A5091648560- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- Advanced NMR Techniques and Applications
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Photocathodes and Microchannel Plates
- Physics of Superconductivity and Magnetism
- Quantum, superfluid, helium dynamics
- Atomic and Molecular Physics
- Magnetic confinement fusion research
- Superconductivity in MgB2 and Alloys
- Radiation Therapy and Dosimetry
- Muon and positron interactions and applications
- Electron and X-Ray Spectroscopy Techniques
- Laser Design and Applications
- Graphene research and applications
- Plasma Diagnostics and Applications
Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara
2016-2025
Istituto Nazionale di Fisica Nucleare
2009-2024
University of Ferrara
2015-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Genova
2017-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
1995-2024
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2008-2024
Forschungszentrum Jülich
2018-2024
Friedrich-Alexander-Universität Erlangen-Nürnberg
2005-2024
European Organization for Nuclear Research
2023
Polo d’Innovazione di Genomica
2014-2023
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...
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.
The beam-spin asymmetry in hard electroproduction of photons has been measured. data have accumulated by the HERMES experiment at DESY using HERA 27.6 GeV longitudinally polarized positron beam and an unpolarized hydrogen-gas target. azimuthal distribution produced angle $\ensuremath{\varphi}$ relative to lepton scattering plane was determined with respect helicity state incoming beam. analyzing power $\mathrm{sin}\ensuremath{\varphi}$ moment measured be...
Polarized deep-inelastic scattering data on longitudinally polarized hydrogen and deuterium targets have been used to determine double-spin asymmetries of cross sections. Inclusive semi-inclusive for the production positive negative pions from were obtained in a reanalysis previously published data. kaons measured target. The separate helicity densities up down quarks anti-up, anti-down, strange sea computed these “leading order” QCD analysis. polarization up-quark is that down-quark...
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...
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...
We measured the triple coincidence A(e,e'np) and A(e,e'pp) reactions on carbon, aluminum, iron, lead targets at Q2 > 1.5 (GeV/c)2, xB 1.1 missing momentum 400 MeV/c. This was first direct measurement of both proton-proton (pp) neutron-proton (np) short-range correlated (SRC) pair knockout from heavy asymmetric nuclei. For all nuclei, average to reduced cross-section ratio is about 6%, in agreement with previous indirect measurements. Correcting for Single-Charge Exchange effects decreased...
The OLYMPUS Collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, R_{2γ}, direct measure contribution hard two-photon exchange section. In measurement, 2.01 GeV electron and positron beams were directed through hydrogen gas target internal DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers time-of-flight scintillators detected elastically scattered leptons in coincidence recoiling...
A single-spin asymmetry in the azimuthal distribution of neutral pions relative to lepton scattering plane has been measured for first time deep-inelastic positrons off longitudinally polarized protons. The analyzing power sinφ moment cross section is 0.019±0.007(stat)±0.003(syst). This result compared asymmetries charged pion production same kinematic range. π0 size as π+ and shows a similar dependence on relevant variables. described by phenomenological calculation based fragmentation...
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.
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
A new method to determine the spin tune is described and tested. In an ideal planar magnetic ring, tune-defined as number of precessions per turn-is given by ν(s)=γG (γ Lorentz factor, G gyromagnetic anomaly). At 970 MeV/c, deuteron spins coherently precess at a frequency ≈120 kHz in Cooler Synchrotron COSY. The deduced from up-down asymmetry deuteron-carbon scattering. time interval 2.6 s, was determined with precision order 10^{-8}, 1×10^{-10} for continuous 100 s accelerator cycle. This...
We observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of magnetic storage ring (COSY). This long spin coherence time is maintained through combination bunching, electron cooling, sextupole field corrections, and suppression collective effects current limits. record required for search an intrinsic electric dipole moment on at statistical sensitivity level approaching 10^{-29} e cm.
Double-spin asymmetries of semiinclusive cross sections for the production identified pions and kaons have been measured in deep inelastic scattering polarized positrons on a deuterium target. Five helicity distributions including those three sea quark flavors were extracted from these data together with reanalyzed previous hydrogen These are consistent zero all flavors. A recently predicted flavor asymmetry polarization light appears to be disfavored by data.
Single-spin asymmetries have been measured for semi-inclusive electroproduction of $\pi^+$, $\pi^-$, $\pi^0$ and $K^+$ mesons in deep-inelastic scattering off a longitudinally polarised deuterium target. The appear the distribution hadrons azimuthal angle $\phi$ around virtual photon direction, relative to lepton plane. corresponding analysing powers $\sin \phi$ moment cross section are $0.012 \pm 0.002 {(stat.)} {(syst.)}$ $0.006 0.003 $0.021 0.005 $0.013 0.006 $K^+$. 2\phi$ moments...
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...