Journal Article

FZJ-2015-02252

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Ab initio calculation of the neutron-proton mass difference

Borsanyi, S. ; Durr, S.FZJ* ; Fodor, Z. (Corresponding Author) ; Hoelbling, C. ; Katz, S. D. ; Krieg, S.FZJ* ; Lellouch, L. ; Lippert, T.FZJ* ; Portelli, A. ; Szabo, K.FZJ* ; Toth, B. C.

2015
American Association for the Advancement of Science64196 Washington, DC [u.a.]

This record in other databases:      

Please use a persistent id in citations: http://hdl.handle.net/2128/10212  doi:10.1126/science.1257050

Abstract: The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14% of the average of the two masses. A slightly smaller or larger value would have led to a dramatically different universe. Here, we show that this difference results from the competition between electromagnetic and mass isospin breaking effects. We performed lattice quantum-chromodynamics and quantum-electrodynamics computations with four nondegenerate Wilson fermion flavors and computed the neutron-proton mass-splitting with an accuracy of 300 kilo–electron volts, which is greater than 0 by 5 standard deviations. We also determine the splittings in the Σ, Ξ, D, and Ξcc isospin multiplets, exceeding in some cases the precision of experimental measurements.

Note: Preprint: http://arxiv.org/abs/arXiv:1406.4088

---

Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)

Research Program(s):

1. 511 - Computational Science and Mathematical Methods (POF3-511) (POF3-511)

Appears in the scientific report 2015

---

Database coverage:
; ; BIOSIS Previews ; Current Contents - Agriculture, Biology and Environmental Sciences ; Current Contents - Life Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; IF >= 30 ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection ; Zoological Record

---