can be…
We consider the muon anomalous magnetic moment $a_{\mu}$ in the string models with dilaton domination with two different string scales : the usual GUT scale and the intermediate scale. After imposing the direct search limits on the lightest…
The proton spin problem triggered by the EMC experiment and its present status are closely examined. Recent experimental and theoretical progresses and their implications are reviewed. It is pointed out that the sign of the sea-quark…
Among the four fundamental forces, only gravity does not couple to particle spins according to the general theory of relativity. We test this principle by searching for an anomalous scalar coupling between the neutron spin and the Earth…
Recent measurements of the proton radius using the Lamb shift in muonic hydrogen are troublingly discrepant with values extracted from hydrogen spectroscopy and electron-proton scattering experiments. This discrepancy, which differs by more…
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…
The recent measurement on the muon anomalous magnetic moment $a_\mu$ shows a $2.6\sigma$ deviation from the standard model value. We show that it puts strong constraints on the parameter space of the two-higgs doublet model (2HDM) II. The…
The electron and muon anomalous magnetic moments (AMM) are measured in experiments and studied in the Standard Model (SM) with the highest precision accessible in particle physics. The comparison of the measured quantity with the SM…
The leading-order contribution of a new boson to the muonic fine-structure anomaly, which refers to a discrepancy between the predicted transition energies and spectroscopic measurements of $\mu-^{90}$Zr, $\mu-^{120}$Sn, and $\mu-^{208}$Pb,…
We present a new measurement of the positive muon magnetic anomaly, $a_\mu \equiv (g_\mu - 2)/2$, from the Fermilab Muon $g\!-\!2$ Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons…
The possible existence of short-range forces between unpolarized and polarized spin-1/2 particles has attracted the attention of physicists for decades. These forces are predicted in various theories and provide a possible new source for…
The spin susceptibility in pure neutron matter is computed from auxiliary field diffusion Monte Carlo calculations over a wide range of densities. The calculations are performed for different spin asymmetries, while using twist-averaged…
Theories beyond the standard model involving a sub-GeV-scale vector $Z_d$ mediator have been largely studied as a possible explanation of the experimental values of the muon and electron anomalous magnetic moments. Motivated by the recent…
We revisit the muon magnetic moment (g-2) in the context of Composite Higgs models and Technicolor, and provide general analytical expressions for computing the muon magnetic moment stemming from new fields such as, neutral gauge bosons,…
The anomalous magnetic moment of the muon is evaluated in the D-brane realization of the Standard Model. It is pointed out that the massive anomalous U(1) gauge bosons predicted, give extra contributions that are compatible with current…
The computation of the muon anomalous magnetic moment in the framework of a proposed extension of the Standard Model to 5 dimensions is presented. The result (a small correction with respect to the SM prediction) is briefly discussed.
The reported discrepancy of the muon abnormal magnetic moment $a_\mu^{}$ has impacts on the low energy phenomenology. In this paper we calculate the corrections to $a_\mu$ in the standard model extended by the TeV scale seesaw models. We…
The current status of the Standard Model prediction for the anomalous magnetic moment of the muon is briefly reviewed and compared with the present experimental value.
We present a more stringent upper limit on long-range axion-mediated forces obtained by the QUAX-g$_p$g$_s$ experiment, located at the INFN - Laboratori Nazionali di Legnaro. We investigate the possible coupling between the electron spins…
In the framework of a recently proposed extension of the Standard Model, with N=1 SuperSymmetry in 5 dimensions, compactified on R^1/(Z_2 x Z'_2), we compute the muon anomalous magnetic moment at one loop to order (M_W R)^2, where R is the…