Angular correlations in the double Drell-Yan process

Kasemets, Tomas; Diehl, Markus

doi:10.1007/jhep01(2013)121

Cited by 36 publications

(29 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relevance of spin correlations in double parton scattering was pointed out long ago [9,10] and recently followed up in [11,12]. The studies in [13] and [14] have shown that spin correlations in the production of two vector bosons by double hard scattering have observable effects both on the interaction rate and on kinematic distributions. Spin correlations between the two partons are quantified by polarized double parton distributions (DPDs), which describe for instance the difference of the probability densities for finding two quarks with equal or with opposite helicities.…”

Section: Introductionmentioning

confidence: 99%

Positivity bounds on double parton distributions

Diehl

Kasemets

2013

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

Double hard scattering in proton-proton collisions is described in terms of double parton distributions. We derive bounds on these distributions that follow from their interpretation as probability densities, taking into account all possible spin correlations between two partons in an unpolarized proton. These bounds constrain the size of the polarized distributions and can for instance be used to set upper limits on the effects of spin correlations in double hard scattering. We investigate the stability of the bounds under leading-order DGLAP evolution to higher scales.

show abstract

Section: Introductionmentioning

confidence: 99%

Positivity bounds on double parton distributions

Diehl

Kasemets

2013

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…where in the last step we have used the definition (4.20). We furthermore have 44) which shows that at z 1 = z 2 = 0 the soft matrix is diagonal in the colour representations R and R ′ . Note that this is not the case for nonzero z 1 , z 2 , as follows immediately from the explicit one-loop expressions in section 7.2.…”

Section: Simplification Of Soft Factors In Collinear Factorisationmentioning

confidence: 83%

“…for a given partonic channel, whereσ 0 is the cross section at lowest order in α s . The expressions forσ 0 can be found in many places, for instance in [44] for the production of an electroweak gauge boson V and its subsequent decay into a lepton pair, and in [85] for Higgs production via gg fusion in the limit of large top mass. The hard-scattering coefficients read…”

Section: Tmd Hard-scattering Cross Sectionsmentioning

confidence: 99%

“…Quark model calculations [35][36][37][38][39][40][41][42] typically yield strong correlations in the valence region, but for the region of small momentum fractions x there is little guidance from models so far. The decrease of spin correlations under evolution to higher scales has been studied in [43], and their influence on final-state distributions has been investigated for several processes [28,44,45]. The generation of parton correlations by the splitting of a single parton into two has been investigated by several groups [27,[46][47][48][49][50]; a simplified implementation into the event generator Pythia is described in [51,52].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Transverse momentum in double parton scattering: factorisation, evolution and matching

Buffing

Diehl

Kasemets

2018

J. High Energ. Phys.

Self Cite

111

View full text Add to dashboard Cite

We give a description of double parton scattering with measured transverse momenta in the final state, extending the formalism for factorisation and resummation developed by Collins, Soper and Sterman for the production of colourless particles. After a detailed analysis of their colour structure, we derive and solve evolution equations in rapidity and renormalisation scale for the relevant soft factors and double parton distributions. We show how in the perturbative regime, transverse momentum dependent double parton distributions can be expressed in terms of simpler nonperturbative quantities and compute several of the corresponding perturbative kernels at one-loop accuracy. We then show how the coherent sum of single and double parton scattering can be simplified for perturbatively large transverse momenta, and we discuss to which order resummation can be performed with presently available results. As an auxiliary result, we derive a simple form for the square root factor in the Collins construction of transverse momentum dependent parton distributions.

show abstract

“…8 Sinceh ⊥ 1,q belongs to a left-moving hadron rather than a right-moving one, it comes with a minus sign compared to h ⊥ 1,q from swapping plus and minus indices in the antisymmetric Levi-Civita tensor (see e.g. [62]).…”

Section: Sum Of the Diagramsmentioning

confidence: 99%

Colour unwound - disentangling colours for azimuthal asymmetries in Drell-Yan scattering

et al. 2017

Self Cite

View full text Add to dashboard Cite

It has been suggested that a colour-entanglement effect exists in the Drell-Yan cross section for the 'double T-odd' contributions at low transverse momentum Q T , rendering the colour structure different from that predicted by the usual factorisation formula [1]. These T-odd contributions can come from the Boer-Mulders or Sivers transverse momentum dependent distribution functions. The different colour structure should be visible already at the lowest possible order that gives a contribution to the double Boer-Mulders (dBM) or double Sivers (dS) effect, that is at the level of two gluon exchanges. To discriminate between the different predictions, we compute the leading-power contribution to the low-Q T dBM cross section at the two-gluon exchange order in the context of a spectator model. The computation is performed using a method of regions analysis with Collins subtraction terms implemented. The results conform with the predictions of the factorisation formula. In the cancellation of the colour entanglement, diagrams containing the three-gluon vertex are essential. Furthermore, the Glauber region turns out to play an important role -in fact, it is possible to assign the full contribution to the dBM cross section at the given order to the region in which the two gluons have Glauber scaling. A similar disentanglement of colour is found for the dS effect.

show abstract

Angular correlations in the double Drell-Yan process

Cited by 36 publications

References 82 publications

Positivity bounds on double parton distributions

Positivity bounds on double parton distributions

Transverse momentum in double parton scattering: factorisation, evolution and matching

Colour unwound - disentangling colours for azimuthal asymmetries in Drell-Yan scattering

Contact Info

Product

Resources

About