Evidence for two JP = 2− strange meson states in the K2 (1770) region

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 total LASS kaon program contained 135 million events collected in 1982. The results were published in [224,[226][227][228][229][230].…”

Section: The Lass Experimentsmentioning

confidence: 74%

Glueballs, hybrids, multiquarks

2007

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“…These could potentially produce reflected structures in the J/ψφ spectrum. In particular, a D-wave contribution to K − p scattering in the mass region around 1.7-1.8 GeV has been reported by several fixed-target experiments [29][30][31]. This is interpreted as two interfering broad J P = 2 − resonances, labeled K 2 (1770) and K 2 (1820), with widths in the range 200-300 MeV.…”

Section: Resultsmentioning

confidence: 90%

Observation of a peaking structure in the J/ψϕ mass spectrum from B±
Chatrchyan¹,
Khachatryan²,
Sirunyan³
et al. 2014
Physics Letters B
128
5
56
0
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A peaking structure in the J/ψφ mass spectrum near threshold is observed in B ± → J/ψφK ± decays, produced in pp collisions at √ s = 7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/ψ, corresponds to an integrated luminosity of 5.2 fb −1 . Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m = 4148.0 ± 2.4 (stat.) ± 6.3 (syst.) MeV and Γ = 28 +15 −11 (stat.) ± 19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/ψφ mass is also reported.Events are chosen using a two-level trigger system. The first level, composed of custom hardware processors, uses information from the muon detectors to select dimuon candidates. The high-level trigger (HLT) runs a special version of the offline software code on a processor farm to select events with nonprompt J/ψ candidates coming from the decays of B mesons.Events containing J/ψ candidates are selected by the HLT dimuon trigger. Because of the increasing LHC instantaneous luminosity, there are two configurations of the HLT, corresponding to two running periods and two distinct data sets. For both data sets, the following require- B The CMS Collaboration

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“…(21) Inserting the masses of states into relations ( 12), ( 20), (21), with the aid of M 2 ss(1 [24,42], we obtain the values of…”

Section: Regge Phenomenology and Mass Relationsmentioning

confidence: 99%

“…The K 2 (1770) was first reported in the reaction K − p → pK − π + π − and K − p → p K0 π − π 0 [20]. Moreover, the evidence for two J P = 2 − strange mesons was presented in the reaction K − p → K − π + π − π 0 p [21]. Unlike the π 2 (1670), η 2 (1645) and η 2 (1870), the kaon has non-diagonal C-parity, the spin-singlet (1 1 D 2 ) and spin-triplet (1 3 D 2 ) can mix to produce the physical states K 2 (1770) and K 2 (1820) [22].…”

Section: Introductionmentioning

confidence: 96%

Towards the Assignments for \(1^{1}D_{2}\) and \(1^{3}D_{2}\) Meson Nonets

Feng¹,

Wei²,

Wu³

et al. 2022

Acta Phys. Pol. B

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A new form of potential is used to treat the optical model unequivocally for the analysis of scattering results of the 58 Ni + 27 Al system. The phenomenological optical potential is formed with the Ginocchio potential for analysis near the Coulomb barrier. Theoretical calculations explain the experimental outcomes over a wide range of colliding energies, and hence exhibit threshold anomaly. An inbuilt non-trivial behaviour in the formulation near the Coulomb barrier position is found essential for a successful explanation of the experimental results.

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Evidence for two JP = 2− strange meson states in the K2 (1770) region

Cited by 13 publications

References 5 publications

Glueballs, hybrids, multiquarks

Glueballs, hybrids, multiquarks

Observation of a peaking structure in the J/ψϕ mass spectrum from B±
Chatrchyan¹,
Khachatryan²,
Sirunyan³
et al. 2014
Physics Letters B
128
5
56
0
View full text Add to dashboard Cite

Towards the Assignments for \(1^{1}D_{2}\) and \(1^{3}D_{2}\) Meson Nonets

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Evidence for two JP = 2− strange meson states in the K2 (1770) region

Cited by 13 publications

References 5 publications

Glueballs, hybrids, multiquarks

Glueballs, hybrids, multiquarks

Observation of a peaking structure in the J/ψϕ mass spectrum from B±Chatrchyan1, Khachatryan2, Sirunyan3 et al. 2014Physics Letters B1285560View full textAdd to dashboardCite

Towards the Assignments for \(1^{1}D_{2}\) and \(1^{3}D_{2}\) Meson Nonets

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Product

Resources

About

Observation of a peaking structure in the J/ψϕ mass spectrum from B±
Chatrchyan¹,
Khachatryan²,
Sirunyan³
et al. 2014
Physics Letters B
128
5
56
0
View full text Add to dashboard Cite