Related papers: Molecular States and 1^-+ Exotic Mesons
Whether molecular states indeed exist in nature has been disputed for a long time. Several new resonances have been observed in the recent experiments and they seem to be of exotic structures and some of them have been proposed to be…
Possible $\Lambda_c\Lambda_c$ hadronic molecule is investigated in the one-pion-exchange potential model. In the study with this model, the heavier meson exchange effects are encoded into a phenomenological cutoff parameter and couplings to…
Orbitally excited heavy-light mesons are potentially important as tools for tagging the flavors and momenta of ground-state pseudoscalars detected through weak decays. We use heavy-quark symmetry supplemented by insights gleaned from…
We estimate the kinematic dependence of the exclusive photo-- and electroproduction of $J^{PC}=1^{-+}$ exotic mesons due to $\pi$ exchange. We show that the kinematic dependence is largely independent of the exotic meson form factor, which…
If the exotic baryon $\Theta^+(1540)$ is a correlated $udud\bar{s}$ with $J^P = {1/2}^+$, then there should exist an exotic meson, $J^P = 1^-$ $\vartheta^+ (S=+2)$ $\to K^+K^0$ $\sim 1.6$GeV with width $O(10-100)$MeV. The $\pi_1(1400;1600)$…
A partial wave analysis of the process $\psi(2S)\rightarrow\gamma\chi_{c1}, \chi_{c1}\rightarrow\pi^+\pi^-\eta^{\prime}$ is performed using $(2712.4\pm14.3)\times10^{6}$ $\psi(2S)$ events collected with the BESIII detector. An isovector…
Experimental data from the 2m propane bubble chamber have been analyzed to search for an exotic baryon states, in the $\Lambda K^0_s$ decay mode for the reaction p+$C_3H_8$ at 10 GeV/c. The invariant mass spectrum $\Lambda K^0_s$ observe a…
It is shown that the list of unusual mesons planned for a careful study in photoproduction can be extended by the exotic states $X^\pm(1600)$ with $I^G(J ^{PC})=2^+(2^{++})$ which should be looked for in the $\rho^\pm\rho^0$ decay channels…
Multiquark systems such as tetraquarks, pentaquarks and hexaquarks states are studied as di-hadronic molecules in a nonrelativistic model. The masses of several di-hadronic states using a molecular interaction provided by asymptotic…
Lattice-QCD predicts the exotic meson $\pi_1(1600)$ to dominantly decay to $b_1\pi$. The $b_1\pi$ decay channel is accessible via the $\omega\pi^{-}\pi^{0}$ final state. COMPASS recorded the so far largest data set of this final state. A…
An analysis of the $J/\psi\to \eta\eta^\prime\gamma$ decay by the BESIII collaboration claims the observation of an exotic state $\eta_1(1855)$ with $I^GJ^{PC}=0^+1^{-+}$. To establish its C-parity partner $\eta^\prime_{1}(1855)$ in the…
$K^-$ mesons offer a unique setting where mesic atoms have been studied both experimentally and theoretically, thereby placing constraints on the possible existence and properties of meson-nuclear quasibound states. Here we review progress…
Recently, a hadronic state named $\eta_1(1855)$, about 1.86 GeV, was observed in the BESIII experiment. This finding has a peculiar interest due to its exotic quantum number $J^{PC}=1^{-+}$. In this paper, we examine the tetraquark…
In this work we present a calculation of exotic charmonium production in ultra-peripheral collisions, in which the exotic state is explicitly treated as a meson molecule. Our formalism is general but we focus on the lightest possible exotic…
We expose arguments concerning the \pi_{1}(1400) observed decaying into \eta\pi and claimed to be an exotic meson. We conclude that this object cannot be a qqbar-g hybrid meson.
A decay width calculation for a hybrid exotic meson h, with JPC=1-+, is presented for the channel h->pi+a1. This quenched lattice QCD simulation employs Luescher's finite box method. Operators coupling to the h and pi+a1 states are used at…
Strange multi-baryonic clusters are an exiting possibility to explore the properties of cold dense baryonic matter. Recent results on searches for exotic narrow resonances with $\Lambda$ hyperon subsystems are reviewed. The observation of…
Experimental data from the 2m propane bubble chamber have been analyzed to search for an exotic baryon states, in the $K_s^0 p$, $K_s^0 \Lambda$ and $\Lambda p$ decay mode for the reaction p+$C_3H_8$ at 10 GeV/c. The invariant mass spectrum…
This work constitutes one part of an investigation of the low-temperature changes of the properties of the eta' meson. In turn these properties are strongly tied to the U(1)_A anomaly of Quantum Chromodynamics. The final aim is to explore…
We describe two-photon photoassociation (PA) experiments operated in an ultracold gas of metastable $^4$He$^*$ atoms in the $2^3S_1$ state. Atom-molecule dark resonances as well as Raman signals provide information on the exotic molecule in…