Abstract
Many neutron star properties, such as the proton fraction, reflect the symmetry energy contributions to the equation of state that dominate when neutron and proton densities differ strongly. To constrain these contributions at suprasaturation densities, we measure the spectra of charged pions produced by colliding rare isotope tin (Sn) beams with isotopically enriched Sn targets. Using ratios of the charged pion spectra measured at high transverse momenta, we deduce the slope of the symmetry energy to be . This value is slightly lower but consistent with the values deduced from a recent measurement of the neutron skin thickness of .
- Received 26 January 2021
- Revised 8 March 2021
- Accepted 22 March 2021
DOI:https://doi.org/10.1103/PhysRevLett.126.162701
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