Coupling Hadron-Hadron Thresholds within a Chiral Quark Model Approach

Heavy hadron spectroscopy was well understood within the naive quark model until the end of the past century. However, in 2003, the X(3872) was discovered, with puzzling properties difficult to understand in the simple naive quark model picture. This state made clear that excited states of heavy mesons should be coupled to two-meson states in order to understand not only the masses but, in some cases, unexpected decay properties. In this work, we will give an overview of a way in which the naive quark model can be complemented with the coupling to two hadron thresholds. This program has been already applied to the heavy meson spectrum with the chiral quark model, and we show some examples where thresholds are of special relevance.

Download Full-text

RELATIVISTIC QUARK MODEL AND PENTAQUARK SPECTROSCOPY

International Journal of Modern Physics E ◽

10.1142/s0218301303001582 ◽

2003 ◽

Vol 12 (06) ◽

pp. 793-807 ◽

Cited By ~ 6

Author(s):

S. M. GERASYUTA ◽

V. I. KOCHKIN

Keyword(s):

Dispersion Relation ◽

Quark Model ◽

Mass Spectra ◽

Relativistic Quark Model ◽

The Masses ◽

Meson States

Relativistic five-quark equations are found in the framework of the dispersion relation technique. The solutions of these equations using the method based on the extraction of the leading singularities of the amplitudes are obtained. The five-quark amplitudes for the low-lying pentaquarks are calculated under the condition that flavor SU(3) symmetry holds. The poles of the five-quark amplitudes determine the masses of the lowest pentaquarks. The mass spectra of pentaquarks which contain only light quarks are calculated. The calculation of pentaquark amplitudes estimates the contributions of three subamplitudes: molecular subamplitude BM, Mqqq subamplitude and [Formula: see text] subamplitude. The main contributions to the pentaquark amplitude are determined by the subamplitudes, which include the meson states M.

Download Full-text

Heavy hadron spectroscopy: A quark model perspective

Nuclear Physics A ◽

10.1016/j.nuclphysa.2012.12.096 ◽

2013 ◽

Vol 914 ◽

pp. 472-481 ◽

Cited By ~ 1

Author(s):

J. Vijande ◽

A. Valcarce ◽

T.F. Caramés ◽

H. Garcilazo

Keyword(s):

Quark Model ◽

Hadron Spectroscopy ◽

Heavy Hadron

Download Full-text

Understanding d*(2380) in a chiral quark model

EPJ Web of Conferences ◽

10.1051/epjconf/201919902017 ◽

2019 ◽

Vol 199 ◽

pp. 02017

Author(s):

F. Huang ◽

Y. B. Dong ◽

P. N. Shen ◽

Z. Y. Zhang

Keyword(s):

Quark Model ◽

Constituent Quark ◽

Constituent Quark Model ◽

Chiral Quark Model ◽

Exotic State ◽

Decay Properties ◽

Decay Widths ◽

Color Components ◽

Good Agreement ◽

Made In

We review our recent progresses made in the study of the structure and decay properties of the newly observed d*(2380) within a chiral constituent quark model. It is found that the d*(2380) can be explained as a compact hexaquark-dominated exotic state with a fraction of hidden color components of about 2/3 in its configuration. Based on this scenario the single- and double- pionic partial decay widths are calculated and the corresponding numerical results are in good agreement with the experimental data.

Download Full-text

HEAVY PSEUDOSCALAR-MESON DECAY CONSTANTS WITH STRANGENESS FROM THE EXTENDED NONLOCAL CHIRAL-QUARK MODEL

Modern Physics Letters A ◽

10.1142/s0217732312501532 ◽

2012 ◽

Vol 27 (27) ◽

pp. 1250153 ◽

Cited By ~ 1

Author(s):

SEUNG-IL NAM

Keyword(s):

Heavy Quark ◽

Quark Model ◽

Weak Decay ◽

Heavy Meson ◽

Effective Field ◽

Numerical Results ◽

Meson Decay ◽

Chiral Quark Model ◽

Decay Constants ◽

Pseudoscalar Mesons

We study the weak-decay constants for the heavy pseudoscalar mesons, D, Ds, B and Bs. For this purpose, we employ the extended nonlocal chiral-quark model (ExNLChQM), motivated by the heavy-quark effective field theory as well as the instanton-vacuum configuration. In addition to the heavy-quark symmetry and the nonlocal interactions between quarks and pseudoscalar mesons in ExNLChQM, a correction for the strange-quark content inside Ds and Bs is also taken into account and found to be crucial to reproduce the empirical values. From those numerical results, we obtain fD, Ds, B, Bs = (207.53, 262.56, 208.13, 262.39) MeV , which are in good agreement with experimental data and other theoretical estimations. Using those numerical results, we estimate the CKM matrix elements and the Cabibbo angle with the various mesonic and leptonic heavy-meson decay channels, resulting in (|Vcd|, |Vcs|, |Vub|, |Vtd|/|Vts|) = (0.224, 0.968, <5.395×10-3, 0.215) and θC = 12.36° which are well compatible with available data.

Download Full-text

EXCITED SCALAR MESONS IN A CHIRAL QUARK MODEL

International Journal of Modern Physics A ◽

10.1142/s0217751x99002165 ◽

1999 ◽

Vol 14 (29) ◽

pp. 4621-4639 ◽

Cited By ~ 16

Author(s):

M. K. VOLKOV ◽

V. L. YUDICHEV

Keyword(s):

Quark Model ◽

Chiral Symmetry Breaking ◽

Standard Form ◽

Form Factors ◽

Radial Excitation ◽

Chiral Quark Model ◽

Scalar Mesons ◽

Pseudoscalar Mesons ◽

Meson States

First radial excitations of the scalar and pseudoscalar meson nonets as well as their ground states are described as quark–antiquark bound systems in the framework of a nonlocal chiral quark model of the NJL type. Glueball states and their possible mixing with members of the [Formula: see text] multiplets are not considered. Radial excitations are described by means of simple polynomial form factors in the momentum–space which are introduced into the four-quark vertices of the quark Lagrangian. The form factors are chosen in the regime of spontaneous chiral symmetry breaking so that the gap equations do not change their standard form, which provides fulfillment of the low energy theorems. All free parameters of the form factors are fixed by experimentally observed masses of pseudoscalar mesons. All masses of the scalar mesons are predicted. The local six-quark 't Hooft interaction is introduced to solve the so-called UA(1)-problem. The (four particle) singlet–octet mixing for the ground and radially excited states of scalar and pseudoscalar mesons is taken into account. The widths of the main strong decays of the first radial excitation of the scalar meson nonet are calculatedin satisfactory agreement with experimental data. Classification of the considered meson nonets is given. It is shown that the meson states a0(1450), f0(1370), fJ(1710) and [Formula: see text] are the first radial excitations of a0(980), f0(400-1200), f0(980), [Formula: see text].

Download Full-text

THE STUDY OF DIBARYON SYSTEMS WITH STRANGENESS ON CHIRAL QUARK MODEL

Modern Physics Letters A ◽

10.1142/s021773230501532x ◽

2005 ◽

Vol 20 (01) ◽

pp. 69-77

Author(s):

HOURONG PANG ◽

JIALUN PING ◽

XIAOHUA WU

Keyword(s):

Binding Energy ◽

Quark Model ◽

Root Mean Square ◽

Bound State ◽

Group Method ◽

Chiral Quark Model ◽

Mean Square ◽

Narrow Resonance ◽

The Masses

We expand Salamanca SU (2) chiral quark model to SU (3) one and calculate promising dibaryon candidates with strangeness S=-3,-6 in the framework of resonating group method. We find that, besides ΩΩ, the mass of NΩ state is about 23–38 MeV lower than its threshold, it might appear as a bound state or a narrow resonance. The effect of K and η exchanges on the masses of strangeness and nonstrangeness systems has been studied and found to be negligible for nonstrangeness systems. However this effect brings some changes (about tens of MeV) on the masses of strangeness systems. We have also studied the sensitivities of binding energy and root mean square radius to the mass of s-quark.

Download Full-text

STUDY OF HYDROGEN-LIKE MESON STATES WITH A SCREENED POTENTIAL MODEL

Modern Physics Letters A ◽

10.1142/s021773239400280x ◽

1994 ◽

Vol 09 (32) ◽

pp. 2967-2977

Author(s):

YU-BING DONG

Keyword(s):

Quark Model ◽

Calculated Result ◽

Potential Model ◽

Future Experiment ◽

Decay Properties ◽

Decay Widths ◽

Calculated Ratio ◽

Meson States

By utilizing the screened potential model, the spectra and decay properties of hydrogen-like mesons [Formula: see text] are studied. The calculated ratio of M1 decay widths for the D*+ and D*0 mesons is 0.0286. This result is much smaller than the data of MARK3 in 1988, but agrees with the observed data of CLEO in 1992. The result indicates that the contradiction between the calculated result and the data of MARK3 for hydrogen-like mesons in the quark model can be understood, if future experiment can confirm the data of CLEO in 1992.

Download Full-text

Heavy mesons in the Quark Model

EPJ Web of Conferences ◽

10.1051/epjconf/201919901012 ◽

2019 ◽

Vol 199 ◽

pp. 01012

Author(s):

D.R. Entem ◽

P.G. Ortega ◽

J. Segovia ◽

F. Fernández

Keyword(s):

Quark Model ◽

Heavy Meson ◽

Heavy Mesons ◽

Meson States

Since the discovery of the J/ψ, the quark model was very successful in describing the spectrum and properties of heavy mesons including only q̄ components. However since 2003, with the discovery of the X(3872), many states that can not be accommodated on the naive quark model have been discovered, and they made unavoidable to include higher Fock components on the heavy meson states. We will give an overview of the success of the quark model for heavy mesons and point some of the states that are likely to be more complicated structures such as meson-meson molecules.

Download Full-text

CONSTITUENT QUARK MODEL DESCRIPTION OF CHARMONIUM PHENOMENOLOGY

International Journal of Modern Physics E ◽

10.1142/s0218301313300269 ◽

2013 ◽

Vol 22 (10) ◽

pp. 1330026 ◽

Cited By ~ 51

Author(s):

J. SEGOVIA ◽

D. R. ENTEM ◽

F. FERNANDEZ ◽

E. HERNANDEZ

Keyword(s):

Quark Model ◽

B Meson ◽

Branching Fractions ◽

Constituent Quark Model ◽

Heavy Meson ◽

Resonance Structure ◽

Model Description ◽

Charm Mesons ◽

Decay Properties ◽

Quark Models

We review how quark models are able to describe the phenomenology of the charm meson sector. The spectroscopy and decays of charmonium and open charm mesons are described in a particular quark model and compared with the data and the results of other existing models in the literature. A quite reasonable global description of the heavy meson spectra is reached. A new assignment of the ψ(4415) resonance as a 3D state leaving aside the 4S state to the X(4360) is tested through the analysis of the resonance structure in e+e- exclusive reactions around the ψ(4415) energy region. We make tentative assignments of some of the XYZ mesons. To elucidate the structure of the 1+cs states, i.e., Ds1(2460) and Ds1(2536), we study the strong decay properties of the Ds1(2536) meson. We also perform a calculation of the branching fractions for the semileptonic decays of B and Bs mesons into final states containing orbitally excited charmed and charmed-strange mesons, which have become a very important source of information about the structure of heavy mesons. Analysis of the nonleptonic B-meson decays into D(*)DsJ are also included.

Download Full-text