PreprintarXiv licencearXiv
Automated two-loop fermion-bubble contributions at high multiplicity
Abstract
We compute the gauge-invariant, helicity-summed two-loop Nf contribution for qq̅→ nγ(*), n=2,…,8. Local ultraviolet renormalisation, infrared factorisation, analytic loop-energy integration and a new automated threshold subtraction yield finite integrals over real spatial momenta. Adaptive multi-channel Monte Carlo samples loop momenta, helicities and identical-particle permutations. We quantify generation and evaluation costs across multiplicities. The same representation is integrated directly with parton distributions through five photons, yielding inclusive and differential virtual corrections.
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BibTeX
@misc{kermanschah2026automated,
title = {{Automated two-loop fermion-bubble contributions at high multiplicity}},
author = {Dario Kermanschah},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.35655},
eprint = {2610.35655},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.35655},
}
RIS
TY - UNPB
TI - Automated two-loop fermion-bubble contributions at high multiplicity
AU - Dario Kermanschah
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2610.35655
UR - https://arxiv.org/abs/2610.35655
AB - We compute the gauge-invariant, helicity-summed two-loop N_f contribution for qq̅→ nγ^(*), n=2,…,8. Local ultraviolet renormalisation, infrared factorisation, analytic loop-energy integration and a new automated threshold subtraction yield finite integrals over real spatial momenta. Adaptive multi-channel Monte Carlo samples loop momenta, helicities and identical-particle permutations. We quantify generation and evaluation costs across multiplicities. The same representation is integrated directly with parton distributions through five photons, yielding inclusive and differential virtual corrections.
ER -