New contributions to central exclusive production of dijets in proton-(anti)proton collisions

Abstract

We consider central exclusive production of gg dijets in proton-proton (proton-antiproton) collisions at LHC and Tevatron for different intermediate and final gluon polarisations. The amplitude for the process is derived within the k ⊥ -factorization approach (with both the standard QCD and the Lipatov's effective three-gluon verticies) and is considered in various kinematical asymptotia, in particular, in the important limit of high-p ⊥ jets. Compared to earlier works we include emissions of gluons from different gluonic t-channel lines as well as emission of quark-antiquark dijets. Rapidity distributions, gluon jet p ⊥ distributions and invariant dijet mass distributions are presented. We explore the competition of the standard diagram with both jets emitted from a single t-channel gluon and the one with the emission from both t-channel gluons. The second mechanism requires a special treatment. We propose two different approaches. Including special kinematics and using properties of off-diagonal gluons at small x and ξ we arrive to correlations in two-dimensional distributions in rapidity of one and second jet. We find that the second contribution is much smaller than that known from the literature. The digluon production constitutes an important background to exclusive Higgs production. was shown in Ref.[9] that the first LHC measurements of the exclusive dijets would significantly reduce the theoretical uncertainty for the central exclusive Higgs boson production. This makes the process under consideration especially important from both theoretical and experimental points of view.Such a process has been recently investigated in detail in Ref. [6], and fairly good description of the Tevatron data has been achieved. We would like to extend such an analysis, both analytically and numerically, by analyzing separate contributions from different final gluon polarisations, various kinematical regions of the 4-particle phase space, which are important for future LHC measurements, and the theoretical uncertainties related with different choice of UGDFs and the factorisation scale. Similarly to Ref.[6], we shall limit ourselves to the lowest-order QCD calculation, and postpone the analysis of the higher order contributions for a separate study.Compared to the previous studies, we would like to perform an estimation of the process when one gluon is emitted from a one t-channel gluon of the QCD ladder and the second gluon is emitted from the other t-channel gluon. This contribution was discussed in Ref.[6] as potentially sizable. In this work, we present the first numerical calculation of this contribution.Recently, the calculation of the exclusive production of quark-antiquark dijets has been performed for heavy cc [10] and bb [7,8] pairs. Here, we extend our previous analysis and present the calculation including both contributions from light (u, d, s) and heavy (c, b) quark/antiquark jets compared to the one from the gluonic jets.A high precision measurement of exclusive bb pair production is required for central exc...

The phenomenology of central exclusive production at hadron colliders

“…There has recently been a renewal of interest in studies of central exclusive production (CEP) processes in high-energy proton-(anti)proton collisions (see [1][2][3][4] for reviews), both theoretically [5][6][7][8][9][10][11][12][13][14] and experimentally [4,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] (see [32,33] for reviews). The CEP of an object X may be written in the form pp(p) → p + X + p(p) , (1.1) where + signs are used to denote the presence of large rapidity gaps.…”

Production of charged Higgs boson pairs in the $p p \to p p H^+ H^-$ reaction at the LHC and FCC

“…and enters into M pp→ppH + H − invariant 2 → 4 amplitude for the diffractive process as in [13,6]. The triple-Higgs coupling constant g hH + H − is model dependent.…”

Central exclusive production within the Durham model: A Review

“…Over the last decade there has been a steady interest in the CEP of new physics objects at the LHC, 1,2,4,5,23,24,177,178,186,187 with the possibility of a simultaneous detection of the forward protons, using dedicated very forward detectors, and the central system opening up a window to a rich physics program, covering a variety of QCD, Electroweak and BSM processes. [188][189][190] One particularly interesting example that has received a great deal of attention is the CEP of the Higgs boson(s).…”