Related papers: Eta Decay and Muonic Puzzles
We investigate the hidden strange light baryon-meson system. With the resonating-group method, two bound states, $\eta'-N$ and $\phi-N$, are found in the quark delocalization color screening model. Focusing on the $\phi-N$ bound state…
A search for a light pseudoscalar Higgs boson (A) produced in association with bottom quarks and decaying into a muon pair is reported. The search uses 19.7 inverse femtobarns of proton-proton collisions at a center-of-mass energy of 8 TeV,…
The SUSY contribution to the muon magnetic moment anomaly, a_mu^SUGRA, and the electron electric dipole moment, d_e, is discussed within the framework of a modified mSUGRA model where the magnitudes of the soft breaking masses are…
Neutrino masses arising from the spontaneous violation of ungauged lepton-number are accompanied by a physical Goldstone boson, generically called Majoron. In the high-density supernova medium the effects of Majoron-emitting neutrino decays…
We report on a search for a resonance $X$ decaying to a pair of muons in $e^{+}e^{-}\rightarrow \mu^+ \mu^- X$ events in the 0.212-9.000 GeV/$c^{2}$ mass range, using 178 fb$^{-1}$ of data collected by the BelleII experiment at the…
Neutrino decay to a lighter neutrino and a massless or almost massless (pseudo)scalar Goldstone boson remains of wide interest, as in the search for ultralight dark matter or for neutrinoless double beta-decay, and for its implications in…
The properties (masses and decay widths) of the $\phi$ meson are investigated in nuclear matter from the $\phi$ meson self-energy, using the tree-level $\phi K\bar{K}$ Lagrangian, and, incorporating in-medium masses of (anti)kaons…
Majoron-like bosons would emerge from a supernova (SN) core by neutrino coalescence of the form $\nu\nu\to\phi$ and $\bar\nu\bar\nu\to\phi$ with 100 MeV-range energies. Subsequent decays to (anti)neutrinos of all flavors provide a flux…
We report a search for a dark vector gauge boson $U^\prime$ that couples to quarks in the decay chain $D^{*+} \to D^0 \pi^+, D^0 \to K^0_S \eta, \eta \to U^\prime \gamma$, $U^\prime \to \pi^+ \pi^-$. No signal is found and we set a…
The upper bounds from the ATLAS and CMS experiments on the decay rate of the Higgs boson to two muons provide the strongest constraint on an imaginary part of the muon Yukawa coupling. This bound is more than an order of magnitude stronger…
Recently, a peak in the light fermion pair spectrum at invariant q^2 approximately equal to 16.7 Me^2. has been observed in the bombardment of Li-7 by protons. This peak has been interpreted in terms of a protophobic interaction of fermions…
A model based on a $U(1)_{T^3_R}$ extension of the Standard Model can address the mass hierarchy between generations of fermions, explain thermal dark matter abundance, and the muon $g - 2$, $R_{(D)}$, and $R_{(D^*)}$ anomalies. The model…
At present, cosmological observations set the most stringent bound on the neutrino mass scale. Within the standard cosmological model ($\Lambda$CDM), the Planck collaboration reports $\sum m_\nu < 0.12\,\text{eV}$ at 95% CL. This bound,…
Assuming the existence of a heavy Majorana neutral particle arising from a composite model scenario we discuss the constraints imposed by present experimental limits of half-life neutrinoless double beta decay $(0\nu\beta\beta ) $…
Searching for new particles beyond the standard model is crucial for understanding several fundamental conundrums in physics and astrophysics. Amongst them, axions or similar hypothetical pseudoscalar bosons would mediate electron-nucleon…
We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAPHNE. This boson, called U, has been searched for in the decay phi --> eta U, U --> e+ e-, analyzing the decay eta --> pi0 pi0 pi0 in a data…
We derive an upper bound on the smuon mass assuming that the muon $g-2$ anomaly is explained by the supersymmetric (SUSY) contribution. In the minimal SUSY standard model, the SUSY contribution to the muon $g-2$ is enhanced when the…
If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino…
We relate possible cosmological variations in the mass ratio mu \equiv m_p/m_e and the fine structure constant alpha to long-range composition-dependent forces mediated by a scalar field. The differential acceleration eta in Eotvos-type…
The pionic decay rates of the excited $L=0,1$ $D$ mesons are calculated with a Hamiltonian model within the framework of the covariant Blankenbecler-Sugar {equation.} The interaction between the light quark and charm antiquark is described…