Universitätspublikationen
3 search hits
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Compression effects in relativistic nucleus-nucleus collisions
(1982)
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Reinhard Stock
R. Bock
R. Brockman
J. W. Harris
A. Sandoval
Herbert Ströbele
K. L. Wolf
H. G. Pugh
L. S. Schroeder
M. Maier
R. E. Renfordt
A. Dacal
M. E. Ortiz
- The negative-pion multiplicity is measured for central collisions of 40Ar with KCl at eight energies from 0.36 to 1.8 GeV/nucleon and for 4He on KCl and 40Ar on BaI2 at 977 and 772 MeV/nucleon, respectively. A systematic discrepancy with a cascade-model calculation which fits proton- and pion-nucleus cross sections but omits potential-energy effects is used to derive the energy going into bulk compression of the system. A value of the incompressibility constant of K=240 MeV is extracted in a parabolic form of the nuclear-matter equation of state.
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Parity of bound dipole states in 208Pb
(1982)
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K. Wienhard
K. Ackermann
K. Bangert
U. E. P. Berg
C. Bläsing
W. Naatz
A. Ruckelshausen
D. Rück
R. K. M. Schneider
Reinhard Stock
- The parities of eleven J=1 levels in 208Pb were determined by nuclear resonance fluorescence scattering of linearly polarized photons. A new 1+ level at Ex=5.846 MeV with Gamma 02 / Gamma =1.2±0.4 eV was found. This level can probably be identified with the theoretically predicted isoscalar 1+ state in 208Pb. All other bound dipole states below 7 MeV with Gamma 02 / Gamma >1.5 eV have negative parity. The 1- assignment to the 4.842-MeV level is of special significance because of previous conflicting results about its parity.
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Pion production and charged-particle multiplicity selection in relativistic nuclear collisions
(1982)
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K. L. Wolf
H. H. Gutbrod
M. G. Meyer
A. M. Poskanzer
A. Sandoval
Reinhard Stock
J. Gosset
J.-C. Jourdain
C. H. King
G. King
Nguyen Van Sen
G. D. Westfall
- Spectra of positive pions with energies of 15-95 MeV were measured for high energy proton, 4He, 20Ne, and 40Ar bombardments of targets of 27Al, 40Ca, 107,109Ag, 197Au, and 238U. A Si-Ge telescope was used to identify charged pions by dE / dx-E and, in addition, stopped pi + were tagged by the subsequent muon decay. In all, results for 14 target-projectile combinations are presented to study the dependence of pion emission patterns on the bombarding energy (from E / A=0.25 to 2.1 GeV) and on the target and the projectile masses. In addition, associated charged-particle multiplicities were measured in an 80-paddle array of plastic scintillators, and used to make impact parameter selections on the pion-inclusive data. NUCLEAR REACTIONS U(20Ne, pi +), E / A=250 MeV; U(40Ar, pi +), Ca(40Ar, pi +), U(20Ne, pi +), Au(20Ne, pi +), Ag(20Ne, pi +), Al(20Ne, pi +), U(4He, pi +), Al(4He, pi +). E / A=400 MeV; Ca(40Ar, pi +), U(20Ne, pi +), U(4He, pi +), U(p, pi +), E / A=1.05), GeV; U(20Ne, pi +), E / A=2.1 GeV; measured sigma (E, theta ), inclusive and selected on associated charged-particle multiplicity.
