Determination of the Magnetic Dipole Moment of the Rho Meson

Abstract

We determine the magnetic dipole moment of the rho meson using preliminary data from the BaBar Collaboration for the e+e- → π+π-2π0 process, in the center of mass energy range from 0.9 to 2.2 GeV. We describe the γ* → 4π vertex using a vector meson dominance model, including all intermediate resonance contributions. We find that μρ = 2.1 ± 0.5 [e/2mρ].

ρmeson form factors in a confining Nambu–Jona-Lasinio model

“…Our purpose here is to compare results within this NJL model with other calculations, for example, constituent quark models [6][7][8][9][10][11][12][13][14], QCD sum rules [15][16][17][18], Dyson-Schwinger equations [19][20][21][22] and the recent lattice QCD studies [25,26]. We first focus on static electromagnetic [19] 0.37 3.28 -0.055 Bhagwat [20] 0.54 2.54 -0.026 Roberts [21] 0.31 2.14 -0.037 Pitschmann [22] -2.13 -Owen [25] 0.670(68) 2.613(97) -0.0452(61) Shultz [26] 0.30 (6) 2.00(9) -0.020(4) Table II.…”

“…We first focus on static electromagnetic [19] 0.37 3.28 -0.055 Bhagwat [20] 0.54 2.54 -0.026 Roberts [21] 0.31 2.14 -0.037 Pitschmann [22] -2.13 -Owen [25] 0.670(68) 2.613(97) -0.0452(61) Shultz [26] 0.30 (6) 2.00(9) -0.020(4) Table II. Comparison of the ρ + charge radius, magnetic moment and quadrupole moment for various theoretical approaches: phenomenological models [6], constituent quark models [8,9,[11][12][13][14], QCD sum rules [16,18], Dyson Schwinger equations [19][20][21][22] and lattice QCD [25,26]. The lightest pion mass used in the lattice calculation in Ref.…”

“…The ρ form factors, or equivalently the polarization amplitudes, have been calculated using a variety of methods, for example, phenomenological models [5,6], constituent quark models in the light front framework [7][8][9][10][11][12][13][14], QCD sum rules [15][16][17][18] and the Dyson-Schwinger equations [19][20][21][22]. The first attempts to compute ρ form factors using lattice QCD were reported in Refs.…”

Multipole moments of heavy vector and axial-vector mesons in QCD

“…It is challenging to measure the magnetic moments of the vector mesons directly since their lifetimes are very short. Even though the indirect measurement is possible [14], however, it has large uncertainty. It should be noted that with the help of the magnetic dipole transitions M1, in which there exists many experimental data, it is possible to determine the transition magnetic moments of heavy mesons.…”