MASS MEASUREMENT OF 45 Cr AND ITS IMPACT ON THE Ca-Sc CYCLE IN X-RAY BURSTS

Masses of neutron-deficient 58 Ni projectile fragments have been measured at the HIRFL-CSR facility in Lanzhou, China employing the isochronous mass spectrometry technique. Masses of a series of short-lived T z = −3/2 nuclides including the 45 Cr nucleus have been measured with a relative uncertainty of about 10 −6 –10 −7 . The new 45 Cr mass turned out to be essential for modeling the astrophysical rp -process. In particular, we find that the formation of the predicted Ca–Sc cycle in X-ray bursts can be excluded.