proton-to-electron mass ratio

Muller, Sébastien; Henkel, Christian, Strong Limit on a Variable Proton-to-Electron Mass Ratio from Molecules in the Distant Universe, Science, 2008-06-20

{\displaystyle 1/{\sqrt {3}}} 。 而凝聚态介质中的音速上限则可能取決於精細結構常數和質子電子質量比（英语：Proton-to-electron mass ratio），約等於每秒36公里。 在固體中有兩種可能的聲波，其中一種是與流體相同的縱波，另一種是流體沒有的橫波，兩種不同的聲波可

Two-photon laser spectroscopy of antiprotonic helium and the antiproton-to-electron mass ratio. Nature. 2011, 475 (7357): 484–8. PMID 21796208. doi:10.1038/nature10260

Muller, Sébastien; Henkel, Christian, Strong Limit on a Variable Proton-to-Electron Mass Ratio from Molecules in the Distant Universe, Science, 2008-06-20

ISBN 978-981-238-071-5.  Senjanovic, G. Probing the Origin of Neutrino Mass: from GUT to LHC. 2011. arXiv:1107.5322  [hep-ph].  Grossman, Y. TASI 2002 lectures