12 research outputs found
The use of GPS-arrays in detecting shock-acoustic waves generated during rocket launchings
This paper is concerned with the form and dynamics of shock-acoustic waves
(SAW) generated during rocket launchings. We have developed a method for
determining SAW parameters (including angular characteristics of the wave
vector, and the SAW phase velocity, as well as the direction towards the
source) using GPS-arrays whose elements can be chosen out of a large set of
GPS-stations of the global GPS network. The application of the method is
illustrated by a case study of ionospheric effects from launchings of launch
vehicles (LV) Proton and Space Shuttle from space-launch complexes Baikonur and
Kennedy Space Center (KSC) in 1998 and 1999 (a total of five launchings). The
study revealed that, in spite of a difference of LV characteristics, the
ionospheric response for all launchings had the character of an N - wave
corresponding to the form of a shock wave, regardless of the disturbance source
(rocket launchings, industrial explosions). The SAW period T is 270--360 s, and
the amplitude exceeds the standard deviation of TEC background fluctuations in
this range of periods under quiet and moderate geomagnetic conditions by
factors of 2 to 5 as a minimum. The angle of elevation of the SAW wave vector
varies from 30 degree to 60 degree, and the SAW phase velocity (900-1200 m/s)
approaches the sound velocity at heights of the ionospheric F-region maximum.Comment: EmTeX-386, 23 pages, 6 figure
Study of doubly strange systems using stored antiprotons
Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P‾ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ−-atoms will be feasible and even the production of Ω−-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ω−-nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions
Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)
This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment, which is being developed for the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. The performance figures are based on extensive prototype tests and radiation hardness studies. The document shows that the EMC is ready for construction up to the front-end electronics interface
Experimental access to Transition Distribution Amplitudes with the P̄ANDA experiment at FAIR
Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (\u3c0N) TDAs from \uafpp \u2192 e+e 12\u3c00 reaction with the future PANDA detector at the FAIR facility. At high center- of-mass energy and high invariant mass squared of the lepton pair q2, the amplitude of the signal channel pp\uaf \u2192 e+e 12\u3c00 admits a QCD factorized description in terms of \u3c0N TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring \uafpp \u2192 e+e 12\u3c00 with the PANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. pp\uaf \u2192 \u3c0+\u3c0 12\u3c00 were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 0.5 in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the PANDA detector will allow to achieve a background rejection factor of 5 \ub7 107 (1 \ub7 107) at low (high) q2 for s = 5 GeV2, and of 1 \ub7 108 (6 \ub7 106) at low (high) q2 for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 fb 121 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with PANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing \u3c0N TDAs
Technical Design Report for the Panda Forward Spectrometer Calorimeter
This document is devoted to the electromagnetic calorimeter of the Forward Spectrometer and describes the design considerations, the technical layout, the expected performance, and the production readiness
Technical Design Report for the Panda Forward Spectrometer Calorimeter
This document is devoted to the electromagnetic calorimeter of the Forward
Spectrometer and describes the design considerations, the technical layout, the
expected performance, and the production readiness