Renormalization of the next-to-leading-power $γγ\to h $ and $gg\to h$ soft quark functions

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Autori principali: Beneke, Martin, Ji, Yao, Wang, Xing
Natura: Preprint
Pubblicazione: 2024
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author Beneke, Martin
Ji, Yao
Wang, Xing
author_facet Beneke, Martin
Ji, Yao
Wang, Xing
contents We calculate directly in position space the one-loop renormalization kernels of the soft operators $O_γ$ and $O_g$ that appear in the soft-quark contributions to, respectively, the subleading-power $γγ\to h$ and $gg\to h$ form factors mediated by the $b$-quark. We present an IR/rapidity divergence-free definition for $O_g$ and demonstrate that with a correspondent definition of the collinear function, a consistent factorization theorem is recovered. Using conformal symmetry techniques, we establish a relation between the evolution kernels of the leading-twist heavy-light light-ray operator, whose matrix element defines the $B$-meson light-cone distribution amplitude (LCDA), and $O_γ$ to all orders in perturbation theory. Application of this relation allows us to bootstrap the kernel of $O_γ$ to the two-loop level. We construct an ansatz for the kernel of $O_g$ at higher orders. We test this ansatz against the consistency requirement at two-loop and find they differ only by a particular constant.
format Preprint
id arxiv_https___arxiv_org_abs_2403_17738
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Renormalization of the next-to-leading-power $γγ\to h $ and $gg\to h$ soft quark functions
Beneke, Martin
Ji, Yao
Wang, Xing
High Energy Physics - Phenomenology
We calculate directly in position space the one-loop renormalization kernels of the soft operators $O_γ$ and $O_g$ that appear in the soft-quark contributions to, respectively, the subleading-power $γγ\to h$ and $gg\to h$ form factors mediated by the $b$-quark. We present an IR/rapidity divergence-free definition for $O_g$ and demonstrate that with a correspondent definition of the collinear function, a consistent factorization theorem is recovered. Using conformal symmetry techniques, we establish a relation between the evolution kernels of the leading-twist heavy-light light-ray operator, whose matrix element defines the $B$-meson light-cone distribution amplitude (LCDA), and $O_γ$ to all orders in perturbation theory. Application of this relation allows us to bootstrap the kernel of $O_γ$ to the two-loop level. We construct an ansatz for the kernel of $O_g$ at higher orders. We test this ansatz against the consistency requirement at two-loop and find they differ only by a particular constant.
title Renormalization of the next-to-leading-power $γγ\to h $ and $gg\to h$ soft quark functions
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2403.17738