Small- x dynamics in forward–central dijet correlations at the LHC

Abstract

We provide a description, within the High Energy Factorization formalism, of central-forward dijet correlation data measured by the CMS experiment and the predictions for nuclear modification ratio R p A in p + Pb collisions. In our study, we use the unintegrated gluon density derived from the BFKL and BK equations supplemented with subleading corrections and a hard scale dependence. The latter is introduced at the final step of the calculation by re-weighting the Monte Carlo generated events using suitable Sudakov form factors, without changing the total cross section. We achieve a good description of data in the whole region of the azimuthal angle.

Improved TMD factorization for forward dijet production in dilute-dense hadronic collisions

“…The equations that combine such effects with the small-x evolution [55,56] show a nontrivial interplay between the non-linearities and the µ 2 dependence and this may, in particular, weaken the saturation effects. At the linear level, the so-called single step inclusion of the hard-scale effects (as demonstrated in [17]) helps in the description of forward-central dijet data, therefore this direction seems to be relevant in order to provide complete predictions. Furthermore, first estimates of azimuthal decorrelations of the forward-forward dijets in the HEF framework, with inclusion of hard scale effects and non-linearities, show that they are of similar relevance for this process [33].…”

“…Separately, the HEF and TMD approaches to dijet production have been extensively studied in the literature [11,[15][16][17][18] and [12,[19][20][21][22][23][24][25], but little connection has been made between them so far. The first result of this paper is to reveal that connection, in the context of dilute-dense collisions, and to show that, in fact, they are both contained in the CGC description.…”

Predictions for p+Pb Collisions at sNN = 5TeV: Comparison with Data

“…The prescription for including the hard scale, µ, dependence in the small x gluon evolution equations using the Sudakov form factor, proposed in Refs. [94,95], is applied. (For other approaches, see Ref.…”

Resummation effects in the forward production ofZ0+jetat the LHC

“…Furthermore it has been recognized in [1] that by studies of associated production of electroweak bosons and jets may provide a new insight into the transverse partonic structure of hadrons at small x, where x is the momentum fraction of the hadron taken by a parton participating in the hard collision. Furthermore, such a final state, being a combination of colorful and colorless particles, gives the opportunity for particularly interesting investigations complementary to results obtained in studies of pure jet final states [2][3][4][5][6] and Drell-Yan pairs [7]. In particular the final state rescatterings due to soft color exchanges should have less impact on the properties of produced final state as compared to pure jet final states.…”