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Related papers: Towards small-$x$ resummed parton distribution fun…

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We extend our previous results on small-x resummation in the pure Yang--Mills theory to full QCD with nf quark flavours, with a resummed two-by-two matrix of resummed quark and gluon splitting functions. We also construct the corresponding…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guido Altarelli , Richard D. Ball , Stefano Forte

I present some comments on the partonic interpretation of the HERA data on the proton structure function. The effects of the resummation of the leading and next-to-leading $\ln x$-contributions are discussed. A new factorization scheme, in…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stefano Catani

The explicit expressions for the non-singlet DIS structure functions obtained at small x by resumming the most singular logarithmic contributions are discussed and compared in detail with the DGLAP evolution for different values of x and…

High Energy Physics - Phenomenology · Physics 2010-03-25 B. I. Ermolaev , M. Greco , S. I. Troyan

We present the first NNPDF full set of Parton Distribution Functions from a comprehensive DIS analysis. This approach, combining a Monte Carlo sampling of the probability measure in the space of PDFs with the use of neural networks as…

High Energy Physics - Phenomenology · Physics 2009-11-13 Maria Ubiali

Using parton density functions (PDFs) with threshold-resummation improvement, we consistently calculate higgsino/gaugino and slepton pair production at next-to-leading order and next-to-leading logarithmic accuracy at the LHC. The smaller…

High Energy Physics - Phenomenology · Physics 2019-09-16 J. Fiaschi , M. Klasen

In this contribution, I present a new QCD fit to final combined HERA deep-inelastic scattering cross-section data incorporating $\ln(1/x)$-resummation terms. This fit has been performed within the xFitter framework. The main effect of…

High Energy Physics - Phenomenology · Physics 2018-05-07 Francesco Giuli

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

I review recent theoretical progress in the resummation of small x contributions to the evolution of parton distributions, in view of its potential significance for accurate phenomenology at future colliders. I show that a consistent…

High Energy Physics - Phenomenology · Physics 2016-09-06 Stefano Forte

We introduce a generalized definition of parton distribution functions (PDFs) for a more consistent all-order treatment of power corrections. We present a new set of modified DGLAP evolution equations for nuclear PDFs, and show that the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zhong-Bo Kang , Jian-Wei Qiu

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

The NNPDF collaboration has recently presented NNPDF3.1, a new determination of the parton distribution functions (PDFs) of the proton including a number of new data, some of which are particularly sensitive to the gluon PDF at large x. In…

High Energy Physics - Phenomenology · Physics 2019-02-25 Emanuele R. Nocera , Maria Ubiali

Small-$x$ resummation has been proven recently to be a crucial ingredient for describing small-$x$ HERA data, and the inclusion of small-$x$ resummation in parton distribution function (PDF) determination has a sizeable effect on the PDFs…

High Energy Physics - Phenomenology · Physics 2018-10-18 Marco Bonvini

We extract the ratio of the down (d) and up (u) parton distribution functions (PDF's) from the ratio of NMC deuteron and proton structure function F_2(d)/F_2(p), using corrections for nuclear binding effects in the deuteron, which are…

High Energy Physics - Phenomenology · Physics 2007-05-23 U. K. Yang , A. Bodek

We consider the impact of the resummation of large logarithms, which appear in the QCD evolution of the heavy-quark distributions, on the phenomenology of deep-inelastic heavy-quark production. The heavy-quark PDFs are derived using the…

High Energy Physics - Phenomenology · Physics 2019-10-25 S. Alekhin , J. Bluemlein , S. Moch

We study the impact of state-of-the-art top-quark data collected at the Large Hadron Collider on parton distribution functions (PDFs). Following the ABMP methodology, the fit extracts simultaneously proton PDFs, the strong coupling…

High Energy Physics - Phenomenology · Physics 2025-02-11 S. Alekhin , M. V. Garzelli , S. -O. Moch , O. Zenaiev

We present recent results of the NNPDF collaboration on a full DIS analysis of Parton Distribution Functions (PDFs). Our method is based on the idea of combining a Monte Carlo sampling of the probability measure in the space of PDFs with…

High Energy Physics - Phenomenology · Physics 2008-05-21 NNPDF Collaboration , M. Ubiali , R. D. Ball , L. Del Debbio , S. Forte , A. Guffanti , J. I. Latorre , A. Piccione , J. Rojo

Parton distribution functions are determined by the comparison of finite-order calculations with data. We briefly discuss the interplay of higher order corrections and PDF determinations, and the use of soft-gluon resummation in global…

High Energy Physics - Phenomenology · Physics 2007-05-23 George Sterman , Werner Vogelsang

We perform the next-to-next-leading-order (NNLO) QCD global fit of PDFs using inclusive charged-lepton and neutrino DIS data down to Q = 1 GeV. We also consider the data on neutrino-nucleon dimuon production, that allows us to disentangle…

High Energy Physics - Phenomenology · Physics 2008-10-28 S. Alekhin , S. Kulagin , R. Petti

We summarize our recent results on small x resummation in full QCD with n_f quark flavours and discuss their phenomenological impact in the extraction of parton distributions from present day structure function data and their extrapolation…

High Energy Physics - Phenomenology · Physics 2009-04-14 Guido Altarelli , Richard D Ball , Stefano Forte

We present an updated set of {\tt SKMHS} diffractive parton distribution functions (PDFs). In addition to the diffractive deep-inelastic scattering (diffractive DIS) data sets, the recent diffractive dijet cross sections measurements by the…

High Energy Physics - Phenomenology · Physics 2023-06-14 Maral Salajegheh , Hamzeh Khanpour , Ulf-G. Meißner , Hadi Hashamipour , Maryam Soleymaninia