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Abstract

Mass measurements with the ISOLTRAP mass spectrometer at CERN-ISOLDE improve mass uncertainties of neutron-deficient tin isotopes towards doubly magic ¹⁰⁰Sn. The mass uncertainty of ¹⁰³Sn was reduced by a factor of 4, and the new value for the mass excess of −67104(18) keV is compared with nuclear ab initio and density functional theory calculations. Based on these results and local trends in the mass surface, the masses of ^101,103Sn, as determined through their QEC values, were found to be inconsistent with the new results. From our measurement for ¹⁰³Sn, we extrapolate the mass excess of ¹⁰¹Sn to −60005(300) keV, which is significantly more bound than previously suggested. By correcting the mass values for ^101,103Sn, we also adjust the values of ¹⁰⁴Sb, ^105,107Te, ¹⁰⁸I, ^109,111Xe, and ¹¹²Cs near the proton drip line which are connected through their α and proton Q values. The results show an overall smoothening of the mass surface, suggesting the absence of deformation energy above the N = 50 shell closure.