A5010049813- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Advanced X-ray Imaging Techniques
- Superconducting Materials and Applications
- Muon and positron interactions and applications
- Gyrotron and Vacuum Electronics Research
- Photocathodes and Microchannel Plates
- Laser-Plasma Interactions and Diagnostics
- Crystallography and Radiation Phenomena
- Scientific Research and Discoveries
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Advanced X-ray and CT Imaging
- Nuclear materials and radiation effects
- Medical Imaging Techniques and Applications
- Adrenal and Paraganglionic Tumors
- Gas Dynamics and Kinetic Theory
- International Science and Diplomacy
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2020-2024
Institut National de Physique Nucléaire et de Physique des Particules
2005-2024
Centre National de la Recherche Scientifique
2005-2024
Université Paris-Saclay
2007-2024
GANIL
2017-2020
Université Paris-Sud
2005-2017
École Polytechnique
2010-2012
McGill University
2011-2012
Laboratoire Leprince-Ringuet
2010-2012
Academia Sinica
2011
Precise measurements of the spin structure functions proton ${g}_{1}^{p}(x,{Q}^{2})$ and deuteron ${g}_{1}^{d}(x,{Q}^{2})$ are presented over kinematic range $0.0041\ensuremath{\le}x\ensuremath{\le}0.9$ $0.18\text{ }\text{ }{\mathrm{GeV}}^{2}\ensuremath{\le}{Q}^{2}\ensuremath{\le}20\text{ }{\mathrm{GeV}}^{2}$. The data were collected at HERMES experiment DESY, in deep-inelastic scattering 27.6 GeV longitudinally polarized positrons off hydrogen deuterium gas targets internal to HERA storage...
We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < or =Q2 =1.0 GeV2. These asymmetries, arising from interference electromagnetic and neutral weak interactions, are sensitive to strange-quark contributions currents proton. The measurements were made at Jefferson Laboratory using a toroidal spectrometer detect recoiling protons liquid hydrogen target. results indicate nonzero, Q2 dependent, provide new information...
The momentum and helicity density distributions of the strange quark sea in nucleon are obtained leading order from charged-kaon production deep-inelastic scattering on deuteron. extracted spin-averaged K+/- multiplicities, inclusive double-spin asymmetries for polarized positrons by a deuterium target. shape distribution is softer than that average ubar dbar quarks. In region measurement 0.02 < x 0.6 Q^2 > 1.0 GeV^2, zero within experimental uncertainties.
A bstract The beam-helicity asymmetry in exclusive electroproduction of real photons by the longitudinally polarized Hera positron beam scattering off an unpolarized hydrogen target is measured at Hermes. arises from deeply virtual Compton and its interference with Bethe-Heitler process. Azimuthal amplitudes are extracted a data sample consisting ep → epγ events detection all particles final state including recoiling proton. installation recoil detector, while reducing acceptance experiment,...
Artificial intelligence is increasingly shaping the way we think, design, build and operate present future particle accelerators for science discovery society.
Longitudinal double-spin asymmetries of charged hadrons with high transverse momentum p T have been measured in electroproduction using the Hermes detector at Hera. Processes involving gluons nucleon enhanced relative to others by selecting typically above 1 GeV. In this kinematic domain gluon polarization has extracted leading order making use model embedded Monte Carlo Generator Pythia 6.2. The obtained from single inclusive range GeV < 2.5 a deuterium target is $ \frac{{\Delta...
ThomX is a new generation Compact Compton Source. It currently commissioned by and at the IJCLab (Laboratoire de physique des 2 infinis - Irène Joliot-Curie (UMR9012)) Orsay. The first beam expected begining of 2021. aim to demonstrate characteristics an intense (lab-size) X-ray source based on Scattering. performances are mostly driven laser optical system which above state art stored power. Proof principle various techniques will be performed thanks versatile beamline. Firstly, this...
The exclusive electroproduction of π+ mesons was studied with the HERMES spectrometer at DESY laboratory by scattering 27.6 GeV positron and electron beams off an internal hydrogen gas target. virtual-photon cross sections were measured as a function Mandelstam variable t squared four momentum −Q2 exchanged virtual photon. A model calculation based on Generalized Parton Distributions is in fair agreement data low values |t| if power corrections are included. Regge formalism gives good...
A measurement of the beam-spin asymmetry in azimuthal distribution pions produced semi-inclusive deep-inelastic scattering off protons is presented. The was performed using {HERMES} spectrometer with a hydrogen gas target and longitudinally polarized 27.6 GeV positron beam HERA. sinusoidal amplitude dependence on angle $\phi$ hadron production plane around virtual photon direction relative to lepton measured for $\pi^+,\pi^-$ $\pi^0$ mesons. this Bjorken scaling variable pion fractional...
The nuclear--mass dependence of azimuthal cross-section asymmetries with respect to charge and longitudinal polarization the lepton beam is studied for hard exclusive electroproduction real photons. observed beam-charge beam-helicity are attributed interference between Bethe-Heitler deeply virtual Compton scattering processes. For various nuclei, extracted both coherent incoherent-enriched regions, which involve different (combinations of) generalized parton distributions. compared those a...
We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2=0.15, 0.25 (GeV/c)2. The results are inconsistent with calculations solely using nucleon intermediate state and generally agree significant inelastic hadronic contributions. A(n) provides a direct probe imaginary component 2gamma exchange amplitude, complete description which is important interpretation data precision electron-scattering experiments.
Spin Density Matrix Elements (SDMEs) describing the angular distribution of exclusive ρ 0 electroproduction and decay are determined in HERMES experiment with 27.6 GeV beam energy unpolarized hydrogen deuterium targets. Eight (fifteen) SDMEs that related (unrelated) to longitudinal polarization extracted kinematic region 1<Q 2<7 GeV2, 3.0<W<6.3 GeV, −t<0.4 GeV2. Within given experimental uncertainties, a hierarchy relative sizes helicity amplitudes is observed. Kinematic dependences all on Q...
ATF2 is a final-focus test beam line which aims to focus the low emittance from ATF damping ring vertical size of about 37 nm and demonstrate nanometer level stability. Several advanced diagnostics feedback tools are used. In December 2008, construction installation were completed commissioning started, supported by an international team Asian, European, U.S. scientists. The present status first results described.
The first measurements of double-hadron production in deep-inelastic scattering within the nuclear medium were made with HERMES spectrometer at DESY HERA using a 27.6 GeV positron beam. By comparing data for deuterium, nitrogen, krypton, and xenon nuclei, influence on ratio to single-hadron yields was investigated. Nuclear effects additional hadron are clearly observed, but little or no difference among xenon, smaller magnitude than seen previously measured multiplicities. compared models...
Promising results obtained with crystal targets for positron production led to the elaboration of a hybrid source made an axially oriented tungsten crystal, as radiator, and amorphous converter. If converter is granular, small spheres, heat dissipation greatly enhanced thermal shocks reduced, allowing consideration such device future linear colliders. A this kind investigated. Previous simulations have shown very promising yield energy deposition PEDD (Peak Energy Deposition Density). Here,...
For the final running period of HERA, a recoil detector was installed at HERMES experiment to improve measurements hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is particular interest as this process provides constraints on generalised parton distributions that give access total angular momenta quarks within nucleon. The designed selection events by direct measurement four-momentum recoiling particle. It consisted three components: two...
Abstract We present an overview of the diagnostics screens stations - named SSTs ThomX compact Compton source. is a light source based on backscattering. It features linac and storage ring in which electrons have energy 50 MeV. Each SST composed three screens, YAG:Ce screen Optical Transition Radiation (OTR) for transverse measurements calibration target magnification resolution characterisation. The optical system commercial lenses that been reverse-engineered. An Arduino used to control...