Related papers: Studies of $\eta^{(')}\pi$ Final States Using Glue…

This article describes the performance of the pair spectrometer installed in experimental Hall D at Jefferson Lab and its operation in multiple experiments with the GlueX detector. The primary purpose of the pair spectrometer is the precise…

A constituent gluon model that is informed by recent lattice field theory is developed. The model is then used to compute hybrid strong decay widths, that can be useful for the GlueX collaboration at Jefferson Lab and the PANDA…

Hybrid/exotic meson spectroscopy searches at Jefferson Lab require the accurate theoretical description of the production mechanism in peripheral photoproduction. We develop a model for $\pi\Delta$ photoproduction at high energies ($5 \leq…

I will review the current status of exotic hadrons in the meson sector. There is currently strong evidence that a scalar glueball mixed into the normal scalar mesons has been found. There is also an interesting candidate for the tensor…

The main goal of the spectroscopy program at COMPASS is to explore the light-meson spectrum below about $2\,\text{GeV}/c^2$ in diffractive production. Our flagship channel is the decay into three charged pions: $p + \pi^-\to \pi^-\pi^-\pi^+…

The effect of the interaction of mesons in the final state is additionally considered within the description of $\tau \to \pi \eta(\eta') \nu_{\tau}$ decays. This interaction is taken into account at the level of production of intermediate…

The COMPASS experiment at CERN is well designed for light-hadron spectroscopy with emphasis on the detection of new states, in particular the search for $J^{PC}$-exotic states and glueballs. We have collected data with 190 GeV/c charged…

The $\eta$ and $\eta^{\prime}$ mesons are nearly unique in the particle universe since they are almost Goldstone bosons and the dynamics of their decays are strongly constrained. The integrated $\eta$-meson samples collected in earlier…

The dark matter and existence of new particles are now a possible explanation of several physics phenomena which evade the predictions of the Standard Model. In this context Axion-Like-Particles (ALP) with masses in the MeV to GeV range…

We propose to enhance the kaon identification capabilities of the GlueX detector by constructing an FDIRC (Focusing Detection of Internally Reflected Cherenkov) detector utilizing the decommissioned BaBar DIRC components. The GlueX FDIRC…

Short history of ideas concerning a possible existence of bound states of the $\eta$-meson and a nucleus is considered. First experiments at BNL and LAMPF on searching for these states are discussed. Another recent experiment using the…

The COMPASS fixed-target experiment at the CERN SPS is dedicated to the study of hadron structure and dynamics. One goal of the physics programme using hadron beams is the search for new states, in particular the search for $J^{PC}$ exotic…

We report on some interesting recent theoretical and experimental advances on J^PC exotics and hybrid mesons. These are the decay selection rules governing J^PC exotic decay, the experimental evidence for a J^PC = 1^-+ exotic in eta pi and…

We have searched for lepton family number violating decays of the $\tau$ lepton using final states with an electron or a muon and one or more $\pi^0$ or $\eta$ mesons but no neutrinos. The data used in the search were collected with the…

We show that hard electroproduction is a promising way to study exotic hybrid mesons, in particular through the hybrid decay channel $H \to \pi\eta $. We discuss the $\pi\eta$ generalized distribution amplitude, calculate the production…

We present a search at Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling $\alpha'$ to electrons. Such a particle $A'$ can be produced in electron-nucleus fixed-target scattering and then decay to an…

Medium-energy electron beam-dump experiments provide an intense sources of secondary muons. These particles can be used to search for muon-coupling light dark scalars that may explain the $(g-2)_\mu$ anomaly. We applied this idea to SLAC…

We introduce strong and electromagnetic interaction selection rules for the two-body decay and production of exotic J^{PC} = 0^{+-}, 1^{-+}, 2^{+-}, 3^{-+} hybrid mesons, four-quark states and glueballs. The rules arise from symmetrization…

Nowadays the field of searching for a new physics became a very interesting subject in a light meson decays due to a recent results from KTeV collaboration which found the 3.3\sigma\ disagreement between Standard Model theory and their…

We present a search for axion-like particles, $a$, produced in photon-proton collisions at a center-of-mass energy of approximately 4 GeV, focusing on the scenario where the $a$-gluon coupling is dominant. The search uses $a\to\gamma\gamma$…