相关论文: An updated view on the ATOMKI nuclear anomalies
The QCD axion remains experimentally viable in the mass range of O(10 MeV) if (i) it couples predominantly to the first generation of SM fermions; (ii) it decays to $e^+ e^-$ with a short lifetime $\tau_a\lesssim 10^{-13}\,$s; and (iii) it…
Motivated by recently reported anomalies in a decay of an excited state of beryllium by the Atomki collaboration, we study a radiative seesaw model with gauged $B-L$ symmetry and a $Z_2$ parity. Assuming that the anomalies originate from…
We reconsider parity violation experiments in atomic hydrogen and deuterium in the light of existing tests of the Electroweak interactions, and assess whether new experiments, using improved experimental techniques, could make useful…
The mystery of dark matter remains an unsettled problem of particle physics. On top of that, experiments show a persistent contention of the muon anomalous magnetic moment (AMM) relative to the Standard Model (SM) prediction. In this work,…
Light new particles can be emitted in decays of excited nuclear states. Experiments analyzing such transitions and incorporating high-resolution detectors can be sensitive to new MeV-scale physics at a level competitive with upcoming…
A measurement of parity violation in the hyperfine structure of $^{138}$Ba$^{19}$F [E. Altunta\c{s} et al. Phys. Rev. Lett. 120, 142501 (2018)] is reinterpreted with electronic structure calculations in terms of beyond Standard Model vector…
A permanent electric dipole moment (EDM) of a particle or system is a separation of charge along its angular-momentum axis and is a direct signal of T-violation and, assuming CPT symmetry, CP violation. For over sixty years EDMs have been…
Measurements of parity-violating longitudinal analyzing powers Az (normalized asymmetries) in polarized proton-proton scattering and in polarized neutron capture on the proton (n+p -> d+gamma) provide a unique window on the interplay…
We discuss whether the NuTeV anomaly can be explained, compatibly with all other data, by QCD effects (maybe, if the strange sea is asymmetric, or there is a tiny violation of isospin), new physics in propagators or couplings of the vector…
Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has…
The new measurement of $W$-boson mass by the CDF collaboration revealed a remarkable $7\sigma$ disagreement with the Standard Model (SM) prediction. If confirmed by other experiments, then the disagreement strongly indicates the existence…
With a design luminosity of 50 ab$^{-1}$ and detectors with tracking capabilities extending beyond 1 m, the Belle II experiment is the perfect laboratory for the search of particles that couple weakly to the Standard Model and have a…
We derive constraints on the couplings of light vector particles to all first-generation Standard Model fermions using leptonic decays of the charged pion, $\pi^+\to e^+ \nu_e X_\mu$. In models where the net charge to which $X_\mu$ couples…
It is shown that the QCD anomaly may lead to an abnormal mixing behavior of the axial vector mesons similar to the pseudoscalar mesons. These mixing effects, involving a gluonic axial vector state, generate a non-vanishing strange quark…
We estimate the values of Yukawa couplings of a light pseudoscalar A with a mass of about 17 MeV, which would explain the $^8Be$ anomaly observed in the Atomki pair spectrometer experiment. The resulting couplings of A to up and down type…
The framed standard model (FSM) predicts a $0^+$ boson with mass around 20 MeV in the "hidden sector", which mixes at tree level with the standard Higgs $h_W$ and hence acquires small couplings to quarks and leptons which can be calculated…
Motivated by the recent XENON1T results, we explore various new physics models that can be discovered through searches for electron recoils in O(keV)-threshold direct-detection experiments. First, we consider the absorption of light bosons,…
The discovery of the atomic electric dipole moment (EDM) would reveal the simultaneous violation of parity (P) and time-reversal (T) invariance. The EDM can be induced by T-odd forces between the nucleus and atomic electrons. As the nuclear…
Quantum phase transitions between competing ground-state shapes of atomic nuclei with an odd number of protons or neutrons are investigated in a microscopic framework based on nuclear energy density functional theory and the…
The anomalous magnetic moment of the muon ($\,a_{\mu}\,$) provides a stringent test of the quantum nature of the Standard Model (SM) and its extensions. To probe beyond the SM physics, one needs to be able to subtract the SM contributions,…