Related papers: Possible Beyond the Standard Model Physics Motivat…
There are several anomalous measurements in the decays induced by the quark level transition $b \to s \mu^+ \mu^-$, which do not agree with the predictions of the Standard Model. These measurements could be considered as signatures of…
Primordial Big-Bang Nucleosynthesis (BBN) tightly constrains the existence of any additional relativistic degrees of freedom at that epoch. However a large asymmetry in electron neutrino number shifts the chemical equilibrium between the…
The uncertainty in the contribution to the Lamb shift in muonic hydrogen, $\Delta E^{subt}$ arising from proton polarizability effects in the two-photon exchange diagram at large virtual photon momenta is shown large enough to account for…
The CDF collaboration has recently reported an updated result on the $W$-boson mass measurement, showing a $7\sigma$ deviation from the standard model prediction. The discrepancy may indicate new contributions to the Fermi coupling…
We investigate the impact of incorporating vector-like leptons into the Standard Model, aiming to address longstanding puzzles related to the anomalous magnetic moments of the muon and electron while maintaining consistency with neutrino…
We measure isotope shifts for five Yb$^+$ isotopes with zero nuclear spin on two narrow optical quadrupole transitions ${}^2S_{1/2} \rightarrow {}^2D_{3/2}$, ${}^2S_{1/2} \rightarrow {}^2D_{5/2}$ with an accuracy of $\sim 300$ Hz. The…
Laser spectroscopy of the Lamb shift (2S-2P energy difference) in light muonic atoms or ions, in which one negative muon $\mu^-$ is bound to a nucleus, has been performed. The measurements yield significantly improved values of the…
The muon (g-2) experiment at BNL has completed four data runs for the positive muon, beginning in 1997 and has just finished its first run for the negative muon. Recently the analysis of a 1.3 ppm result based on the 1999 run was completed…
The Fermilab Muon $g-2$ experiment recently reported its first measurement of the anomalous magnetic moment $a_\mu^{\textrm{FNAL}}$, which is in full agreement with the previous BNL measurement and pushes the world average deviation $\Delta…
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…
The magnetic dipole interaction played a central role in the development of QED, and continued in that role for the Standard Model. The muon anomalous magnetic moment has served as a benchmark for models of new physics, and the present…
In view of a possible upgrade of the RHIC-Spin program at BNL, concerning both the machine and the detectors, we give some predictions concerning the potentialities of New Physics detection with polarized proton beams. We focus on…
A review of the theoretical and experimental values for the charged lepton (electron and muon) anomalous magnetic moment $a_l= (g_l-2)/2$ is presented. Employing the most accurate value for the fine structure constant $\alpha^{-1}=…
The Standard Model of Particle Physics and its description of Nature have been recently challenged by a series of precision measurements performed via different accelerator machines. Statistically significant anomalies emerged in the heavy…
In these proceedings I present a personal perspective of the challenges for new physics (NP) searches in the flavour sector. Since the CKM mechanism of flavour violation has been established to a very high precision, we know that physics…
Significant discrepancies between the different determinations of the Cabibbo angle have been observed. Here, we point out that this "Cabibbo-angle anomaly" can be explained by lepton flavour universality (LFU) violating New Physics (NP) in…
We show that new physics explanations of the muon $g-2$ anomaly by the contributions of new leptons mediated by the standard model Higgs boson necessarily lead to large rates for $\mu^+ \mu^- \to hh$ and $\mu^+ \mu^- \to hhh$ irrespectively…
Precise measurement of the Electric Dipole Moment (EDM) and anomalous magnetic moment ($g$-2) of particles are important tests of Beyond Standard Model (BSM) physics. It is generally believed that the tau lepton couples more strongly to BSM…
The Muon $g-2$ collaboration at Fermilab has announced their final result of the anomalous magnetic moment of the muon. By adopting the lattice-QCD evaluation of the leading-order hadronic-vacuum-polarization, this result is now in…
The main possibilities of investigation of leptons and bosons production in interaction of polarized photons are considered. The usage of $\gamma\gamma\to f\bar{f}[+\gamma]$ reactions for the luminosity measurement on linear photon collider…