A. Bressan
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- High-Energy Particle Collisions Research
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Calibration and Measurement Techniques
- Photocathodes and Microchannel Plates
- Muon and positron interactions and applications
- Geophysics and Gravity Measurements
- Advanced NMR Techniques and Applications
- Particle accelerators and beam dynamics
- Computational Physics and Python Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear physics research studies
- Spectroscopy and Laser Applications
- Medical Imaging Techniques and Applications
- Astronomical Observations and Instrumentation
- Electron and X-Ray Spectroscopy Techniques
- Crystallization and Solubility Studies
University of Trieste
2015-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2015-2024
Istituto di Matematica Applicata e Tecnologie Informatiche
2024
University of Padua
2023
University of Aveiro
2017-2020
Università degli Studi del Piemonte Orientale “Amedeo Avogadro”
2019
Istituto Nazionale di Fisica Nucleare, Sezione di Torino
2009-2019
Bielefeld University
2014
Istituto Nazionale di Fisica Nucleare
2011-2014
European Organization for Nuclear Research
1997-2009
First measurements of the Collins and Sivers asymmetries charged hadrons produced in deep-inelastic scattering muons on a transversely polarized 6-LiD target are presented. The data were taken 2002 with COMPASS spectrometer using muon beam CERN SPS at 160 GeV/c. asymmetry turns out to be compatible zero, as does measured within present statistical errors.
We present the final results of spin asymmetries A1 and structure functions g1 proton deuteron in kinematic range 0.0008<x<0.7 0.2<Q2<100GeV2. For determination A1, addition to usual method which employs inclusive scattering events includes a large radiative background at low x, we use new minimizes by selecting with least one hadron as well muon state. find that this gives smaller errors for x<0.02, so it is combined provide optimal set results.Received 18 May...
We have measured the spin-dependent structure function g1p in inclusive deep-inelastic scattering of polarized muons off protons, kinematic range 0.003<x<0.7 and 1GeV2<Q2<60GeV2. A next-to-leading order QCD analysis is used to evolve g1p(x,Q2) a fixed Q02. The first moment at Q02=10GeV2 Γ1p=0.136±0.013 (stat) ±0.009 (syst) ±0.005 (evol). This result below prediction Ellis-Jaffe sum rule by more than two standard deviations. singlet axial charge a0 found be 0.28±0.16. In Adler-Bardeen...
The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV μ+ beam and transversely polarised NH3 target. Sivers proton been extracted Bjorken x range 0.003<x<0.7. new measurements have small statistical systematic uncertainties few percent confirm with considerably better accuracy previous measurement. is found to be compatible zero for negative positive hadrons, clear...
The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use CERN SPS 190 GeV/c π^{-} beam and a transversely polarized ammonia target. Three giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3 GeV/c^{2} 8.5 GeV/c^{2}. Within experimental uncertainties, observed sign Sivers asymmetry found be consistent...
New results for the double spin asymmetry A1p and proton longitudinal structure function g1p are presented. They were obtained by COMPASS Collaboration using polarised 200 GeV muons scattered off a longitudinally NH3 target. The data collected in 2011 complement those recorded 2007 at 160 GeV, particular lower values of x. improve statistical precision g1p(x) about factor two region x≲0.02. A next-to-leading order QCD fit to g1 world is performed. It leads new determination quark...
Measurements of the Collins and Sivers asymmetries for charged pions neutral kaons produced in semi-inclusive deep-inelastic scattering high energy muons off transversely polarised protons are presented. The results were obtained using all available COMPASS proton data, which taken years 2007 2010. exhibit valence region a non-zero signal there hints also kaons. found to be positive compatible with zero otherwise.
We present a new measurement of the spin-dependent structure function g1d deuteron in deep inelastic scattering 190 GeV polarised muons on deuterons, kinematic range 0.003 < x 0.7 and 1 GeV2 Q2 60 GeV2. This is found to be negative at small x. The first moment Γ1d=∫01g1ddx evaluated Q02 = 10 0.034 ± 0.009 (stat.) 0.006 (syst.). value below Ellis-Jaffe sum rule prediction by three standard deviations. Using our earlier determination Γ1p, we obtain Γ1p − Γ1n 0.199 0.038 which agrees with Bjorken rule.
We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering polarised muons on protons deuterons in the range 0.003<x<0.7 Q2>1 GeV2. Compared to our previous publication this subject, with new data statistical errors have been reduced by nearly factor two. From these inclusive we determine quark distributions valence quarks non-strange sea at Q2=10 The u distribution, Δuv(x), is positive polarisation increases x. d...
We present a determination of the gluon polarization Delta G/G in nucleon, based on helicity asymmetry quasi-real photoproduction events, Q^2<1(GeV/c)^2, with pair large transverse-momentum hadrons final state. The data were obtained by COMPASS experiment at CERN using 160 GeV polarized muon beam scattered 6-LiD target. for selected events is = 0.002 +- 0.019(stat.) 0.003(syst.). From this value, we obtain leading-order QCD analysis G/G=0.024 0.089(stat.) 0.057(syst.) x_g 0.095 and mu^2...