How to impose initial conditions for QCD evolution of double parton distributions?

Golec-Biernat, K.; Lewandowska, Emilia

doi:10.1103/physrevd.90.014032

Cited by 22 publications

(14 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To satisfy the GS sum rules, we have argued in [40,41] that a practical approach is the top-down method, where one starts with n-body parton distributions with the longitudinal momentum fractions constrained with δ(1 − x 1 − ... − x n ), and subsequently generates distributions with a lower number of partons via marginal projections. This avoids complications of bottom-up attempts in constructing dPDFs from known sPDFs, which cannot be unique and where one encounters problems [48,50]. Also, note a recent study [51] devoted to a verification of the GS sum rules in covariant perturbation theory and in light-cone perturbation theory.…”

Section: Basic Definitions and Propertiesmentioning

confidence: 97%

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

Broniówski

Arriola

2020

Phys. Rev. D

View full text Add to dashboard Cite

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.

show abstract

Section: Basic Definitions and Propertiesmentioning

confidence: 97%

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

Broniówski

Arriola

2020

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…For the double distributions, such sum rules relate the integrals of the DPDFs to the single PDFs, thus placing important constraints on the allowed forms of the initial conditions. This makes the construction of the initial conditions for the DPDFs much more complicated, see [62][63][64] for various proposals. For the case when Q 1 = Q 2 = Q, the momentum sum rules for the DPDFs can be expressed in the following form…”

Section: Initial Conditions For the Evolution Equationsmentioning

confidence: 99%

Numerical analysis of the unintegrated double gluon distribution

Elias

Golec-Biernat

Staśto

2018

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

We present detailed numerical analysis of the unintegrated double gluon distribution which includes the dependence on the transverse momenta of partons. The unintegrated double gluon distribution was obtained following the Kimber-Martin-Ryskin method as a convolution of the perturbative gluon splitting function with the collinear integrated double gluon distribution and the Sudakov form factors. We analyze the dependence on the transverse momenta, longitudinal momentum fractions and hard scales. We find that the unintegrated gluon distribution factorizes into a product of two single unintegrated gluon distributions in the region of small values of x, provided the splitting contribution is included and the momentum sum rule is satisfied.

show abstract

“…If one uses a value of 5 mb, more in line with the conclusions of our study of prompt J/ψ + Z [46], np R(J/ψ + Z) 3 Let us recall at this stage our caveat mentioned in the introduction that there do not exist proofs of such a formula and that factorisation-breaking effects have been discussed in a number of recent studies (see e.g. [6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]).…”

Section: Discussion About the Dps Contributionsmentioning

confidence: 63%

Phenomenological analysis of associated production of Z0+b in the b→J/ψX decay channel at the LHC

Lansberg

Shao

2017

Nuclear Physics B

View full text Add to dashboard Cite

The ATLAS collaboration recently reported on the first observation of associated-production of a Z 0 boson with a J/ψ. We recently claimed that the corresponding yield of the prompt J/ψ was dominated by double parton scatterings in the ATLAS acceptance with a somewhat small value of σ eff . We also found out that single parton scatterings were only dominant at large transverse momenta. We present here the first phenomenological analysis of another part of the ATLAS data sample, namely of a Z 0 boson plus a non-prompt J/ψ. Our study is performed at next-to-leading order in α s and includes parton-shower effects via the MadGraph5 aMC@NLO framework. We find out that the data, unlike the case of prompt J/ψ + Z 0 , do not hint at significant DPS contributions. Owing to the current experimental and theoretical uncertainties, there is still a room for these but with a lower limit of σ eff close to 5 mb. We stress the importance of QCD corrections to account for the ATLAS data.commonly used-assumption whereby both scatterings occur independently without affecting each others' kinematics. As such, their individual cross sections appear in a factorised way, in what we call the "pocket formula". As of today, there do not exist proofs of such a factorised formula. Recent and less recent theoretical DPS studies have identified factorisation-breaking effects (see e.g. , 29]) and have thus shown that such a factorised "pocket formula" can only be an approximation and we stress that it should only be considered as such. That being said, given the other theoretical and experimental uncertainties involved in such extractions, such a simplification is perfectly sound.Quarkonia being produced via the gluon-gluon initial states, their pair production could help us probe the transverse correlations of the gluon-gluon in a proton (see e.g. [20]). In fact, many quarkonium associated production processes have been recently measured. Let us cite J/ψ pair production by LHCb [30], D0 [1], CMS [31] and ATLAS [32] , J/ψ + Υ production by D0 [3], Υ(1S ) pair production by CMS [33], J/ψ + Z 0 /W ± production by ATLAS [34,35], J/ψ/Υ + charm by LHCb [36,37], with their theory counterparts for J/ψ + J/ψ [38,39,40,2,41,42,43,44,45],The observed different trend between the extracted values of σ eff for jets and quarkonia may be the first hint of a nontrivial flavour dependence of these correlations. Along these lines, the associated production of a vector boson with heavy flavours, which we treat here, could be an unique playground to probe corresponding quark-gluon correlations.In this paper, we are in particular interested in the associated production of a Z 0 boson with a b quark, via the observation of a non-prompt J/ψ, as measured by the ATLAS collaboration [34]. This production channel is thus supposed to probe the underlying process pp → Z 0 + bb + X 1 . At the LHC, such partonic reactions are usually proposed to be studied via Z 0 plus b-jet. We however stress that both final states are complementary since looking at the b via non-prompt J/ψ...

show abstract

How to impose initial conditions for QCD evolution of double parton distributions?

Cited by 22 publications

References 44 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

Numerical analysis of the unintegrated double gluon distribution

Phenomenological analysis of associated production of Z0+b in the b→J/ψX decay channel at the LHC

Contact Info

Product

Resources

About