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Nuclear parton distribution functions (NPDFs) are determined by a global analysis of experimental measurements on structure-function ratios F_2^A/F_2^{A'} and Drell-Yan cross section ratios \sigma_{DY}^A/\sigma_{DY}^{A'}, and their…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , T. -H. Nagai

We consider some trends, achievements and a series of remaining problems in the precision determination of parton distribution functions. For the description of the scaling violations of the deep-inelastic scattering data, forming the key…

High Energy Physics - Phenomenology · Physics 2018-09-05 S. Alekhin , J. Bluemlein , S. -O. Moch

We examine the sources of parton distribution errors in the $W$ mass measurement, and point out shortcomings in the existing literature. Optimistic assumptions about strategies to reduce the error by normalizing to $Z$ observables are…

High Energy Physics - Phenomenology · Physics 2015-08-26 Seth Quackenbush , Zack Sullivan

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

The xFitter project (former HERAFitter project) is an open-source package that provides a framework for the determination of the parton distribution functions (PDFs) of the proton for many different kinds of analyses in Quantum…

High Energy Physics - Phenomenology · Physics 2017-09-06 Francesco Giuli

We provide an analysis of the x-dependence of the bare unpolarized, helicity and transversity iso-vector parton distribution functions (PDFs) from lattice calculations employing (maximally) twisted mass fermions. The x-dependence of the…

We perform the analysis of existing light-targets deep-inelastic-scattering (DIS) data in the leading-order (LO), next-to-leading-order (NLO), and next-to-next-to-leading-order (NNLO) QCD approximations and extract PDFs simultaneously with…

High Energy Physics - Phenomenology · Physics 2009-11-07 Sergey Alekhin

The potential of the LHeC, a future electron-proton collider, for precision Deep Inelastic Scattering measurements is reviewed with particular emphasis on the reduction of uncertainties on the parton distribution functions (PDFs) of the…

High Energy Physics - Phenomenology · Physics 2019-08-14 A M Cooper-Sarkar

In the framework of quantum chromodynamics (QCD), parton distribution functions (PDFs) quantify how the momentum and spin of a hadron are divided among its quark and gluon constituents. Two main approaches exist to determine PDFs. The first…

We present the first official release of the nCTEQ nuclear parton distribution functions with errors. The main addition to the previous nCTEQ PDFs is the introduction of PDF uncertainties based on the Hessian method. Another important…

High Energy Physics - Phenomenology · Physics 2016-08-17 A. Kusina , K. Kovarik , T. Jezo , D. B. Clark , C. Keppel , F. Lyonnet , J. G. Morfin , F. I. Olness , J. F. Owens , I. Schienbein , J. Y. Yu

Global perturbative QCD analyses, based on large data sets from electron-proton and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear…

High Energy Physics - Phenomenology · Physics 2014-11-20 Paloma Quiroga-Arias , Jose Guilherme Milhano , Urs Achin Wiedemann

We propose a new experimental method to probe the photon parton distribution function inside the proton (photon PDF) at LHC energies. The method is based on the measurement of dilepton production from the $\gamma p\rightarrow\ell^+\ell^-+X$…

High Energy Physics - Phenomenology · Physics 2019-06-19 Mateusz Dyndal , Alexander Glazov , Marta Luszczak , Renat Sadykov

We show for the first time preliminary results of nuclear parton distribution function analysis of charged lepton DIS and Drell-Yan data within the CTEQ framework including error PDFs. We compare our error estimates to estimates of…

High Energy Physics - Phenomenology · Physics 2013-07-15 K. Kovarik , T. Jezo , A. Kusina , F. I. Olness , I. Schienbein , T. Stavreva , J. Y. Yu

We present preliminary results on the determination of spin-dependent, or polarised, Parton Distribution Functions (PDFs) from all relevant inclusive polarised DIS data. The analysis is performed within the NNPDF approach, which provides a…

High Energy Physics - Phenomenology · Physics 2012-06-26 Emanuele R. Nocera , Stefano Forte , Giovanni Ridolfi , Juan Rojo

A thorough understanding of the issues surrounding the determination of parton distributions is crucial due to their importance to calculations of LHC observables. However, it is still not fully understood how much of an impact…

High Energy Physics - Phenomenology · Physics 2014-09-16 Christopher S. Deans

We study the sources of systematic errors in the measurement of the W to lepton and neutrino cross-sections at the LHC. We consider the systematic errors in both the total cross-section and acceptance for anticipated experimental cuts. We…

High Energy Physics - Phenomenology · Physics 2009-02-18 Nadia E. Adam , Valerie Halyo , Scott A. Yost , Wenhan Zhu

We present three new sets of next-to-leading order parton distribution functions (PDFs) determined by global fits to a wide variety of data for hard scattering processes. The analysis includes target mass and higher twist corrections needed…

High Energy Physics - Phenomenology · Physics 2013-05-15 J. F. Owens , A. Accardi , W. Melnitchouk

We review the series of specific nCTEQ analyses of nuclear parton distribution functions (PDFs) published since 2020 and present preliminary results of a new global analysis. Building on a modern proton baseline without nuclear data and…

High Energy Physics - Phenomenology · Physics 2025-10-08 M. Klasen

We study the dependence of the transverse mass distribution of the charged lepton and the missing energies on the parton distributions (PDFs) adapted to the $W$ boson mass measurements at the CDF and ATLAS experiments. We compare the shape…

High Energy Physics - Phenomenology · Physics 2022-05-10 Jun Gao , DianYu Liu , Keping Xie

The parton distribution functions (PDFs) of the proton play a role in determining the lineshape of $Z$ and $W$ bosons produced at the LHC. In particular, the mode of the gauge boson virtuality is shifted with respect to the pole due to the…

High Energy Physics - Experiment · Physics 2020-04-27 Valerio Bertacchi , Lorenzo Bianchini , Elisabetta Manca , Gigi Rolandi , Suvankar Roy Chowdhury