C. Hadjidakis
A5028733998- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Advanced NMR Techniques and Applications
- Nuclear physics research studies
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Quantum, superfluid, helium dynamics
- Superconducting Materials and Applications
- Crystallography and Radiation Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Statistical Methods and Bayesian Inference
- Medical Imaging Techniques and Applications
- Advanced X-ray Imaging Techniques
- Atomic and Molecular Physics
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Electron and X-Ray Spectroscopy Techniques
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Quantum chaos and dynamical systems
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2020-2025
Institut National de Physique Nucléaire et de Physique des Particules
2014-2025
Université Paris-Saclay
2016-2025
Centre National de la Recherche Scientifique
2014-2025
A. Alikhanyan National Laboratory
2016-2024
Institut de Physique
2012-2021
Technical University of Munich
2021
Université Paris-Sud
2010-2019
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2010-2016
Enrico Fermi Center for Study and Research
2012-2016
Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering positrons are measured the first time with transverse target polarization. The asymmetry depends on azimuthal angles both pion ($\ensuremath{\phi}$) and spin axis (${\ensuremath{\phi}}_{S}$) about virtual-photon direction relative to lepton plane. extracted Fourier component $\mathbf{⟨}\mathrm{sin}(\ensuremath{\phi}+{\ensuremath{\phi}}_{S}){\mathbf{⟩}}_{UT}^{\ensuremath{\pi}}$ is a...
In an exclusive measurement of the reaction gammad-->K(+)K(-)pn, a narrow peak that can be attributed to exotic baryon with strangeness S=+1 is seen in K(+)n invariant mass spectrum. The at 1.542+/-0.005 GeV/c(2) measured width 0.021 FWHM, which largely determined by experimental resolution. statistical significance (5.2+/-0.6)sigma. and observed are consistent recent reports other groups.
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...
Azimuthal single-spin asymmetries of lepto-produced pions and charged kaons were measured on a transversely polarized hydrogen target. Evidence for naive-T-odd, transverse-momentum-dependent parton distribution function is deduced from non-vanishing Sivers effects pi+, pi0, K+, K-, as well in the difference pi+ pi- cross sections.
High-statistics cross sections for the reactions gamma + p --> K^+ Lambda and Sigma^0 have been measured using CLAS at Jefferson Lab center-of-mass energies W between 1.6 2.53 GeV, -0.85 < cos theta_{K^+}^{c.m.}< +0.95. In channel we confirm a resonance-like structure near W=1.9 GeV backward kaon angles. The position width of this change with angle, indicating that more than one resonance is likely playing role. forward angles all well described by t-channel scaling characteristic Regge...
We report the first results of beam-spin asymmetry measured in reaction $\stackrel{\ensuremath{\rightarrow}}{e}p\ensuremath{\rightarrow}\mathrm{ep}\ensuremath{\gamma}$ at a beam energy 4.25 GeV. A large with $\mathrm{sin}\ensuremath{\varphi}$ modulation is observed, as predicted for interference term deeply virtual compton scattering (DVCS) and Bethe-Heitler process. The amplitude this...
The ratios of inclusive electron scattering cross sections 4He, 12C, and 56Fe to 3He have been measured at 1<xB<3. At Q2>1.4 GeV2, the exhibit two separate plateaus, 1.5<xB<2 xB>2.25. This pattern is predicted by models that include 2- 3-nucleon short-range correlations (SRC). Relative A=3, per-nucleon probabilities SRC are 2.3, 3.1, 4.4 times larger for A=4, 12, 56. first measurement in nuclei.Received 16 August 2005DOI:https://doi.org/10.1103/PhysRevLett.96.082501©2006 American Physical Society
The reaction gamma p-->pi(+)K(-)K(+)n was studied at Jefferson Laboratory using a tagged photon beam with an energy range of 3-5.47 GeV. A narrow baryon state strangeness S=+1 and mass M=1555+/-10 MeV/c(2) observed in the nK(+) invariant spectrum. peak's width is consistent CLAS resolution (FWHM=26 MeV/c(2)), its statistical significance (7.8+/-1.0)sigma. positive has exotic structure cannot be described framework naive constituent quark model. predicted by chiral soliton model for Theta(+)...
Single-spin asymmetries for pions and charged kaons are measured in semi-inclusive deep-inelastic scattering of positrons electrons off a transversely nuclear-polarized hydrogen target. The dependence the cross section on azimuthal angles target polarization (phi_S)and produced hadron (phi) is found to have substantial sin(phi+phi_S) modulation production pi+, pi- K+. This Fourier component can be interpreted terms non-zero transversity distribution functions favored disfavored Collins...
Cross-sections and recoil polarizations for the reactions gamma + p --> K^+ Lambda Sigma^0 have been measured with high statistics good angular coverage center-of-mass energies between 1.6 2.3 GeV. In K^+Lambda channel we confirm a structure near W=1.9 GeV at backward kaon angles, but our data shows more complex s- u- resonance than previously seen. This is present forward angles not central its position width change angle, indicating that one playing role. Rising back-angle cross sections...
Multiplicities in semi-inclusive deep-inelastic scattering are presented for each charge state of ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ and ${\mathrm{K}}^{\ifmmode\pm\else\textpm\fi{}}$ mesons. The data were collected by the HERMES experiment at HERA storage ring using 27.6 GeV electron positron beams incident on a hydrogen or deuterium gas target. results as function kinematic quantities ${x}_{\mathrm{B}}$, ${Q}^{2}$, $z$, ${P}_{h\ensuremath{\perp}}$. They represent unique set...
Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}+p\ensuremath{\rightarrow}{K}^{+}+\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\Lambda}}$ and $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}+p\ensuremath{\rightarrow}{K}^{+}+{\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\Sigma}}}^{0}$. The data were obtained using CEBAF Large Acceptance Spectrometer (CLAS)...
The ratios of inclusive electron scattering cross sections $^4$He, $^{12}$C, and $^{56}$Fe to $^3$He have been measured for the first time. It is shown that these are independent $x_B$ at Q$^2>$1.4 (GeV/c)$^2$ $x_B>$ 1.5 where section depends primarily on high-momentum components nuclear wave function. observed scaling shows momentum distributions high-momenta same shape all nuclei differ only by a scale factor. onset $x_B >$1.5 consistent with kinematical expectation two nucleon short range...
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.
We report the first evidence for a nonzero beam-spin azimuthal asymmetry in electroproduction of positive pions deep-inelastic kinematic region. Data reaction $e\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{'}}{\ensuremath{\pi}}^{+}X$ have been obtained using polarized electron beam 4.3 GeV with CEBAF Large Acceptance Spectrometer at Thomas Jefferson National Accelerator Facility. The amplitude $\mathrm{sin}\ensuremath{\varphi}$ modulation increases momentum pion relative to virtual...
We report results for the virtual photon asymmetry $A_1$ on nucleon from new Jefferson Lab measurements. The experiment, which used CEBAF Large Acceptance Spectrometer and longitudinally polarized proton ($^{15}$NH$_3$) deuteron ($^{15}$ND$_3$) targets, collected data with a electron beam at energies between 1.6 GeV 5.7 GeV. In present paper, we concentrate our $A_1(x,Q^2)$ related ratio $g_1/F_1(x,Q^2)$ in resonance deep inelastic regions lowest highest energies, covering range momentum...
The azimuthal cos{\phi} and cos2{\phi} modulations of the distribution hadrons produced in unpolarized semi-inclusive deep-inelastic scattering electrons positrons off hydrogen deuterium targets have been measured HERMES experiment. For first time these were determined a four-dimensional kinematic space for positively negatively charged pions kaons separately, as well unidentified hadrons. These dependences are sensitive to transverse motion polarization quarks within nucleon via, e.g.,...
Beam-helicity and beam-charge asymmetries in the hard exclusive leptoproduction of real photons from an unpolarised hydrogen target by a 27.6 GeV lepton beam are extracted HERMES data set 2006-2007 using missing-mass event selection technique. The asymmetry amplitudes this more precise than those earlier 1996-2005 previously analysed same manner HERMES. results two sets compatible with each other. Results these combined constitute most amplitude measurements made kinematic region
Differential cross sections for gammap-->etap have been measured with tagged real photons incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information protons scattered in the production process. The data provide first extensive angular distribution measurements process above W=1.75 Comparison preliminary results a constituent quark model support suggestion that third S11 resonance approximately 1.8 GeV couples etaN channel.
The cross section for the reaction ep-->e(')ppi(+)pi(-) was measured in resonance region 1.4<W<2.1 GeV and 0.5<Q2<1.5 GeV(2)/c(2) using CLAS detector at Jefferson Laboratory. data show resonant structures not visible previous experiments. comparison of our to a phenomenological prediction available information on N(*) Delta states shows an evident discrepancy. A better description is obtained either by sizable change properties P13(1720) or introducing new baryon state, reported published analyses.
The longitudinal target-spin asymmetry ${A}_{\mathrm{UL}}$ for the exclusive electroproduction of high-energy photons was measured first time in $e\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\rightarrow}{e}^{\ensuremath{'}}p\ensuremath{\gamma}$. data have been accumulated at JLab with CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized ${\mathrm{NH}}_{3}$ target. A significant azimuthal angular dependence observed, resulting from interference deeply virtual Compton...
The first observation of an azimuthal cross section asymmetry with respect to the charge incoming lepton beam is reported from a study hard exclusive electroproduction real photons. data have been accumulated by HERMES experiment at DESY, in which HERA 27.6 GeV electron or positron scattered off unpolarized hydrogen gas target. observed attributed interference between Bethe-Heitler process and deeply virtual Compton scattering (DVCS) process. term sensitive DVCS amplitudes, provide most...