Single-diffractive production of dijets within the $k_t$-factorization approach

We discuss single-diffractive production of dijets. The cross section is calculated within the resolved Pomeron picture, for the first time in the $k_t$-factorization approach, neglecting transverse momentum of the Pomeron. We use Kimber-Martin-Ryskin unintegrated parton (gluon, quark, antiquark) distributions in both the proton as well as in the Pomeron or subleading Reggeon. The unintegrated parton distributions are calculated based on conventional mmht2014nlo parton distribution functions in the proton and H1 Collaboration diffractive parton distribution functions used previously in the analysis of diffractive structure function and dijets at HERA. For comparison, we present results of calculations performed within the collinear-factorization approach. Our results remain those obtained in the next-to-leading-order approach. The calculation is (must be) supplemented by the so-called gap survival factor, which may, in general, depend on kinematical variables. We try to describe the existing data from Tevatron and make detailed predictions for possible LHC measurements. Several differential distributions are calculated. The ${\overline{E}}_T$, $\overline{\eta }$ and $x_{\overline{p}}$ distributions are compared with the Tevatron data. A reasonable agreement is obtained for the first two distributions. The last one requires introducing a gap survival factor which depends on kinematical variables. We discuss how the phenomenological dependence on one kinematical variable may influence dependence on other variables such as ${\overline{E}}_T$ and $\overline{\eta }$. Several distributions for the LHC are shown.

Figure 1

A diagrammatic representation of the considered mechanisms of single-diffractive dijet production within the resolved Pomeron model extended in the present paper to the $k_t$-factorization approach.

Figure 2

Distribution in average ${\overline{E}}_T$ (left panel) and in average $\overline{\eta }$ (right panel). Here, $S_G=0.1$.

Figure 3

Two-dimensional distribution in transverse momenta of partons on the nondiffractive side ($k_{1T}$) and on the diffractive side ($k_{2T}$). Here, $S_G=0.1$.

Figure 4

Transverse momentum distribution for leading and subleading jets (left panel) and the influence of the cut on $t$ on the leading jet (right panel). Here, $S_G=0.1$.

Figure 5

The Pomeron and subleading Reggeon contribution for ${\overline{E}}_T$ (left panel) and $\overline{\eta }$ (right panel).

Figure 6

The average transverse energy distribution for $\sqrt{s}=1.8\mathrm{TeV}$ (left panel) and for $\sqrt{s}=630\mathrm{GeV}$ (right panel).

Figure 7

The average rapidity distribution for $\sqrt{s}=1.8\mathrm{TeV}$ (left panel) and for $\sqrt{s}=630\mathrm{GeV}$ (right panel).

Figure 8

Distribution in $x_{\overline{p}}$ for $\sqrt{s}=1.8\mathrm{TeV}$ (left panel) and for $\sqrt{s}=630\mathrm{GeV}$ (right panel). No gap survival factor was included here.

Figure 9

The ratio of single-diffractive to nondiffractive cross sections as a function of $x_{\overline{p}}$. The lines are fits of $S_G$ to the CDF data.

Figure 10

${\overline{E}}_T$ distribution for collinear (left panel) and $k_t$-factorization (right panel) approaches with and without the inclusion of the dependence of $S_G$ on $x_{\overline{p}}$.

Figure 11

$\overline{\eta }$ distribution for collinear (left panel) and $k_t$-factorization (right panel) approaches with and without the inclusion of the dependence of $S_G$ on $x_{\overline{p}}$.

Figure 12

Distribution in the jet transverse momentum for leading (left panel) and subleading (right panel) jets for $\sqrt{s}=13\mathrm{TeV}$ and for the ATLAS cuts. Here, $S_G=0.05$.

Figure 13

The contribution of the Pomeron and subleading Reggeon for transverse momentum distribution for the leading (left panel) and subleading (right panel) jets for $\sqrt{s}=13\mathrm{TeV}$ and for the ATLAS cuts. Here, $S_G=0.05$.

Figure 14

Distribution in the jet rapidity for leading (left panel) and subleading (right jet) jets for $\sqrt{s}=13\mathrm{TeV}$. Here, $S_G=0.05$.

Figure 15

Our predictions for azimuthal angle correlations between the leading and subleading jets. Here, $S_G=0.05$.

Figure 16

Two-dimensional distributions in parton transverse momenta for the Pomeron (left panel) and subleading Reggeon (right panel). In this calculation, $\sqrt{s}=13\mathrm{TeV}$ and ATLAS cuts were imposed. Here, $S_G=0.05$.