| Zugriffsnummer | 22649 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Laboratory limits for temporal variations of fundamental constants: an update |
| Autor(in); Institution |
Peik, Ekkehard; 4.4, Zeit und Frequenz, PTB-Braunschweig
Lipphardt, Burghard; 4.4, Zeit und Frequenz, PTB-Braunschweig
Schnatz, Harald; 4.3, Quantenoptik und Längeneinheit, PTB-Braunschweig
Tamm, Christian; 4.4, Zeit und Frequenz, PTB-Braunschweig
Weyers, Stefan; 4.4, Zeit und Frequenz, PTB-Braunschweig
Wynands, Robert; 4.4, Zeit und Frequenz, PTB-Braunschweig
|
| Quelle/Jahr | The Eleventh Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Gravitation and Relativistic Field Theories : proceedings of the MG11 Meeting on General Relativity. Part A:(2008), 941 - 951 |
| Herausgeber(in) |
Kleinert, Hagen
|
| ISBN | 981-283-427-3 ; 978-981-283-427-0 |
| Verlag | New Jersey [u.a.]: World Scientific |
| Konferenzangaben | Marcel Grossmann Meeting, Berlin, 23-29, July, 2006, Germany |
| Freie Schlagworte | atomic frequency standards ; frequency measurements ; fundamental constants |
| Zusammenfassung | Precision comparisons of different atomic frequency standards over a period of a few years can be used for a sensitive search for temporal variations of fundamental constants. We present recent frequency measurements of the 688 THz transition in the 171Yb+ ion. For this transition frequency a record over six years is now available, showing that a possible frequency drift relative to a cesium clock can be constrained to (-0.54 ± 0.97) Hz/yr, i.e. at the level of 2·10-15 per year. Combined with precision frequency measurements of an optical frequency in 199Hg+ and of the hyperfine ground state splitting in 87Rb, a stringent limit on temporal variations of the fine structure constant α: d ln α/ dt = (-0.26 ± 0.39) ·10-15 yr-1 and a model-dependent limit for variations of the proton-to-electron mass ratio μ in the present epoch can be derived: d ln μ /dt= (-1.2 ± 2.2) ·10-15 yr-1. We discuss these results in the context of astrophysical observations that apparently indicate changes in both of these constants over the last 5-10 billion years. |
