Proton dissociation into three jets


We explore the possibility to observe hard exclusive three-jet production in early LHC runs, corresponding to diffractive dissociation of the incident proton into three jets with large but compensating transverse momenta. This process is sensitive to the proton unintegrated gluon distribution at small x and to the distribution of the three valence quarks in the proton at small transverse distances. The corresponding cross section is calculated using an approach based on kt factorization. According to our estimates, observation of hard diffractive three-jet production at LHC is feasible for jet transverse momenta q⊥ ∼ 5 GeV. 1. The physics potential of forward detectors at LHC, within and beyond the standard model, is attracting a lot of attention, cf. [1, 2, 3, 4, 5]. In this Letter we explore the possibility to observe hard exclusive diffractive dissociation of a proton into three hard jets in protonproton collisions p(p1) + p(p2) → jet(q1) + jet(q2) + jet(q3) + p(p ′ 2) , (1) cf. [6] In this process one proton stays intact and the other one dissociates into a system of three hard jets separated by a large rapidity gap from the recoil proton, see Fig. 1. The main aim of our study is to estimate the cross section of this reaction and the corresponding event rates at LHC and Tevatron. Note that we are interested in exclusive three–jet production which constitutes a small fraction of the inclusive single diffraction cross section. The exclusive and inclusive mechanisms have different final state topologies and can be distinguished experimentally. A characteristic quantity is e.g. the ratio Rjets of the three-jet mass to the total invariant mass of the system produced in the diffractive interaction. Exclusive production corresponds to the region where Rjets is close to unity. This strategy was used recently at the Tevatron [7] where central exclusive dijet production, pp̄ → p+ jet+ jet+ p̄, in double–Pomeron collisions was measured for the first time. Exclusive dijet production in the central region has much in common with the exclusive Higgs boson production process, pp̄ → p+H + p̄. In [8] it was argued that studies of exclusive dijet production and other diffractive processes at the early data runs of the LHC can provide

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@inproceedings{Braun2008ProtonDI, title={Proton dissociation into three jets}, author={Vladimir M. Braun and D . Yu and Andreas Sch{\"a}fer}, year={2008} }