Systematics of quark  antiquark states and scalar exotic mesons

Anisovich, V.V.

doi:10.3367/ufnr.0174.200401d.0049

Cited by 44 publications

(41 citation statements)

References 129 publications

(19 reference statements)

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“…For light mesons, the Regge trajectories are suggested to be linear although the parameters take different values [78][79][80][81][82][83]. By fitting the experimental data, we find that the new Regge trajectory is better than the linear one even for π mesons, see Fig.…”

Section: Nonlinear Regge Trajectoriesmentioning

confidence: 84%

Regge trajectories for heavy quarkonia from the quadratic form of the spinless Salpeter-type equation

Chen

2018

Eur. Phys. J. C

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In this paper, we present one new form of the Regge trajectories for heavy quarkonia which is obtained from the quadratic form of the spinless Salpeter-type equation (QSSE) by employing the Bohr-Sommerfeld quantization approach. The obtained Regge trajectories take the parameterized form M 2 = β(c l l + π n r + c 0 ) 2/3 + c 1 , which are different from the present Regge trajectories. Then we apply the obtained Regge trajectories to fit the spectra of charmonia and bottomonia. The fitted Regge trajectories are in good agreement with the experimental data and the theoretical predictions.

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Section: Nonlinear Regge Trajectoriesmentioning

confidence: 84%

Regge trajectories for heavy quarkonia from the quadratic form of the spinless Salpeter-type equation

Chen

2018

Eur. Phys. J. C

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“…For small momentum transfers between the proton and the neutron (−t < 0.1 GeV 2 ), the scalar amplitudes show a dip around 1 GeV, while f 0 (980) is observed as a peak for large momentum transfers (−t > 0.4 GeV 2 ). This observation has been interpreted as evidence for a hard component in the f 0 (980) [35,899,907,1118]. However, the strong dependence of f 0 (980)-production on the momentum transfer between proton and neutron can also well be reproduced by a change of the interference between the resonance structure and the non-resonant background when and a 1 (1230) scattering are considered, and the data are fully compatible with the molecular picture of f 0 (980) [1119][1120][1121][1122].…”

Section: Production Of F 0 (980) As a Function Of Tmentioning

confidence: 95%

“…Such analyses have the distinctive advantage that a complete meson spectrum emerges which sums the combined knowledge from very different reactions into one unified picture. A summary of results can be found in [907].…”

Section: Systematic Of Qq Mesons In (N M 2 ) and (J M 2 ) Planesmentioning

confidence: 96%

Glueballs, hybrids, multiquarks

2007

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Glueballs, hybrids and multiquark states are predicted as bound states in models guided by quantum chromo dynamics (QCD), by QCD sum rules or QCD on a lattice. Estimates for the (scalar) glueball ground state are in the mass range from 1000 to 1800 MeV, followed by a tensor and a pseudoscalar glueball at higher mass. Experiments have reported evidence for an abundance of meson resonances with 0 −+ , 0 ++ and 2 ++ quantum numbers. In particular, the sector of scalar mesons is full of surprises starting from the elusive and mesons. The a 0 (980) and f 0 (980), discussed extensively in the literature, are reviewed with emphasis on their Janus-like appearance as KK molecules, tetraquark states or qq mesons. Most exciting is the possibility that the three mesons f 0 (1370), f 0 (1500), and f 0 (1710) might reflect the appearance of a scalar glueball in the world of quarkonia. However, the existence of f 0 (1370) is not beyond doubt and there is evidence that both f 0 (1500) and f 0 (1710) are flavour octet states, possibly in a tetraquark composition. We suggest a scheme in which the scalar glueball is dissolved into the wide background into which all scalar flavour-singlet mesons collapse.There is an abundance of meson resonances with the quantum numbers of the . Three states are reported below 1.5 GeV/c 2 whereas quark models expect only one, perhaps two. One of these states, (1440), was the prime glueball candidate for a long time. We show that (1440) is the first radial excitation of the meson.Hybrids may have exotic quantum numbers which are not accessible by qq mesons. There are several claims for J P C = 1 −+ exotics, some of them with properties as predicted from the flux tube model interpreting the quark-antiquark binding by a gluon string. The evidence for these states depends partly on the assumption that meson-meson interactions are dominated by s-channel resonances. Hybrids with non-exotic quantum numbers should appear as additional states. Light-quark mesons exhibit a spectrum of (squared) masses which are proportional to the sum of orbital angular momentum and radial quantum numbers. Two states do not fall under this classification. They are discussed as hybrid candidates.The concept of multiquark states has received revived interest due to new resonances in the spectrum of states with open and hidden charm. The new states are surprisingly narrow and their masses and their decay modes often do not agree with simple quark-model expectations.Lattice gauge theories have made strong claims that glueballs and hybrids should appear in the meson spectrum. However, the existence of a scalar glueball, at least with a reasonable width, is highly questionable. It is possible that hybrids will turn up in complex multibody final states even though so far, no convincing case has been made for them by experimental data. Lattice gauge theories fail to identify the nonet of scalar mesons. Thus, at the present status of approximations, lattice gauge theories seem not to provide a trustworthy guide into unknown territory ...

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“…The extra state, which was found and investigated in [5,6,8], namely, f bare 0 (1580), should be identified as a scalar glueball, for its decay couplings satisfy the requirements inherent in the gluonium, see discussion in [3]. So, …”

Section: The K-matrix Analysis Of the (Ijmentioning

confidence: 99%

Systematics of Quark-Antiquark States: Where are the Lightest Glueballs?

Anisovich¹

2004

AIP Conference Proceedings

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The analysis of the experimental data of Crystal Barrel Collaboration on the pp annihilation in flight with the production of mesons in the final state resulted in a discovery of a large number of mesons over the region 1900-2400 MeV, thus allowing us to systematize quark-antiquark states in the (n, M 2 ) and (J, M 2 ) planes, where n and J are radial quantum number and spin of the meson with the mass M . The data point to meson trajectories in these planes being approximately linear, with a universal slope. Basing on these data and results of the recent K-matrix analysis a nonet classification is performed. In the scalar-isoscalar sector, the broad resonance state f0(1200−1600) is superfluous for the qq classification, i.e. it is an exotic state. The ratios of coupling constants for the transitions f0 → ππ, KK, ηη, ηη point to the gluonium nature of the broad state f0(1200 − 1600). The problem of the location of the lightest pseudoscalar glueball is also discussed.The search for exotic mesons should be based on the classification of qq-states. Exotic mesons are those which are superfluous for the qq systematics. The quark-antiquark systematics means: (i) classification of qq states as states located on the (n, M 2 ) and (J, M 2 ) trajectories, and (ii) determination of the quark-gluonium content of states from the analysis of the decay coupling constants, namely, hadronic and radiative decay couplings as well as weak ones.For the hadronic decay coupling constants, the most reliable information comes from the K-matrix analysis. In addition, the K-matrix analysis allows us to study bare states (the states before the onset of the decay processes).1.Systematics of the qq-states on the (n, M 2 ) and (J, M 2 ) planes. The analysis of experimental data on the pp annihilation in flight with the production of mesons in the final state resulted in a discovery of the large number of mesons over the region 1900-2400 MeV [1]. This allowed us to systematize quark-antiquark states on the (n, M 2 ) and (J, M 2 ) planes. The data point to almost the linear meson trajectories on these planes, with a universal slope [2].In Fig. 1, one can see the (n, M 2 ) trajectories for the (I = 1) states, which are drown for the a 1 -and a 3 -mesons (Fig. 1a), π-, π 2 -and π 4 -mesons (Fig. 1b), b 1 -and b 3 -mesons (Fig. 1c). All these trajectories reveal linear behaviour, such aswith µ 2 1.2 GeV 2 ; M 0 is the mass of the ground (basic) state, n = 1. The pion, being beyond the trajectory, is an exception, that is not a surprise, for the pion is a special particle in certain respect. In the classification, all these mesons should be treated as qq-states. Using the spectroscopy notations for qq-states, 2S+1 L J where S is the quark spin and L is their orbital momentum, we assign the trajectories to mesons as follows: a 1 (1230) trajectory: n 3 P 1 qq-states, a 3 (2030) trajectory: n 3 F 3 qq-states; π(140) trajectory: n 1 S 0 qq-states, π 2 (1670) trajectory: n 1 D 2 qq-states, π 4 (2250) trajectory: n 1 G 4 qq-states; b 1 (1235) trajectory: ...

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Systematics of quark antiquark states and scalar exotic mesons

Cited by 44 publications

References 129 publications

Regge trajectories for heavy quarkonia from the quadratic form of the spinless Salpeter-type equation

Regge trajectories for heavy quarkonia from the quadratic form of the spinless Salpeter-type equation

Glueballs, hybrids, multiquarks

Systematics of Quark-Antiquark States: Where are the Lightest Glueballs?

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Systematics of quark  antiquark states and scalar exotic mesons

Cited by 44 publications

References 129 publications

Regge trajectories for heavy quarkonia from the quadratic form of the spinless Salpeter-type equation

Regge trajectories for heavy quarkonia from the quadratic form of the spinless Salpeter-type equation

Glueballs, hybrids, multiquarks

Systematics of Quark-Antiquark States: Where are the Lightest Glueballs?

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Systematics of quark antiquark states and scalar exotic mesons