The photoproduction of isolated photons is measured using diffractive events
recorded by the ZEUS detector at HERA. Cross sections are evaluated in the
photon transverse-energy and pseudorapidity ranges $5 < E_T^{\gamma} < 15$ GeV
and $-0.7 < \eta^{\gamma} < 0.9$, inclusively and with a jet with
transverse-energy and pseudorapidity in the ranges $4 < E_T^{\rm jet} < 35$ GeV
and $-1.5 <...
Measurements of D∗(2010) meson production are presented in diffractive deep inelastic scattering (5<Q²<100 GeV²), based on 287 pb−1 of H1 HERA-II data recorded at the centre-of-mass energy sqrt(s)=319 GeV. The event topology is given by ep→eXY, where the system X, containing at least one D∗ meson, is separated from a leading low-mass proton...
The exclusive deep inelastic electroproduction of psi(2S) and J/\psi(1S)
at an ep centre-of-mass energy of 317 GeV has been studied with the ZEUS
detector at HERA in the kinematic range 2 < Q2 < 80 GeV2, 30 < W < 210 GeV
and |t| < 1 GeV2, where Q2 is the photon virtuality, W is the photon--proton
centre-of-mass energy and t is the squared four-momentum transfer at the
proton vertex. The data...
We present the first calculations for dijet production in diffractive deep-inelastic scattering (DIS) at next-to-next-to-leading order accuracy (NNLO). The calculations are based on the antenna subtraction formalism, where the hard coefficients are convoluted with available PDFs for diffractive scattering (DPDFs). Unfortunately, these DPDFs are currently available only in NLO precision.
We...
The presentation discusses the process of colour-singlet parton–parton scattering, which in hadron–hadron collision can lead to production of jet events, where a rapidity gap is present between the jets. The dynamics of the process is calculated within LL BFKL approximation. Using Pythia 8 MC generator, hadronic shapes of jet–gap–jet events are studied, in particular the distributions of the...
The cross-section for central exclusive production of J/psi and Psi(2S) mesons at 13 TeV is measured using the LHCb detector. Proton dissociative backgrounds are significant reduced compared to previous measurements through the use of forward shower counters, recently installed for Run 2. Plans for future measurements are also presented to exploit the new Run2 dataset.
We will present recent results of diffractive and exclusive measurements with the CMS experiment.
In the absence of forward proton tagging, exclusive processes can be distinguished in the central part of the ATLAS detector exploiting the large rapidity gap in the central region and the absence of charged particles reconstructed in the inner tracking detector. This strategy has been adopted to study the exclusive production of dilepton pairs (ee and mumu) in
proton-proton collision data...
The measurements of diffractive and exclusive processes in proton-proton collisions at 8 and 13 TeV are presented, covering results of hard single-diffractive and low-mass central diffractive processes. Events are selected by requiring the presence of scattered protons reconstructed in the Roman Pot detectors of the TOTEM experiment. Results from special data taking periods at 8 and 13 TeV...
I discuss the possibilities for using the LHC as a photon-photon
collider.I demonstrate that the photon parton
density in the proton is currently quite well known and consider the
implications for the LHC phenomenology. In addition, the colour
singlet nature of the photon means that it can readily lead to
exclusive or semi-exclusive events, with limited or no extra particle
production in the...
We present the possibilities for the measurement of two-photon production of the
Higgs boson and of $W^{+}W^{-}$ pairs in $e^{+}e^{-}$, $PbPb$ and $pPb$ collisions at the Future Circular Collider (FCC). The processes are simulated with dedicated Monte Carlo codes, using the effective photon approximation for the $e^{+}e^{-}$, $PbPb$ and $pPb$ photon fluxes, at several center of mass energies....
The ATLAS Forward Proton (AFP) detector provides measurements of the momentum and emission angle of very forward protons. This enables the observation and measurement of a range of processes where one or both protons remain intact. Such processes are associated with elastic and diffractive scattering. In this talk, we give on overview of the technical details of the AFP, its current status as...
The CT-PPS (CMS-TOTEM Precision Proton Spectrometer) detector system consists of silicon tracking stations as well as timing detectors to measure both the position and direction of protons and their time-of-flight with precision of the order of 20 ps. They are located at around 200 m from the interaction point in the very forward region on both sides of the CMS experiment. CT-PPS is built to...
A model for exclusive diffractive resonance production in proton-proton
collisions at high energies is presented. Cross sections are calculated by folding
the Pomeron-Pomeron total cross section (∗) with the Donnachie-Landshoff
parameterisation of the Pomeron flux in the proton(∗∗). The single differential
cross section dsigma/dM as well as the double differential cross section
dsigma/dMdp_T...
