Constraints on the time-scale of nuclear breakup from thermal hard-photon emission

Abstract

Measured hard photon multiplicities from second-chance nucleon-nucleon collisions are used in combination with a kinetic thermal model, to estimate the break-up times of excited nuclear systems produced in nucleus-nucleus reactions at intermediate energies. The obtained nuclear break-up time for the ${}^{129}${Xe} + ${}^{nat}${Sn} reaction at 50{\it A} MeV is $\Delta$$\tau$ $\approx$ 100 -- 300 fm/$c$ for all reaction centralities. The lifetime of the radiating sources produced in seven other different heavy-ion reactions studied by the TAPS experiment are consistent with $\Delta$$\tau$ $\approx$ 100 fm/$c$, such relatively long thermal photon emission times do not support the interpretation of nuclear breakup as due to a fast spinodal process for the heavy nuclear systems studied.

arXiv comment11 pages, 9 figures, submitted to EPJA

References in corpus (9)

• A unitary isobar model for pion photo- and electroproduction on the proton up to 1 GeV
• Analysis of Pion Photoproduction Data
• First measurement of the Gerasimov-Drell-Hearn integral for Hydrogen from 200 to 800 MeV
• Multipole analysis of pion photoproduction based on fixed t dispersion relations and unitarity
• The helicity amplitudes A${}_{1/2}$ and A${}_{3/2}$ for the D${}_{13}(1520)$ resonance obtained from the $\vec{\gamma }\vec{p}\to p{\pi }^0$ reaction}
• Parameterisation of σ_{1/2}-σ_{3/2} for Q^2 \geq 0 and non-resonance contribution to the GDH sum rule
• Leading and higher twists in the proton polarized structure function at large Bjorken x
• The Drell-Hearn-Gerasimov Sum Rule
• The GDH sum rule for the deuteron

Cited by in corpus (2)

• SPring-8 LEPS2 beamline: A facility to produce a multi-GeV photon beam via laser Compton scattering
• The Gerasimov-Drell-Hearn sum-rule with nuclear targets