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Related papers: The spin-dependent quark beam function at NNLO

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We consider the quark beam function that describes collinear initial-state radiation that is constrained by a veto on reconstructed jets. As the veto is imposed on the transverse momenta of the jets, the beam function is subject to rapidity…

High Energy Physics - Phenomenology · Physics 2023-02-01 Guido Bell , Kevin Brune , Goutam Das , Marcel Wald

We present a Next-to-Leading order perturbative QCD analysis of world data on the spin dependent structure functions $g_1^p, g_1^n$, and $g_1^d$, including the new experimental information on the $Q^2$ dependence of $g_1^n$. Careful…

High Energy Physics - Phenomenology · Physics 2008-11-26 The SLAC E154 Collaboration , K. Abe

A next-to-leading order QCD analysis of spin asymmetries and structure functions in polarized deep inelastic lepton nucleon scattering is presented within the framework of the radiative parton model. A consistent NLO formulation of the…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. Gluck , E. Reya , M. Stratmann , W. Vogelsang

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

The method originally developed for the exact calculations in QED theory is applied for the calculation of NLO effects in QCD Compton processes. QCD corrections to the structure functions and sum rules are obtained. Different…

High Energy Physics - Phenomenology · Physics 2014-11-17 I. Akushevich , A. Ilyichev , N. Shumeiko

We compute the complete third-order contributions to the coefficient functions for the longitudinal structure function F_L, thus completing the next-to-next-to-leading order (NNLO) description of unpolarized electromagnetic deep-inelastic…

High Energy Physics - Phenomenology · Physics 2010-04-05 S. Moch , J. A. M. Vermaseren , A. Vogt

We compute the gluon beam function for jet-veto resummation to next-to-next-to-leading order (NNLO) in the strong-coupling expansion. Our calculation is based on an automated framework that was previously used for the computation of the…

High Energy Physics - Phenomenology · Physics 2024-03-25 Guido Bell , Kevin Brune , Goutam Das , Ding Yu Shao , Marcel Wald

We present a first QCD analysis of next-to-next-leading-order (NNLO) contributions of the spin-dependent parton distribution functions (PPDFs) in the nucleon and their uncertainties using the Jacobi polynomial approach. Having the NNLO…

High Energy Physics - Phenomenology · Physics 2016-06-24 F. Taghavi Shahri , Hamzeh Khanpour , S. Atashbar Tehrani , Z. Alizadeh Yazdi

We compute the N-jettiness soft function in hadronic collisions to next-to-next-to-leading order (NNLO) in the strong-coupling expansion. Our calculation is based on an extension of the SoftSERVE framework to soft functions that involve an…

High Energy Physics - Phenomenology · Physics 2024-08-08 Guido Bell , Bahman Dehnadi , Tobias Mohrmann , Rudi Rahn

In this paper we firstly demonstrate step by step that the factorization hypothesis is valid at the next-to-leading order (NLO) for the exclusive process $\rho \gamma^{\star} \to \rho$ by employing the collinear factorization approach, and…

High Energy Physics - Phenomenology · Physics 2016-02-10 Ya-lan Zhang , Shan Cheng , Jun Hua , Zhen-jun Xiao

We use the next-to-next-to-leading order (NNLO) contributions to anomalous dimension governing the evolution of non-singlet quark distributions. We use the xF3 data of the CCFR collaboration to obtain some unknown parameters which exist in…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ali N. Khorramian , S. Atashbar Tehrani

We compute the next-to-next-to-leading order (NNLO) QCD corrections to the decay $t(\uparrow) \to X_b +W^+$ of a polarized top quark. The spin-momentum correlation in this quasi two-body decay is described by the polar angle distribution…

High Energy Physics - Phenomenology · Physics 2018-05-16 A. Czarnecki , S. Groote , J. G. Körner , J. H. Piclum

The $N$-jettiness subtraction has proven to be an efficient method to perform differential QCD next-to-next-to-leading order (NNLO) calculations in the last few years. One important ingredient of this method is the NNLO soft function. We…

High Energy Physics - Phenomenology · Physics 2017-02-03 Hai Tao Li , Jian Wang

At high values of the pair invariant mass the differential cross section for top-quark pair production at hadron colliders factorizes into soft, hard, and fragmentation functions. In this paper we calculate the next-to-next-to-leading-order…

High Energy Physics - Phenomenology · Physics 2015-06-05 Andrea Ferroglia , Ben D. Pecjak , Li Lin Yang

The precise description of jet processes requires observables capable of efficiently capturing the dynamics of the energy flow in hadronic final states. We consider a class of tranverse-momentum like resolution variables that smoothly…

High Energy Physics - Phenomenology · Physics 2025-08-28 Luca Buonocore , Massimiliano Grazzini , Flavio Guadagni , Jürg Haag , Luca Rottoli

We report on the first calculation of the structure function g_1 in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Vogt , S. Moch , M. Rogal , J. A. M. Vermaseren

We present the next-to-next-to-leading order (NNLO) contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark-quark and gluon-quark splitting…

High Energy Physics - Phenomenology · Physics 2015-06-22 S. Moch , J. A. M. Vermaseren , A. Vogt

We compute the complete set of two-loop beam functions for the transverse momentum distribution of the leading jet produced in association with an arbitrary colour-singlet system. Our results constitute the last missing ingredient for the…

High Energy Physics - Phenomenology · Physics 2023-05-17 Samuel Abreu , Jonathan R. Gaunt , Pier Francesco Monni , Luca Rottoli , Robert Szafron

We present the first computation of next-to-next-to-leading order (NNLO) pure QED and mixed QCD$\otimes$QED corrections to unpolarized and polarized semi-inclusive deep-inelastic scattering (SIDIS). Building on our previous NNLO QCD…

High Energy Physics - Phenomenology · Physics 2025-10-22 Saurav Goyal , Roman N. Lee , Sven-Olaf Moch , Vaibhav Pathak , V. Ravindran

We present a calculation of the NLO QCD corrections to heavy flavor photoproduction with longitudinally polarized beams. We apply our results to study the spin asymmetry for total charm quark production which will be used for a first direct…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Stratmann