Evidence for a breakdown of the isobaric multiplet mass equation: A study of the A=35,T=3/2 isospin quartet

Abstract

Mass measurements on radionuclides along the potassium isotope chain have been performed with the ISOLTRAP Penning trap mass spectrometer. For K35 (T1/2=178 ms) to K46 (T1/2=105 s) relative mass uncertainties of 2×10-8 and better have been achieved. The accurate mass determination of K35 (δm=0.54 keV) has been exploited to test the isobaric multiplet mass equation for the A=35,T=3/2 isospin quartet. The experimental results indicate a deviation from the generally adopted quadratic form. © 2007 The American Physical Society.