| 1. |
- Abdallah, J., et al.
(author)
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A study of b(b)over-bar production in e(+)e(-) collisions at root s=130-207 GeV
- 2009
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In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 60:1, s. 1-15
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Journal article (peer-reviewed)abstract
- Measurements are presented of R-b, the ratio of the b (b) over bar cross-section to the q (q) over bar cross-section in e(+)e(-) collisions, and the forward-backward asymmetry A(FB)(b) at twelve energy points in the range root s = 130-207 GeV. These results are found to be consistent with the Standard Model expectations. The measurements are used to set limits on new physics scenarios involving contact interactions.
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| 2. |
- Abdallah, J., et al.
(author)
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Search for one large extra dimension with the DELPHI detector at LEP
- 2009
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In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 60:1, s. 17-23
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Journal article (peer-reviewed)abstract
- Single photons detected by the DELPHI experiment at LEP2 in the years 1997-2000 are reanalysed to investigate the existence of a single extra dimension in a modified ADD scenario with slightly warped large extra dimensions. The data collected at centre-of-mass energies between 180 and 209 GeV for an integrated luminosity of similar to 650 pb(-1) agree with the predictions of the Standard Model and allow a limit to be set on graviton emission in one large extra dimension. The limit obtained on the fundamental mass scale M-D is 1.69 TeV/c(2) at 95% CL, with an expected limit of 1.71 TeV/c(2).
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| 3. |
- Abdallah, J, et al.
(author)
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Correlations between polarisation states of W particles in the reaction e(-)e(+)-> W-W+ at LEP2 energies 189-209 GeV
- 2009
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In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 63:4, s. 611-623
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Journal article (peer-reviewed)abstract
- In a study of the reaction e(-)e(+)-> W-W+ with the DELPHI detector, the probabilities of the two W particles occurring in the joint polarisation states transverse-transverse (T T), longitudinal-transverse plus transverse-longitudinal (LT) and longitudinal-longitudinal (LL) have been determined using the final states WW -> lvq (q) over bar (l = e, mu). The two-particle joint polarisation probabilities, i.e. the spin density matrix elements rho T T, rho LT, rho LL, are measured as functions of the W- production angle, theta(W-), at an average reaction energy of 198.2 GeV. Averaged over all cos.W-, the following joint probabilities are obtained: (rho) over barT T = (67 +/- 8)%, (rho) over barL T = (30 +/- 8)%, (rho) over barL T = (3 +/- 7)%. These results are in agreement with the Standard Model predictions of 63.0%, 28.9% and 8.1%, respectively. The related polarisation cross-sections sigma(TT), sigma(LT) and sigma(LL) are also presented.
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| 4. |
- Abdallah, J, et al.
(author)
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Inclusive single-particle production in two-photon collisions at LEP II with the DELPHI detector
- 2009
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In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 678:5, s. 444-449
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Journal article (peer-reviewed)abstract
- A study of the inclusive charged hadron production in two-photon collisions is described. The data were collected with the DELPHI detector at LEP II. Results on the inclusive single-particle p(T) distribution and the differential charged hadrons d sigma/dp(T) cross-section are presented and compared to the predictions of perturbative NLO QCD calculations and to published results. (C) 2009 Elsevier B.V. All rights reserved.
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| 5. |
- Adriani, O., et al.
(author)
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Measurements of quasi-trapped electron and positron fluxes with PAMELA
- 2009
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In: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 114, s. A12218-
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Journal article (peer-reviewed)abstract
- This paper presents precise measurements of the differential energy spectra of quasi-trapped secondary electrons and positrons and their ratio between 80 MeV and 10 GeV in the near-equatorial region (altitudes between 350 km and 600 km). Latitudinal dependences of the spectra are analyzed in detail. The results were obtained from July until November 2006 onboard the Resurs-DK satellite by the PAMELA spectrometer, a general purpose cosmic ray detector system built around a permanent magnet spectrometer and a silicon-tungsten calorimeter.
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| 6. |
- Adriani, O., et al.
(author)
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Latest results from the Pamela experiment
- 2009
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In: Proceedings of Science. ; , s. 1-6
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Conference paper (peer-reviewed)abstract
- In this paper we present the latest results of the Pamela satellite experiment, focusing in particular on the p̄/p and the e +/(e+ +e-) ratios.
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| 7. |
- Adriani, O., et al.
(author)
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Positrons and electrons in primary cosmic rays as measured in the PAMELA experiment
- 2009
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In: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738. ; 73:5, s. 568-570
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Journal article (peer-reviewed)abstract
- The PAMELA experiment is being carried out on board the Russian satellite Resurs DK1 placed in the near-earth near-polar orbit on June 15, 2006. The apparatus comprising a silicon-strip magnetic spectrometer and an electromagnetic calorimeter allows measurement of electron and positron fluxes in cosmic rays in a wide energy interval from ∼100 MeV to hundreds of GeV. The high-energy electron and positron separation technique is discussed and the data on positron-to-electron ratio in primary cosmic rays up to E ≃ 10 GeV from the 2006 - 2007 measurements are reported in this work.
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| 8. |
- Mocchiutti, E., et al.
(author)
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Precision studies of cosmic rays with the PAMELA satellite experiment
- 2009
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In: 2009 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-5. - : IEEE. - 9781424439621 ; , s. 2125-2130
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Conference paper (peer-reviewed)abstract
- The PAMELA satellite experiment was launched into low earth orbit on June 15th 2006. The combination of a permanent magnet silicon strip spectrometer, and a silicon-tungsten imaging calorimeter allows precision studies of the charged cosmic radiation to be conducted over a wide energy range (100 MeV - 200 GeV). A primary scientific goal is to search for dark matter particle annihilations by measuring the energy spectra of cosmic ray antiparticles. Latest results from the PAMELA experiment will be reviewed with a particular focus on cosmic ray antiprotons and positrons. The status of PAMELA measurements for other cosmic ray species will also be reviewed.
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| 9. |
- Mocchiutti, E., et al.
(author)
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The PAMELA space experiment
- 2009
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In: Proceedings of the 44th Rencontres de Moriond - 2009 Electroweak Interactions and Unified Theories, EW 2009. - : Gioi Publishers. ; , s. 317-324
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Conference paper (peer-reviewed)abstract
- The 15th of June 2006, the PAMELA satellite-borne experiment was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. The apparatus comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail counter scintillator and a neutron detector. The combination of these devices allows precision studies of the charged cosmic radiation to be conducted over a wide energy range (100 MeV - 100's GeV) with high statistics. The primary scientific goal is the measurement of the antiproton and positron energy spectrum in order to search for exotic sources, such as dark matter particle annihilations. PAMELA is also searching for primordial antinuclei (anti-helium) and testing cosmic-ray propagation models through precise measurements of the anti-particle energy spectrum and precision studies of light nuclei and their isotopes. Moreover, PAMELA is investigating phenomena connected with solar and earth physics.
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| 10. |
- Papini, P., et al.
(author)
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Latest results from PAMELA
- 2009
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Conference paper (peer-reviewed)abstract
- The PAMELA experiment is a satellite-borne apparatus designed to study charged particles in the cosmic radiation, with a particular focus on antiparticles. The detector is housed on the Resurs-DK1 satellite and it is taking data since June 2006. The main parts of the apparatus are a magnetic spectrometer, which is equipped with a silicon-microstrip tracking system and which is used to measure the rigidity and the charge of particles, and a silicon/tungsten electromagnetic calorimeter which provides particle identification. The main results about the antiparticles component of cosmic rays obtained during the first 500 days of data taking are summarized here.
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