171 research outputs found
High resolution study of the Lambda p final state interaction in the reaction p + p -> K+ + (Lambda p)
The reaction pp -> K+ + (Lambda p) was measured at Tp=1.953 GeV and Theta = 0
deg with a high missing mass resolution in order to study the Lambda p final
state interaction. The large final state enhancement near the Lambda p
threshold can be described using the standard Jost-function approach. The
singlet and triplet scattering lengths and effective ranges are deduced by
fitting simultaneously the Lambda p invariant mass spectrum and the total cross
section data of the free Lambda p scattering.Comment: submitted to Physics Letters B, 10 pages, 3 figure
Upper limits for a narrow resonance in the reaction p + p -> K^+ + (Lambda p)
The reaction pp -> K^+ + (Lambda p) has been measured at T_p = 1.953 GeV and
\Theta = 0 deg with a high missing mass resolution in order to study the Lambda
p final state interaction. Narrow S = -1 resonances predicted by bag model
calculations are not visible in the missing mass spectrum. Small structures
observed in a previous experiment are not confirmed. Upper limits for the
production cross section of a narrow resonance are deduced for missing masses
between 2058 and 2105 MeV/c^2.Comment: 8 pages, 5 figure
Measurement of p + d -> 3He + eta in S(11) Resonance
We have measured the reaction p + d -> 3He + eta at a proton beam energy of
980 MeV, which is 88.5 MeV above threshold using the new ``germanium wall''
detector system. A missing--mass resolution of the detector system of 2.6% was
achieved. The angular distribution of the meson is forward peaked. We found a
total cross section of (573 +- 83(stat.) +- 69(syst.))nb. The excitation
function for the present reaction is described by a Breit Wigner form with
parameters from photoproduction.Comment: 8 pages, 2 figures, corrected typos in heade
Meson Production in p+d Reactions
The production of neutral and charged pions as well as eta mesons is studied
in the Delta and N* resonance region, respectively. Heavy A=3 recoils were
measured with the GEM detector. The differential cross sections covering the
full angular range are compared with model calculations.Comment: 4 pages, latex, 4 figures, talk presented at the XVIIth European
Conference on Few-Body Problems in Physics, Evora, Portugal, September 2000;
to be published in Nucl. Phys.
Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
This document is the Technical Design Report covering the two large
spectrometer magnets of the PANDA detector set-up. It shows the conceptual
design of the magnets and their anticipated performance. It precedes the tender
and procurement of the magnets and, hence, is subject to possible modifications
arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti
Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski,
Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy),
Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy
Structure effects in Ne-20+Pb-208 quasi-elastic scattering
Preliminary results of an analysis of experiments devoted to a study of the sensitivity of the 20Ne + 208Pb quasi-elastic angular distributions at two near-barrier energies and the previously measured corresponding
barrier distribution to the value of the nuclear quadrupole deformation length of 20Ne are reported
Indirect Study of the 16O+16O Fusion Reaction Toward Stellar Energies by the Trojan Horse Method
The 16 O+ 16 O fusion reaction is important in terms of the explosive oxygen burning process during late evolution stage of massive stars as well as understanding of the mechanism of low-energy heavy-ion fusion reactions. We aim to determine the excitation function for the most major exit channels, α + 28 Si and p + 31 P, toward stellar energies indirectly by the Trojan Horse Method via the 16 O( 20 Ne , α 28 Si) α and 16 O( 20 Ne , p 31 P) α three-body reactions. We report preliminary results involving reaction identification, and determination of the momentum distribution of α - 16 O intercluster motion in the projectile 20 Ne nucleus
Variation of nonequilibrium processes in p+Ni system with beam energy
The energy and angular dependence of double differential cross sections
dsigma/dOmega dE were measured for p, d, t, 3,4He, 6,7Li, 7,9Be, and 10,11B
produced in collisions of 0.175 GeV protons with Ni target. The analysis of
measured dfferential cross sections allowed to extract total production cross
sections for ejectiles listed above. The shape of the spectra and angular
distributions indicate the presence of other nonequilibrium processes besides
the emission of nucleons from the intranuclear cascade, and besides the
evaporation of various particles from remnants of intranuclear cascade. These
nonequilibrium processes consist of coalescence of nucleons into light charged
particles during the intranuclear cascade, of the fireball emission which
contributes to the cross sections of protons and deuterons, and of the break-up
of the target nucleus which leads to the emission of intermediate mass
fragments. All such processes were found earlier at beam energies 1.2, 1.9, and
2.5 GeV for Ni as well as for Au targets, however, significant differences in
properties of these processes at high and low beam energy are observed in the
present study.Comment: 10 pages, 9 figure
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