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Title: Radiative decay of vector quarkonium: Constraints on glueballs and light gluinos

Journal Article · · Physical Review, D (Particles Fields); (United States)
;  [1]
  1. Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States)

Given a resonance of known mass, width, and [ital J][sup [ital P][ital C]], we can determine its gluonic branching fraction [ital b][sub [ital R][r arrow][ital g][ital g]] from data on it s production in radiative vector quarkonium decay [ital V][r arrow][gamma][ital R]. For most resonances [ital b][sub [ital R][r arrow][ital g][ital g]] is found to be [similar to]10%, consistent with being [ital q[bar q]] states, but we find that both pseudoscalars observed in the 1440 MeV region have [ital b][sub [ital R][r arrow][ital g][ital g]][similar to]1/2[minus]1, and [ital b]([ital f][sub 0][sup ++][r arrow][ital gg])[similar to]1/2. As data improve, [ital b][sub [ital R][r arrow][ital g][ital g]] should be a useful discriminator between [ital q[bar q]] and gluonic states and may permit quantitative determination of the extent to which a particular resonance is a mixture of glueball and [ital q[bar q]]. We also examine the regime of validity of PQCD for predicting the rate of [ital V][r arrow][gamma][eta][sub [ital [tilde g]]], the extra'' pseudoscalar bound state which would exist if there were light gluinos. From the CUSB limit on peaks in [Upsilon][r arrow][gamma][ital X], the mass range 3 GeV[approx lt][ital m]([eta][sub [ital [tilde g]]])[approx lt]7 GeV can be excluded. An experiment must be significantly more sensitive to exclude an [eta][sub [ital [tilde g]]] lighter than this.

OSTI ID:
7142482
Journal Information:
Physical Review, D (Particles Fields); (United States), Vol. 50:5; ISSN 0556-2821
Country of Publication:
United States
Language:
English