Dr
sebastian white
(Brookhaven National Lab)
PHENIX has observed a very large spin dependent asymmetry in
forward neutron production in pp collisions at several energies up
to Sqrt[s]= 500 GeV. We present results on beam energy and x_F
dependence of this asymmetry and discuss the large discrepancy
with currently available calculations of this effect.
Prof.
Gerardo Herrera Corral
(Depto de Fisica, CINVESTAV)
LHC and post-LHC
A proposal to incorporate a new subdetector into the ALICE detector
at the LHC is presented. The new system consists of four stations
of scintillator pads at 20 and 55 meters from the interaction point
on both sides. The system would extend the rapidity coverage
increasing the sensitivity of the experiment to tag the diffractive
rapidity gap.
The new system would enhance the...
Dr
Kirill Semenov-Tian-Shansky
(CPHT Ecole Polytechnique, LPT Orsay)
Diffraction in DIS
The concept of generalized parton distributions (GPDs),
non-diagonal matrix elements of quark-antiquark or gluon-gluon
non local operators on the light cone, has recently been extended
to baryon to meson and (and baryon to baryon)
transition distribution amplitudes (TDAs), non diagonal matrix elements
of three quark operators between two hadronic states of different baryon number
(or...
Dr
Christophe Royon Royon
(IRFU-SPP, CEA Saclay)
We present a new method to test the Standard Model expectations at the LHC
using photon-induced WW production. Both W decay in the main ATLAS or CMS
detectors while scattered protons are measured in forward detectors.
The sensitivity to anomalous WW gamma quartic and triple gauge coupling
can be improved respectively by more than three orders of magnitude or
a factor 30 compared to the...
Dr
Rainer Schicker
(Phys. Inst., University Heidelberg)
LHC and post-LHC
The abstract is under review by ALICE Conference Committee, I will send
when approved
Antonio Vilela Pereira
(TO)
The observation of inclusive diffraction at LHC with the CMSdetector at √s=900, 2360 and 7000 GeV is presented, along with a comparison of the data with thepredictions of the PYTHIA and PHOJET generators.
Prof.
Laszlo Jenkovszky
(Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine)
Saturation in deep inelastic scattering (DIS) and deeply virtual Compton scattering (DVCS) is associated with a phase transition between the partonic gas, typical of moderate x and Q^2, and, a partonic fluid, created at increasing Q^2 and decreasing Bjorken x. In the statistical interpretation of DIS, the large-x, (1-x)^n factor in the structure function (SF) is associated with a perfect gas,...
Dr
Sergey Troshin
(IHEP, Protvino, Russia)
Diffraction in nuclear physics
The role of reflective scattering in formation of the deconfined state will be discussed along with the role of rotating matter coherent effects. These effects lead to the new interesting conclusions on the phase structure of strongly interacting matter and quark-gluon plasma formation.
Prof.
Risto Orava
(Helsinki Inst. of Physics and Univ. of Helsinki, CERN)
LHC and post-LHC
Abstract
Photon bremsstrahlung is proposed to be used to identify elastic proton-proton interactions at the LHC. In addition to a measurement of the elastic pp cross section (assuming that the elastic slope is known), the bremsstrahlung photons will allow the evaluation of the total pp cross section, luminosity and to align the Zero Degree Calorimeters (ZDCs).
Mr
Marek Tasevsky
(Institute of Physics of ASCR, Prague)
LHC and post-LHC
Diffractive physics program for the ATLAS experiment is discussed with emphasis
on the Central Exclusive production. While making up a large part of the total
proton-proton cross section, the experimental definition of diffractive
processes is still under discussion. At low luminosities,
a L1 trigger based on requiring rapidity gaps can be used, while at high
luminosities, the use of...
Prof.
Konstantin Goulianos
(The Rockefeller University)
Results on diffractive W and Z production and an update on the diffractive structure function extracted from dijet production are presented and compared with previously reported results and with expectations.
Claudio Ciofi Degli Atti
(Department of Physics University of Perugia and INFN Sezione di Perugia, Italy)
The cross sections for a variety of diffractive processes in proton-nucleus scattering, associated with large gaps in rapidity, are calculated [1] within an improved Glauber-Gribov theory, where the inelastic shadowing corrections are summed to all orders by employing the dipole representation [2] and the effects of nucleon-nucleon correlations, leading to a modification of the nuclear...
Mr
Gustavo Gil da Silveira
(Universidade Federal do Rio Grande do Sul)
A new mechanism is presented for the Central Exclusive Diffractive production of the Standard Model Higgs boson in Ultraperipheral Collisions at LHC. The Higgs boson is centrally produced by Double Pomeron Exchange with two Large Rapidity Gaps emerging in the final state, being the main experimental signature for this process. The Higgs boson photoproduction is studied within this new...
Dr
Sergey Baranov
(P.N.Lebedev Institute of Physics)
Diffraction in DIS
Diffractive production of D* mesons at HERA is considered in the framework
of collinear two-gluon exchange model. Theoretical results are compared with recent experimental data collected by the H1 and ZEUS collaborations both in the real photoproduction and the deep inelastic regimes, and a reasonably
good agreement is found in all cases.
Mrs
Anna Cisek
(Institute of Nuclear Physics PAN, Krakow)
Diffraction in DIS
Protons and antiprotons at collider energies are a source of high energy Weizs\"acker--Williams photons. This opens up a possibility to study at the LHC exclusive photoproduction of heavy vector mesons at energies much larger than possible at the HERA accelerator.
We present selected results on the production of vector mesons $\rho$, $\omega$, $\phi$, $J/\Psi$ and $\Upsilon$. I will show...
Prof.
Douglas Ross
(Southampton University)
Saturation
Using a modification of the BFKL equation which admits discrete pomeron pole solutions, we obtain a good fit to HERA data on structure functions at low-x, including the Q^2 dependence of the 1/x slope. The fit is very sensitive to the running of the QCD coupling, up to high energies and therefore sensitive to any new physics which may be encountered. It is suggested that the quality of such...
Christoffer Flensburg
(Lund University)
Saturation
Diffractive excitation is usually described by the Good--Walker formalism for low masses, and by the triple-Regge
formalism for high masses. In the Good--Walker formalism the cross section is determined by the fluctuations in the interaction. By taking the fluctuations in the BFKL ladder into account, it is possible to describe both low and high mass excitation by the Good--Walker...
Dr
Nigel Buttimore
(Trinity College Dublin)
Total cross sections and the phases of forward collision amplitudes form part of the early studies when a new energy window becomes available as is provided by the Large Hadron Collider. Enhancement of the forward elastic differential cross section above that expected from estimates of dispersion and optical theorem values may result from the presence of hadronic spin dependence in addition...
Dr
Krzysztof Kutak
(University of Antwerp)
LHC and post-LHC
We will discuss phenomena of production of forward jet at the LHC.
After brief introduction to high energy factorization we will present matrix elements relevant for production of forward jets focusing on their high energy behavior and dependence on transversal momentum of off shell gluon. We will also investigate effects of angular ordered parton shower and its interplay with matrix...
Dr
Amir Rezaeian
(Santa Maria Universidad)
Saturation
In high density QCD the hadron production stems from decay of mini-jets that have the transverse momenta of the order of the saturation scale. I will show that this idea is able to describe in a unique fashion the first data from the LHC for the inclusive charged-hadron production in pp collisions, the deep inelastic scattering at HERA at small Bjorken-x, and the hadron multiplicities in AA...
Prof.
Eugene Levin
(UTFSM and Tel Aviv University)
Saturation
Two main approaches will be discussed. The first one is the high energy phenomenology based on Pomeron interactions. The main questions that I would like to answer, is what kind of soft model can we trust theoretically and what we can predict for the inclusive production at LHC.
The second approach is the gluon saturation (Clor Glass Condensate} in which the hadron production stems from the...
Mr
Prometeusz Jasinski
(Institut für Kernphysik, Mainz)
COMPASS is a fixed target experiment using secondary high-energetic hadron beams provided by the CERN SPS. In 2008 and 2009, a large amount of data has been collected with a 190 GeV/c pion beam for the investigation of the hadron spectrum in diffractive and central production processes.
A big variety of observed final states, including $\pi\pi\pi$, $\pi\pi^0\pi^0$, $\pi\eta\eta$, $\pi K_s...
Vladimir Zoller
(ITEP, Moscow)
Diffraction in DIS
The non-conservation of charmed-strange current in the neutrino deep inelastic scattering
strongly affects the longitudinal structure function, $F_L$, at small values of Bjorken $x$.
The corresponding correction to $F_L$ is a higher twist effect enhanced at small-$x$ by the rapidly growing gluon density factor. As a result, the component of $F_L$ induced by the...
Prof.
Laszlo Jenkovszky
(Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine)
A models for low missing mass M_X diffraction dissociation (DD), based on the factorization properties of the high-energy, Pomeron-exchange scattering amplitude, is constructed. The properties of the inelastic Pp-->M_X transition form factors (inelastic vertices) are those known from \gamma-p scattering at JLab, with the photon-Pomeron similarity assumed. The direct-channel, low-energy...
Dr
Jan Friedrich
(Physik Department E18, Technische Universität München)
COMPASS at CERN uses hadron and muon beams with up to 200 GeV/c momentum,
produced from the SPS proton beam, for investigations in hadron structure
and spectroscopy.
From a pilot run with a 190 GeV/c pion beam on a lead target, various
results will be presented, including the observation of the spin-exotic
\pi_1(1600) resonance in the momentum transfer region...
Prof.
Yogendra Srivastava
(University of Perugia & INFN)
To settle the question whether the growth with energy is universal for different hadronic total cross-sections, we present results from theoretical models for $\pi p$ and ($pp$,$p\bar{p}$) total cross-sections obtained with the same input. We show that present and planned experiments at LHC can differentiate between different models, all of which are consistent with presently available (lower...
Mr
Mikael Kuusela
(Helsinki Institute of Physics)
LHC and post-LHC
Close to one half of the LHC events are expected to be due to elastic or inelastic diffractive scattering. Still, predictions based on extrapolations of experimental data at lower energies differ by large factors in estimating the relative rate of diffractive event categories at the LHC energies.
Measurement of inelastic activity, such as multiplicity and energy flows, in forward and...
Prof.
Ivan Schmidt
(Universidad Tecnica Federico Santa Maria, Valparaiso, Chile)
Saturation
Colliding nuclei consist of nucleons with a shifted scale, which makes such a medium more opaque for dipoles. Therefore J/Psi will be more suppressed than predicts a simple extrapolation from pA to AA. Another effect is an enhanced color transparency. A ccbar dipole propagates simultaneously through both colliding nuclei. Due to color filtering one nucleus absorbs dipoles of larger size, and...
Dr
Stephen Pate
(New Mexico State University)
The flavor-separated polarized parton distribution functions for light quarks and anti-quarks in the proton can be studied in the production of W bosons in p+p collisions. The Ws are produced in processes like $u+\bar{d}\rightarrow W^+$ and $\bar{u}+\d \rightarrow W^-$ and we observe
the lepton (an electron or muon) from the decay channel $W^{+\-}\rightarrow l^{+\-}\nu$. The electron energy...
Dr
sebastian white
(Brookhaven National Lab)
The measurement of forward neutrons and photons is a common feature of all RHIC experiments. It was motivated by the role of forward neutrons in event characterization and in accessing diffractive phenomena in nuclear collisions.
In pp collisions at RHIC measurement of forward neutrons has been useful:
since ~40% of the time the leading baryon in a non-diffractive collision is a neutron,...
Dr
Roman Ryutin
(IHEP, Protvino)
LHC and post-LHC
We discuss a possibility of an experiment at the LHC with leading neutrons production (charge exchange and double charge exchange processes). The latter could be used to extract from it $\pi^+ p$ and $\pi^+\pi^+$ cross-sections. In this work we give some estimates for the cases of total, elastic and inclusive di-jet cross-sections and discuss related problems and prospects. All the steps from...
Prof.
Jacques Soffer
(Temple University, Philadelphia, PA, USA)
Diffraction in DIS
We first recall some recent successful predictions obtained from the statistical approach of the parton distributions for unpolarized and polarized both in Deep Inelastic Scattering and hadronic collisions.
The statistical approach has been extended to the interesting situation where the PDF have, in addition to the usual Bjorken $x$ dependence, an explicit $k_T$ transverse momentum...
Dr
Abdellah Ahmidouch
(North Carolina A&T State University)
The Spin Asymmetry on the Nucleon Experiment (SANE) at Jefferson Lab measures spin observables A1p, A2p and structure functions g1p and g2p over a broad range of Bjorken scaling variable x from 0.3 to 0.8, for four-momentum transfers from 2.5 GeV^2 to 6.5 GeV^2. Inclusive double spin asymmetries were measured by scattering 4.7 and 5.9-GeV longitudinally polarized electron beam off a...
David Salek
(IPNP, Charles University, Prague)
Diffraction in DIS
We study the scaling properties in deep inelastic scattering using the most recent combined structure
function data F2 from the H1 and ZEUS collaborations. We also perform a direct fit to the F2
data inspired by the scaling properties.
Prof.
M.Beatriz Gay Ducati
(Universidade Federal do Rio Grande do Sul- UFRGS)
The single diffractive production of the Standard Model Higgs boson is computed using the diffractive factorization formalism, taking into account a parametrization for the Pomeron structure function provided by the H1 Collaboration. we compute the cross sections at NLO accuracy for the gluon fusion process, since it is the leading mechanism to the Higgs boson production. The gap survival...
Dr
Roman Pasechnik
(Uppsala University)
Diffraction in DIS
We construct a QCD-based model where soft gluon rescattering between final state partons in
deep inelastic scattering leads to events with large rapidity gaps and a leading proton. The model successfully describes the precise HERA data on the diffractive deep inelastic structure function in the whole available kinematical range. Further developments and applications of the model are discussed.
Valery Khoze
(IPPP, Durham)
We discuss the ongoing studies by the Durham group on central exclusive production processes Detailed comparison with the existing Tevatron data on quarkonium production are performed and predictions for RHIC and LHC are given.
Giovanni Antonio Chirilli
(Cpht-Polytechnique & LPT d'Orsay)
To study the scattering amplitudes at the high-energy, the
T-product of two currents can be expanded in terms of coefficient
functions (impact factors) and matrix elements of ``composite color
dipoles'' made of Wilson line with rapidity cutoff preserving conformal
invariance.
In the leading order, the high-energy evolution of color dipoles is governed
by the non-linear...
Dr
Bernhard Musch
(Jefferson Lab)
Diffraction in DIS
Transverse momentum dependent parton distribution functions (TMDs) provide a framework to study the spin-dependent motion of quarks inside the nucleon. They are relevant for our understanding of azimuthal asymmetries in, e.g., semi-inclusive DIS. We present lattice calculations of TMDs based on spacially separated quark operators connected by a gauge link. Studies with straight gauge links...
Prof.
Konstantin Goulianos
(The Rockefeller University)
Results on factorization breaking in soft and hard hadron-hadron collisions, photo-production and deep inelastic scattering are shown to exhibit a universal behavior in a (renormalization) model where diffraction is mediated by a saturated colorless exchange with vacuum quantum numbers. Formulas for cross sections and final state event properties are obtained, and a scheme is proposed for...
George Igo
(University of California Los Angeles)
The production of W bosons in longitudinally polarized p+p collisions at
RHIC provides a new means of studying the spin-flavor asymmetries of the proton
sea quark distributions. W bosons are produced in \bar u+d(\bar d u) collisions and
can be detected through their leptonic decays where only the
charged lepton is detected. Precise tracking information, provided by the STAR
Time...
