| K. Turzo,G. Auger,M.L. Begemann-Blaich,N. Bellaize,R. Bittiger,F. Bocage,
B. Borderie,R. Bougault,B. Bouriquet,J.L.Charvet,A.Chbihi,R.Dayras,D.Durand,
J.D. Frankland, E.Galichet, D.Gourio,D. Guinet, S. Hudan,G.Immé, P.Lautesse,
F. Lavaud,A. LeFèvre,R. Legrain†,O. Lopez,J.Lukasik,U.Lynen, W.F.J. Müller,
L. Nalpas,H.Orth, E. Plagnol, G. Raciti, E. Rosato, A. Saija, C. Schwarz ,
W. Seidel, C. Sfienti, B. Tamain, W. Trautmann, A.Trzcinski,E.Vient,
M. Vigilante, C. Volant ,B. Zwieglinski, and A.S. Botvina |
Low-energy pion+ (Epion < 35 MeV) from 12C+ 197 Au collisions at incident energies from 300
to 1800 MeV per nucleon were detected with the Si-Si(Li)-CsI(Tl) calibration telescopes of the INDRA
multidetector. The inclusive angular distributions are approximately isotropic, consistent with multiple
rescattering in the target spectator. The multiplicity correlations of the low-energy pions and of energetic
protons (Ep >150 MeV) with intermediate-mass fragments were determined from the measured coincidence
data. The deduced correlation functions 1 + R ~˜ 1.3 for inclusive event samples reflect the strong
correlations evident from the common impact parameter dependence of the considered multiplicities. For
narrow impact parameter bins (based on charged-particle multiplicity), the correlation functions are close
to unity and do not indicate strong additional correlations. Only for pions at high particle multiplicities
(central collisions) a weak anticorrelation is observed, probably due to a limited competition between these
emissions. Overall, the results are consistent with the equilibrium assumption made in statistical multifragmentation
scenarios. Predictions obtained with intranuclear-cascade models coupled to the Statistical
Multifragmentation Model are in good agreement with the experimental data. |
