TY  - JOUR
AU  - Catani, S.
AU  - Cieri, L.
PY  - 2022
DA  - 2022//
TI  - Multiple soft radiation at one-loop order and the emission of a soft quark-antiquark pair
T2  - Eur. Phys. J. C
JO  - European Physical Journal C
SP  - 97 - 27pp
VL  - 82
IS  - 2
PB  - Springer
AB  - We consider the radiation of two or more soft partons in QCD hard-scattering at one-loop order. The corresponding scattering amplitude is singular, and the singular behaviour is controlled by a process-independent soft current. Using regularization in d = 4 – 2 epsilon space-time dimensions, we explicitly evaluate the ultraviolet and infrared divergent (epsilon-pole) terms of the one-loop soft current for emission of an arbitrary number of soft partons in a generic hard-scattering process. Then we consider the specific case of soft quark-antiquark (q (q) over bar) emission and we compute the one-loop current by including the finite terms. We find that the one-loop soft-q (q) over bar current exhibits a new type of transverse-momentum singularity, which has a quantum (absorptive) origin and a purely non-abelian character. At the squared amplitude (cross section) level, this transverse-momentum singularity produces contributions to multijet production processes in hadron collisions. The one-loop squared current also leads to charge asymmetry terms, which are a distinctive features of soft-q (q) over bar radiation. We also extend these results to the cases of QED and mixed QCDxQED radiative corrections for soft fermion-antifermion emission.
SN  - 1434-6044
UR  - https://arxiv.org/abs/2108.13309
UR  - https://doi.org/10.1140/epjc/s10052-022-10001-z
DO  - 10.1140/epjc/s10052-022-10001-z
LA  - English
N1  - WOS:000749553600001
ID  - Catani+Cieri2022
ER  -