Neutron halo and the impact-parameter dependence of the ${\pi }^{+}-{\pi }^{-}$ asymmetry in heavy ion collisions

Abstract

The theoretical nuclear physics predictions and experimental results on antiprotonic atoms lead to different proton and neutron spatial distributions. At CERN SPS energies production of positive and negative pions differs for $pp$, $pn$, $np$ and $nn$ scattering. These two facts lead to an impact parameter dependence of the ${\pi }^{+}$ to ${\pi }^{-}$ ratio in ${}^{208}Pb{+}^{208}Pb$ collisions. A recent experiment at CERN seems to confirm qualitatively these predictions. The results for two models considered are almost identical. It may open a new possibility for determination of neutron density distribution in nuclei.

arXiv comment9 pages, including 4 figures

References in corpus (6)

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• Parity Violating Measurements of Neutron Densities
• Nuclear Skins and Halos in the Mean-Field Theory
• Hartree Fock Calculations in the Density Matrix Expansion Approach
• Neutron Densities from a Global Analysis of Medium Energy Proton Nucleus Elastic Scattering
• Nucleon density in the nuclear periphery determined with antiprotonic x-rays: cadmium and tin isotopes

Cited by in corpus (4)

• The Spectator Electromagnetic Effect on Charged Pion Spectra in Peripheral Ultrarelativistic Heavy-Ion Collisions
• Paramaterizations of inclusive cross sections for pion production in proton-proton collisions. II. Comparison to new data
• The effect of the spectator charge on the charged pion spectra in peripheral ultrarelativistic heavy-ion collisions
• Unlocking the initial neutron density distribution from the two-pion HBT correlation function in heavy-ion collisions