arXiv subjects

John Paul Archambault

Publications and source records attributed to John Paul Archambault.

2 recordsLinked to original sources

arXiv2004

Three-loop QCD corrections and b-quark decays

We present three-loop (NNNLO) corrections to the heavy-to-heavy quark transitions in the limit of equal initial and final quark masses. In analogy with the previously found NNLO corrections, the bulk of the result is due to the beta_0^2 alpha_s^3 corrections. The remaining genuine three-loop effects for the semileptonic b --> c decays are estimated to increase the decay amplitude by 0.2(2)%. The perturbative series for the heavy-heavy axial current converges very well.

hep-ph↗

arXiv2004

Electric Dipole Moments of Leptons in the Presence of Majorana Neutrinos

We calculate the two-loop diagrams that give a non-zero contribution to the electric dipole moment d_l of a charged lepton l due to possible Majorana masses of neutrinos. Using the example with one generation of the Standard Model leptons and two heavy right-handed neutrinos, we demonstrate that the non-vanishing result for d_l first appears in order O(m_l m_ν^2 G_F^2), where m_νis the mass of the light neutrino and the see-saw type relation is imposed. This effect is beyond the reach of presently planned experiments.

hep-ph↗