New analysis and synthesis approaches are introduced for high energy diffraction, especially for central exclusive processes at the LHC. The synthesis features include differential screening, an expendable set of process amplitudes with adaptive Monte Carlo sampling, spin systematics and a generator framework using modern computational techniques. For the analysis of inclusive events, a...
We will describe the results on quartic anomalous coupling between photons, W, Z bosons at the LHC.
b production via a double muon tag
The installation of scintillating pad detectors (Herschel), bracketing the LHCb detector along the beamline, have significantly enhanced LHCb's sensitivity to central exclusive production. Additionally, dedicated triggers during the early measurement period of Run 2 have produced an extended CEP dataset. A summary of results from Run 1 as well as early results from Run 2 will be shown.
We discuss the prospects of searches for pair production
at the LHC with forward proton detectors
of new BSM states with subsequent decays into cosmologically
stable dark matter.
As a topical example we consider production of slepton and chargino pairs
in the MSSM with compressed mass spectra, where the natural candidate for cold dark matter is
the lightest neutralino.
Special attention is...
We discuss the prospects of searches for pair production
at the LHC with forward proton detectors
of new BSM states with subsequent decays into cosmologically
stable dark matter.
As a topical example we consider production of slepton and chargino pairs
in the MSSM with compressed mass spectra, where the natural candidate for cold dark matter is
the lightest neutralino.
Special attention...
Collective effects in DIS at HERA
Possible diffractive PDFs measurements at the LHeC will be presented.
A simple model based on Regge approach is proposed for description of the exclusive central production of the light tensor glueball associated with the soft Pomeron
Regge trajectory.
At the LHC, the highly boosted electromagnetic field of the beam particles represents a source of quasi-real photon. Vector meson photo-production measurements in Pb-Pb collisions are sensitive to the gluon parton distribution functions in the nucleus. LHCb results on charmonium production in ultra-peripheral Pb-Pb collisions at 5.02 TeV will be presented.
Fits to high-x data and measurement of charm production in charged current
We propose a new process which probes the BFKL dynamics in the high energy proton-proton scattering, namely the forward Drell-Yan production accompanied by a forward jet, separated from the DY lepton pair by a large rapidity interval.
The ALICE experiment is equipped with a broad range of
detectors which allows one to study photon-induced and diffractive
processes characterized by large rapidity gaps. The forward detectors of
ALICE are used to detect rapidity gaps and to trigger on diffraction
events. Special attention is given to double gap events, dominated by
central-exclusive processes, because of the...
In this talk, we review the current status of global analyses in QCD of diffractive parton distribution functions (diffractive PDFs) and their uncertainties, focusing on very recent diffractive PDFs analysis of {\tt GKG18-DPDFs}, which is the first diffractive PDFs extracted from high-precision data from H1/ZEUS combined inclusive diffractive cross sections measurements. {\tt GKG18-DPDFs} is...
An excess of $J/\psi$ yield at very low transverse momentum ($p_T<0.3$ GeV/c) has been observed by the ALICE collaboration in peripheral collisions Pb-Pb at forward rapidity. It was also confirmed by the STAR collaboration in peripheral collisions Au-Au and U-U at mid-rapidity. Assuming the coherent photoproduction is the main mechanism behind this effect, the rapidity distribution and nuclear...
Heavy quarkoinium QQ̄ states created (together with hot hadron/quark-gluon matter) in high
energy hadron-hadron/ion-ion collisions can be used as a thermometer. This is one of the motiva-
tion to study the heavy quarks dynamics in a broad range of temperatures T . On the other hand,
not only light but also heavy quarks physics is sensitive to one of the properties of QCD vacuum
–...
Recent jet results in pA and AA collisions will be presented.
We present latest results of diffractive and exclusive measurements with the CMS experiment, such as measurements of exclusive upsilon and rho production, and studies of central exclusive production (CEP) processes. Exclusive Rho0 meson photoproduction in ultra-peripheral pPb collisions at √sNN =5.02 TeV is studied, for the first time, at the LHC with the CMS Collaboration. The cross sections...
Light-by-light scattering (γγ→γγ) is a quantum-mechanical process that is forbidden in the classical theory of electrodynamics. This reaction is accessible at the Large Hadron Collider thanks to the large electromagnetic field strengths generated by ultra-relativistic colliding lead (Pb) ions. Using 480 μb−1 of Pb+Pb collision data recorded at a centre-of-mass energy per nucleon pair of 5.02...
The production of exclusive γγ→μ+μ− events in proton--proton collisions at a centre-of-mass energy of 13 TeV is measured with the ATLAS detector at the LHC, using data corresponding to an integrated luminosity of 3.2 fb−1. The measurement is performed for a dimuon invariant mass of 12 GeV <mμ+μ−< 70 GeV. The integrated cross-section is determined within a fiducial acceptance region of the...
We present results of the measurement of the total and elastic cross sections in proton--proton collisions at $\sqrt s = 200$ GeV with the Roman Pot setup in Run 2015 of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The Roman Pots were operated during standard data collection at STAR at the distance of about $8\sigma_y$ from the beam, where $\sigma_y$ is the beam gaussian...
The total pp cross section is a fundamental observable at the LHC. It can be derived from the measurement of the elastic cross section, using the optical theorem. Measurements of the elastic proton-proton cross section were performed at a center-of-mass energy of 8 TeV at various settings of the beam optics using the ALFA detector.
The ALFA detector is also used to tag forward protons in...
We present the results of the diffractive measurement with the STAR Roman Pot detectors at RHIC. The measurement is focused on the spectra of identified charged particles as pions, kaons, protons and their antiparticle counterparts in Single Diffraction Dissociation $\left(p+p\to p+X\right)$ and Central Diffraction $\left(p+p\to p+X+p \right)$ processes. The spectra of inclusive charged...
By using a Regge-pole model, including pomeron and odderon exchanges as double poles we analyze the recently discovered phenomena in elastic proton-proton scattering at the LHC: the low-|t| "break" (departure from the exponential behavior of the diffraction cone), the accelerating rise with energy of the forward slope B(s), the absence of secondary dips and bumps on the cone and the unexpected...
A study is presented to extend the measurements of photon-photon
scattering in ultra-peripheral Pb-Pb collisions at the LHC into
the mass region of the pseudoscalar resonances eta and eta'.
The elementary photon-photon scattering cross section discussed in
Ref.1 is extended to the low masses of these pseudoscalars. The main
background to two-photon final states, arising from double...
We discuss production of $W^+ W^-$ pairs in proton-proton collisions induced by two-photon fusion including, for a first time, transverse momenta of incoming photons. The unintegrated inelastic fluxes (related to proton dissociation) of photons are calculated based on modern parametrizations of deep inelastic structure functions in a broad range of their arguments ($x$ and $Q^2$). In our...
We present latest results of soft and small-x QCD measurements with the CMS experiment, such as minimum bias/underlying event physics, and studies on forward jet production.
We present latest results of diffractive and exclusive measurements with the CMS experiment, such as inelastic cross section measurements, diffractive jet production, measurements of exclusive upsilon and rho production, and studies of central exclusive production (CEP) processes.
The TOTEM experiment at the interaction point 5 of the LHC has measured the total, elastic and inelastic proton-proton cross sections in a centre-of-mass energy range from 2.76 to 13 TeV, mostly in dedicated fills with special beam optics.
Most recently, TOTEM has performed a series of detailed measurements at $\sqrt{s}$ = 13 TeV. The total, elastic and inelastic proton-proton cross-sections...
We will describe recent results from PPS on exclusive dileptons and diphotons and prospects for future analyses.
The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) performs studies of diffractive processes with the focus on the exclusive production of particles in central range of rapidity. In 2015 STAR collected 18 pb$^{-1}$ of data in polarized proton-proton collisions at $\sqrt{s}$ = 200 GeV to measure Central Exclusive Production (CEP) process $pp\to pXp$ through Double Pomeron...
The existence of an axion-like particle (ALP) would induce anomalous scattering of light by light. This process can be probed at the Large Hadron Collider in central exclusive production of photon pairs in proton-proton collisions by tagging the surviving protons using proton spectrometers. We estimate the expected bounds on the ALP--photon coupling for a wide range of masses. We show that the...
The forward acceptance of LHCb, 2.0 < y < 5.0, provides a complementary reach to the general purpose detectors on LHC for studies of minimum bias properties. Recent measurements in this area at LHCb, including measurements of bose-einstein correlations, will be presented.
A new release of the SuperChic Monte Carlo event generator for central exclusive production (CEP) processes will be presented. Updates include: the addition of photon and QCD-induced production in heavy ion collisions (with a full treatment of absorptive effects); the addition of a range of new processes, such as the production of axion-like particles, electroweakly coupled SUSY states,...
The production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the gluon density function of the proton.
The ATLAS collaboration has performed numerous cross section measurements of prompt photon production, among which are a precise measurement of the production of isolated prompt photons in association with heavy flavor...
Analysis of the new experimental data obtained by the TOTEM Collaborations at LHC at $\sqrt{s} = 13 $ TeV at small momentum transfer is presented in the framework of the simplest form of the hadron scattering amplitude. The impact of the different assumptions on the extraction of the parameters of the elastic scattering amplitude, especially on the size of the $\rho(t=0)$, is examined. The...
The existence of the odderon, odd C-parity counterpart of the pomeron, was never questioned seriously simply because there is no constrain (“selection rule”) forbidding its existence. We discuss open questions concerning constraints imposed on the odderon by analyticity and unitarity, explicit parameterizations as well as possible manifestation of the odderon in experiment.
The PPS detector from CMS and TOTEM will be presented
The recent ALICE data clearly demonstrate the universality of suppression of different high-pT hadrons containing light quarks produced inclusively in heavy ion collisions at Large Hadron Collider (LHC). Moreover, the last ATLAS results on production of prompt charmonia show almost the same attenuation as is observed in production of light hadrons. This fact leads naturally to a conclusion...
Sone new results on Psi(2S). D meson, di-photon productions from CMS will be presented.
