Related papers: Final state interaction and a light mass "exotic" …
Exceptional points (EPs), singularities of non-Hermitian physics where complex spectral resonances degenerate, are one of the most exotic features of nonequilibrium open systems with unique properties. For instance, the emission rate of…
We will discuss the spectrum of the eta mesons making use of the Nambu-Jona-Lasinio (NJL) model supplemented with a model of confinement. We will go on to discuss the properties of mesons at finite temperature and the phenomenon of…
The QCD gauge field is modeled as an ensemble of statistically independent selfdual and antiselfdual regions. This model is motivated from instanton physics. The scale anomaly then allows to relate the topological susceptibility to the…
An overview is given of the study of final state interactions in hadronically decaying W pairs produced in e^+e^--collisions as it is performed by the four LEP experiments. Bose-Einstein correlations are investigated by comparing like- with…
We reconsider the discrepancy between theory and data in the momentum distribution of slow J/psi in B decays. Beside an update of the standard color singlet and color octet QCD components, we include the contribution from XY Z exotic…
The review on the 2m propane bubble chamber experiment data analysis aimed to searches for an exotic baryon states for $K^0_s$-meson subsystems. The observation of $\Sigma^0$, $\Sigma^{*+}$(1385) and $K^{*\pm}$(892) well known resonances…
We present a theoretical estimate for the cross-section of exclusive $\rho^+\rho^-$ and $\rho^0\rho^0$-meson production in two photon collisions when one of the initial photons is highly virtual. We focus on the discussion of the twist 4…
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…
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…
Results of resonance searches in the Xi- pi-, Xi- pi+, antiXi+ pi- and antiXi+ pi+ invariant mass spectra in proton-proton collisions at sqrt{s}=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi- pi- baryon…
Recent results on meson spectroscopy from lattice QCD are reviewed. The emphasis is on interesting states near thresholds like $Z_c^+(3900)$, $X(3872)$ and $D_{s0}^*(2317)$. Another focus is on the meson resonances in light, strange and…
We show that in photoproduction experiments there are propitious conditions to study the exotic state $1^{-+}$ in the $\pi\eta$ and $\pi\eta'$ channels. We show that for unpolarized photon beam the contributions with natural and unnatural…
A selection of results for searches for exotic physics at the LHC are presented. These include a search for massive resonances, dark matter with a high energy jet in association with large missing transverse momentum, long-lived neutral…
Basing on the latest results of the PNPI (Gatchina) and QM&W College (London) groups, I discuss systematics of the IJ^{PC} q anti-q states in terms of trajectories on the (n,M^2) plane, where n is the radial quantum number and M is its…
We study the large $N_c$ behavior of couplings among light meson states with different compositions in terms of quarks and gluons. We shortly review the most common compositions of mesons, which are of interest for the understanding of…
We investigate the mass of the $1^{-+}$ exotic meson, created with hybrid interpolating fields. Access to light quark masses approaching 25 MeV is facilitated by the use of the Fat-Link Irrelevant Clover (FLIC) fermion action, and large…
In this paper I review a number of recent results in the field of exotic atoms. Recent experiments or ongoing experiments with muonic, pionic and antiprotonic hydrogen, as well as recent measurement of the pion mass are described. These…
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…
Recent results on studies of exotic hadrons at the LHCb experiment are summarised. These are the observation of new resonances decaying to J/$\psi K^{+}$ and J/$\psi\phi$, evidence of a J/$\psi\Lambda$ structure and observation of excited…
Two-photon collisions at the e$^+$e$^-$ colliders allow to investigate the formation and the properties of resonant states in a very clean experimental environment. A remarkable number of new results have been recently obtained giving…