Numerical analysis of the unintegrated double gluon distribution

Elias, Edgar; Golec-Biernat, K.; Staśto, Anna

doi:10.1007/jhep01(2018)141

Cited by 9 publications

(9 citation statements)

References 66 publications

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“…The qualitative argument here is that at large µ, with many partons present, the constraint of the longitudinal momentum is effective only when one of the considered partons takes a large momentum fraction, thus leaving significantly less of available phase space for the other parton. We remark that a qualitatively similar effect has been found for gluodynamics in [59][60][61].…”

Section: Numerical Results Of Evolutionsupporting

confidence: 85%

Double parton distribution of valence quarks in the pion in chiral quark models

Broniówski

Arriola

2020

Phys. Rev. D

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The valence double parton distribution of the pion is analyzed in the framework of chiral quark models, where in the chiral limit factorization between the longitudinal and transverse degrees of freedom occurs. This feature leads, at the quark-model scale, to a particularly simple distribution of the form D(x1, x2, y) = δ(1−x1 −x2)F (y), where x1,2 are the longitudinal momentum fractions carried the valence quark and antiquark, and y is the separation of their transverse positions. For y = 0 this result complies immediately to the Gaunt-Sterling sum rules. The DGLAP evolution to higher scales is carried out in terms of the Mellin moments. We then explore its role on the longitudinal correlation quantified with the ratio of the double distribution to the product of single distributions, D(x1, x2, y)/D(x1)D(x2). We point out that the ratios of moments x n 1 x m 2 / x n 1 x m 2 are independent of the evolution, providing particularly suitable measures to be tested in the upcoming lattice simulations. The transverse form factor F (y) is obtained in variants of the Nambu-Jona-Lasinio model with the spectral and Pauli-Villars regularizations. Interestingly, with the spectral regularization of the model, the effective cross section for the double parton scattering of pions is exactly equal to the geometric cross section, σ eff = π y 2 and yields about 20 mb.

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Section: Numerical Results Of Evolutionsupporting

confidence: 85%

Double parton distribution of valence quarks in the pion in chiral quark models

Broniówski

Arriola

2020

Phys. Rev. D

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“…In addition, there are important theoretical constraints on DPDs. On the one hand, there is the perturbative splitting of one parton into two [34][35][36][37][38][39]41,42,45,57,[65][66][67][68][69][70][71][72][73][74][75][76], which determines the behaviour of DPDs at small y and likewise puts constraints on DPDs depending on Δ. On the other hand, there are sum rules [77,78], which involve DPDs integrated over y (or evaluated at Δ = 0) and express the conservation of momentum and quark number.…”

Section: Introductionmentioning

confidence: 99%

Sum rule improved double parton distributions in position space

et al. 2020

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Models for double parton distributions that are realistic and consistent with theoretical constraints are crucial for a reliable description of double parton scattering. We show how an ansatz that has the correct behaviour in the limit of small transverse distance between the partons can be improved step by step, such as to fulfil the sum rules for double parton distributions with an accuracy around 10%.

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“…While for single-scale observables, such as total inclusive cross-section of some hard process with hard scale Q, the DPS contribution is always suppressed by powers of Λ 2 /Q 2 , where Λ is some typical hadronic scale, the DPS contribution can be comparable with Single Parton Scattering contribution for the differential distributions in some regions of phase space [3]. In the DPS picture, longitudinal and transverse-momentum correlations of small-x partons, participating in two independent hard scatterings, are quickly washed-out by effects of scale evolution of two-parton PDFs [4], so that double parton PDF effectively factorizes into a product of usual PDFs, leading to the "pocket-formula" description of DPS as:…”

Section: Introductionmentioning

confidence: 99%

“…TeV and √ S = 8 TeV. We use the unPDFs obtained by the KMR formula(3,4) from the LO collinear PDFs MSTW-2008[33] and the corresponding value of α s (M Z ) = 0.13939. We set the renormalization and factorization scales to µ R = for the central lines of our predictions, and we vary 1/2 < ξ < 2 to estimate the scale-uncertainty of our prediction, which is shown in the figures by the gray band for the curve corresponding to the sum of all contributions.In the Figs.…”

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confidence: 99%

Evidence in favor of single parton scattering mechanism in ϒ and D associated production at the LHC

2019

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Associated production of prompt Υ(1S) and D +,0 mesons has been proposed as a golden channel for the search of Double Parton Scattering, because Single Parton Scattering contribution to the cross-section is believed to be negligible on a basis of leading order calculations in the Collinear Parton Model. We study this process in the leading order approximation of the Parton Reggeization Approach. Hadronization of bb-pair into bottomonium states is described within framework of the NRQCD-factorization approach while production of D mesons is described in the fragmentation model with scale-dependent fragmentation functions. We have found good agreement with LHCb data for various normalized differential distributions, except for the case of spectra on azimuthal angle differences at the small ∆ϕ values. Crucially, the total cross-section in our Single Parton Scattering model accounts for more than one half of observed cross-section, thus dramatically shrinking the room for Double Parton Scattering mechanism.

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Numerical analysis of the unintegrated double gluon distribution

Cited by 9 publications

References 66 publications

Double parton distribution of valence quarks in the pion in chiral quark models

Double parton distribution of valence quarks in the pion in chiral quark models

Sum rule improved double parton distributions in position space

Evidence in favor of single parton scattering mechanism in ϒ and D associated production at the LHC

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