Related papers: Higher Quarkonia
The experimental status of stable bound states made out of heavy quarks is reviewed. The need for a way to deal with the non-perturbative transitions involved calls for precision measurements on one hand, and for discovery of as yet…
I briefly review the estimate of the gluonia masses, decay and mixings in QCD with massless quarks from QCD spectral sum rules and some low-energy theorems. The data in the $0^{++}$ channel can be explained with some maximal…
We present the new developments in the physics of XYZ mesons and glueballs and discuss the connection between properties of the $XYZ$ mesons and glueballs, and the structure of the QCD vacuum. It is shown that the mixing between quark and…
We use the method of QCD sum rules to investigate a possible hybrid baryon with the quantum numbers of the $\Lambda$. Using a current composed of uds quarks in a color octet and a gluon, a strange hybrid, the $\Lambda_H$ is found about 500…
In this paper we propose an approach which demonstrates the dependence of quarkoni production on the multiplicity of the accompanying hadrons. Our approach is based on the three gluons fusion mechanism, without assuming the multiplicity…
Exclusive processes at large momentum transfer Q factor into perturbatively calculable short-distance parts and long-distance hadronic wave functions. Usually, only contributions from the leading Fock states have to be included to leading…
The empirical identification of bound states of gluons has remained a central goal of hadron spectroscopy. We suggest an experimentally challenging, but model--independent way to assess which zero charge, isospin-zero mesons have a large…
QCD-motivated models for hadrons predict an assortment of "exotic" hadrons that have structures that are more complex then the quark-antiquark mesons and three-quark baryons of the original quark-parton model. These include pentaquark…
This study examines the properties of heavy quarkonia $X$ by treating them as bound states of $Q$ and $\bar{Q}$ at the LO level within the NRQCD framework, where $Q$ represents either a charm or a bottom quark. The branching ratios for the…
Fragmentation is the dominant production mechanism for heavy hadronic bound states with large transverse momentum. We numerically calculate the initial $g\rightarrow H(Q\bar{Q})$ fragmentation functions (FFs) using the nonrelativistic QCD…
We consider hybrid states with heavy quarks in the frame of recently proposed constituent gluon model. Limiting regimes for model Hamiltonian are discussed. It is shown that these regimes match smoothly, hence predictions of the model are…
In this letter, we propose that a proper constituent gluon mass $m_g$=450 MeV can be applied to identify the hybrids composed of quarks and gluons. By investigating the spectra and decay widths of the light hybrids $(q\bar{q}g)$ with…
We present results for the hybrid meson spectrum produced by gluonic excitations in full QCD using Wilson fermions. For the spin-exotic mesons with J^{PC}=1^{-+}, 0^{+-}, and 2^{+-} we find the lightest state to be 1^{-+} with a mass of…
The existence of non-q\bar{q} hadrons such as glueballs and hybrids is one of the most important qualitative questions in QCD. The COMPASS experiment offers the possibility to unambiguously identify such states and map out the glueball and…
We give a pedagogical introduction to heavy quarkonia -- bound states of a heavy quark and its antiquark (e.g., charmonium $c\bar{c}$, bottomonium $b\bar{b}$) -- as well as to the exotic hadrons containing two heavy quarks that have been…
There are strong indications that ultra-relativistic heavy ion collisions, produced in accelarators, lead to the formation of a new state of matter: the quark gluon plasma (QGP). This deconfined QCD matter is expected to exist just for very…
We have examined decays of low-lying gluonic excitations of mesons (hybrids) by chromoelectric flux-tube breaking. An analytical calculation of non-relativistic flux-tube model decay amplitudes is performed in an harmonic oscillator…
The possibility of formation for a bound state of a $t$ quark and a lighter one is investigated using potential model predictions and heavy quark effective theory approach. Resulting estimates for the 1S--2S splitting of the energy levels…
Exotic quarkonia are candidates to new types of hadrons including four quarks or gluonic degrees of freedom as constituents, the latter being a unique feature of QCD. We review recent developments in nonrelativistic EFTs to describe exotic…
The potential of decays of mesons containing heavy quarks [including $B$ mesons and the $\Upsilon(1S)$] for producing final states of matter with unusual quark configurations, such as $q q \bar q \bar q$ or $q q q q \bar q$, is…