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Related papers: Quark correlation functions at three-loop order an…

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We provide results for the one-loop triple-collinear color/spin-space splitting operators for the five possible processes, $q \to qq'\bar{q}'$, $q \to qq\bar{q}$, $q \to qgg$, $g \to gq\bar{q}$ and $g \to ggg$. The expressions are exact in…

High Energy Physics - Phenomenology · Physics 2022-07-11 Michał Czakon , Sebastian Sapeta

Transverse-momentum-dependent parton distribution functions (TMDs) can be studied from first principles by a perturbative matching onto lattice-calculable quantities: so-called lattice TMDs, which are a class of equal-time correlators that…

High Energy Physics - Phenomenology · Physics 2022-05-18 Markus A. Ebert , Stella T. Schindler , Iain W. Stewart , Yong Zhao

We report a complete computation of next-to-next-to-leading order (NNLO) helicity and transversity Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) splitting functions, in both space-like and time-like kinematics. These results are…

High Energy Physics - Phenomenology · Physics 2026-03-31 Yu Jiao Zhu

We consider the expansion of small-$x$ resummed DGLAP splitting functions at next-to-leading logarithmic (NLL) accuracy to four-loop order, namely next-to-next-to-next-to-leading order (N$^3$LO). From this, we extract the exact LL and NLL…

High Energy Physics - Phenomenology · Physics 2018-07-06 Marco Bonvini , Simone Marzani

In this talk results from a new QCD analysis in leading (LO) and next--to--leading (NLO) order are presented. New parametrizations of the polarized quark and gluon densities are derived together with parametrizations of their fully…

High Energy Physics - Phenomenology · Physics 2009-09-29 J. Blümlein , H. Böttcher

We present our most recent results on the calculation of the heavy flavor contributions to deep-inelastic scattering at 3-loop order in the large $Q^2$ limit, where the heavy flavor Wilson coefficients are known to factorize into light…

High Energy Physics - Phenomenology · Physics 2014-09-08 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. Hasselhuhn , A. von Manteuffel , C. Raab , M. Round , S. Schneider , F. Wißbrock

Quasi and pseudo distributions provide a new approach to determining parton distribution functions (PDFs) from first principles' calculations of quantum chromodynamics (QCD). Here I calculate the flavor nonsinglet unpolarized quasi…

High Energy Physics - Lattice · Physics 2024-09-26 Christopher Monahan

We present the high-precision result for the zero-jettiness soft function at next-to-next-to-next-to-leading order (N3LO) in perturbative QCD. At this perturbative order, the soft function is the last missing ingredient required for the…

High Energy Physics - Phenomenology · Physics 2025-05-19 Daniel Baranowski , Maximilian Delto , Kirill Melnikov , Andrey Pikelner , Chen-Yu Wang

We compute the expansion of the 3-d Lattice QCD free energy to four loop order by means of Numerical Stochastic Perturbation Theory. The first and second order are already known and are correctly reproduced. The third and fourth order…

High Energy Physics - Lattice · Physics 2009-11-10 F. Di Renzo , A. Mantovi , V. Miccio , Y. Schroder

The formulas directly connecting parton distribution functions (PDFs) and fragmentation functions (FFs) at the next to leading order (NLO) QCD with the same quantities at the leading order (LO) are derived. These formulas are universal,…

High Energy Physics - Phenomenology · Physics 2013-06-12 O. Yu. Shevchenko

Computing disconnected diagrams in Lattice QCD (operator insertion in a quark loop) entails the computationally demanding problem of taking the trace of the all to all quark propagator. We first outline the basic algorithm used to compute a…

High Energy Physics - Lattice · Physics 2016-11-09 Arjun Singh Gambhir , Andreas Stathopoulos , Kostas Orginos , Boram Yoon , Rajan Gupta , Sergey Syritsyn

We review the long term project of the ALPHA collaboration to compute in QCD the running coupling constant and quark masses at high energy scales in terms of low energy hadronic quantities. The adapted techniques required to numerically…

High Energy Physics - Lattice · Physics 2015-01-09 Rainer Sommer , Ulli Wolff

The non-first-order-factorizable contributions (The terms 'first-order-factorizable contributions' and 'non-first-order-factorizable contributions' have been introduced and discussed in Refs. \cite{Behring:2023rlq,Ablinger:2023ahe}. They…

High Energy Physics - Phenomenology · Physics 2024-05-15 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

We present the first calculation of a fully-unintegrated parton distribution (beam function) at next-to-next-to-leading order (NNLO). We obtain the fully-differential beam function for quark-initiated processes by matching it onto standard…

High Energy Physics - Phenomenology · Physics 2015-01-05 Jonathan R. Gaunt , Maximilian Stahlhofen

We have computed the four lowest even-N moments of all four splitting functions for the evolution of flavour-singlet parton densities of hadrons at the fourth order in the strong coupling constant alpha_s. The perturbative expansion of…

High Energy Physics - Phenomenology · Physics 2022-01-05 S. Moch , B. Ruijl , T. Ueda , J. A. M. Vermaseren , A. Vogt

We describe the decomposition of one-loop QCD amplitudes in terms of colour-ordered building blocks. We give new expressions for the coefficients of QCD colour structures in terms of ordered objects called primitive amplitudes, for…

High Energy Physics - Phenomenology · Physics 2015-06-03 Harald Ita , Kemal Ozeren

We calculate four-loop QCD corrections to the electroweak $\rho$ parameter with a non-vanishing $b$ quark mass. At three loops, it was observed that elliptic integrals contribute to this observable. This prompts the question of which…

High Energy Physics - Phenomenology · Physics 2024-08-01 Samuel Abreu , Arnd Behring , Andrew McLeod , Ben Page

We study the effects of next-to-leading order corrections on the evolution of the twist-two non-forward parton distribution functions in the flavour non-singlet sector. It is found that the deviation from leading order evolution is small…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. V. Belitsky , D. Mueller , L. Niedermeier , A. Schaefer

We present the first results for the next-to-next-to leading order (NNLO) corrections to the semi-inclusive deep-inelastic scattering process in perturbative quantum chromodynamics. We consider the quark initiated flavor non-singlet process…

High Energy Physics - Phenomenology · Physics 2024-03-21 Saurav Goyal , Sven-Olaf Moch , Vaibhav Pathak , Narayan Rana , V. Ravindran

We consider the anomalous dimension of the flavor non-singlet twist-two quark operator of arbitrary Lorentz spin N at four loops in QCD and construct its contribution proportional to zeta(3) in analytic form by applying advanced methods of…

High Energy Physics - Phenomenology · Physics 2025-03-27 B. A. Kniehl , V. N. Velizhanin