Two loop anomalous dimension of the chromomagnetic moment of a heavy quark

Jan, 1997
13 pages
Published in:
  • Phys.Lett.B 401 (1997) 81-90
e-Print:
Report number:
  • CERN-TH-97-003,
  • CERN-TH-97-03,
  • CERN-TH-97-3

Citations per year

1997200420112018202301234567
Abstract:
We find that the anomalous dimension (in the MSˉ\bar{MS} scheme) of the chromo-magnetic operator gshˉvσμνG μνhvg_s\bar h_v\sigma_{\mu\nu} G~{\mu\nu} h_v in the heavy-quark effective theory is \gamma_{mag} = (C_A\alpha_s / 2\pi) [1 + ( 17/18 C_A - 13/18 T_F n_f)\alpha_s/\pi + O(\alpha_s~2)] generalizing the one-loop expression known previously. To derive the two-loop result, we use the reparametrization invariance and the virial theorem. After performing infrared subtractions, all two-loop integrals are of propagator type and are evaluated by a recurrence relation for tensor integrals.
Note:
  • 13 pages, 4 figures Report-no: CERN-TH/97-3
  • HQET model
  • quark: magnetic moment
  • perturbation theory: higher-order
  • higher-order: 2
  • invariance: reparametrization
  • renormalization
  • numerical calculations: interpretation of experiments