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Related papers: Four-loop splitting functions at small $x$

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We report on a major milestone in the construction of logarithmically accurate final-state parton showers, achieving next-to-next-to-leading-logarithmic (NNLL) accuracy for the wide class of observables known as event shapes. The key to…

We investigate threshold resummation effects in the production of a color sextet (antitriplet) scalar at next-to-next-to-leading logarithmic (NNLL) order at the LHC in the frame of soft-collinear effective theory. We show the total cross…

High Energy Physics - Phenomenology · Physics 2014-03-04 Yong Chuan Zhan , Ze Long Liu , Shi Ang Li , Chong Sheng Li , Hai Tao Li

The next-to-next-to-leading order (NNLO) corrections in massless perturbative QCD are derived for the parton distributions of the photon and the deep inelastic structure functions F_1^gamma and F_2^gamma. We present the full photonic…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Moch , J. A. M. Vermaseren , A. Vogt

We present first results on the resummation of Next-to-Soft Virtual (NSV) logarithms for the threshold production of pseudoscalar Higgs boson through gluon fusion at the LHC. These results are presented after resumming the NSV logarithms of…

High Energy Physics - Phenomenology · Physics 2022-06-22 Arunima Bhattacharya , M. C. Kumar , Prakash Mathews , V. Ravindran

In the following we present our recent results on the resummation of soft gluon corrections to the $pp\rightarrow t\bar{t}H$ cross section at the LHC. The resummation was carried out at next-to-next-to-leading-logarithmic (NNLL) accuracy…

High Energy Physics - Phenomenology · Physics 2017-10-18 Anna Kulesza , Leszek Motyka , Tomasz Stebel , Vincent Theeuwes

We formulate a collinear partonic shower algorithm that achieves next-to-single-logarithmic (NSL, $\alpha_s^n L^{n-1}$) accuracy for collinear-sensitive non-singlet fragmentation observables. This entails the development of an algorithm for…

High Energy Physics - Phenomenology · Physics 2024-09-16 Melissa van Beekveld , Mrinal Dasgupta , Basem Kamal El-Menoufi , Jack Helliwell , Pier Francesco Monni , Gavin P. Salam

I present the calculation of the QCD short distance coefficient $\eta_3$ of the $|\Delta S|=2$-hamiltonian in the next-to-leading order (NLO) of renormalization group improved perturbation theory. It involves the two-loop mixing of bilocal…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Herrlich

In this article we present a number of developments within the scheme of Local Analytic Sector Subtraction for infrared divergences in QCD. First, we extend the scheme to deal with next-to-leading-order (NLO) singularities related to…

High Energy Physics - Phenomenology · Physics 2025-03-24 Gloria Bertolotti , Giovanni Limatola , Paolo Torrielli , Sandro Uccirati

We analyze the iterative structure of unfactorized partonic structure functions in the large-x limit, and derive all-order expressions for the leading-logarithmic off-diagonal splitting functions P_gq and P_qg and the corresponding…

High Energy Physics - Phenomenology · Physics 2014-11-21 A. Vogt

Nonsinglet contributions to the $g_1(x,Q^2)$ structure function are calculated in the double-logarithmic approximation of perturbative QCD in the region $x \ll 1$. Double logarithmic contributions of the type $(\alpha_s \ln ^2 (1/x))^k$…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Bartels

We report work on the matching of the next-to-leading logarithmic approximation (NLLA) onto the fixed next-to-next-to-leading order (NNLO) calculation for event shape variables in electron-positron annihilation. The correction of the…

High Energy Physics - Phenomenology · Physics 2008-10-21 T. Gehrmann , G. Luisoni , H. Stenzel

We report on the status of the ongoing calculation of multiparticle contributions to the inclusive radiative $\bar{B} \rightarrow X_s \gamma$ decay at next-to leading order. This effort amounts to the evaluation of the four-particle process…

High Energy Physics - Phenomenology · Physics 2019-12-18 Tobias Huber , Lars-Thorben Moos

We review recent progress in the development of an approach valid to any order which unifies the fixed-order DGLAP evolution of fragmentation functions at large x with soft-gluon logarithmic resummation at small x. At leading order, this…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. A. Kniehl

We present a more reliable approach to approximate the unknown next-to-next-to-next-to-leading order (N3LO) transverse momentum distribution of colourless final states, namely the Higgs boson produced via gluon fusion and the lepton pair…

High Energy Physics - Phenomenology · Physics 2022-07-26 Niccolò Laurenti , Tanjona R. Rabemananjara , Roy Stegeman

It was shown recently that standard resummation of logarithms of $Q/p_T$ can be supplemented with the resummation of logarithmic contributions at large $x=Q^2/s$ in the case of a colourless final state such as Higgs produced via gluon…

High Energy Physics - Phenomenology · Physics 2021-09-09 Tanjona R. Rabemananjara

We report on the results of an ongoing calculation of massive scalar one-loop one-, two-, three- and four-point functions needed in the NNLO calculation of heavy hadron production.

High Energy Physics - Phenomenology · Physics 2009-11-10 J. G. Körner , Z. Merebashvili , M. Rogal

We present the third-order contributions to the quark-gluon and gluon-quark timelike splitting functions for the evolution of fragmentation functions in perturbative QCD. These quantities have been derived by studying physical evolution…

High Energy Physics - Phenomenology · Physics 2015-05-28 A. A. Almasy , A. Vogt , S. Moch

We extend the ARES method for next-to-next-to-leading-logarithmic (NNLL) QCD resummations to three-jet event shapes in $e^+ e^-$ collisions in the near-to-planar limit. In particular, we define a NNLL radiator for three hard emitters, and…

High Energy Physics - Phenomenology · Physics 2020-08-26 Luke Arpino , Andrea Banfi , Basem Kamal El-Menoufi

Inspired by the recent observation of the Higgs boson radiative decay into $Z^0$ by {\tt ATLAS} and {\tt CMS} Collaborations, we investigate the next-to-leading-order (NLO) electroweak correction to this rare decay process in Standard Model…

High Energy Physics - Phenomenology · Physics 2024-09-23 Wen-Long Sang , Feng Feng , Yu Jia

QCD sum-rule mass predictions for tetraquark states provide insights on the interpretations and internal structure of experimentally-observed exotic mesons. However, the overwhelming majority of tetraquark QCD sum-rule analyses have been…

High Energy Physics - Phenomenology · Physics 2022-09-28 B. A. Cid-Mora , T. G. Steele