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Mass Splittings and Ghost Tadpoles

Ball, J. S. and Zachariasen, F. (1969) Mass Splittings and Ghost Tadpoles. Physical Review, 177 (5). pp. 2264-2272. ISSN 0031-899X. doi:10.1103/PhysRev.177.2264.

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The neutron-proton mass difference is expressed, on the assumption that it is purely electromagnetic in origin, in terms of partial-wave amplitudes for the process NN→γγ at zero total energy, and also in terms of the single n=0, M=0 O(4) amplitude for the same process. This representation allows quite directly a qualitative understanding of the sign of the n-p mass difference, and also allows, with more drastic assumptions, an approximate numerical evaluation of the mass difference based on experimentally determined parameters from the A_2 Regge trajectory. This numerical estimate is in reasonable agreement with experiment. The approach is easily generalized to other electromagnetic mass differences, and is shown to yield the tadpole model.

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Additional Information:© 1969 American Physical Society. Received 11 September 1968; published in the issue dated January 1969. Work supported in part by the National Science Foundation, and by the U. S. Atomic Energy Commission under Contract No. AT(11-1)-68 of the San Francisco Operations office, U. S. Atomic Energy Commission. Finally, we wish to express our gratitude for the hospitality of the Aspen Center for Physics, where the major part of this work was carried out, and to Professor W. Frazer and Professor D. Geffen for some valuable comments.
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Atomic Energy CommissionAT(11-1)-68
Issue or Number:5
Record Number:CaltechAUTHORS:20120815-120523899
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Official Citation:Mass Splittings and Ghost Tadpoles J. S. Ball and F. Zachariasen pp. 2264-2272
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:33218
Deposited By: Ruth Sustaita
Deposited On:15 Aug 2012 21:39
Last Modified:09 Nov 2021 21:33

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