Neutron-proton bremsstrahlung from intermediate energy heavy-ion reactions as a probe of the nuclear symmetry energy?

Abstract

Hard photons from neutron-proton bremsstrahlung in intermediate energy heavy-ion reactions are examined as a potential probe of the nuclear symmetry energy within a transport model. Effects of the symmetry energy on the yields and spectra of hard photons are found to be generally smaller than those due to the currently existing uncertainties of both the in-medium nucleon-nucleon cross sections and the photon production probability in the elementary process $pn\to pn\gamma$. Very interestingly, nevertheless, the ratio of hard photon spectra $R_{1/2}(\gamma )$ from two reactions using isotopes of the same element is not only approximately independent of these uncertainties but also quite sensitive to the symmetry energy. For the head-on reactions of ${}^{132}Sn{+}^{124}Sn$ and ${}^{112}Sn{+}^{112}Sn$ at $E_{beam}/A=50$ MeV, for example, the $R_{1/2}(\gamma )$ displays a rise up to 15% when the symmetry energy is reduced by about 20% at $\rho =1.3{\rho }_0$ which is the maximum density reached in these reactions.

arXiv commentAdded new results in Fig. 6 and new references [27.28]. Phys. Lett. B in press

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Cited by in corpus (17)

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• Probing isospin- and momentum-dependent nuclear effective interactions in neutron-rich matter
• Probing nuclear symmetry energy at high densities using pion, kaon, eta and photon productions in heavy-ion collisions
• Imprints of high-momentum nucleons in nuclei on hard photons from heavy-ion collisions around the Fermi Energy
• The interplay of short-range correlations and nuclear symmetry energy in hard photon productions from heavy-ion reactions at Fermi energies
• In-medium and isospin effects on particle production near threshold energies in heavy-ion collisions
• Constraining nucleon high momentum in nuclei
• A direct probe of the in-medium pn scattering cross section
• Decomposition of sensitivity of the symmetry energy observables
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• A CsI hodoscope on CSHINE for Bremsstrahlung γ-rays in Heavy Ion Reactions
• Preequilibrium particle emissions and in-medium effects on the pion production in heavy-ion collisions
• Effects of neutron-skin thickness on direct hard photon emission from reactions induced by the neutron-rich projectile ${}^{50}$Ca
• Determination of the density region of the symmetry energy probed by the ${\pi }^{-}/{\pi }^{+}$ ratio
• Measurement of the high energy $\gamma$-rays from heavy ion reactions using Čerenkov detector
• Initialization effect in heavy-ion collisions at intermediate energies
• The "ab initio" approach to the nuclear equation of state: review and discussion