Implementation of Skewed Gaussian Fitting for Phase-Imaging Ion-Cyclotron-Resonance Calculations*

Atomic masses are one of the fundamental properties of atomic nuclei, and their measurement provides access to information on nuclear binding energies, nuclear states, and nuclear reaction Q-values. This has applications as varied as neutrino physics, inputs to nuclear astrophysics models, and the search for beyond-the-Standard Model physics, all of which need precise and accurate mass measurements. Hence, the Canadian Penning Trap (CPT) at Argonne National Laboratory has measured the masses of over 300 isotopes produced by the CAlifornium Rare Isotope Breeder Upgrade (CARIBU) ²⁵²Cf spontaneous fission source using the Phase-Imaging Ion-Cyclotron- Resonance (PI-ICR) technique. However, PI-ICR data can sometimes have a tail behind the cluster of ions that can arise from many different sources such as ion-ion interactions, incomplete excitations, poorly-tuned beams, or temporal drifts in the system during the measurements. I will present results of the analysis of measurements of masses of Sn, Sb, Te, and I isotopes and isomers around A≈130, alongside my implementation of a skewed Gaussian fitting model in an attempt to improve the precision of the analysis by accounting for the tail.