A5071991643- Solar and Space Plasma Dynamics
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Ionosphere and magnetosphere dynamics
- Atmospheric Ozone and Climate
- Geomagnetism and Paleomagnetism Studies
- Radiation Therapy and Dosimetry
- Particle Detector Development and Performance
- Earthquake Detection and Analysis
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Solar Radiation and Photovoltaics
- Nuclear physics research studies
- Neutrino Physics Research
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Gamma-ray bursts and supernovae
- Electron and X-Ray Spectroscopy Techniques
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Radiation Detection and Scintillator Technologies
- Calibration and Measurement Techniques
- Distributed and Parallel Computing Systems
- Quantum, superfluid, helium dynamics
- Radiation Shielding Materials Analysis
University of Milano-Bicocca
2012-2025
Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca
2016-2025
Stanford University
2023
Kavli Institute for Particle Astrophysics and Cosmology
2023
Istituto Nazionale di Fisica Nucleare, Laboratori Acceleratori e Superconduttività Applicata
2023
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2000-2023
University of Bologna
2000-2023
University of Iceland
2023
Nordic Institute for Theoretical Physics
2023
Karlsruhe Institute of Technology
2020
A precision measurement by AMS of the antiproton flux and antiproton-to-proton ratio in primary cosmic rays absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} events 2.42×10^{9} proton events. The fluxes ratios charged elementary particles are also presented. In ∼60 ∼500 GV, p[over ¯], p, positron e^{+} found have nearly identical dependence electron e^{-} exhibits a different dependence. Below 60 (p[over ¯]/p), ¯]/e^{+}), (p/e^{+}) each reaches maximum. From show no...
The Alpha Magnetic Spectrometer (AMS) is a precision particle physics detector on the International Space Station (ISS) conducting unique, long-duration mission of fundamental research in space. objectives include precise studies origin dark matter, antimatter, and cosmic rays as well exploration new phenomena. Following 16-year period construction testing, precursor flight Shuttle, AMS was installed ISS May 19, 2011. In this report we present results based 120 billion charged ray events up...
Knowledge of the rigidity dependence boron to carbon flux ratio (B/C) is important in understanding propagation cosmic rays. The precise measurement B/C from 1.9 GV 2.6 TV, based on 2.3 million and 8.3 nuclei collected by AMS during first 5 years operation, presented. detailed variation with spectral index reported for time. does not show any significant structures contrast many ray models that require such at high rigidities. Remarkably, above 65 GV, well described a single power law R^{Δ}...
A measurement of the cosmic ray positron fraction e+/(e++e−) in energy range 1–30 GeV is presented. The based on data taken by AMS-01 experiment during its 10 day Space Shuttle flight June 1998. proton background suppression order 106 reached identifying converted bremsstrahlung photons emitted from positrons.
We report the observation of new properties primary cosmic rays He, C, and O measured in rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, 7.0×10^{6} oxygen nuclei collected by Alpha Magnetic Spectrometer (AMS) during first five years operation. Above 60 GV, these three spectra have identical dependence. They all deviate from a single power law above 200 harden an way.
Precision measurements of cosmic ray positrons are presented up to 1 TeV based on 1.9 million collected by the Alpha Magnetic Spectrometer International Space Station. The positron flux exhibits complex energy dependence. Its distinctive properties (a) a significant excess starting from 25.2±1.8 GeV compared lower-energy, power-law trend, (b) sharp dropoff above 284+91−64 GeV, (c) in entire range is well described sum term associated with produced collision rays, which dominates at low...
We report on the observation of new properties secondary cosmic rays Li, Be, and B measured in rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total 5.4×10^{6} nuclei collected by AMS during first five years operation aboard International Space Station. The Li fluxes have an identical dependence above 7 all three 30 Li/Be flux ratio 2.0±0.1. deviate from single power law 200 way. This behavior has also been observed measurement primary He, C, O but dependences are...
Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based $28.1\ifmmode\times\else\texttimes\fi{}{10}^{6}$ collected by Alpha Magnetic Spectrometer International Space Station. In entire electron and positron spectra have distinctly different magnitudes dependences. The flux exhibits a significant excess starting $42.{1}_{\ensuremath{-}5.2}^{+5.4}\text{ }\text{ }\mathrm{GeV}$ compared lower trends, but nature of this is above...
We present results over an 11-year Solar cycle of cosmic antiprotons based on <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mn>1.1</a:mn><a:mo>×</a:mo><a:msup><a:mn>10</a:mn><a:mn>6</a:mn></a:msup></a:math> events in the rigidity range from 1.00 to 41.9 GV. The <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mover accent="true"><c:mi>p</c:mi><c:mo stretchy="false">¯</c:mo></c:mover></c:math> fluxes exhibit distinct properties. magnitude...
Local interstellar spectra (LIS) for protons, helium, and antiprotons are built using the most recent experimental results combined with state-of-the-art models propagation in Galaxy heliosphere. Two packages, GALPROP HelMod, to provide a single framework that is run reproduce direct measurements of cosmic-ray (CR) species at different modulation levels both polarities solar magnetic field. To do so self-consistent way, an iterative procedure was developed, where LIS output fed into...
We present the precision measurement from May 2011 to 2017 (79 Bartels rotations) of proton fluxes at rigidities 1 60 GV and helium 1.9 based on a total 1×10^{9} events collected with Alpha Magnetic Spectrometer aboard International Space Station. This is in solar cycle 24, which has maximum April 2014. observed that, below 40 GV, flux show nearly identical fine structures both time relative amplitude. The amplitudes decrease increasing rigidity vanish above GV. are reduced during period,...
Composition and spectra of Galactic cosmic rays (CRs) are vital for studies high-energy processes in a variety environments on different scales, interpretation γ-ray microwave observations, disentangling possible signatures new phenomena, understanding our local neighborhood. Since its launch, AMS-02 has delivered outstanding-quality measurements the p¯ , e±, nuclei: 1H-8O, 10Ne, 12Mg, 14Si. These resulted number breakthroughs; however, heavier nuclei especially low-abundance not expected...
We report the observation of new properties primary iron (Fe) cosmic rays in rigidity range 2.65 GV to 3.0 TV with 0.62×106 nuclei collected by Alpha Magnetic Spectrometer experiment on International Space Station. Above 80.5 dependence ray Fe flux is identical He, C, and O fluxes, Fe/O ratio being constant at 0.155±0.006. This shows that unexpectedly belong same class which different from Ne, Mg, Si class.Received 2 October 2020Revised 22 November 2020Accepted 9 December...
We present high-statistics, precision measurements of the detailed time and energy dependence primary cosmic-ray electron flux positron over 79 Bartels rotations from May 2011 to 2017 in range 1 50 GeV. For first time, charge-sign dependent modulation during solar maximum has been investigated detail by leptons alone. Based on 23.5×10^{6} events, we report observation short-term structures timescale months coincident both flux. These are not visible e^{+}/e^{-} ratio. The across polarity...
A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2×10^{6} events is presented. The detailed dependence spectral index presented for first time. rapidly hardens at high rigidities and becomes identical indices primary He, C, O cosmic rays above ∼700 GV. We observed that Φ_{N} can be as sum its component Φ_{N}^{P} secondary Φ_{N}^{S}, Φ_{N}=Φ_{N}^{P}+Φ_{N}^{S}, we found well described by weighted oxygen Φ_{O} (primary rays)...
We report the observation of new properties primary cosmic rays, neon (Ne), magnesium (Mg), and silicon (Si), measured in rigidity range 2.15 GV to 3.0 TV with 1.8×10^{6} Ne, 2.2×10^{6} Mg, 1.6×10^{6} Si nuclei collected by Alpha Magnetic Spectrometer experiment on International Space Station. The Ne Mg spectra have identical dependence above 3.65 GV. three 86.5 GV, deviate from a single power law 200 harden an way. Unexpectedly, rays is different He, C, O. This shows that O are two classes rays.
We present the precision measurement of daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total 2824 days or 114 Bartels rotations) rigidity interval 1 100 GV based on 5.5×10^{9} protons collected with Alpha Magnetic Spectrometer aboard International Space Station. The exhibit variations multiple timescales. From 2014 2018, we observed recurrent flux a period 27 days. Shorter periods 9 and 13.5 are 2016. strength all three periodicities changes time rigidity....
Precision measurements by the Alpha Magnetic Spectrometer (AMS) on International Space Station of ^{3}He and ^{4}He fluxes are presented. The based 100 million nuclei in rigidity range from 2.1 to 21 GV 18 1.9 15 collected May 2011 November 2017. We observed that exhibit nearly identical variations with time. relative magnitude decreases increasing rigidity. dependence ^{3}He/^{4}He flux ratio is measured for first Below 4 GV, was found have a significant long-term time dependence. Above be...
We present the precision measurement of 2824 daily helium fluxes in cosmic rays from May 20, 2011 to October 29, 2019 rigidity interval 1.71 100 GV based on 7.6×10^{8} nuclei collected with Alpha Magnetic Spectrometer (AMS) aboard International Space Station. The flux and proton ratio exhibit variations multiple timescales. In nearly all time intervals 2014 2018, we observed recurrent a period 27 days. Shorter periods 9 days 13.5 are 2016. strength three periodicities changes rigidity....
We present the precision measurements of 11 years daily cosmic electron fluxes in rigidity interval from 1.00 to 41.9 GV based on 2.0×10^{8} electrons collected with Alpha Magnetic Spectrometer (AMS) aboard International Space Station. The exhibit variations multiple timescales. Recurrent flux periods 27 days, 13.5 and 9 days are observed. find that show distinctly different time proton fluxes. Remarkably, a hysteresis between is observed significance greater than 6σ at rigidities below 8.5...