A. Fantoni
A5045158225- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Dark Matter and Cosmic Phenomena
- Advanced NMR Techniques and Applications
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Statistical Methods and Bayesian Inference
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Atomic and Molecular Physics
- Particle Accelerators and Free-Electron Lasers
- Computational Physics and Python Applications
- CCD and CMOS Imaging Sensors
- Electron and X-Ray Spectroscopy Techniques
- Stochastic processes and statistical mechanics
- Muon and positron interactions and applications
- Crystallography and Radiation Phenomena
- Quantum, superfluid, helium dynamics
- Radiation Therapy and Dosimetry
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2016-2025
A. Alikhanyan National Laboratory
2017-2024
University of Pisa
2023
Technical University of Munich
2021
Istituto Nazionale di Fisica Nucleare
2008-2020
Center for Research and Advanced Studies of the National Polytechnic Institute
2020
Aligarh Muslim University
2020
Budker Institute of Nuclear Physics
2020
Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear
2020
California Polytechnic State University
2020
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 HERMES experiment is collecting data on inclusive and semi-inclusive deep inelastic scattering of polarised positrons from targets H, D, 3He. These give information the spin structure nucleon. This paper describes forward angle spectrometer built for this purpose. includes numerous tracking chambers (micro-strip gas chambers, drift proportional chambers) in front behind a 1.3 T.m magnetic field, as well an extensive set detectors particle identification (a lead-glass calorimeter,...
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...
Results are reported from the HERMES experiment at HERA on a measurement of neutron spin structure function $g_1^n(x,Q^2)$ in deep inelastic scattering using 27.5 GeV longitudinally polarized positrons incident $^3$He internal gas target. The data cover kinematic range $0.023
Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured the first time. A significant target-spin asymmetry of distribution azimuthal angle straight phi relative to lepton plane was formed pi(+) electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power sinstraight moment cross section is 0.022+/-0.005+/-0.003. This result can be interpreted as effect terms involving chiral-odd spin functions...
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...
The flavor asymmetry of the light quark sea nucleon is determined in kinematic range $0.02<x<0.3$ and $1<{Q}^{2}<10{\mathrm{GeV}}^{2}$ for first time from semi-inclusive deep-inelastic scattering. quantity $[\overline{d}(x)\ensuremath{-}\overline{u}(x)]/[u(x)\ensuremath{-}d(x)]$ derived a relationship between yields positive negative pions unpolarized hydrogen deuterium targets. $\overline{d}\ensuremath{-}\overline{u}$ found to be nonzero $x$ dependent, showing an excess $\overline{d}$ over...
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
We present a measurement of the longitudinal spin asymmetry A(||) in photoproduction pairs hadrons with high transverse momentum p(T). Data were accumulated by HERMES experiment using 27.5 GeV polarized positron beam and hydrogen target internal to HERA storage ring. For h(+)h(-) p(h(1))(T)>1.5 GeV/c p(h(2))(T)>1.0 GeV/c, measured is = -0. 28+/-0.12(stat)+/-0.02(syst). This negative value contrast positive asymmetries typically deep inelastic scattering from protons, interpreted arise gluon...
The total photoabsorption cross section for $^{7}\mathrm{Li}$, C, Al, Cu, Sn, Pb has been measured in the energy range 300--1200 MeV at Frascati with jet-target tagged photon beam. A 4\ensuremath{\pi} NaI crystal detector and a lead-glass shower counter were used, respectively, to measure hadronic events reject electromagnetic background. Data above 600 clearly indicate broadening of higher nucleon resonance peaks nuclei reduction absolute value per respect free-nucleon case. This large...
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...