Varlen Grabski
A5078431844- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Digital Radiography and Breast Imaging
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- advanced mathematical theories
- Radiation Detection and Scintillator Technologies
- Gamma-ray bursts and supernovae
- Nuclear reactor physics and engineering
- Computational Physics and Python Applications
- Medical Imaging Techniques and Applications
- Nuclear physics research studies
- Advanced X-ray and CT Imaging
- Radiation Therapy and Dosimetry
- Statistical Methods and Bayesian Inference
- Black Holes and Theoretical Physics
- Pulsars and Gravitational Waves Research
- Atmospheric Ozone and Climate
- Stochastic processes and statistical mechanics
- Geomagnetism and Paleomagnetism Studies
Universidad Nacional Autónoma de México
2016-2025
University of Houston
2023-2024
A. Alikhanyan National Laboratory
2001-2024
European Organization for Nuclear Research
2012-2023
Technical University of Munich
2021
University of Hawaii System
2020
Kurchatov Institute
2018
University of Rochester
2018
University of Wisconsin–Madison
2012
Azerbaijan National Academy of Sciences
2011-2012
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}...
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 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,...
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...
Precise knowledge of the charge and rigidity dependence secondary cosmic ray fluxes secondary-to-primary flux ratios is essential in understanding propagation. We report properties heavy fluorine F R range 2.15 GV to 2.9 TV based on 0.29 million events collected by Alpha Magnetic Spectrometer experiment International Space Station. The spectrum deviates from a single power law above 200 GV. heavier F/Si ratio distinctly different lighter B/O (or B/C) dependence. In particular, 10 GV, F/SiB/O...
We report the properties of sodium (Na) and aluminum (Al) cosmic rays in rigidity range 2.15 GV to 3.0 TV based on 0.46 million 0.51 nuclei collected by Alpha Magnetic Spectrometer experiment International Space Station. found that Na Al, together with nitrogen (N), belong a distinct ray group. In this group, we observe that, similar N flux, both flux Al are well described sums primary component (proportional silicon flux) secondary fluorine flux). The fraction increases for N, Na, fluxes...
We report the properties of primary cosmic-ray sulfur (S) in rigidity range 2.15 GV to 3.0 TV based on 0.38×10^{6} nuclei collected by Alpha Magnetic Spectrometer experiment (AMS). observed that above 90 dependence S flux is identical Ne-Mg-Si fluxes, which different from He-C-O-Fe fluxes. found that, similar N, Na, and Al cosmic rays, over entire range, traditional rays S, Ne, Mg, C all have sizeable secondary components, Mg fluxes are well described weighted sum silicon fluorine flux,...