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Title: Baryon octet to decuplet electromagnetic transitions

Journal Article · · Physical Review, D (Particles Fields); (United States)
 [1];  [2];  [3]
  1. Department of Physics and Center for Theoretical Physics, University of Maryland, College Park, Maryland 20742 (United States)
  2. Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)
  3. TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada)

The electromagnetic transition moments of the SU(3)-flavor baryon octet to decuplet are examined within a lattice simulation of quenched QCD. The magnetic transition moment for the [ital N][gamma][leftrightarrow][Delta] channel is found to be in agreement with recent experimental analyses. The lattice results indicate [mu][sub [ital p][Delta]]/[mu][sub [ital p]]=0.88(15). In terms of the Particle Data Group convention, [ital f][sub [ital M]1]=0.231(41) GeV[sup [minus]1/2] for [ital p][gamma][leftrightarrow][Delta][sup +] transitions. Lattice predictions for the hyperon [ital M]1 transition moments agree with those of a simple quark model. However the manner in which the quarks contribute to the transition moments in the lattice simulation is different from that anticipated by quark model calculations. The scalar quadrupole form factor exhibits a behavior consistent with previous multipole analyses. The [ital E]2/[ital M]1 multipole transition moment ratios are also determined. The lattice results suggest [ital R][sub EM][equivalent to][minus][ital scrG][sub [ital E]2]/[ital scrG][sub [ital M]1]=+3[plus minus]8% for [ital p][gamma][leftrightarrow][Delta][sup +] transitions. Of particular interest are significant nonvanishing signals for the [ital E]2/[ital M]1 ratio in [Xi][sup [minus]] and [Sigma][sup [minus]] electromagnetic transitions.

DOE Contract Number:
FG05-87ER40322; FG05-84ER40154
OSTI ID:
6025647
Journal Information:
Physical Review, D (Particles Fields); (United States), Vol. 48:5; ISSN 0556-2821
Country of Publication:
United States
Language:
English