A gaussian sum-rule analysis of scalar glueballs

Citation
D. Harnett et Tg. Steele, A gaussian sum-rule analysis of scalar glueballs, NUCL PHYS A, 695, 2001, pp. 205-236
Citations number
49
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
NUCLEAR PHYSICS A
ISSN journal
0375-9474 → ACNP
Volume
695
Year of publication
2001
Pages
205 - 236
Database
ISI
SICI code
0375-9474(200112)695:<205:AGSAOS>2.0.ZU;2-O
Abstract
Although marginally more complicated than the traditional Laplace sum-rules , gaussian sum-rules have the advantage of being able to probe excited and ground states with similar sensitivity. Gaussian sum-rule analysis techniqu es are applied to the problematic scalar glueball channel to determine mass es, widths and relative resonance strengths of low-lying scalar glueball st ates contributing to the hadronic spectral function. A feature of our analy sis is the inclusion of instanton contributions to the scalar gluonic corre lation function. Compared with the next-to-leading gaussian sum-rule, the a nalysis of the lowest-weighted sum-rule (which contains a large scale-indep endent contribution from the low energy theorem) is shown to be unreliable because of instability under QCD uncertainties. However, the presence of in stanton effects leads to approximately consistent mass scales in the lowest weighted and next-lowest weighted sum-rules. The analysis of the next-to-l eading sum-rule demonstrates that a single narrow resonance model does not provide an adequate description of the hadronic spectral function. Conseque ntly, we consider a wide variety of phenomenological models which distribut e resonance strength over a broad region - some of which lead to excellent agreement between the theoretical prediction and phenomenological models. I ncluding QCD uncertainties, our results indicate that the hadronic contribu tions to the spectral function stem from a pair of resonances with masses i n the range 0.8-1.6 GeV, with the lighter of the two potentially having a l arge width. (C) 2001 Elsevier Science B.V. All rights reserved.