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Related papers: Four-loop splitting functions in QCD -- The quark-…

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We study the factorial moments (Fq), the factorial cumulants (Kq) and the ratio of Kq to Fq (Hq = Kq=Fq) in pp/pp collisions using an updated approach, in which the multiplicity distribution is related to the eikonal function. The QCD…

High Energy Physics - Phenomenology · Physics 2013-06-19 Paulo Cesar Beggio

The factorisation of QCD matrix elements in the limit of two external partons becoming collinear is described by process-independent splitting amplitudes, which can be expanded systematically in perturbation theory. Working in conventional…

High Energy Physics - Phenomenology · Physics 2015-06-23 Claude Duhr , Thomas Gehrmann , Matthieu Jaquier

We compute the gluon transverse-momentum-dependent fragmentation function (TMDFF) at next-to-leading order (NLO) into heavy quarkonium in the color-octet $^3S_1^{[8]}$ channel, based on the NRQCD factorization approach. The spurious…

High Energy Physics - Phenomenology · Physics 2024-01-02 Miguel G. Echevarria , Samuel F. Romera , Ignazio Scimemi

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 a framework for constructing Generalized Parton Distributions (GPDs) using holographic QCD in the large $N_c$ limit, with a focus on low-x and finite skewness. Our approach utilizes holographic amplitudes for exclusive…

High Energy Physics - Phenomenology · Physics 2023-07-04 Kiminad A. Mamo , Ismail Zahed

We have calculated the complete matrix of three-loop helicity-difference (`polarized') splitting functions Delta P_ik^(2), i,k = q,g, in massless perturbative QCD. In this note we briefly discuss some properties of the polarized splitting…

High Energy Physics - Phenomenology · Physics 2014-05-15 A. Vogt , S. Moch , J. A. M. Vermaseren

Second- and third-order results are presented for the structure functions of charged-current deep-inelastic scattering in the framework of massless perturbative QCD. We write down the two-loop differences between the corresponding…

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

We present the matching condition for the strong coupling contant alpha_s at a heavy quark threshold to four loops in the modified minimal subtraction scheme. Our results lead to further decrease of the theoretical uncertainty of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. G. Chetyrkin , J. H. Kühn , C. Sturm

The fragmentation functions for $c$ or $\bar{b}$ quark to $B_c$ or $B_c^*$ meson are derived up to QCD next-to-leading order (NLO). They are further computed numerically and presented in figures precisely. In order to reach a higher…

High Energy Physics - Phenomenology · Physics 2020-01-01 Xu-Chang Zheng , Chao-Hsi Chang , Tai-Fu Feng , Xing-Gang Wu

We consider the singular behaviour of one-loop QCD matrix elements when several external partons become simultaneously parallel. We present a new factorization formula that describes the singular collinear behaviour directly in colour…

High Energy Physics - Phenomenology · Physics 2010-04-05 Stefano Catani , Daniel de Florian , German Rodrigo

We demonstrate the QCD factorization for inclusive hadron production in $pA$ collisions in the saturation formalism at one-loop order, with explicit calculation of both real and virtual gluon radiation diagrams. The collinear divergences…

High Energy Physics - Phenomenology · Physics 2013-05-30 Giovanni A. Chirilli , Bo-Wen Xiao , Feng Yuan

In the limit where partons become collinear to each other, scattering amplitudes factorize into a product of universal, process-independent building blocks and scattering amplitudes involving fewer partons. We compute these universal…

High Energy Physics - Phenomenology · Physics 2024-08-07 Xin Guan , Franz Herzog , Yao Ma , Bernhard Mistlberger , Adi Suresh

We present the results of our QCD analysis for non-singlet unpolarized quark distributions and structure function $F_2(x,Q^2)$ up to N$^3$LO. In this regards 4-loop anomalous dimension can be obtain from the Pad\'e approximations. The…

High Energy Physics - Phenomenology · Physics 2010-02-03 Ali N. Khorramian , H. Khanpour , S. Atashbar Tehrani

In this talk we examine how one-loop soft and collinear splitting functions occur in the calculation of next-to-next-to-leading order (NNLO) corrections to production rates, and we present the one-loop gluon soft and splitting functions,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Zvi Bern , Vittorio Del Duca , William B. Kilgore , Carl R. Schmidt

In this review, we discuss the results on the parton-to-pion fragmentation functions obtained in a combined NLO fit to data of single-inclusive hadron production in electron-positron annihilation, proton-proton collisions, and…

High Energy Physics - Phenomenology · Physics 2016-11-23 R. J. Hernández-Pinto , M. Epele , D. de Florian , R. Sassot , M. Stratmann

We study the unpolarized gluon quasidistribution function in the nucleon at one loop level in the large momentum effective theory. For the quark quasidistribution, power law ultraviolet divergences arise in the cut-off scheme and an…

High Energy Physics - Phenomenology · Physics 2018-02-22 Wei Wang , Shuai Zhao , Ruilin Zhu

We gauge the impact of soft-gluon resummation on quark distributions by performing a simple fit of Deep Inelastic Scattering structure function data using next-to-leading order (NLO) and next-to-leading-logarithmic (NLL)-resummed…

High Energy Physics - Phenomenology · Physics 2009-11-11 Gennaro Corcella , Lorenzo Magnea

We compute the approximate cross section $\sigma_n^{(0)}$ for producing $n-2$ {\it resolved} gluons in a gluon-gluon collision, using the Parke-Taylor formula regularized in a Lorentz invariant manner. We find, in double leading logarithm…

High Energy Physics - Phenomenology · Physics 2009-10-22 Haim Goldberg , Rogerio Rosenfeld

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

We study the fragmentation function of the gluon to color-octet $^3S_1$ heavy quark-antiquark pair using the soft gluon factorization (SGF) approach, which expresses the fragmentation function in a form of perturbative short-distance hard…

High Energy Physics - Phenomenology · Physics 2021-11-18 An-Ping Chen , Xiao-Bo Jin , Yan-Qing Ma , Ce Meng
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