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Related papers: Proton structure at the LHC

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We present a set of parton distribution functions (PDFs), based on the NNPDF2.3 set, which includes a photon PDF, and QED contributions to parton evolution. We describe the implementation of the combined QCD+QED evolution in the NNPDF…

We discuss the determination of the parton substructure of hadrons by casting it as a peculiar form of pattern recognition problem in which the pattern is a probability distribution, and we present the way this problem has been tackled and…

High Energy Physics - Phenomenology · Physics 2020-08-31 Stefano Forte , Stefano Carrazza

Recently a new set of Parton Distribution Functions (NNPDF1.2) has been produced and released by the NNPDF Collaboration. The inclusion of dimuon data in the analysis allows a determination of the strange content of the proton with faithful…

High Energy Physics - Phenomenology · Physics 2009-07-28 Alberto Guffanti , Juan Rojo , Maria Ubiali

A method to facilitate the consistent inclusion of cross-section measurements based on complex final-states from HERA, TEVATRON and the LHC in proton parton density function (PDF) fits has been developed. This can be used to increase the…

High Energy Physics - Phenomenology · Physics 2014-11-20 Tancredi Carli , Dan Clements , Amanda Cooper-Sarkar , Claire Gwenlan , Gavin P. Salam , Frank Siegert , Pavel Starovoitov , Mark Sutton

Parton Distribution Functions (PDFs) play a central role in describing experimental data at colliders and provide insight into the structure of nucleons. As the LHC enters an era of high-precision measurements, a robust PDF determination…

High Energy Physics - Phenomenology · Physics 2026-01-21 Amedeo Chiefa , Luigi Del Debbio , Richard Kenway

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

We present a systematic investigation of jet production at hadron colliders from a phenomenological point of view, with the dual aim of providing a validation of theoretical calculations and guidance to future determinations of parton…

The interest into parton distribution functions (PDFs) and fragmentation functions (FFs) in current high energy physics research is twofold. On the one hand, they are fundamental objects to conduct precision phenomenology studies, e.g. at…

High Energy Physics - Phenomenology · Physics 2025-09-22 Tanishq Sharma

This contribution to the Italian "Workshop sui Monte Carlo, la Fisica e le Simulazioni a LHC", held at LNF, Frascati, in February, May and October 2006, summarises the status of parton density functions (PDF's) and the impact of their…

High Energy Physics - Experiment · Physics 2019-08-13 A. Tricoli

The full exploitation of the increasingly precise LHC measurements is essential in order to reduce the uncertainty of theoretical predictions at hadron colliders. The NNPDF2.3 fit was the first PDF determination including the effect of the…

High Energy Physics - Phenomenology · Physics 2014-07-14 Maria Ubiali

We discuss the main features of the recent NNPDF2.1 NLO set, a determination of parton distributions from a global set of hard scattering data using the NNPDF methodology including heavy quark mass effects. We present the implications for…

High Energy Physics - Phenomenology · Physics 2011-07-07 Francesco Cerutti

We present a next-to-leading order QCD calculation of inclusive dijet photoproduction in ultraperipheral Pb-Pb collisions at the LHC and show that the results agree very well with various kinematic distributions measured by the ATLAS…

High Energy Physics - Phenomenology · Physics 2019-09-20 V. Guzey , M. Klasen

We present new sets of nuclear parton distribution functions (nPDFs) at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO). Our analyses are based on deeply inelastic scattering data with charged-lepton and neutrino beams…

High Energy Physics - Phenomenology · Physics 2019-12-17 Marina Walt , Ilkka Helenius , Werner Vogelsang

An overwhelming number of theoretical predictions for hadron colliders require parton distribution functions (PDFs), which are an important ingredient of theory infrastructure for the next generation of high-energy experiments. This…

Achieving the highest precision for theoretical predictions at the LHC requires the calculation of hard-scattering cross-sections that include perturbative QCD corrections up to (N)NNLO and electroweak (EW) corrections up to NLO. Parton…

In this paper we explore the use of results on forward particle production at the LHC to constrain nuclear Parton Density Functions (nPDFs). The case study here is based on a possible future measurement of forward photon production with the…

High Energy Physics - Phenomenology · Physics 2019-09-13 Marco van Leeuwen

Parton Density Functions (PDFs) and their uncertainties are extremely important topics for both the Tevatron and the LHC. Experiments at the Tevatron can enhance this knowledge not only by constraining the PDF fits, but also by developing…

High Energy Physics - Phenomenology · Physics 2007-05-23 D Bourilkov , R C Group , M R Whalley

Perturbative quantum chromodynamics (QCD) ceases to be applicable at low interaction energies due to the rapid increase of the strong coupling. In that limit, the non-perturbative regime determines the properties of quarks and gluons…

High Energy Physics - Phenomenology · Physics 2021-10-06 Rabah Abdul Khalek

We present a next-to-next-to-leading order (NNLO) global QCD analysis of the proton's helicity parton distribution functions (PDFs), the first of its kind. To obtain the distributions, we use data for longitudinal spin asymmetries in…

High Energy Physics - Phenomenology · Physics 2025-03-31 Ignacio Borsa , Daniel de Florian , Rodolfo Sassot , Marco Stratmann , Werner Vogelsang

The photon parton distribution function (PDF) of the proton is crucial for precise comparisons of LHC cross sections with theoretical predictions. However, it was previously affected by very large uncertainties of around ${\cal O}(100\%)$…

High Energy Physics - Phenomenology · Physics 2024-08-26 Aneesh Manohar , Paolo Nason , Gavin Salam , Giulia Zanderighi