NNLO logarithmic expansions and exact solutions of the DGLAP equations from x-space: New algorithms for precision studies at the LHC

Cafarella, Alessandro; Corianò, Claudio; Guzzi, Marco

doi:10.1016/j.nuclphysb.2006.05.010

Cited by 50 publications

(40 citation statements)

References 22 publications

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“…At higher order, structure functions are obtained by convoluting the quark and gluon distributions with the corresponding pertuabative coefficient functions. Having the next-to-next-to-leading order (NNLO) contributions of the quark-quark and gluonquark splitting functions in perturbative QCD [41], one can obtain the evolution of longitudinally polarized parton densities of hadrons up to NNLO order of QCD [42]. The NNLO spin-dependent proton structure functions, g p 1 (x, Q 2 ), can be written as a linear combination of po-larized parton distribution functions ∆q, ∆q and ∆g as,…”

Section: Polarized Pdfs Analysis Methodsmentioning

confidence: 99%

Next-to-next-to-leading order QCD analysis of spin-dependent parton distribution functions and their uncertainties: Jacobi polynomials approach

Taghavi-Shahri

Khanpour

Tehrani³

et al. 2016

Phys. Rev. D

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We present a first QCD analysis of next-to-next-leading-order (NNLO) contributions of the spindependent parton distribution functions (PPDFs) in the nucleon and their uncertainties using the Jacobi polynomial approach. Having the NNLO contributions of the quark-quark and gluon-quark splitting functions in perturbative QCD (Nucl. Phys. B 889 (2014) 351-400), one can obtain the evolution of longitudinally polarized parton densities of hadrons up to NNLO accuracy of QCD. A very large sets of recent and up-to-date experimental data of spin structure functions of the proton g p 1 , neutron g n 1 , and deuteron g d 1 have been used in this analysis. The predictions for the NNLO calculations of the polarized parton distribution functions as well as the proton, neutron and deuteron polarized structure functions are compared with the corresponding results of the NLO approximation. We form a mutually consistent set of polarized PDFs due to the inclusion of the most available experimental data including the recently high-precision measurements from COMPASS16 experiments (Phys. Lett. B 753 (2016) 18-28). We have performed a careful estimation of the uncertainties using the most common and practical method, the Hessian method, for the polarized PDFs originating from the experimental errors. The proton, neutron and deuteron structure functions and also their first moments, Γ p,n,d , are in good agreement with the experimental data at small and large momentum fraction of x. We will discuss how our knowledge of spin-dependence structure functions can improve at small and large value of x by the recent COMPASS16 measurements at CERN, the PHENIX and STAR measurements at RHIC, and at the future proposed colliders such as Electron-Ion collider (EIC).

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Section: Polarized Pdfs Analysis Methodsmentioning

confidence: 99%

Next-to-next-to-leading order QCD analysis of spin-dependent parton distribution functions and their uncertainties: Jacobi polynomials approach

Taghavi-Shahri

Khanpour

Tehrani³

et al. 2016

Phys. Rev. D

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“…2 Several techniques to accomplish a numerical solution of these integro-differential equations have been developed both in x-space [7,8], and Mellin space [9]. …”

Section: The Techniquementioning

confidence: 99%

Current state of nPDFs and future facilities

Andrés¹

2018

Proceedings of QCD Evolution 2017 — PoS(QCDEV2017)

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“…A C (x) = (P 0 − M 0 ) + (P 1 − M 1 ) · Log (Log(x)) (P 0 + M 0 ) + (P 1 + M 1 ) · Log (Log(x)) (A.11) with dA C (x) dx = 2 · (P 1 M 0 − P 0 M 1 ) x · Log(x) · [(P 0 + M 0 ) + (P 1 + M 1 ) · Log (Log(x))] 2 (A. 12) and, since x > 0 (in practice x > 10 GeV) and Log(x) > 0,…”

Section: A22 Polynomials Of Log (Log(x))mentioning

confidence: 99%

A New Method for Indirect Mass Measurements using the Integral Charge Asymmetry at the LHC

Muanza¹,

Serre²

2016

Proceedings of XXIII International Workshop on Deep-Inelastic Scattering — PoS(DIS2015)

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Processes producing a charged final state at the LHC have a positive or null integral charge asymmetry. We propose a novel method for an indirect measurement of the mass of these final states based upon the process integral charge asymmetry. We present this method in three stages. Firstly, the theoretical prediction of the integral charge asymmetry and its related uncertainties are studied through parton level cross sections calculations. Secondly, the experimental extraction of the integral charge asymmetry of a given signal, in the presence of some background, is performed using particle level simulations. Process dependent templates enable to convert the measured integral charge asymmetry into an estimated mass of the charged final state. Thirdly, a combination of the experimental and the theoretical uncertainties determines the full uncertainty of the indirect mass measurement. This new method applies to all charged current processes at the LHC. In this article, we demonstrate its effectiveness at extracting the mass of the W boson, as a first step, and the sum of the masses of a chargino and a neutralino in case these supersymmetric particles are produced by pair, as a second step.

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NNLO logarithmic expansions and exact solutions of the DGLAP equations from x-space: New algorithms for precision studies at the LHC

Cited by 50 publications

References 22 publications

Next-to-next-to-leading order QCD analysis of spin-dependent parton distribution functions and their uncertainties: Jacobi polynomials approach

Next-to-next-to-leading order QCD analysis of spin-dependent parton distribution functions and their uncertainties: Jacobi polynomials approach

Current state of nPDFs and future facilities

A New Method for Indirect Mass Measurements using the Integral Charge Asymmetry at the LHC

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