Dipole moments of the ρ meson

Abstract

The electric and magnetic dipole moments of the meson are calculated using the propagators and vertices derived from the QCD Dyson-Schwinger equations. Results obtained from using the Bethe-Salpeter amplitude studied by Chappell, Mitchell, and Tandy, and Pichowsky and Lee, are compared. The meson electric dipole moment is generated through the inclusion of a quark electric dipole moment, which is left as a free variable. These results are compared to the perturbative results to obtain a measure of the effects of quark interactions and confinement. The two dipole moments are also calculated using the phenomenological MIT bag model to provide a further basis for comparison. ͓S0556-2813͑98͒01405-8͔

Electromagnetic form factors of theρmeson in light cone QCD sum rules

“…(4), (5) and (6) we present the dependence of the charge G C , magnetic We observe from these figures that the dependence of the form factors on s 0 is rather weak and when s 0 vary from s 0 = 1.8 GeV 2 to s 0 = 2.2 GeV 2 . Unfortunately, the sum rules fail working at small Q 2 , and hence do not allow determination of the magnetic moment of the ρ meson with better accuracy compared to the results in the literature, such as, the results predicted by the sum rules [6,7], Dyson-Schwinger based models [15,16], Covariant light-front approach with constituent quark model [17], light-front formalism [18] and lightfront quark model [19]. Our analysis predicts that, starting from Q 2 = 0.5 GeV 2 , the ratio [19] (we use the same parametrization for the form factors as in [19]).…”

Electric dipole moment of theρmeson

“…herein DSE [13] BM [13] nrQM [13] [13] summarises results obtained from momentumdependent DSE input, BM [13] reports a bag-model result, and nrQM [13] is the non-relativistic constituentquark value. We depict the current-quark mass dependence of this contribution in Fig.…”

“…Not that there is any hope of measuring a ρ-meson EDM but because the nonperturbative methods necessary can most readily be illustrated in the case of systems defined by two valence-quark degrees-of-freedom. In taking this path, we follow other authors [13][14][15] but will nonetheless expose novel insights, especially because we consider more operator structures than have previously been considered within a single unifying framework. It is worth remarking here that particles with spin also possess a magnetic dipole moment.…”

Effects of the magnetic dipole moment of charged vector mesons in their radiative decay distribution

“…In analogy with the W ± magnetic dipole moment in the standard electroweak theory, κ = 1 can be considered as the natural or canonical value for the vector mesons [9]. However, substantial deviations from this canonical value can be expected and in fact, some available calculations of ∆κ ≡ κ − 1 in the context of phenomenological quark models indicate values as large as ∆κ ∼ 2.6 [10] for the ρ meson.…”