Collapse and the Tritium Endpoint Pileup

The beta-decay of a tritium nucleus produces an entangled quantum system, a beta electron, a helium nucleus, and an antineutrino. For finite collapse times, the postcollapse beta electron energy can originate from a range of pre-collapse energies due to the uncertainty principle. Long collapse times give negligible uncertainty, so the pre-collapse spectrum must approach that of isolated nuclei. We calculate the postcollapse electron spectrum which shows a collapse-dependent pileup near the endpoint. Comparison with observation shows that a collapse time of 1 x 10−17 s explains the observed pileup. The collapse of the entangled quantum system must be triggered by the environment: most likely an atomic (molecular) electron initially bound to the atomic (molecular) tritium source or perhaps ambient gas molecules. Coincidentally, the 40 eV tritium atom-helium ion energy level shift is unobservably small for times shorter than the system collapse time. We conclude that an atomic (molecular) electron triggers the collapse once the 40 eV shift becomes detectible and the electron detects the helium nucleus. Thus collapse may explain the tritium endpoint pileup. [Version 1.0, ‘Collapse Accounts for More at the Endpoint’, prepared for the Fall Meeting of the New England Section of the American Physical Society at the University of New Hampshire, Durham, NH. Version 1.1 posted post-meeting at www.public.wit.edu/faculty/shurtleffr/. This is version 2.0.] PACS number(s): 14.60.Pq and 23.40.-s