Magnetic moments and charge radii of decuplet baryons in a field-theoretic quark model

Abstract

We make nonrelativistic as well as relativistic estimations of the magnetic moments and charge radii of decuplet baryons in a field-theoretic quark model, where translationally invariant decuplet baryon states are described by constituent quark field operators and harmonic oscillator wave functions. The relativistic estimations of the magnetic moments made are, however, O(lp'j/m) corrections over the nonrelativistic contribution where the higher order corrections for the ground states treated here, being small, are neglected. The constituent quark field operators here with a particular ansatz satisfy the equal time algebra and are also Lorentz boosted in a definite manner to describe the baryons in motion. The estimations for the magnetic moments and their ratios, with a single harmonic oscillator radius parameter for the octet as well as decuplet baryons, show a reasonable agreement with the most recent experimental measurements for A++ and R -, which have constrained different models of hadrons to explain both. We feel that the final results in this regard, expected in the near future in succeeding experiments, can further constrain different theoretical models. However, because of the lack of experimental data, the estimated charge radii in the present model stand as model predictions which may be verified in future experiments.PACS number(s): 13.40. Em, 12.39.Ki, 14.20.Gk

Octet to decuplet electromagnetic transition in a relativistic quark model

“…Our results for the decay widths in Table VII are comparable with most of the predictions presented in the literature [11][12][13][14][15]17,[20][21][22][23][24]27,65]. The exception is the result for the Á !…”

“…Ã decay width are in the range 150-300 keV for a large variety of quark models, algebraic models of hadron structure, Skyrme, and soliton models [11][12][13][14][15]17,[20][21][22]. Only HB PT has a window 252-540 keV [24], while the large N c limit predicts 336 AE 81 keV [27] and may overestimate the result of 300 keV, as well as the QCD sum rules with 409 keV [23].…”

“…The exception is the result for the Á ! N reaction, where most of the models underestimate the experimental data by more than 200 keV [11,14,15,17,21,22,28], except for the heavy baryon chiral perturbation theory (HB PT) [24], large N c limit [27], and QCD sum rules [23].…”

“…[4][5][6][7][8].) In the past, several theoretical studies of the octet to decuplet electromagnetic transitions were performed in nonrelativistic and relativistic quark models [9][10][11][12][13][14][15][16][17][18][19], Skyrme and soliton models [20][21][22], QCD sum rules [23], chiral perturbation theory [24][25][26], large N c limit [27], algebraic models of hadron structure [28], and lattice QCD [29]. In particular, lattice QCD studies for the à N !…”

Effect of the Casimir energy on the bag model phenomenology of light hadrons

“…Particles [20], the translationally invariant model with harmonic oscillator wave functions [21,22], the chiral constituent quark model [23], the chiral perturbation theory [24,25], the six-parameter fit based on the chiral bag sum rules [26], the eight-parameter fit based on the large-N c chiral perturbation theory [27], the eight-parameter fit based on 1/N c expansion [28], the QCD sum rules [29,30], and the lattice calculations [31,32].…”