Sensitivity of Ti-44 and Ni-56 production in shock-driven nucleosynthesis to nuclear reaction rate variations and the case of 39K(p,g)40Ca.

Recent observational advances have enabled high resolution mapping of Ti-44 in core-collapse supernova (CCSN) remnants. Comparisons between observations and 3D models provide stringent constraints on the CCSN mechanism. However, recent work has identified several uncertain nuclear reaction rates that influence Ti-44 and Ni-56 production in model calculations of shock-driven nucleosynthesis. We evolved 15M, 18M, 22M and 25M stars from ZAMS to CCSN in MESA (Modules for Experiments in Stellar Astrophysics) and investigated previously identified sensitivities of Ti-44 and Ni-56 production in CCSN to varied reaction rates. I will present our final results of this sensitivity study. I will also briefly discuss the current analysis status of direct cross section measurement of 39K(p,g) which is motivated by the sensitivity study.