P.S. Marrocchesi
University of Siena
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Featured researches published by P.S. Marrocchesi.
The Astrophysical Journal | 2010
H. S. Ahn; P. Allison; M. G. Bagliesi; J. J. Beatty; G. Bigongiari; J.T. Childers; N. B. Conklin; S. Coutu; Michael A. DuVernois; O. Ganel; J. H. Han; J. A. Jeon; K. C. Kim; M.H. Lee; L. Lutz; P. Maestro; A. Malinin; P.S. Marrocchesi; S. Minnick; S. I. Mognet; J. Nam; S. Nam; S. Nutter; I. H. Park; N. Park; E. S. Seo; R. Sina; J. Wu; J. Yang; Y.S. Yoon
The balloon-borne Cosmic Ray Energetics And Mass experiment launched five times from Antarctica has achieved a cumulative flight duration of about 156 days above 99.5% of the atmosphere. The instrument is configured with complementary and redundant particle detectors designed to extend direct measurements of cosmic-ray composition to the highest energies practical with balloon flights. All elements from protons to iron nuclei are separated with excellent charge resolution. Here, we report results from the first two flights of ~70 days, which indicate hardening of the elemental spectra above ~200 GeV/nucleon and a spectral difference between the two most abundant species, protons and helium nuclei. These results challenge the view that cosmic-ray spectra are simple power laws below the so-called knee at ~1015 eV. This discrepant hardening may result from a relatively nearby source, or it could represent spectral concavity caused by interactions of cosmic rays with the accelerating shock. Other possible explanations should also be investigated.
The Astrophysical Journal | 2011
Y.S. Yoon; H. S. Ahn; P. Allison; M. G. Bagliesi; J. J. Beatty; G. Bigongiari; P. J. Boyle; J.T. Childers; N. B. Conklin; S. Coutu; Michael A. DuVernois; O. Ganel; J. H. Han; J. A. Jeon; K. C. Kim; M.H. Lee; L. Lutz; P. Maestro; A. Malinine; P.S. Marrocchesi; S. Minnick; S. I. Mognet; S. Nam; S. Nutter; I. H. Park; N. Park; E. S. Seo; R. Sina; Simon P. Swordy; S. P. Wakely
Cosmic-ray proton and helium spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass experiment flown for 42 days in Antarctica in the 2004–2005 austral summer season. High-energy cosmic-ray data were collected at an average altitude of �38.5 km with an average atmospheric overburden of �3.9 g cm −2 . Individual elements are clearly separated with a charge resolution of �0.15 e (in charge units) and �0.2 e for protons and helium nuclei, respectively. The measured spectra at the top of the atmosphere are represented by power laws with a spectral index of 2.66 ± 0.02 for protons from 2.5 TeV to 250 TeV and –2.58 ± 0.02 for helium nuclei from 630 GeV nucleon −1 to 63 TeV nucleon −1 . They are harder than previous measurements
The Astrophysical Journal | 2009
H. S. Ahn; P. Allison; M. G. Bagliesi; Loius M. Barbier; J. J. Beatty; G. Bigongiari; T. J. Brandt; J.T. Childers; N. B. Conklin; S. Coutu; Michael A. DuVernois; O. Ganel; J. H. Han; J. A. Jeon; K. C. Kim; M.H. Lee; P. Maestro; A. Malinine; P.S. Marrocchesi; S. Minnick; S. I. Mognet; S. Nam; S. Nutter; I. H. Park; N. Park; E. S. Seo; R. Sina; P. Walpole; J. Wu; J. Yang
We present new measurements of the energy spectra of cosmic-ray (CR) nuclei from the second flight of the balloon-borne experiment Cosmic-Ray Energetics And Mass (CREAM). The instrument included different particle detectors to provide redundant charge identification and measure the energy of CRs up to several hundred TeV. The measured individual energy spectra of C, O, Ne, Mg, Si, and Fe are presented up to ~1014 eV. The spectral shape looks nearly the same for these primary elements and it can be fitted to an E –2.66 ± 0.04 power law in energy. Moreover, a new measurement of the absolute intensity of nitrogen in the 100-800 GeV/n energy range with smaller errors than previous observations, clearly indicates a hardening of the spectrum at high energy. The relative abundance of N/O at the top of the atmosphere is measured to be 0.080 ± 0.025 (stat.)±0.025 (sys.) at ~800 GeV/n, in good agreement with a recent result from the first CREAM flight.
Physics Letters B | 1984
S.R. Amendolia; B. Badelek; G. Batignani; G.A. Beck; F. Bedeschi; E.H. Bellamy; E. Bertolucci; D. Bettoni; H. Bilokon; G. Bologna; L. Bosisio; C. Bradaschia; M. Budinich; A. Codino; M.J. Counihan; M. Dell'Orso; B. D'Ettorre Piazzoli; F. Fabbri; F. Fidecaro; L. Foà; E. Focardi; S.G.F. Frank; A. Giazotto; M. A. Giorgi; M.G. Green; J.F. Harvey; G.P. Heath; M.P.J. Landon; P. Laurelli; F. Liello
Abstract We report a measurement of the negative pion electromagnetic form factor in the range of space-like four-momentum transfer 0.014 q 2 c ) 2 . The measurement was made by the NA7 collaboration at the CERN SPS, by observing the interaction of 300 GeV pions with the electrons of a liquid hydrogen target. The form factor is fitted by a pole form with a pion radius of 〈r 2 〈 1 2 = 0.657 ± 0.012 fm.
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment | 1991
W. B. Atwood; T. Barczewski; Lat Bauerdick; L. Bellantoni; E. Blucher; W. Blum; J. F. Boudreau; O. Boyle; D. Cinabro; J. Conway; G. Cowan; D. F. Cowen; I. Efthymiopoulos; P. Faure; Z. Feng; F. Fidecaro; B. Gobbo; A.W. Halley; Stephen Haywood; A. Jahn; R. C. Jared; R. P. Johnson; M. Kasemann; K. Kleinknecht; B.W. LeClaire; I. Lehraus; B. Lofstedt; T. Lohse; D. Lueke; A. Lusiani
Abstract The performance of the ALEPH Time Projection Chamber (TPC) has been studied using data taken during the LEP running periods in 1989 and 1990. After correction of residual distortions and optimisation of coordinate reconstruction algorithms, single coordinate resolutions of 173 μm in the azimuthal and 740 μm in the longitudinal direction are achieved. This results in a momentum resolution for the TPC of Δp / p 2 = 1.2 × 10 −3 (GeV/ c ) −1 . In combination with the ALEPH Inner Tracking Chamber (ITC), a total momentum resolution of Δp / p 2 = 0.8 × 10 −3 (GeV/ c ) −1 is obtained. With respect to particle identification, the detector achieves a resolution of 4.4% for the measurement of the ionisation energy loss.
Physics Letters B | 1984
S.R. Amendolia; B. Badelek; G. Batignani; G.A. Beck; E.H. Bellamy; E. Bertolucci; D. Bettoni; H. Bilokon; A. Bizzeti; G. Bologna; L. Bosisio; C. Bradaschia; M. Budinich; M. Dell'Orso; B. D'Ettorre Piazzoli; M. Enorini; F. Fabbri; F. Fidecaro; L. Foà; E. Focardi; S.G.F. Frank; P. Giannetti; A. Giazotto; M. A. Giorgi; J.F. Harvey; G.P. Heath; M.P.J. Landon; P. Laurelli; F. Liello; G. Mannocchi
Abstract The EM form factor of the pion has been studied in the time-like region by measuring σ (e + e − → π + π − ) normalized to σ (e + e − → μ + μ − ). Results have been obtained for q 2 down to the physical threshold.
Nuclear Physics B - Proceedings Supplements | 2002
F. Cadoux; F. Cervelli; V. Chambert-Hermel; Gen Chen; H.S. Chen; G. Coignet; S. Di Falco; J.M. Dubois; E. Falchini; A. Franzoso; D. Fougeron; N. Fouque; S. Galeotti; L. Girard; C. Goy; R. Hermel; M. Incagli; R. Kossakowski; B. Lieunard; Y. Liu; Z. Liu; T. Lomtadze; P. Maestro; P.S. Marrocchesi; R. Paoletti; F. Pilo; S. Rosier-Lees; F. Spinella; N. Turini; G. Valle
Abstract The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a lead-scintillanting fibers sampling calorimeter characterized by high granularity that allows to image the longitudinal and lateral showers development, a key issue to provide high electron/hadron discrimination. The light collection system and the FE electronics are designed to let the calorimeter operate over a wide energy range from few GeV up to 1 TeV. A full-scale prototype of the e.m. calorimeter was tested at Cern in October 2001 using electrons and pions beams with energy ranging from 3 to 100 GeV. Effective sampling thickness, linearity and energy resolution were measured.
The Astrophysical Journal | 2010
H. S. Ahn; P. Allison; M. G. Bagliesi; Loius M. Barbier; J. J. Beatty; G. Bigongiari; T. J. Brandt; J.T. Childers; N. B. Conklin; S. Coutu; Michael A. DuVernois; O. Ganel; J. H. Han; J. A. Jeon; K. C. Kim; Jue-Yeon Lee; M.H. Lee; P. Maestro; A. Malinin; P.S. Marrocchesi; S. Minnick; S. I. Mognet; G. W. Na; J. Nam; S. Nam; S. Nutter; I. H. Park; N. Park; E. S. Seo; R. Sina
We present measurements of the relative abundances of cosmic-ray nuclei in the energy range of 500-3980 GeV/nucleon from the second flight of the Cosmic Ray Energetics And Mass balloon-borne experiment. Particle energy was determined using a sampling tungsten/scintillating-fiber calorimeter, while particle charge was identified precisely with a dual-layer silicon charge detector installed for this flight. The resulting element ratios C/O, N/O, Ne/O, Mg/O, Si/O, and Fe/O at the top of atmosphere are 0.919 ? 0.123stat ? 0.030syst, 0.076 ? 0.019stat ? 0.013syst, 0.115 ? 0.031stat ? 0.004syst, 0.153 ? 0.039stat ? 0.005syst, 0.180 ? 0.045stat ? 0.006syst, and 0.139?? 0.043stat ? 0.005syst, respectively, which agree with measurements at lower energies. The source abundance of N/O is found to be 0.054 ? 0.013stat ? 0.009syst+0.010esc ?0.017. The cosmic-ray source abundances are compared to local Galactic (LG) abundances as a function of first ionization potential and as a function of condensation temperature. At high energies the trend that the cosmic-ray source abundances at large ionization potential or low condensation temperature are suppressed compared to their LG abundances continues. Therefore, the injection mechanism must be the same at TeV/nucleon energies as at the lower energies measured by HEAO-3, CRN, and TRACER. Furthermore, the cosmic-ray source abundances are compared to a mixture of 80% solar system abundances and 20% massive stellar outflow (MSO) as a function of atomic mass. The good agreement with TIGER measurements at lower energies confirms the existence of a substantial fraction of MSO material required in the ~TeV per nucleon region.
arXiv: Instrumentation and Methods for Astrophysics | 2013
A. M. Galper; O. Adriani; R.L. Aptekar; I.V. Arkhangelskaja; A.I. Arkhangelskiy; M. Boezio; V. Bonvicini; K. A. Boyarchuk; M. I. Fradkin; Yu. V. Gusakov; V. A. Kaplin; V. A. Kachanov; M. D. Kheymits; A. Leonov; F. Longo; E. P. Mazets; P. Maestro; P.S. Marrocchesi; I. A. Mereminskiy; V. V. Mikhailov; A. A. Moiseev; E. Mocchiutti; N. Mori; I. V. Moskalenko; P. Yu. Naumov; P. Papini; P. Picozza; V. G. Rodin; M. F. Runtso; R. Sparvoli
The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is ∼0.01° (Eγ > 100 GeV), the energy resolution ∼1% (Eγ > 10 GeV), and the proton rejection factor ∼106. GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.
Bulletin of The Russian Academy of Sciences: Physics | 2015
N. P. Topchiev; A. M. Galper; V. Bonvicini; O. Adriani; R.L. Aptekar; I.V. Arkhangelskaja; A.I. Arkhangelskiy; L. Bergstrom; E. Berti; G. Bigongiari; S. G. Bobkov; E. A. Bogomolov; M. Boezio; M. Bongi; S. Bonechi; S. Bottai; K. A. Boyarchuk; A. Vacchi; E. Vannuccini; G. Vasilyev; G. Castellini; P. W. Cattaneo; P. Cumani; G. L. Dedenko; V.A. Dogiel; C. De Donato; B.I. Hnatyk; M. S. Gorbunov; Yu. V. Gusakov; N. Zampa
The development of the GAMMA-400 γ-ray telescope continues. The GAMMA-400 is designed to measure fluxes of γ-rays and the electron-positron cosmic-ray component possibly associated with annihilation or decay of dark matter particles; and to search for and study in detail discrete γ-ray sources, to measure the energy spectra of Galactic and extragalactic diffuse γ-rays, and to study γ-ray bursts and γ-rays from the active Sun. The energy range for measuring γ-rays and electrons (positrons) is from 100 MeV to 3000 GeV. For 100-GeV γ-rays, the γ-ray telescope has an angular resolution of ∼0.01°, an energy resolution of ∼1%, and a proton rejection factor of ∼5 × 105. The GAMMA-400 will be installed onboard the Russian Space Observatory.