Related papers: Four-quark state in QCD
We show that confinement of spinless heavy quarks in fundamental representation of $SU(N_{c})$ gauge group can be treated as decoherence of pure colour state into a white mixture of states. Decoherence rate is found to be proportional to…
Models proposed to explain recently discovered heavy-light four-quark states already assume certain internal structures, i.e. the (anti)quark constituents are grouped into diquark/antidiquark clusters, heavy-meson/light-meson clusters…
A new color basis system and confinement mechanism for multi-quark systems are proposed according to the string-type picture of QCD. The color string configurations in the strong coupling QCD are implemented in the set of color basis…
We construct the diquark-diquark-diquark type vector six-quark currents to investigate the vector and scalar hexaquark states in the framework of the QCD sum rules in a consistent way, and make predictions for the hexaquark masses. We can…
In addition to the conventional $q\bar{q}$ and $qqq$ bound states of quarks $q$, exotic hadrons, such as the four-quark $q\bar{q}q\bar{q}$ and the five-quark $qqqq\bar{q}$ bound states, can be constructed by assuming colour confinement in…
In this article, we take the tensor currents $\bar{Q}(x)\sigma_{\mu\nu}Q(x)$ to interpolate the $P$-wave spin-singlet heavy quarkonium states $h_Q$, and study the masses and decay constants with the Borel sum rules and moments sum rules.…
Spectrum of the doubly heavy tetraquarks, $bb\bar q\bar q$, is studied in a constituent quark model. Four-body problem is solved in a variational method where the real scaling technique is used to identify resonant states above the…
The full version of QCD light-cone sum rule method is applied to tetraquarks containing a single heavy $b$ or $c$ quark. To this end, investigations of the strong vertices $X_{b}X_{b}\rho$ and $X_{c}X_{c}\rho$ are performed, where…
In this article, we study the $J^{PC}=0^{++}$ and $2^{++}$ $QQ\bar{Q}\bar{Q}$ tetraquark states with the QCD sum rules, and obtain the predictions $M_{X(cc\bar{c}\bar{c},0^{++})} =5.99\pm0.08\,\rm{GeV}$, $M_{X(cc\bar{c}\bar{c},2^{++})}…
A comprehensive study of the $S$-wave heavy tetraquark states with identical quarks and antiquarks, specifically $QQ{\bar Q'}\bar Q'$ ($Q, Q'=c,b$), $QQ\bar s\bar s$/$\bar Q\bar Q ss$, and $QQ\bar q\bar q$/$\bar Q\bar Q qq$ ($q=u,d$), are…
We carry out a systematic study of exotic $QQ^\prime \bar q\bar q$ four-quark states containing distinguishable heavy flavors, $b$ and $c$. Different generic constituent models are explored in an attempt to extract general conclusions. The…
In this article, we take the point of view that the $0^{++}$ nonet mesons below $1 GeV$ are diquark-antidiquark states $(qq)_{\bar{3}}(\bar{q}\bar{q})_3$, and devote to determine their masses in the framework of the QCD sum rules approach…
We investigate 4-quark ($qq\bar{q}\bar{q}$) systems as well as multi-quark states with a large number of quarks and anti-quarks using the chromodielectric model. In the former type of systems the flux distribution and the corresponding…
We investigate the light quarkonium hybrid mesons of various spin-parities in QCD. Considering different interpolating currents made of the valence light quarks and single gluon, we calculate the mass and current coupling of the strange and…
In this work, we calculate the mass spectrum of doubly heavy baryons with the diquark model in terms of the QCD sum rules. The interpolating currents are composed of a heavy diquark field and a light quark field. Contributions of the…
We study the pair description of heavy tetraquark systems $|QQ\bar Q \bar Q\rangle$ in the frame of a non-relativistic potential model. By taking the two heavy quark pairs $(Q\bar Q)$ as colored clusters, the four-quark Schr\"odinger…
We construct the interpolating currents for the fourteen p-wave excited heavy baryons in the framework of heavy quark effective theory (HQET). At the leading order in the 1/m_Q expansion these interpolating currents do not mix different…
QCD equation of state is calculated in (2+1) flavor QCD at temperatures corresponding fermion action on lattices with temporal extent $N_{\tau}=8$. The results are compared with previous calculations performed at twice larger values of the…
We investigate three possible pentaquark candidates, one of which contains a single charm quark and the other two contain triple charm quarks in their substructure. To this end we apply QCD sum rule method and take into account both the…
In the paper, we construct eight color singlet-singlet type five-quark currents with distinguished isospins to study the $\bar{D}\Xi^{\prime}$, $\bar{D}\Xi_c^{*}$, $\bar{D}^{*}\Xi_c^{\prime}$ and $\bar{D}^{*}\Xi_c^{*}$ molecular states with…