A gaussian sumrule analysis of scalar glueballs
Abstract
Although marginally more complicated than the traditional Laplace sumrules, gaussian sumrules have the advantage of being able to probe excited and ground states with similar sensitivity. Gaussian sumrule analysis techniques are applied to the problematic scalar glueball channel to determine masses, widths and relative resonance strengths of lowlying scalar glueball states contributing to the hadronic spectral function. A feature of our analysis is the inclusion of instanton contributions to the scalar gluonic correlation function. Compared with the nexttoleading gaussian sumrule, the analysis of the lowestweighted sumrule (which contains a large scaleindependent contribution from the low energy theorem) is shown to be unreliable because of instability under QCD uncertainties. However, the presence of instanton effects leads to approximately consistent mass scales in the lowest weighted and nextlowest weighted sumrules. The analysis of the nexttoleading sumrule demonstrates that a single narrow resonance model does not provide an adequate description of the hadronic spectral function. Consequently, we consider a wide variety of phenomenological models which distribute resonance strength over a broad region — some of which lead to excellent agreement between the theoretical prediction and phenomenological models. Including QCD uncertainties, our results indicate that the hadronic contributions to the spectral function stem from a pair of resonances with masses in the range 0.81.6 GeV, with the lighter of the two potentially having a large width.
 Publication:

Nuclear Physics A
 Pub Date:
 December 2001
 DOI:
 10.1016/S03759474(01)010946
 arXiv:
 arXiv:hepph/0011044
 Bibcode:
 2001NuPhA.695..205H
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 latex2e, 22 pages, 5 figures. Analysis extended in revised version