Related papers: Exotic Meson candidates in COMPASS data
Meson states with exotic quantum numbers arise naturally in a covariant bound-state framework in QCD. We investigate the consequences of shifting quark masses such that the states are no longer restricted to certain C-parities, but only by…
The evidence for the existence of mesons with exotic quantum numbers and of hybrid candidates with non-exotic quantum numbers is critically reviewed, including candidates with hidden charm. Aims and methods of future searches for hybrid…
An effective Coulomb gauge Hamiltonian, H_eff, is used to calculate the light (u-ubar-g), strange (s-sbar-g) and charmed (c-cbar-g) hybrid meson spectra. For the same two parameter H_eff providing glueball masses consistent with lattice…
We present results for the spectrum of light and strange mesons on configurations with two flavors of mass-degenerate Chirally Improved sea quarks. The calculations are performed on seven ensembles of lattice size 16^3x32 at three different…
An exotic meson, the $\pi_1(1400)$ with $J^{PC}=1^{-+}$, has been seen to decay into a p-wave $\eta\pi$ system. If this decay conserves flavor SU(3), then it can be shown that this exotic meson must be a four-quark state ($q\bar q+q\bar q$)…
We discuss the status of analyses of data recorded in the 2008 and 2009 runs of the COMPASS experiment at CERN with sepcific focus on final states with $K^0_S K^0_S \pi^-$ and $K^+K^-\pi^-$ produced in $\pi^-(190\,\textrm{GeV})p$…
COMPASS is a fixed-target experiment at the CERN SPS which focused on light-quark hadron spectroscopy during the data taking periods in 2008 and 2009. A world-leading data set was collected with a 190GeV/c hadron beam impinging on a liquid…
A search for exotic mesons in the $\pi^{+}\pi^{+}\pi^{-}$ system photoproduced by the charge exchange reaction $\gamma p\to \pi^{+}\pi^{+}\pi^{-}(n)$ was carried out by the CLAS collaboration at Jefferson Lab. A tagged-photon beam with…
The recently discovered $\eta_1(1855)$ and the previously observed $\pi_1(1600)$ state present a valuable opportunity for the investigation of the $J^{P(C)}=1^{-(+)}$ light hybrid nonet. In this study, we employ a semirelativistic quark…
The first observation of exotic states with a new quark content $c \bar{c} u \bar{s}$ decaying to the $J/\psi K^+$ final state is reported with high significance from an amplitude analysis of the $B^+ \to J/\psi \phi K^+$ decay. The…
The COMPASS experiment at the CERN-SPS studies the spectrum and the structure of hadrons by scattering high energy hadrons and polarised muons off various fixed targets. Recent results for the hadron programme comprise highlights from…
COMPASS is a fixed-target experiment at CERN SPS which focused on light-quark meson spectroscopy during the data-taking periods in 2008 and 2009. The central exclusive production of glueball candidates is studied with a 190GeV/c proton beam…
We comment on the quantum numbers and decay channels of the possible proton antiproton bound state observed by BES Collaboration. Based on the general symmetry consideration and available experimental information, we conclude that the…
We enlarge the chiral model, the so-called extended Linear Sigma Model (eLSM), by including the low-lying hybrid nonet with exotic quantum numbers $J^{PC}=1^{-+}$ and the nonet of their chiral partners with $J^{PC}=1^{+-}$ to a global…
We calculate the coupling constants of the decay modes $1^{-+}\rightarrow\rho\pi, f_1\pi, b_1\pi, \eta\pi, \eta'\pi, a_1\pi, f_1\eta$ within the framework of the light-cone QCD sum rule. Then we calculate the partial width of these decay…
We present a robust analysis of the $\eta^{(\prime)} \pi$ system in COMPASS data. We fit the extracted relative phases and intensities with a coupled-channel formalism enforcing both unitarity and analyticity. We provide a robust extraction…
We describe a pion physics program attainable with the CERN COMPASS spectrometer, involving tracking detectors and an electromagnetic calorimeter. COMPASS can realize state-of-the-art pion beam hybrid meson and meson radiative transition…
We extend previous calculations of leading-order correlation functions of spin-0 and spin-1 light quarkonium hybrids to include QCD condensates of dimensions five and six, with a view to improving the stability of QCD sum-rules analyses in…
The spin-exotic hybrid meson $\pi_{1}(1600)$ is predicted to have a large decay rate to the $\omega\pi\pi$ final state. Using 76.6~pb$^{-1}$ of data collected with the GlueX detector, we measure the cross sections for the reactions $\gamma…
We present a spectrum of highly excited charmonium mesons up to around 4.5 GeV calculated using dynamical lattice QCD. Employing novel computational techniques and the variational method with a large basis of carefully constructed…