| 1. |
- Balkeståhl, Li Caldeira, et al.
(författare)
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Prospects for pp rarr YY studies at PANDA
- 2014
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Ingår i: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 229:1-3, s. 79-83
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Tidskriftsartikel (refereegranskat)abstract
- Strangeness and charm production provide an excellent probe of QCD in the confinement domain. With the PANDA detector at FAIR, this can be studied in e.g., hyperon production in the pp rarr YY reactions. In PANDA, all ground state strange hyperons and single charmed Lambda's will be accessible. Simulations show that the differential cross sections and spin observables can be well reconstructed for these reaction channels.
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| 2. |
- Boezio, M., et al.
(författare)
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The PAMELA experiment and antimatter in the universe
- 2014
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Ingår i: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 228:1-3, s. 101-109
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Tidskriftsartikel (refereegranskat)abstract
- On 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 primary scientific goal is the measurement of the antiproton and positron energy spectra. Antiparticles are a natural component of the cosmic radiation being produced in the interaction between cosmic rays and the interstellar matter. They have been shown to be extremely interesting for understanding the propagation mechanisms of cosmic rays. Furthermore, novel sources of primary cosmic-ray antiparticles of either astrophysical or exotic origin (e.g. annihilation of dark matter particles) can also be probed. In this paper we review the PAMELA antiparticle results and their significance for the field of astroparticle physics.
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| 3. |
- Boezio, M., et al.
(författare)
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The PAMELA space mission for antimatter and dark matter searches in space
- 2012
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Ingår i: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 213:1-3, s. 147-158
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Tidskriftsartikel (refereegranskat)abstract
- The PAMELA satellite-borne experiment has presented new results on cosmic-ray antiparticles that can be interpreted in terms of DM annihilation or pulsar contribution. The instrument was launched from the Baikonur cosmodrome and it has been collecting data since July 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 with high statistics. The primary scientific goal is the measurement of the antiproton and positron energy spectrum in order to search for exotic sources. PAMELA is also searching for primordial antinuclei (anti-helium), and testing cosmic-ray propagation models through precise measurements of the antiparticle energy spectrum and precision studies of light nuclei and their isotopes. This talk illustrates the most recent scientific results obtained by the PAMELA experiment.
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| 4. |
- Butler, E., et al.
(författare)
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Towards antihydrogen trapping and spectroscopy at ALPHA
- 2011
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Ingår i: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 199:1, s. 39-48
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Tidskriftsartikel (refereegranskat)abstract
- Spectroscopy of antihydrogen has the potential to yield high-precision tests of the CPT theorem and shed light on the matter-antimatter imbalance in the Universe. The ALPHA antihydrogen trap at CERN’s Antiproton Decelerator aims to prepare a sample of antihydrogen atoms confined in an octupole-based Ioffe trap and to measure the frequency of several atomic transitions. We describe our techniques to directly measure the antiproton temperature and a new technique to cool them to below 10 K. We also show how our unique position-sensitive annihilation detector provides us with a highly sensitive method of identifying antiproton annihilations and effectively rejecting the cosmic-ray background.
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| 5. |
- Hobein, Matthias, 1981-, et al.
(författare)
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SMILETRAP II
- 2011
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Ingår i: Hyperfine Interactions. - : Springer Netherlands. - 0304-3843 .- 1572-9540. ; 199:1-3, s. 141-150
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Tidskriftsartikel (refereegranskat)abstract
- The new Penning trap mass spectrometer SMILETRAP II has been set up at the AlbaNova Research Center, Stockholm. Based on the former spectrometer SMILETRAP I, it uses the merits of highly-charged ions to achieve high precision in the mass measurements. Various improvements over the SMILETRAP I setup will allow to routinely perform mass measurements with relative uncertainties of 10−10 and below. In this paper we will discuss the limitations of SMILETRAP I and present the corresponding improvements of SMILETRAP II. An overview on the SMILETRAP II setup is given.
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| 6. |
- Jonsell, Svante, et al.
(författare)
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Metastable states in antihydrogen formation
- 2014
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Ingår i: Hyperfine interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; , s. 81-83
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Konferensbidrag (refereegranskat)abstract
- Formation of antihydrogen atoms from antiprotons immersed in a positron plasma is simulated. Special attention is devoted to the role of metastable states, arising from the near conservation of the energy stored in the cyclotron motion of the positrons. We find that the decay of such states changes the density scaling of the formation rate.
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| 7. |
- Malbrunot, C., et al.
(författare)
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Spectroscopy apparatus for the measurement of the hyperfine structure of antihydrogen
- 2014
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Ingår i: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 228:1-3, s. 61-66
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Tidskriftsartikel (refereegranskat)abstract
- The ASACUSA CUSP collaboration at the Antiproton Decelerator (AD) of CERN is planning to measure the ground-state hyperfine splitting of antihydrogen (H̄) using an atomic spectroscopy beamline. We describe here the latest developments on the spectroscopy apparatus developed to be coupled to the H̄ production setup (CUSP).
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| 8. |
- Marsh, B. A., et al.
(författare)
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The ISOLDE RILIS pump laser upgrade and the LARIS Laboratory
- 2010
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Ingår i: Hyperfine Interactions. - : Springer Nature. - 0304-3843 .- 1572-9540. ; 196:1-3, s. 129-141
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Tidskriftsartikel (refereegranskat)abstract
- On account of its high efficiency, speed and unmatched selectivity, the Resonance Ionization Laser Ion Source (RILIS) is the preferred method for ionizing the nuclear reaction products at the ISOLDE on-line isotope separator facility. By exploiting the unique electronic energy level 'fingerprint' of a chosen element, the RILIS process of laser step-wise resonance ionization enables an ion beam of high chemical purity to be sent through the mass selective separator magnet. The isobaric purity of a beam of a chosen isotope is therefore greatly increased. The RILIS, comprising of up to three frequency tunable pulsed dye lasers has been upgraded with the installation of a Nd:YAG pump laser as a replacement for the old Copper Vapor Laser (CVL) system. A summary of the current Nd:YAG pumped RILIS performance is given. To accompany the RILIS pump laser upgrade, a new ionization scheme for manganese has been developed at the newly constructed LAser Resonance Ionization Spectroscopy (LARIS) laboratory and successfully applied for on-line RILIS operation. An overview of the LARIS facility is given along with details of the ionization scheme development work for manganese.
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| 9. |
- Piszczatowski, Konrad, et al.
(författare)
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Four-body calculations of elastic scattering in H-H collisions
- 2014
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Ingår i: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 228:1-3, s. 85-89
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Tidskriftsartikel (refereegranskat)abstract
- We present a nonadiabatic treatment of the hydrogen-antihydrogen system. The technique used to describe H- H collisions is based on the coupled rearrangement channels method. Within this approach the total, nonadiabatic wave function of the system is divided into two parts: an inner and an outer one. To describe the inner part a set of square-integrable 4-body functions is used. These functions are obtained by a diagonalization of the total Hamiltonian projected on a chosen L2 subspace, they explicitly contain components of various arrangement channels expressed in terms of corresponding Jacobi coordinates. The outer part of the total wave function reflects its asymptotic character. Our procedure leads to the system of non-local integro-differential equations that are solved iteratively and simultaneously determine both the shape of the outer part of the wave function and the coefficients in the four-body expansion of the inner part. Using this formalism we perform the one-channel calculation of the elastic scattering to obtain the S-matrix and nonadiabatic scattering length.
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| 10. |
- Pyszniak, Andrzej, et al.
(författare)
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A pellet tracking system for the PANDA experiment
- 2014
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Ingår i: Hyperfine Interactions. - : Springer Science and Business Media LLC. - 0304-3843 .- 1572-9540. ; 229:1-3, s. 159-163
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Tidskriftsartikel (refereegranskat)abstract
- Frozen microspheres of hydrogen (pellets) will be one of the target types for the future hadron physics experiment PANDA at FAIR (GSI, Darmstadt, Germany) [1]. Pellets with a diameter of 25- mum are generated about 3 meters above the interaction region, to which they travel with a velocity around 80 m/s inside a narrow pipe. The interaction region is defined by the overlap of the pellet stream and the accelerator beam and has a size of a few millimeters. One would like to know the interaction point more precisely, to have better possibilities to reconstruct particle tracks and events e.g. in charmonium decay studies. One would also like to suppress background events that do not originate in a pellet, but e.g. may occur in rest gas, that is present in the beam pipe. A solution is provided by the presented pellet tracking system together with a target operation mode that provides one and only one pellet in the interaction region most of the time. The goal is to track individual pellets in order to know their position with a resolution of a few tenths of a millimeter at the time of an interaction. The system must also be highly efficient and provide tracking information for essentially all pellets that pass the interaction region. Presented results from the design studies show that the goals can be fulfilled by this solution.
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