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M. Aguilar - One of the best experts on this subject based on the ideXlab platform.
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Properties of Iron Primary Cosmic Rays: Results from the Alpha Magnetic Spectrometer.
Physical review letters, 2021Co-Authors: M. Aguilar, L. Ali Cavasonza, Giovanni Ambrosi, Luísa Arruda, N. Attig, F. Barao, L. Barrin, M S Allen, B Alpat, A. BartoloniAbstract:We report the observation of new properties of Primary iron (Fe) Cosmic Rays in the rigidity range 2.65 GV to 3.0 TV with 0.62×10^{6} iron nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. Above 80.5 GV the rigidity dependence of the Cosmic ray Fe flux is identical to the rigidity dependence of the Primary Cosmic ray He, C, and O fluxes, with the Fe/O flux ratio being constant at 0.155±0.006. This shows that unexpectedly Fe and He, C, and O belong to the same class of Primary Cosmic Rays which is different from the Primary Cosmic Rays Ne, Mg, and Si class.
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Properties of Neon, Magnesium, and Silicon Primary Cosmic Rays Results from the Alpha Magnetic Spectrometer.
Physical review letters, 2020Co-Authors: M. Aguilar, L. Ali Cavasonza, Giovanni Ambrosi, Luísa Arruda, N. Attig, F. Barao, L. Barrin, A. Bartoloni, S. Başeğmez-du Pree, R. BattistonAbstract:We report the observation of new properties of Primary Cosmic Rays, neon (Ne), magnesium (Mg), and silicon (Si), measured in the rigidity range 2.15 GV to 3.0 TV with 1.8 × 10$^{6}$ Ne, 2.2 × 10$^{6}$ Mg, and 1.6 × 10$^{6}$ Si nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The Ne and Mg spectra have identical rigidity dependence above 3.65 GV. The three spectra have identical rigidity dependence above 86.5 GV, deviate from a single power law above 200 GV, and harden in an identical way. Unexpectedly, above 86.5 GV the rigidity dependence of Primary Cosmic Rays Ne, Mg, and Si spectra is different from the rigidity dependence of Primary Cosmic Rays He, C, and O. This shows that the Ne, Mg, and Si and He, C, and O are two different classes of Primary Cosmic Rays.
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observation of new properties of secondary Cosmic Rays lithium beryllium and boron by the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, A BarrauAbstract:: We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station
Phys.Rev.Lett., 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, S Aupetit, L. Ali Cavasonza, A BarrauAbstract:We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of $5.4 \times 10^6$ nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of $2.0 \pm 0.1$. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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antiproton flux antiproton to proton flux ratio and properties of elementary particle fluxes in Primary Cosmic Rays measured with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2016Co-Authors: M. Aguilar, N. Attig, B Alpat, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, F. BaraoAbstract:A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in Primary Cosmic Rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 × 105 antiproton events and 2.42 × 109 proton events. The fluxes and flux ratios of charged elementary particles in Cosmic Rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton ¯p, proton p, and positron eþ fluxes are found to have nearly identical rigidity dependence and the electron e− flux exhibits a different rigidity dependence. Below 60 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
A Bachlechner - One of the best experts on this subject based on the ideXlab platform.
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observation of new properties of secondary Cosmic Rays lithium beryllium and boron by the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, A BarrauAbstract:: We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station
Phys.Rev.Lett., 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, S Aupetit, L. Ali Cavasonza, A BarrauAbstract:We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of $5.4 \times 10^6$ nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of $2.0 \pm 0.1$. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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antiproton flux antiproton to proton flux ratio and properties of elementary particle fluxes in Primary Cosmic Rays measured with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2016Co-Authors: M. Aguilar, N. Attig, B Alpat, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, F. BaraoAbstract:A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in Primary Cosmic Rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 × 105 antiproton events and 2.42 × 109 proton events. The fluxes and flux ratios of charged elementary particles in Cosmic Rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton ¯p, proton p, and positron eþ fluxes are found to have nearly identical rigidity dependence and the electron e− flux exhibits a different rigidity dependence. Below 60 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
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precision measurement of the helium flux in Primary Cosmic Rays of rigidities 1 9 gv to 3 tv with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2015Co-Authors: M. Aguilar, N. Attig, B Alpat, D Aisa, A Alvino, G Ambrosi, K Andeen, L Arruda, P Azzarello, A BachlechnerAbstract:Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of Cosmic Rays. A precise measurement of the helium flux in Primary Cosmic Rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.
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precision measurement of the proton flux in Primary Cosmic Rays from rigidity 1 gv to 1 8 tv with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2014Co-Authors: M. Aguilar, N. Attig, B Alpat, D Aisa, A Alvino, G Ambrosi, K Andeen, L Arruda, P Azzarello, A BachlechnerAbstract:: A precise measurement of the proton flux in Primary Cosmic Rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of Cosmic Rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.
N. Attig - One of the best experts on this subject based on the ideXlab platform.
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Properties of Iron Primary Cosmic Rays: Results from the Alpha Magnetic Spectrometer.
Physical review letters, 2021Co-Authors: M. Aguilar, L. Ali Cavasonza, Giovanni Ambrosi, Luísa Arruda, N. Attig, F. Barao, L. Barrin, M S Allen, B Alpat, A. BartoloniAbstract:We report the observation of new properties of Primary iron (Fe) Cosmic Rays in the rigidity range 2.65 GV to 3.0 TV with 0.62×10^{6} iron nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. Above 80.5 GV the rigidity dependence of the Cosmic ray Fe flux is identical to the rigidity dependence of the Primary Cosmic ray He, C, and O fluxes, with the Fe/O flux ratio being constant at 0.155±0.006. This shows that unexpectedly Fe and He, C, and O belong to the same class of Primary Cosmic Rays which is different from the Primary Cosmic Rays Ne, Mg, and Si class.
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Properties of Neon, Magnesium, and Silicon Primary Cosmic Rays Results from the Alpha Magnetic Spectrometer.
Physical review letters, 2020Co-Authors: M. Aguilar, L. Ali Cavasonza, Giovanni Ambrosi, Luísa Arruda, N. Attig, F. Barao, L. Barrin, A. Bartoloni, S. Başeğmez-du Pree, R. BattistonAbstract:We report the observation of new properties of Primary Cosmic Rays, neon (Ne), magnesium (Mg), and silicon (Si), measured in the rigidity range 2.15 GV to 3.0 TV with 1.8 × 10$^{6}$ Ne, 2.2 × 10$^{6}$ Mg, and 1.6 × 10$^{6}$ Si nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The Ne and Mg spectra have identical rigidity dependence above 3.65 GV. The three spectra have identical rigidity dependence above 86.5 GV, deviate from a single power law above 200 GV, and harden in an identical way. Unexpectedly, above 86.5 GV the rigidity dependence of Primary Cosmic Rays Ne, Mg, and Si spectra is different from the rigidity dependence of Primary Cosmic Rays He, C, and O. This shows that the Ne, Mg, and Si and He, C, and O are two different classes of Primary Cosmic Rays.
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observation of new properties of secondary Cosmic Rays lithium beryllium and boron by the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, A BarrauAbstract:: We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station
Phys.Rev.Lett., 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, S Aupetit, L. Ali Cavasonza, A BarrauAbstract:We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of $5.4 \times 10^6$ nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of $2.0 \pm 0.1$. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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antiproton flux antiproton to proton flux ratio and properties of elementary particle fluxes in Primary Cosmic Rays measured with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2016Co-Authors: M. Aguilar, N. Attig, B Alpat, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, F. BaraoAbstract:A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in Primary Cosmic Rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 × 105 antiproton events and 2.42 × 109 proton events. The fluxes and flux ratios of charged elementary particles in Cosmic Rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton ¯p, proton p, and positron eþ fluxes are found to have nearly identical rigidity dependence and the electron e− flux exhibits a different rigidity dependence. Below 60 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
G Ambrosi - One of the best experts on this subject based on the ideXlab platform.
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observation of new properties of secondary Cosmic Rays lithium beryllium and boron by the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, A BarrauAbstract:: We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station
Phys.Rev.Lett., 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, S Aupetit, L. Ali Cavasonza, A BarrauAbstract:We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of $5.4 \times 10^6$ nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of $2.0 \pm 0.1$. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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antiproton flux antiproton to proton flux ratio and properties of elementary particle fluxes in Primary Cosmic Rays measured with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2016Co-Authors: M. Aguilar, N. Attig, B Alpat, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, F. BaraoAbstract:A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in Primary Cosmic Rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 × 105 antiproton events and 2.42 × 109 proton events. The fluxes and flux ratios of charged elementary particles in Cosmic Rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton ¯p, proton p, and positron eþ fluxes are found to have nearly identical rigidity dependence and the electron e− flux exhibits a different rigidity dependence. Below 60 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
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precision measurement of the helium flux in Primary Cosmic Rays of rigidities 1 9 gv to 3 tv with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2015Co-Authors: M. Aguilar, N. Attig, B Alpat, D Aisa, A Alvino, G Ambrosi, K Andeen, L Arruda, P Azzarello, A BachlechnerAbstract:Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of Cosmic Rays. A precise measurement of the helium flux in Primary Cosmic Rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.
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precision measurement of the proton flux in Primary Cosmic Rays from rigidity 1 gv to 1 8 tv with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2014Co-Authors: M. Aguilar, N. Attig, B Alpat, D Aisa, A Alvino, G Ambrosi, K Andeen, L Arruda, P Azzarello, A BachlechnerAbstract:: A precise measurement of the proton flux in Primary Cosmic Rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of Cosmic Rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.
L Arruda - One of the best experts on this subject based on the ideXlab platform.
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observation of new properties of secondary Cosmic Rays lithium beryllium and boron by the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, A BarrauAbstract:: We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station
Phys.Rev.Lett., 2018Co-Authors: M. Aguilar, N. Attig, F. Barao, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, S Aupetit, L. Ali Cavasonza, A BarrauAbstract:We report on the observation of new properties of secondary Cosmic Rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of $5.4 \times 10^6$ nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of $2.0 \pm 0.1$. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary Cosmic Rays has also been observed in the AMS measurement of Primary Cosmic Rays He, C, and O but the rigidity dependences of Primary Cosmic Rays and of secondary Cosmic Rays are distinctly different. In particular, above 200 GV, the secondary Cosmic Rays harden more than the Primary Cosmic Rays.
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antiproton flux antiproton to proton flux ratio and properties of elementary particle fluxes in Primary Cosmic Rays measured with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2016Co-Authors: M. Aguilar, N. Attig, B Alpat, G Ambrosi, L Arruda, P Azzarello, A Bachlechner, Ali L Cavasonza, S Aupetit, F. BaraoAbstract:A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in Primary Cosmic Rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 × 105 antiproton events and 2.42 × 109 proton events. The fluxes and flux ratios of charged elementary particles in Cosmic Rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton ¯p, proton p, and positron eþ fluxes are found to have nearly identical rigidity dependence and the electron e− flux exhibits a different rigidity dependence. Below 60 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
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precision measurement of the helium flux in Primary Cosmic Rays of rigidities 1 9 gv to 3 tv with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2015Co-Authors: M. Aguilar, N. Attig, B Alpat, D Aisa, A Alvino, G Ambrosi, K Andeen, L Arruda, P Azzarello, A BachlechnerAbstract:Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of Cosmic Rays. A precise measurement of the helium flux in Primary Cosmic Rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.
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precision measurement of the proton flux in Primary Cosmic Rays from rigidity 1 gv to 1 8 tv with the alpha magnetic spectrometer on the international space station
Physical Review Letters, 2014Co-Authors: M. Aguilar, N. Attig, B Alpat, D Aisa, A Alvino, G Ambrosi, K Andeen, L Arruda, P Azzarello, A BachlechnerAbstract:: A precise measurement of the proton flux in Primary Cosmic Rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of Cosmic Rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.
