Vector boson pair production at one loop: analytic results for the process $$ \mathrm{q}\overline{\mathrm{q}}\ell \overline{\ell}{\ell}^{\prime }{\overline{\ell}}^{\prime}\mathrm{g} $$

Abstract

We present compact analytic results for the one-loop amplitude for the process 0 → $$ q\overline{q}\ell \overline{\ell}{\ell}^{\prime }{\overline{\ell}}^{\prime }g $$ q q ¯ ℓ ℓ ¯ ℓ ′ ℓ ¯ ′ g , relevant for both the production of a pair of Z and W-bosons in association with a jet. We focus on the gauge-invariant contribution mediated by a loop of quarks. We explicitly include all effects of the loop-quark mass m, appropriate for the production of a pair of Z-bosons. In the limit m → 0, our results are also applicable to the production of W-boson pairs, mediated by a loop of massless quarks. Implemented in a numerical code, the results are fast. The calculation uses novel advancements in spinor-helicity simplification techniques, for the first time applied beyond five-point massless kinematics. We make use of primary decompositions from algebraic-geometry, which now involve non-radical ideals, and p-adic numbers from number theory. We show how to infer whether numerator polynomials belong to symbolic powers of non-radical ideals through numerical evaluations.

Two-loop five-parton leading-colour finite remainders in the spinor-helicity formalism

“…To achieve compact results, it is important to control the evaluation of the coefficients in degenerate kinematic limits in complex kinematics [45], which generalize the familiar concepts of soft and collinear limits. To reconcile this type of evaluations with exact arithmetic the use of -adic numbers was proposed [46] and then further investigated in relation to multivariate partial fraction decompositions [47,48]. Another recent development was the use of Q[ì ] linear relations [49] to facilitate reconstruction.…”

Les Houches 2021—physics at TeV colliders: report on the standard model precision wishlist

“…In [59], a related method for extracting analytic expressions from high-precision floating point evaluations was introduced. This technique has been used to compute analytic one-loop amplitudes for H + 4j [60], the pp → W( → lν) + γ [61] process and ¢ ¢ qqll l l g ¯¯¯ [ 62]. In [63], a related approach to reconstructing analytic expressions from evaluations using p-adic numbers was presented.…”