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200 papers

Heavy quark parton distribution functions (PDFs) play an important role in several Standard Model and New Physics processes. Most analyses rely on the assumption that the charm and bottom PDFs are generated perturbatively by gluon splitting…

High Energy Physics - Phenomenology · Physics 2016-08-08 Florian Lyonnet , Aleksander Kusina , Tomáš Ježo , Karol Kovařík , Fred Olness , Ingo Schienbein , Ji-Young Yu

Novel PDFs taking into account resummation-improved matrix elements, albeit only in the fit of a reduced data set, allow for consistent NLO+NLL calculations of slepton pair production at the LHC. We apply a factorisation method to this…

High Energy Physics - Phenomenology · Physics 2018-04-18 J. Fiaschi , M. Klasen

Hadron spin physics is now one of the most active fields of physics. Especially in the last ten years, great progress has been made both theoretically and experimentally that has considerably improved our knowledge of the spin structure of…

High Energy Physics - Phenomenology · Physics 2009-10-31 Jiro Kodaira , Kazuhiro Tanaka

A new release of the Monte Carlo program Herwig++ (version 2.1) is now available. This version includes a number of significant improvements including: an eikonal multiple parton-parton scattering model of the underlying event; the…

High Energy Physics - Phenomenology · Physics 2007-11-21 M. Bahr , S. Gieseke , M. Gigg , D. Grellscheid , K. Hamilton , O. Latunde-Dada , S. Platzer , P. Richardson , M. H. Seymour , A. Sherstnev , B. R. Webber

We summarize several projects carried out by the CTEQ global analysis of parton distribution functions (PDFs) of the proton during 2010. We discuss a recently released CT10 family of PDFs with a fixed and variable QCD coupling strength;…

High Energy Physics - Phenomenology · Physics 2011-01-04 Marco Guzzi , Pavel Nadolsky , Edmond Berger , Hung-Liang Lai , Fredrick Olness , C. -P. Yuan

We present and discuss the release of novel sets of collinear, variable-flavor-number-scheme fragmentation functions for axial-vector, fully heavy $T_{4c}(1^{+-})$ and $T_{4b}(1^{+-})$ tetraquarks. Working within the single-parton…

High Energy Physics - Phenomenology · Physics 2025-06-04 Francesco Giovanni Celiberto

We present next-to-next-to-leading order (NNLO) parton distribution functions (PDFs) from the CTEQ-TEA group. The CT10NNLO PDF fit is based on essentially the same global data sets used in the CT10 and CT10W NLO PDF analyses. After…

High Energy Physics - Phenomenology · Physics 2014-08-21 Jun Gao , Marco Guzzi , Joey Huston , Hung-Liang Lai , Zhao Li , Pavel Nadolsky , Jon Pumplin , Daniel Stump , C. -P. Yuan

The parton distribution functions (PDFs) which characterize the structure of the proton are currently one of the dominant sources of uncertainty in the predictions for most processes measured at the Large Hadron Collider (LHC). Here we…

We present the MMHT2015qed PDF set, resulting from the inclusion of QED corrections to the existing set of MMHT Parton Distribution Functions (PDFs), and which contain the photon PDF of the proton. Adopting an input distribution from the…

High Energy Physics - Phenomenology · Physics 2021-05-10 L. A. Harland-Lang , A. D. Martin , R. Nathvani , R. S. Thorne

In this paper, using the stochastic modeling of the non-equilibrium statistical mechanics in the momentum space, the evolution equations of the parton distribution functions (PDF) usually used in the hadrons phenomenology are generated.…

High Energy Physics - Phenomenology · Physics 2021-08-04 N. Olanj , E. Moradi , M. Modarres

The level of precision achieved by the experimental measurements at the LHC requires the inclusion of higher order electroweak effects to the processes of $ pp $ scattering. In particular the photon-induced process $ \gamma\gamma \to…

High Energy Physics - Phenomenology · Physics 2014-01-07 Renat Sadykov

New methods of solutions of the DGLAP equation and their implementation through NNLO in QCD are briefly reviewed. We organize the perturbative expansion that describes in $x$-space the evolved parton distributions in terms of scale…

High Energy Physics - Phenomenology · Physics 2008-12-30 Alessandro Cafarella , Claudio Coriano , Marco Guzzi

We present a quark-parton model to describe polarized and unpolarized nucleon structure functions. The twist-two matrix elements for the QCD evolution analysis of lepton-hadron scattering are calculated within a light-front covariant quark…

High Energy Physics - Phenomenology · Physics 2011-04-15 Marco Traini , Pietro Faccioli , Vicente Vento

The impact of recent measurements of heavy-flavour production in deep inelastic $ep$ scattering and in $pp$ collisions on parton distribution functions is studied in a QCD analysis in the fixed-flavour number scheme at next-to-leading…

We study inclusive photoproduction of hadrons at HERA via both direct and resolved photons to next-to-leading order (NLO) in the QCD-improved parton model. We predict transverse-momentum ($\pt$) and rapidity ($\ylab$) distributions and…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bernd A. Kniehl

It is anticipated that hard double parton scatterings will occur frequently in the collisions of the LHC, producing interesting signals and significant backgrounds to certain single scattering processes. For double scattering processes in…

High Energy Physics - Phenomenology · Physics 2015-03-13 Jonathan R. Gaunt , W. James Stirling

A new code for the scale evolution of modified-minimal-subtraction-scheme parton densities is described. Through next-to-leading order the program uses exact splitting functions. In next-to-next-to-leading order approximate splitting…

High Energy Physics - Phenomenology · Physics 2011-01-25 A. Chuvakin , J. Smith

We present NNPDF4.0MC, a variant of the NNPDF4.0 set of parton distributions (PDFs) at LO, NLO and NNLO, with and without inclusion of the photon PDF, suitable for use with Monte Carlo (MC) event generators, which require PDFs to satisfy…

High Energy Physics - Phenomenology · Physics 2024-08-29 Juan Cruz-Martinez , Stefano Forte , Niccolo Laurenti , Tanjona R. Rabemananjara , Juan Rojo

The 't Hooft model (two-dimensional QCD in the limit of large number of colors) is used as a laboratory for exploring various aspects of the heavy quark expansions in the nonleptonic and semileptonic decays of heavy flavors. We perform a…

High Energy Physics - Phenomenology · Physics 2014-11-17 I. Bigi , M. Shifman , N. Uraltsev , A. Vainshtein

We present a new QCD evolution library for unpolarized parton distribution functions: EKO. The program solves DGLAP equations up to next-to-next-to-leading order. The unique feature of EKO is the computation of solution operators, which are…

High Energy Physics - Phenomenology · Physics 2022-11-15 Alessandro Candido , Felix Hekhorn , Giacomo Magni