Related papers: Light unflavor vector meson spectroscopy around th…
We study the phenomenology of light scalars of masses $m_1$ and $m_2$ coupling to heavy flavour-violating vector bosons of mass $m_V$. For $m_{1,2}\lesssim $ few GeV, this scenario triggers the rare $B$ meson decays $B_s^0\to 3\mu^+…
$L_\mu -L_\tau$ gauge boson ($Z'$) with a mass in the MeV to GeV region can resolve not only the muon $g-2$ excess, but also the gap in the high-energy cosmic neutrino spectrum at IceCube. It was recently proposed that such a light gauge…
Recent Belle II data on $B^+ \to K^+ E_{\rm miss}$ show an excess consistent with a two-body decay involving a light invisible particle with mass around $2.1\,\mathrm{GeV}$. We present a UV-complete explanation based on a Higgsed $U(1)'$…
We investigate collider signatures of standard model extensions featuring vector-like leptons and a flavorful scalar sector. Such a framework arises naturally within asymptotically safe model building, which tames the UV behavior of the…
We analyze neutrino masses and Lepton Flavor Violation (LFV) in charged leptons with a minimal ansatz about the breaking of the U(3)^5 flavor symmetry, consistent with the U(2)^3 breaking pattern of quark Yukawa couplings, in the context of…
In this work, we present the mass spectrum of higher charomona around and above 4.6 GeV by adopting the unquenched potential model. We perform a combined fit to the updated experimental data of $e^+e^- \to \psi(2S)\pi^+\pi^-$ and $e^+e^-\to…
The current situation for vector meson spectroscopy is outlined, and it is shown that the data are inconsistent with the generally-accepted model for meson decay. A possible resolution in terms of exotic (hybrid) mesons is given. Although…
Charged-lepton-flavor-violation is predicted in several new physics scenarios. We update the analysis of $\tau$ lepton decays into a light charged lepton ($\ell$ = $e^{\pm}$ or $\mu^{\pm}$) and a vector meson ($V^0$ = $\rho^0$, $\phi$,…
Using a data set of 2.93 fb$^{-1}$ taken at a center-of-mass energy $\sqrt{s}$ = 3.773 GeV with the BESIII detector at the BEPCII collider, we perform a search for an extra U(1) gauge boson, also denoted as a dark photon. We examine the…
We propose a new search for light scalar singlets in rare meson decays. For tiny interactions, the scalar is long-lived at detector scales and decays into displaced pairs of leptons or light mesons. We show that Belle II has a remarkable…
We reanalyze the problems in the assignment of 3$^3S_1$ and 4$^3S_1$ light mesons, which have not yet been well established with the $q\bar{q}$ quark model. Regge trajectories and the $^3P_0$ decay model are used respectively to study the…
We search for lepton-flavor-violating $\tau^-\to e^-\alpha$ and $\tau^-\to\mu^-\alpha$ decays, where $\alpha$ is an invisible spin-0 boson. The search uses electron-positron collisions at $10.58$ GeV center-of-mass energy with an integrated…
We investigate a dark sector containing a pair of light non-degenerate scalar particles, with masses in the MeV-GeV range, coupled to the visible sector through heavier mediators. The heaviest dark state is long-lived, and its decays offer…
BESIII experiment has collected about 20 fb$^{-1}$ luminosity data between $\sqrt{s}=3.8$ and 4.7 GeV via $e^{+}e^{-}$ collision. In this talk, we present the recent $XYZ$ results at BESIII, including mass and width measurements of…
We present results for the light meson masses and decay constants as obtained from calculations with the non-perturbatively improved (`Alpha') action and operators on a 24^3 \times 64 lattice at beta = 6.2, in the quenched approximation.…
We consider strategies for using new datasets to probe scenarios in which light right-handed SM fermions couple to a new gauge group, $U(1)_{T3R}$. This scenario provides a natural explanation for the light flavor sector scale, and a…
We have searched for lepton flavor violating decays of the tau lepton with one or two KS0 mesons in the final state. The data used in the search were collected with the CLEO II and II.V detectors at the Cornell Electron Storage Ring (CESR)…
We have searched for lepton flavor violating decays of the tau lepton with one or two KS0 mesons in the final state. The data used in the search were collected with the CLEO II and II.V detectors at the Cornell Electron Storage Ring (CESR)…
We propose that the spectrum of light mesons (the $\pi$ and $\rho$, together with their radial excitations) can be calculated in the limit of vanishing light quark masses by studying gauge theory (open string theory) on suitable higher…
We present the first results from the MEG experiment for the search of the Lepton Flavour Violating decay $\mu^+ \to e^+ \gamma$ . LFV decays are forbidden in the SM and highly suppressed in any minimal SM extension with tiny neutrino…