scholarly journals The explanation of some exotic states in the $$cs{\bar{c}}{\bar{s}}$$ tetraquark system

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
Xuejie Liu ◽  
Hongxia Huang ◽  
Jialun Ping ◽  
Dianyong Chen ◽  
Xinmei Zhu
Keyword(s):  
Energy Range ◽  
Recent Observation ◽  
Experimental Tests ◽  
Resonance State ◽  
Bound State ◽  
Lhcb Collaboration ◽  
Channel Coupling ◽  
Resonance States ◽  
Exotic States ◽  
Resonant States

AbstractInspired by the recent observation of $$\chi _{c0}(3930)$$ χ c 0 ( 3930 ) , X(4685) and X(4630) by the LHCb Collaboration and some exotic resonances such as X(4350), X(4500), etc. by several experiment collaborations, the $$cs{\bar{c}}{\bar{s}}$$ c s c ¯ s ¯ tetraquark systems with $$J^{PC}=0^{++}$$ J PC = 0 + + , $$1^{++}$$ 1 + + , $$1^{+-}$$ 1 + - and $$2^{++}$$ 2 + + are systematically investigated in the framework of the quark delocalization color screening model(QDCSM). Two structures, the meson–meson and diquark–antidiquark structures, as well as the channel-coupling of all channels of these two configurations are considered in this work. The numerical results indicate that the molecular bound state $$D^{-}_{s}D_{s}^{+}$$ D s - D s + with $$J^{PC}=00^{++}$$ J PC = 00 + + can be supposed to explain the $$\chi _{c0}(3930)$$ χ c 0 ( 3930 ) . Besides, by using the stabilization method, several resonant states are obtained. Among these states, X(4350), X(4500) and X(4700) can be explained as the compact tetraquark states with $$J^{PC}=00^{++}$$ J PC = 00 + + , and the X(4274) is possible to be a candidate of the compact tetraquark state with $$J^{PC}=1^{++}$$ J PC = 1 + + . Apart from that, the $$J^{PC}=0^{++}$$ J PC = 0 + + resonance state with energy range 4028–4033 MeV, the two $$J^{PC}=2^{++}$$ J PC = 2 + + resonance states with energy range of 4394–4448 MeV and 4526–4536 MeV are possible to be new exotic states, which are indeed worthy of attention. More experimental tests are expected to check the existence of all these possible resonance states.

scholarly journals Full-heavy tetraquarks in constituent quark models

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Xin Jin ◽  
Yaoyao Xue ◽  
Hongxia Huang ◽  
Jialun Ping
Keyword(s):  
Quark Model ◽  
Constituent Quark ◽  
Resonance State ◽  
Bound State ◽  
Chiral Quark Model ◽  
Present Calculation ◽  
Resonance States ◽  
Screening Model ◽  
Quantum Numbers ◽  
Quark Models

AbstractThe full-heavy tetraquarks $$bb{\bar{b}}{\bar{b}}$$ b b b ¯ b ¯ and $$cc{\bar{c}}{\bar{c}}$$ c c c ¯ c ¯ are systematically investigated within the chiral quark model and the quark delocalization color screening model. Two structures, meson–meson and diquark–antidiquark, are considered. For the full-beauty $$bb{\bar{b}}{\bar{b}}$$ b b b ¯ b ¯ systems, there is no any bound state or resonance state in two structures in the chiral quark model, while the wide resonances with masses around $$19.1-19.4$$ 19.1 - 19.4 GeV and the quantum numbers $$J^{P}=0^{+}$$ J P = 0 + , $$1^{+}$$ 1 + , and $$2^{+}$$ 2 + are possible in the quark delocalization color screening model. For the full-charm $$cc{\bar{c}}{\bar{c}}$$ c c c ¯ c ¯ systems, the results are qualitative consistent in two quark models. No bound state can be found in the meson–meson configuration, while in the diquark–antidiquark configuration there may exist the resonance states, with masses range between 6.2 to 7.4 GeV, and the quantum numbers $$J^{P}=0^{+}$$ J P = 0 + , $$1^{+}$$ 1 + , and $$2^{+}$$ 2 + . And the separation between the diquark and the antidiquark indicates that these states may be the compact resonance states. The reported state X(6900) is possible to be explained as a compact resonance state with $$IJ^{P}=00^{+}$$ I J P = 00 + in present calculation. All these full-charm resonance states are worth searching in the experiments further.

Differential cross-section measurements in positron–argon collisions

1996 ◽  
Vol 74 (7-8) ◽  
pp. 505-508 ◽  
Author(s):  
R. M. Finch ◽  
Á. Kövér ◽  
M. Charlton ◽  
G. Laricchia
Keyword(s):  
Elastic Scattering ◽  
Differential Cross Section ◽  
Inelastic Scattering ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Coupling Effect ◽  
Channel Coupling ◽  
Scattering Cross

Differential cross sections for elastic scattering and ionization in positron–argon collisions as a function of energy (40–150 eV) are reported at 60°. Of particular interest is the energy range 55–60 eV, where earlier measurements by the Detroit group found a drop in the elastic-scattering cross section of a factor of 2. This structure has been tentatively attributed to a cross channel-coupling effect with an open inelastic-scattering channel, most likely ionization. Our results indicate that ionization remains an important channel over the same energy range and only begins to decrease at an energy above 60 eV.

scholarly journals New LHCb pentaquarks as hadrocharmonium states

2020 ◽  
Vol 35 (18) ◽  
pp. 2050151 ◽  
Author(s):  
Michael I. Eides ◽  
Victor Yu. Petrov ◽  
Maxim V. Polyakov
Keyword(s):  
Experimental Data ◽  
Binding Energy ◽  
Hyperfine Splitting ◽  
Theoretical Estimate ◽  
Bound State ◽  
Lhcb Collaboration ◽  
Color Singlet ◽  
Natural Explanation ◽  
Multipole Interaction ◽  
New Formula

New LHCb Collaboration results on pentaquarks with hidden charm1 are discussed. These results fit nicely in the hadrocharmonium pentaquark scenario.[Formula: see text] In the new data the old LHCb pentaquark [Formula: see text] splits into two states [Formula: see text] and [Formula: see text]. We interpret these two almost degenerated hadrocharmonium states with [Formula: see text] and [Formula: see text], as a result of hyperfine splitting between hadrocharmonium states predicted in Ref. 2. It arises due to QCD multipole interaction between color-singlet hadrocharmonium constituents. We improve the theoretical estimate of hyperfine splitting[Formula: see text] that is compatible with the experimental data. The new [Formula: see text] state finds a natural explanation as a bound state of [Formula: see text] and a nucleon, with [Formula: see text], [Formula: see text] and binding energy 42 MeV. As a bound state of a spin-[Formula: see text] meson and a nucleon, hadrocharmonium pentaquark [Formula: see text] does not experience hyperfine splitting. We find a series of hadrocharmonium states in the vicinity of the wide [Formula: see text] pentaquark that can explain its apparently large decay width. We compare the hadrocharmonium and molecular pentaquark scenarios and discuss their relative advantages and drawbacks.

REACTIVE RESONANCE AND FORMATION MECHANISM STUDIES OF THE H + NO → N + OH OR O + NH REACTION

2006 ◽  
Vol 05 (01) ◽  
pp. 43-50
Author(s):  
QIANG WANG ◽  
ZHENGTING CAI ◽  
DACHENG FENG
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Formation Mechanism ◽  
Energy Surface ◽  
Resonance State ◽  
Basis Set ◽  
Resonance States

The partial potential energy surface (PPES) of H + NO → N + OH or O + NH of 3A″ symmetry is first constructed using QCISD (T) method with 6-311++g** basis set, and then we speculate the existence of the scattering resonance states of these reactions. Finally, we estimate that the lifetime of scattering resonance state is about 1.5 ps, which is in agreement with Schatz's conclusion (~1.2 ps ). The scattering resonance states of the two reactions belong to the Feshbach type. The results are consistent with the probabilities calculations reported in the literatures.

DOUBLY HEAVY EXOTICS

2014 ◽  
Vol 35 ◽  
pp. 1460432
Author(s):  
MAREK KARLINER
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Light Quark ◽  
Bound State ◽  
Exotic State ◽  
Decay Modes ◽  
Exotic States ◽  
Quantum Numbers ◽  
Heavy Baryons ◽  
Molecular Picture

During the last three years strong experimental evidence from B and charm factories has been accumulating for the existence of exotic hadronic quarkonia, narrow resonances which cannot be made from a quark and an antiquark. Their masses and decay modes show that they contain a heavy quark-antiquark pair, but their quantum numbers are such that they must also contain a light quark-antiquark pair. The main theoretical challenge has been to determine the nature of these resonances. The main possibilities are that they are either "genuine tetraquarks", i.e. two quarks and two antiquarks within one confinement volume, or "hadronic molecules" of two heavy-light mesons. In the last few months there is more and more evidence in favor of the latter. I discuss the experimental data and its interpretation and provide fairly precise predictions for masses and quantum numbers of the additional exotic states which are naturally expected in the molecular picture but have yet to be observed. I also provide arguments in favor of the existence of an even more exotic state – a hypothetical deuteron-like bound state of two heavy baryons.

$\bar{D}$ and B nuclei with one pion exchange potential

2014 ◽  
Vol 29 ◽  
pp. 1460226
Author(s):  
Y. Yamaguchi ◽  
A. Hosaka ◽  
S. Yasui
Keyword(s):  
Spin Symmetry ◽  
Pion Exchange ◽  
Exchange Potential ◽  
Exotic States ◽  
Resonant States ◽  
Quark Spin ◽  
Heavy Quark Spin Symmetry ◽  
The One ◽  
Three Body ◽  
Coupled Channel

We discuss the possible existence of exotic dibaryons with a heavy antiquark, being realized three-body systems, [Formula: see text] and B(*)NN. These are genuinely exotic states with no quark-antiquark annihilation. We consider the heavy quark spin symmetry and chiral symmetry, and introduce the one pion exchange potential between a [Formula: see text] meson and a nucleon N. As for the NN interaction, we employ the Argonne [Formula: see text] potential. By solving the coupled-channel equations for PNN and [Formula: see text], we find bound and resonant states near the thresholds both in charm and bottom sectors.

Analysis of Vibrationally Highly Excited Bound and Resonance States of DCO (X ˜2A′) Using an Effective Polyad Hamiltonian

2001 ◽  
Vol 215 (2) ◽  
Author(s):  
A. Troellsch ◽  
F. Temps
Keyword(s):  
Resonance State ◽  
State Structure ◽  
Resonance States

The vibrational bound and resonance state structure of highly excited DCO (X

scholarly journals X(6200) as a compact tetraquark in the QCD string model

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
A. V. Nefediev
Keyword(s):  
String Model ◽  
Mass Range ◽  
Bound State ◽  
Lhcb Collaboration ◽  
Plausible Assumption ◽  
Compact Component ◽  
Molecular Interpretation ◽  
Channel Analysis ◽  
Coupled Channel ◽  
Qcd String

AbstractRecently the LHCb Collaboration announced the first observation of nontrivial structures in the double-$$J/\psi $$ J / ψ mass spectrum in the mass range 6.2–7.2 GeV, and a theoretical coupled-channel analysis of these data performed in Dong et al. (Phys Rev Lett 126:132001, 2021) evidenced the existence of a new state X(6200) close to the double-$$J/\psi $$ J / ψ threshold. Although its molecular interpretation seems the most plausible assumption, the present data do not exclude an admixture of a compact component in its wave function, for which a fully-charmed compact tetraquark is the most natural candidate. It is argued in this work that the QCD string model is compatible with the existence of a compact $$cc{\bar{c}}{\bar{c}}$$ c c c ¯ c ¯ state bound by QCD forces just below the double-$$J/\psi $$ J / ψ threshold. A nontrivial interplay of the quark dynamics associated with this compact state and the molecular dynamics provided by soft gluon exchanges between $$J/\psi $$ J / ψ mesons is discussed and the physical X(6200) is argued to be a shallow bound state, in agreement with the results of the aforementioned coupled-channel analysis of the LHCb data.

STUDY OF $N\bar{N}$ INTERACTION WITH CHANNEL-COUPLING IN CONSTITUENT QUARK MODELS

2011 ◽  
Vol 26 (16) ◽  
pp. 1231-1241 ◽  
Author(s):  
HONGXIA HUANG ◽  
HOURONG PANG ◽  
JIALUN PING
Keyword(s):  
Radiative Decay ◽  
Constituent Quark ◽  
Good Description ◽  
Bound State ◽  
Nucleon Nucleon ◽  
Group Method ◽  
Model Parameters ◽  
S Wave ◽  
Channel Coupling ◽  
Quark Models

The nucleon–antinucleon interaction is studied by using resonating-group-method in the framework of two constituent quark models: the chiral quark model and the quark delocalization color screening model, which can give a good description of baryon properties and nucleon–nucleon interaction. The experimental data of proton–antiproton S-wave elastic scattering cross-section can be well reproduced by adjusting properly one-gluon annihilation coupling constant. With the fixed model parameters, a dynamical calculation of all possible S-wave nucleon–antinucleon states with channel-coupling is performed. The calculated results show that the effect of channel-coupling is not strong to form a bound state as indicated by a strong enhancement at threshold of [Formula: see text] in J/ψ radiative decay.

Sign in / Sign up

Export Citation Format

Share Document