scholarly journals Impact of instrumental systematic errors on fine-structure constant measurements with quasar spectra

2014 ◽  
Vol 447 (1) ◽  
pp. 446-462 ◽  
Author(s):  
J. B. Whitmore ◽  
M. T. Murphy
Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 344
Author(s):  
T. D. Le

Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.


2001 ◽  
Vol 327 (4) ◽  
pp. 1223-1236 ◽  
Author(s):  
M. T. Murphy ◽  
J. K. Webb ◽  
V. V. Flambaum ◽  
C. W. Churchill ◽  
J. X. Prochaska

2019 ◽  
Vol 218 ◽  
pp. 02012
Author(s):  
Graziano Venanzoni

I will report on the recent measurement of the fine structure constant below 1 GeV with the KLOE detector. It represents the first measurement of the running of α(s) in this energy region. Our results show a more than 5σ significance of the hadronic contribution to the running of α(s), which is the strongest direct evidence both in time-and space-like regions achieved in a single measurement. From a fit of the real part of Δα(s) and assuming the lepton universality the branching ratio BR(ω → µ+µ−) = (6.6 ± 1.4stat ± 1.7syst) · 10−5 has been determined


2012 ◽  
Vol 85 (10) ◽  
Author(s):  
Eloisa Menegoni ◽  
Maria Archidiacono ◽  
Erminia Calabrese ◽  
Silvia Galli ◽  
C. J. A. P. Martins ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document