TY - JOUR
T1 - Effective theory calculation of resonant high-energy scattering
AU - Beneke, M.
AU - Chapovsky, A. P.
AU - Signer, A.
AU - Zanderighi, G.
N1 - Funding Information:
We thank M. Kalmykov for correspondence. The work of M.B. and A.C. is supported by the DFG Sonderforschungsbereich/Transregio 9 “Computergestützte Theoretische Teilchenphysik”. We also acknowledge the use of the Mathematica packages FeynCalc and FeynArts [22] for performing some of the loop calculations.
PY - 2004/5/10
Y1 - 2004/5/10
N2 - Tests of the Standard Model and its hypothetical extensions require precise theoretical predictions for processes involving massive, unstable particles. It is well-known that ordinary weak-coupling perturbation theory breaks down due to intermediate singular propagators. Various pragmatic approaches have been developed to deal with this difficulty. In this paper we construct an effective field theory for resonant processes utilizing the hierarchy of scales between the mass of the unstable particle, M, and its width, Γ. The effective theory allows calculations to be systematically arranged into a series in g2 and Γ/M, and preserves gauge invariance in every step. We demonstrate the applicability of this method by calculating explicitly the inclusive line shape of a scalar resonance in an Abelian gauge-Yukawa model at next-to-leading order in Γ/M and the weak couplings. We also discuss the extension to next-to-next-to-leading order and compute an interesting subset of these corrections.
AB - Tests of the Standard Model and its hypothetical extensions require precise theoretical predictions for processes involving massive, unstable particles. It is well-known that ordinary weak-coupling perturbation theory breaks down due to intermediate singular propagators. Various pragmatic approaches have been developed to deal with this difficulty. In this paper we construct an effective field theory for resonant processes utilizing the hierarchy of scales between the mass of the unstable particle, M, and its width, Γ. The effective theory allows calculations to be systematically arranged into a series in g2 and Γ/M, and preserves gauge invariance in every step. We demonstrate the applicability of this method by calculating explicitly the inclusive line shape of a scalar resonance in an Abelian gauge-Yukawa model at next-to-leading order in Γ/M and the weak couplings. We also discuss the extension to next-to-next-to-leading order and compute an interesting subset of these corrections.
UR - http://www.scopus.com/inward/record.url?scp=1842661086&partnerID=8YFLogxK
U2 - 10.1016/j.nuclphysb.2004.03.016
DO - 10.1016/j.nuclphysb.2004.03.016
M3 - Article
AN - SCOPUS:1842661086
SN - 0550-3213
VL - 686
SP - 205
EP - 247
JO - Nuclear Physics, Section B
JF - Nuclear Physics, Section B
IS - 1-2
ER -