English
Related papers

Related papers: Why $\alpha_s$ Cannot be Determined from Hadronic …

200 papers

We determine the strong coupling alpha_s at NNLO in perturbative QCD using the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and charged current deep-inelastic scattering, Drell-Yan, vector boson production and…

High Energy Physics - Phenomenology · Physics 2015-05-30 Richard D. Ball , Valerio Bertone , Luigi Del Debbio , Stefano Forte , Alberto Guffanti , Jose I. Latorre , Simone Lionetti , Juan Rojo , Maria Ubiali

We determine a new set of parton distribution functions (ABMP16), the strong coupling constant $\alpha_s$ and the quark masses $m_c$, $m_b$ and $m_t$ in a global fit to next-to-next-to-leading order (NNLO) in QCD. The analysis uses the…

High Energy Physics - Phenomenology · Physics 2017-07-26 S. Alekhin , J. Blümlein , S. Moch , R. Placakyte

The brief overview of the definite determinations of the QCD coupling constant $\alpha_s$ from the characteristics of deep-inelastic scattering processes is given.

High Energy Physics - Phenomenology · Physics 2008-02-03 Andrei L. Kataev

The detailed comprehension of momentum fraction and energy dependence of proton structure functions is among the major difficulties in high-energy physics. Perturbative quantum chromodynamics (QCD) plays as an extensive foundation for…

High Energy Physics - Phenomenology · Physics 2025-09-25 Akbari Jahan , Diptimonta Neog

Precise determinations of the strong coupling constant in hadronic collisions demand sets of parton densities spanning a sufficiently wide range of values for the QCD scale parameter Lambda. For such applications, we supplement the recent…

High Energy Physics - Phenomenology · Physics 2009-10-28 A. Vogt

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…

Parton distribution functions (PDFs) describe universal properties of bound states and allow us to calculate scattering amplitudes in processes with large momentum transfer. Calculating PDFs involves the evaluation of matrix elements with a…

High Energy Physics - Lattice · Physics 2025-02-10 Mari Carmen Bañuls , Krzysztof Cichy , C. -J. David Lin , Manuel Schneider

A survey is given on the present status of the nucleon parton distributions and related precision calculations and precision measurements of the strong coupling constant $\alpha_s(M_Z^2)$. We also discuss the impact of these quantities on…

High Energy Physics - Phenomenology · Physics 2014-11-21 Johannes Blümlein

We provide an assessment of the impact of parton distributions on the determination of LHC processes, and of the accuracy with which parton distributions (PDFs) can be extracted from data, in particular from current and forthcoming HERA…

Parton distribution functions play a pivotal role in hadron collider phenomenology. They are non-perturbative quantities extracted from fits to available data, and their scale dependence is dictated by the DGLAP evolution equations. In this…

High Energy Physics - Phenomenology · Physics 2024-08-08 Salvador A. Ochoa-Oregon , David F. Rentería-Estrada , Roger J. Hernández-Pinto , German F. R. Sborlini , Pia Zurita

The correct description of Double Parton Scattering (DPS), which represents a background in several channels for the search of new Physics at the LHC, requires the knowledge of double parton distribution functions (dPDFs). These quantities…

High Energy Physics - Phenomenology · Physics 2016-11-23 Matteo Rinaldi , Sergio Scopetta , Marco Claudio Traini , Vicente Vento

One of the main open questions in physics is the understanding of the internal structure of the strongly interacting particles, or hadrons. It is still a challenge to describe consistently the dynamics of scattering processes and hadronic…

High Energy Physics - Phenomenology · Physics 2011-11-28 A. Courtoy

Parton distributions are an essential ingredient of the LHC program. PDFs are relevant for precision Standard Model measurements, for Higgs boson characterization as well as for New Physics searches. In this contribution I review recent…

High Energy Physics - Phenomenology · Physics 2013-05-16 Juan Rojo

We review the latest progress in lattice QCD calculations of the partonic structure of hadrons. This structure is, in particular, described in terms of $x$-dependent distributions, the simplest of which are the standard parton distribution…

High Energy Physics - Lattice · Physics 2021-10-18 Krzysztof Cichy

The production of single top-quarks in the t-channel at hadron colliders imposes strong analytic constraints on parton distribution functions (PDFs) through its double deeply inelastic scattering (DDIS) form. We exploit this to provide…

High Energy Physics - Phenomenology · Physics 2021-12-01 John Campbell , Tobias Neumann , Zack Sullivan

We formulate a general approach to the inclusion of theoretical uncertainties, specifically those related to the missing higher order uncertainty (MHOU), in the determination of parton distribution functions (PDFs). We demonstrate how,…

The photon PDF of the proton is needed for precision comparisons of LHC cross sections with theoretical predictions. In a recent paper, we showed how the photon PDF could be determined in terms of the electromagnetic proton structure…

High Energy Physics - Phenomenology · Physics 2018-01-17 Aneesh V. Manohar , Paolo Nason , Gavin P. Salam , Giulia Zanderighi

The need for accurate and precise polarised parton distribution functions (PDFs) is becoming increasingly crucial in view of the Electron-Ion Collider experimental program foreseen in the coming years. Two global PDF determinations at…

High Energy Physics - Phenomenology · Physics 2024-09-17 Amedeo Chiefa

Parton distributions given by deep inelastic lepton scattering (DIS) are not equal to the probabilities of finding those partons in the parent wave function. Soft rescattering of the struck parton within the coherence length of the hard…

High Energy Physics - Phenomenology · Physics 2009-11-07 Paul Hoyer

We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology at LO and NNLO in perturbative QCD, thereby generalizing to these orders the NNPDF2.1 NLO parton…