Abstract
Hadron phenomenology inspired by quantum chromodynamics (QCD) has made great progress in explaining, in a semi-quantitative way, the spectroscopy and decay rates of mesons containing heavy (b, c) quarks. Light (u, d, s) quark spectroscopy was vital for the early successes of the SU6 quark model; these early successes were, however, never permitted to grow into a quantitatively descriptive, much less a predictive, theory of light quarks and antiquarks bound together by gluons, in a rigorous QCD framework. In the present lecture, we restrict ourselves to meson spectroscopy in the low-mass region ≲ 2.2 GeV/c2, and to the attempts to understand their mass and symmetry structure. We point up some particularly vexing open questions and problems. We then review the information that has recently become available from heavy quarkonium (mainly charmonium) decays into light-quark-based mesons. It turns out that these decays, observable largely in the center-of-mass frame, with large counting rates and low multiplicities, are able to permit valuable insights into the quark content and symmetry structure of this regime of u, d, s-based mesons. The lecture is organized as follows:
-
2.
Open questions in the lowest-mass \( q\bar{q} \) nonets.
-
3.
The use of charmonium decays to define projection operators of quark content and symmetry structure.
-
4.
Information available from hadronic and radiative \( c\bar{c} \) decays: a case-by-case review.
-
5.
Do gluonia show up in radiative decays?
-
6.
Exotic candidates: do \( c\bar{c} \) decays have unique information to contribute?
-
7.
A score sheet.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
For a description of the basic non-relativistic quark model, see R.H. Dalitz, in High Energy Physics,Les Houches 1965 Lectures, C. de Witt and M. Jacob, eds., Gordon & Breach, New York (1966) pp. 251 ff. The QCD-inspired version was first worked out by A. de Rujula, H. Georgi, S.L. Glashow, Phys. Rev. D12, 147 (1975).
See the excellent review article by N.A. Tórngvist, Acta Phys. Pol.,B16, 513 (1985);
N. Isgur, in The New Aspects of Subnuclear Physics,A Zichichi, ed., Plenum Press, New York, (1980).
Such calculations were explicitly done for low-mass pseudoscalar mesons: J.F. Donoghue, and H. Gomm, Phys. Lett. 121b, 49 (1983).
See also the summary talk of Hadron ‘87 by J.L. Rosner in the Proceedings volume, KEK 87–7(1987).
Ideal mixing corresponds in the standard mixing scheme (here illustrated for the case of the pseudoscalars), \( \eta =\cos \theta {{\eta }^{(8)}}+\sin \theta {{\eta }^{(1)}}, \) \(\eta ' = - \sin \theta {\eta ^{(8)}} + \cos \theta {\eta ^{(1)}},\) to an angle θ ≈ 35°. With the usual η (8), η (1) quark assignments, it would lead to \( \eta =\frac{1}{\sqrt{2}}(u\bar{u}+d\bar{d}), \) \(\eta ' = - s\bar s.\)
G. t’Hooft, Phys. Rev. Lett. 37, 8 (1976);
G. t’Hooft, Phys. Rep. 142, 357 (1986);
R. Crewther, Phys. Lett. 70B, 349 (1977);
R. Crewther, Riv. Nuovo Cim. 2, 63 (1979).
S.J. Brodsky and G.P. LePage, Phys. Rev. D24, 2848 (1981).
N.N. Achasov et al., Soy. J. Nucl. Phys., 32, 566 (1980).
V. Novikov et al.,Nucl. Phys. B165, 67 (1980); for a lucid explanation of the instanton concept, read chapter 7 of S. Coleman, Aspects of Symmetry (Selected Erice Lectures), Cambridge Univ. Press (1985).
B. Barish and R. Stroynowski, Phys. Rep. 157, 1 (1988).
The MARK III detector is described in D. Bernstein et al., Nucl. Instrum. & Methods 226, 301 (1984);
the DM2 detector in J.E. Augustin et al., Physica Scripta 23, 623 (1981).
J.L. Rosner, Phys. Rev. D27, 1101 (1983)
H.E. Haber and J. Perrier, Phys. Rev. D32, 2961 (1985).
R. Baltrusaitis et al., (MARK III Collaboration), Phys. Rev. D32, 2883 (1985).
H. Aihara et al., Phys. Rev. Lett. 57, 51 (1986).
J. Adler et al., (MARK III Collaboration), Contribution to the EPS Conference on High Energy Physics, Uppsala (1987), to be published; Z. Ajaltouni et al., (DM2 Collaboration), Contributions to the 1987 Lepton-Photon Symposium, Hamburg.
Numerous such schemes have been suggested; see, e.g., F. Caruso et al., Z. Phys. C30, 493 (1986).
S.C. Chao et al., Phys. Lett. B172, 253 (1986).
S.V. Chung et al.,Phys. Rev. Lett. 55, 779 (1985).
A. Ando et al.,Phys. Rev. Lett. 57, 1296 (1986).
H. Aihara et al., Phys. Rev. Lett. 57, 2500 (1982);
G. Gidal et al.,(MARK II Collaboration) Phys. Rev. Lett. 59, 2016 (1987).
This signal is observed in the charge modes K s K ± π ∓, K+K− π 0, K s K s π 0, by the MARK III Collaboration. (J. Richman, CalTech thesis (1983), unpublished), and by the DM2 Collaboration (J. Augustin, et al., LAL-85/27 1985)).
This state (see J. Richman, previous ref.) was originally identified with ι(1460); its important radiative width (Г(X) → γρ 0= 1.9 ± 0.7 MeV) was taken as an argument in opposition to the gluonium interpretation of ι(1460). See J. Donoghue in Particles and Fields 1981, C.A. Heusch and W.T. Kirk, eds. AIP, New York (1982).
F. Close, in Quarks and Hadronic Matter, Yukon Advanced Studies Institute (1984), originally proposed this test of the ι wavefunction, in the context of vector-dominance relations between photon and vector mesons.
N. Wermes, Proc. 5th Conference on Physics in Collision, Autun, France, World Scientific (1986).
Note that S-wave qq scattering lengths would lead naturally to an appearance of 0−+ characteristics. A quantitative evaluation is presently in progress.
The recent DM2 results (D. Bisello et al.,Contributions to the 1987 Lepton-Photon Symposium, Hamburg, and L. Stanco, Orsay preprint LAL-87–40) present the most consistent data sample. Note that the decay η c → φφ permitted the MARK III Collaboration to confirm the identity of the state by way of a straightforward spin-parity analysis (R. Baltrusaitis et al., Phys. Rev. Lett. 52, 2126 (1984).
L. Köpke (MARK III Collaboration), Proceedings of the XXIIrd International Conference on High Energy Physics, S. Loken, ed., World Scientific, Singapore (1986).
J.E. Augustin et al., LAL 85/27 (1985).
D.M. Coffman et al., (MARK III Collaboration), SLAC-PUB-4460 (to be published).
W. Lockman (MARK III Collaboration), Proceedings, 1986 San Miniato Workshop (to be published).
W. Lockman (MARK III Collaboration), Proceedings, 1986 Lake Louise Conference on Intersections of Nuclear and Particle Physics.
H. Kolanski and P. Zerwas, DESY Preprint 87–175 (1987).
D. Aston et al., DPNU 87/15; SLAC-PUB-4279 (1987); to be published in Nucl. Phys. B.
L. Köpke (MARK III Collaboration), SCIPP/MARK III Memo (1986). Unpublished.
See the contributions of C. Heusch and A. Seiden to the MARK III Pow-Wow; SLAC-Report 323 (1988).
J. Adler et al., (MARK III), to be published. T. Bolton, Ph.D. thesis, M.I.T. (1988); unpublished.
R. Baltrusaitis et al., (MARK III), Phys. Rev. D35, 2077 (1987).
C. Edwards et al., (Crystal Ball Collaboration), Phys. Rev. Lett. 48, 458 (1982).
J. Adler et al.,(MARK III), Contribution to the Proceedings of the EPS Conference, Uppsala (1987), G. Dubois, editor. Note that the MARK III data are severely limited due to the absence of a neutral trigger; this is presently being installed.
D. Alde et al., Nucl. Phys. B269, 485 (1986).
Should this scenario turn out to be correct, the confusing nomenclature of these states would obviously be redefined.
R. Baltrusaitis et al., (MARK III), Phys. Rev. Lett. 56, 107 (1986).
D. Alde et al., Phys. Lett. 177B, 120 (1986).
The interest of the final state ηη’ in the context of gluonium searches has been discussed by S.S. Gershtein et al., Z. Phys. C24, 305 (1984).
H.F. Lipkin, Phys. Lett. 109B, 326 (1982).
A. Etkin et al., Phys. Lett. 165B, 217 (1985).
J. Adler et al., (MARK III Collaboration), as quoted by G. Dubois in Proceedings of the EPS Conference, Uppsala (1987)
L. Stanco et al., (DM2 Collaboration), LAL 87–42 (1987).
For recent gluonium reviews, see, e.g., F.E. Close, R/XL-87–072 to be published in Rep. Progr. Phys.; F. Couchot, LAL 87–40 (1987); C.A. Heusch, Proceedings, Multiparticle Symposium, Seewinkel, World Scientific, Singapore (1986); M.S. Chanowitz, in Hadron ‘87, KEK, Tsukuba (1987).
J.D. Bjorken, Proceedings, 1979 SLAC Summer School, A. Mosher ed., SLAC Report 224 (1980). See also M. Chanowitz, Ref. 53, and S. Gershtein et al., Ref. 44.
S. Godfrey, Phys. Lett. 141B, 439 (1984).
S.J. Lindenbaum, Comments Nucl. Part. Physics 13, 285 (1984).
M. Chanowitz (Proc. V I th International Workshop on Photon-Photon Colli sions, World Scientific, Singapore (1984)) defined this relative gluon affinity as “stickiness” \(S = {\left( {\frac{{ms}}{{k*(\not \upsilon \to \gamma X)}}} \right)^3}\frac{{\Gamma (Y \to \gamma X)}}{{\Gamma (X \to \gamma \gamma )}}.\). This measure can serve as a comparison of states with equal quantum number: for J PC=0−+, S(ι):S(η′):S(η) =(>65):4:1; for J PC=2++, S(Θ):S(f′):S(f)=(>20):3:1.
The values for Rγ and R V , given by C.A. Heusch in Ref. 49 have to be updated using recent MARK II data on γγ →ι(1460) limits- G. Gidal, et al., Phys. Rev. Lett. 59, 2016 (1987).
F. Binon (GAMS Collaboration), Proceedings of the Hadron ‘87 Conference, KEK, Tsukuba (1987); a similar signal may have been seen by W.D. Apel et al., Nucl. Phys. B193, 269 (1983).
S.I. Bityukov et al., Phys. Lett. B188, 383 (1987).
F.S. Close, H.J. Lipkin, RAL 87/046 (1987), and M. Boutemeur, in Hadrons, Quarks, and Gluons, J. Tran Thanh Van, ed., Editions Frontières, Paris (1987).
This feature was postulated long ago: T. Barnes, Z. Phys. C10, 275 (1981). Note, however, that preliminary data of both the DM2 and MARK III Collaborations show indications of a non-pseudoscalar enhancement at m(4π) 1285 MeV/c2, in the radiative decay process J/ψ→γπ + π − π + π −. If this state is to be identified with f 1 (1285), the argument has to be modified from “absence” to “suppression” of states not accessible to two transverse gluons.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1990 Plenum Press, New York
About this chapter
Cite this chapter
Heusch, C.A. (1990). Light-Quark Spectroscopy from Charmonium Decay. In: Zichichi, A. (eds) The Superworld II. The Subnuclear Series, vol 25. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-7467-1_9
Download citation
DOI: https://doi.org/10.1007/978-1-4684-7467-1_9
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4684-7469-5
Online ISBN: 978-1-4684-7467-1
eBook Packages: Springer Book Archive