Related papers: Four-lepton decays of neutral vector mesons
A search is performed for long-lived particles that decay into final states that include a pair of electrons or a pair of muons. The experimental signature is a distinctive topology consisting of a pair of charged leptons originating from a…
We estimate the rates of lepton flavor violating decays of the vector mesons $\rho, \omega, \phi \to e \mu$. The theoretical tools are based on an effective Lagrangian approach without referring to any specific realization of the physics…
I analyze a fourth generation lepton sector in which the lightest particle is a stable Majorana neutrino. In this scenario fourth generation neutrinos have both a Dirac and Majorana mass, resulting in two Majorana neutrino mass eigenstates.…
We study the radiative $\rho$, $\omega$ and $\phi$ decay into $\pi^0 \pi^0 \gamma$ and $\pi^0 \eta \gamma $ taking into account mechanisms in which there are two sequential vector-vector-pseudoscalar or axial-vector--vector--pseudoscalar…
An anomaly-free U(1) charge $Q'$ has recently been identified within the group E$_6$ for which the familiar leptons (the left- and right-handed electron and the left-handed neutrino) have $Q' = 0$. It is pointed out that the $Q'$ charges of…
The axial-vector mesons $f_1(1285)$ and $f_1(1420)$ are particularly viewed as the mixtures of flavor states $f_n$ and $f_s$ with mixing angle $\varphi$. In order to determine this angle, we study the $B_{d,s}^0\to J/\psi f_1(1285,1420)$…
We report preliminary results from a study of the charmless exclusive semileptonic decay B0 -> pi- l+ nu based on the data collected at the Upsilon(4S) resonance using the BABAR detector at SLAC. The analysis uses events in which the signal…
Searches for the exclusive decays of the Higgs and $Z$ bosons into a $J/\psi$, $\psi(2S)$, or $\Upsilon(nS)$ ($n=1,2,3$) meson and a photon are performed with a $pp$ collision data sample corresponding to an integrated luminosity of 36.1…
The LFV charged lepton decays mu to e + gamma, tau to e + gamma and tau to mu + gamma and thermal leptogenesis are analysed in the MSSM with see-saw mechanism of neutrino mass generation and soft SUSY breaking with universal boundary…
A dark photon is an Abelian gauge boson from a new $U(1)_D$ gauge symmetry, coupled to the Standard Model via kinetic mixing, with $\varepsilon$ inducing an effective coupling to the electromagnetic current and $g_\chi$ to a stable dark…
This paper investigates the $e^-e^+\to Zh_1$ sensitivity for Higgs boson's rare decay into heavy neutrinos $h_1 \to NN$ at the proposed electron-positron collider, with the focus on multi-lepton final states that contain same-sign lepton…
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 have not…
In the last 25 years, many $e^+e^-$ experiments and fixed-target experiments performed to search for and study the leptonic decays of the $D^+$ and $D^+_s$ mesons. By 2012, more than 530 signal events of the $D^+$ leptonic decays and about…
We present a benchmark in the parameter space of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) that provides for a dramatic multi-lepton signal and no jets containing 5 or more leptons resulting from the cascade decays of the…
Using a data sample of $(1310.6 \pm 7.0)\times 10^6$ $J/\psi$ events collected with the BESIII detector operating at the BEPCII collider, we perform the first experimental search for invisible decays of a light vector meson…
It is well known that finding and measuring the masses of particles in the Minimal Supersymmetric Standard Model (MSSM) at the Large Hadron Collider (LHC) may be possible using invariant mass distributions in exclusive channels containing…
We present a search for the decay B+ -> tau+ nu using 288 inverse femtobarns of data collected at the Upsilon(4S) resonance with the BaBar detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed semileptonic B decay…
The weak decays of the $D_{(s)}$ meson provide a pivotal platform to advance our understanding of the Standard Model (SM) and to explore New Physics (NP). In recent years, experiments have collected a significant amount of data on the…
We present a low-scale type-I seesaw scenario with discrete flavor and CP symmetries. This scenario not only explains the measured values of the lepton mixing angles, but also makes predictions for leptonic CP violation, and connects the…
We study a set of exclusive decay modes of the Standard Model Higgs boson into a vector meson and a dilepton pair: $h\to V \ell^+ \ell^-$, with $V=\Upsilon, J/\psi,\phi$, and $\ell=\mu, \tau$, determining the decay rates, the dilepton mass…