Related papers: Atomic Physics Constraints on the X Boson
The virtual massive gauge boson effects on several observables in the process of charged fermion pairs production at $e^+e^-$ colliders are computed up to the TeV energy range in the Standard Model, working in the ``$Z$-peak subtracted''…
We investigate here ground state properties of atoms, in which substitute fermions -- electrons by bosons, e.g. $\pi $ - meson. We perform some calculations in the frame of modified Hartree-Fock (HF) equation. The modification takes into…
Newly calculated bounds on the strength of the coupling of an electron to a proton or a neutron by a fifth force are presented. These results are derived from the high precision spectroscopic data currently available for hydrogen,…
The present work deals with the e+ e- pair production in the d(p,e+e-)3He and d(n,e+ e-)3H processes, in order to evidentiate possible effects due to the exchange of a hypothetical low-mass boson, the so-called X17. These processes are…
The "proton size puzzle" and the "muon anomalous moment problem" are incomplete descriptions of significant discrepancies of Standard Model calculations with experiments. What is particularly new is that the experiments and theory confront…
We study the impact of the coupling of neutrinos with a new light neutral gauge boson, $Z^\prime$, with a mass of less than 500 {\rm MeV} in FASER$\nu$ experiment. Scenarios in which a light gauge boson is coupled to neutrinos are motivated…
In quantum interferometry, it is vital to control and utilize nonlinear interactions for achieving high-precision measurements. Attribute to their long coherent time and high controllability, ultracold atoms including Bose condensed atoms…
We report on a neutron particle physics experiment, which provides for the first time an upper limit on the strength of an axial coupling constant for a new light spin 1 boson in the millimeter range. Such a new boson would mediate a new…
The effect of inelastic excitation of exotic light projectiles (proton- as well as neutron-rich) $^{17}$F and $^{11}$Be on fusion with heavy target has been studied at near-barrier energies. The calculations have been performed in the…
For the first time, the nuclear effects in the reaction \nu p -> \mu^- p \pi^+ on bound protons are investigated at E_\nu = 9 GeV and the effective atomicweight A = 21 of the composite nuclear target using the data obtained with SKAT bubble…
A quantum molecular model for fermions is investigated which works with antisymmetrized many-body states composed of localized single-particle wave packets. The application to the description of atomic nuclei and collisions between them…
Regular sequences of narrow peaks have been observed in the missing mass spectra in the reactions pp --> p pi^+ X and pd --> ppX_1 below pion-production threshold. They are interpreted in the literature as manifestations of supernarrow…
Mixed fermion-boson stars are stable, horizonless, everywhere regular solutions of the coupled Einstein-(complex, massive) Klein-Gordon-Euler system. While isolated neutron stars and boson stars are uniquely determined by their central…
Measurements of light hadron production in ultrarelativistic nuclear collisions provide essential insight into final-state effects arising from both hot and cold nuclear matter. They probe collective behavior, hadronization via…
The nuclear symmetry energy at densities above saturation density ($\rho_0\sim 0.16 fm^{-3}$) is poorly constrained theoretically and very few relevant experimental data exist. Its study is possible through Heavy Ion Collisions (HIC) at…
Being inspired by a phenomenological success of a charged lepton mass formula, a model with U(3)-family nonet Higgs bosons is proposed. Here, the Higgs bosons $\phi_L$ ($\phi_R$) couple only between light fermions (quarks and leptons) $f_L$…
Proto-neutron stars formed during core-collapse supernovae are hot and dense environments that contain a sizable population of muons. If these interact with new long-lived particles with masses up to roughly 100 MeV, the latter can be…
Pairing gaps for fermionic atoms in harmonic oscillator traps are calculated for a wide range of interaction strengths and particle number, and compared to pairing in nuclei. Especially systems, where the pairing gap exceeds the level…
We examine the physics of two, three, and four heavy fermions interacting with a single light fermion via short-range interactions. Four-particle bosonic Efimov states have proven important experimentally and also been the subject of…
We identify potential sources of decoherence for $U(1)$ gauge bosons from a cosmological standpoint. Besides interactions with different species in the cosmological medium, we also consider effects due to the expansion of the Universe,…