arXiv subjects

L. Fekésházy

Publications and source records attributed to L. Fekésházy.

5 recordsLinked to original sources

arXiv2026

LinApart3: efficient algorithm for multivariate partial fraction decomposition with linear denominators

We present LinApart3, an efficient multivariate partial fraction decomposition algorithm for rational functions with linear denominators. Our decomposition algorithm guarantees that each term contains at most as many distinct denominators from the original set as partial fraction variables, introduces no spurious singularities, is independent of variable ordering, and is insensitive to the presence of spectator variables. While general multivariate approaches based on Gröbner bases or Leinartas' method handle arbitrary polynomial denominators, they suffer from intermediate expression swell. LinApart3 replaces polynomial-ideal computations with linear algebra and residue extraction by exploiting the geometry of the hyperplane arrangement defined by the denominators, circumventing this issue just as LinApart did in the univariate case. Because the individual basis contributions are independent, the algorithm is moreover naturally parallelizable. To showcase the utility of our algorithm we implemented the algorithm both in Wolfram Mathematica and FORM.

hep-ph↗

arXiv2026

CoLoRFulNNLO for color-singlet processes: An update on NNLOCAL

We give an update on the status of NNLOCAL, a parton-level Monte Carlo program implementing the extension of the completely local subtraction scheme CoLoRFulNNLO to color-singlet production in hadron-hadron collisions. The construction of the counterterms in our scheme is generic, being based on the standard IR factorization formulae of QCD. Furthermore, the integration of the counterterms over the phase space of unresolved emissions is performed fully analytically, allowing for good control of the numerical stability of our predictions. We validate our method by computing NNLO corrections to fully differential cross sections for the LHC.

hep-ph↗

arXiv2026

CoLoRFulNNLO for hadron collisions: integrating the iterated single unresolved subtraction terms

We present the analytic integration of the iterated single-unresolved subtraction terms in the extension of the CoLoRFulNNLO subtraction scheme to color-singlet production in hadron collisions. We exploit the fact that, in this scheme, subtraction terms are defined through momentum mappings which lead to exact phase space convolutions for real emissions. This allows us to write the integrated subtraction terms as parametric integrals, which can be evaluated using standard tools. Finally, we show that the integrated iterated single-unresolved approximate cross section can be written as a convolution of the Born cross section with an appropriately defined insertion operator.

hep-ph↗

arXiv2026

CoLoRFul for hadron collisions: Integrating the counterterms

In order to numerically compute scattering cross sections in QCD, one needs to deal with various kinematic divergences that appear at intermediate stages of the calculation. One way of doing this is by setting up an IR subtraction scheme. In this talk we give an update on the status of extending the CoLoRFul subtraction scheme, which has been successfully used in the past for processes with only final-state hadrons, to hadron-hadron collisions. In particular we discuss the analytic computation of the integrated counterterms.

hep-ph↗

arXiv2025

NNLOCAL: completely local subtractions for color-singlet production in hadron collisions

We present NNLOCAL, a proof-of-concept parton-level Monte Carlo program implementing the extension of the completely local subtraction scheme CoLoRFulNNLO to the case of color-singlet production in hadron collisions. We have built general local subtraction terms that regularize all single and double unresolved infrared singularities in real radiation phase space. The subtractions are then integrated fully analytically to the required order in the parameter of dimensional regularization. Combining the integrated counterterms with the virtual contributions we demonstrate the cancellation of all infrared poles explicitly. We validate our procedure by computing the fully differential cross section for the production of a Higgs boson at the LHC in an effective field theory with gluons only. Our code provides the first public implementation of a completely local analytic subtraction scheme at next-to-next-to-leading order accuracy.

hep-ph↗