Calculations of central exclusive production are affected by very large perturbative and non-perturbative corrections. In this talk, we summarize the results of a study of the uncertainties on these corrections in the case of exclusive dijet production.
We investigate the effect of soft gluon radiations on the azimuthal angle correlation between the total and relative momenta of two jets in inclusive and exclusive dijet processes. We show that the final state effect induces a sizable $cos(2phi)$ ani
sotropy due to gluon emissions near the jet cones. The phenomenological consequences of this observation are discussed for various collider experiments, including diffractive processes in ultraperipheral $pA$ and $AA$ collisions, inclusive and diffractive dijet production at the EIC, and inclusive dijet in $pp$ and $AA$ collisions at the LHC.
We investigate the theoretical description of the central exclusive production process, $h_1 + h_2 to h_1+X+h_2$. Taking Higgs production as an example, we compute the subset of next-to-leading order corrections sensitive to the Sudakov factor appear
ing in the process. Our results agree with those originally presented by Khoze, Martin and Ryskin except that the scale appearing in the Sudakov factor, $mu=0.62 sqrt{hat{s}}$, should be replaced with $mu=sqrt{hat{s}}$, where $sqrt{hat{s}}$ is the invariant mass of the centrally produced system. We show that the replacement leads to approximately a factor 2 suppression in the cross-section for central system masses in the range 100--500GeV.
In view of the recent diffractive dijet data from CDF run II, we critically re-evaluate the standard approach to the calculation of central production of dijets in quasi-elastic hadronic collisions. We find that the process is dominated by the non-pe
rturbative region, and that even perturbative ingredients, such as the Sudakov form factor, are not under theoretical control. Comparison with data allows us to fix some of the uncertainties. Although we focus on dijets, our arguments apply to other high-mass central systems, such as the Higgs boson.
Central diffractive production of heavy states (massive dijets, Higgs boson) is studied in the exclusive mode using a new Hybrid Pomeron Model (HPM). Built from Hybrid Pomerons defined by the combination of one hard and one soft color exchanges, the
model describes well the centrally produced diffractive dijet data at the Tevatron. Predictions for the Higgs boson and dijet exclusive production at the LHC are presented.
The prospects for central exclusive diffractive (CED) production of MSSM Higgs bosons at the LHC are reviewed. It is shown that the CED channels, making use of forward proton detectors at the LHC installed at 220 m and 420 m distance around ATLAS and
/ or CMS, can provide important information on the Higgs sector of the MSSM. In particular, CED production of the neutral CP-even Higgs bosons h and H and their decays into bottom quarks has the potential to probe interesting regions of the M_A--tan_beta parameter plane of the MSSM and may give access to the bottom Yukawa couplings of the Higgs bosons up to masses of M_H approx 250 GeV.