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Limit on the temporal variation of the fine-structure constant using atomic dysprosium
A Cingöz1, A Lapierre, A-T Nguyen
1Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA.
Physical Review Letters
|March 16, 2007
Summary
Scientists monitored atomic dysprosium (Dy) isotopes to test the fine-structure constant (alpha). Measurements indicate no significant variation in alpha, setting new sensitivity limits for this fundamental constant.
Area of Science:
- Atomic Physics
- Metrology
- Fundamental Constants
Background:
- The fine-structure constant (alpha) is a fundamental constant in physics.
- Measuring its potential variation is crucial for testing fundamental theories.
- Atomic systems with opposite-parity levels offer unique sensitivity to alpha variations.
Purpose of the Study:
- To monitor transition frequencies in atomic dysprosium (Dy) isotopes.
- To constrain the rate of change of the fine-structure constant (alpha).
- To utilize a direct radiofrequency electric-dipole transition for precise measurements.
Main Methods:
- Monitoring of transition frequencies between nearly degenerate, opposite-parity levels in two Dy isotopes ((163)Dy and (162)Dy) over 8 months.
- Utilizing a radiofrequency electric-dipole transition to directly probe energy differences.
- Calculating the fractional variation of alpha based on measured frequency drifts.
Main Results:
- Measured frequency variations of 9.0+/-6.7 Hz/yr for (163)Dy and -0.6+/-6.5 Hz/yr for (162)Dy.
- Derived a fractional variation rate of alpha of (-2.7+/-2.6) x 10(-15) yr(-1) (1 sigma).
- Results indicate no significant variation of alpha at the current sensitivity level.
Conclusions:
- The study provides stringent limits on the variation of the fine-structure constant.
- The dysprosium system offers a promising approach for future precision measurements.
- Absence of significant variation supports the stability of fundamental constants.
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