hi all,
- introduction
LDM hypothesis to explain INTEGRAL/SPI => mass estimated < 100 MeV => "scalar particle" coupled to light Z' boson
sections 2, 3, 4 lead to:
5.1 "scalar particle" coupled to light Z' boson AND "scalar particle" coupled to heavy fermion
6.3 there is some small difference f(10^{-11}) [the function f is not given]
between alpha measured by the Quantum Hall experiment
http://en.wikipedia.org/wiki/Quantum_Hall_effect
and a "theoretical" estimate made assuming the standard model of p.p. including QED and the results of the "g-2" muon experiments related to supersymmetry testing:
http://en.wikipedia.org/wiki/Supersymmetry#Muon_g.E2.88.922_experiment
The authors say that this difference could be due to different precision levels in the QH versus the experiments contributing to the QED "theoretical" estimate.
Equality between the two is obtained for m_LDM \sim 3-9 MeV.
In other words: the QH and g-2 experiments give different results for alpha. The difference is not (yet) statistically significant, but a light scalar coupled to a heavy particle, needed for the LDM hypothesis, would give this difference for m_LDM \sim 3-9 MeV. (The real mass might be higher since this assumes smooth distribution of matter in the DM halo, ignores the fact that some part of the emission might be from point sources, etc.)
still it's elusive to me, but if I understand correctly you say only about two different , and possibly giving different results, methods of measuring alpha. where is the part about it's evolution ? and the alpha is made of three fundamental physical constants: due to change of which one is the hypotetised evolution ascribed to ?
So improvements in the QH effect experiments could support the LDM hypothesis and explain the present possible discrepancy in alpha estimates.
This is, coincidentally(?), roughly on the same order of magnitude as the alpha evolution claims in quasar absorption systems, since the QSO claims were of order 10^{-6} or over \sim 5 billion yr or so, and if convert this to 8kpc = 3000yr then we get
delta(alpha)/alpha \sim 10^{-12} between the Sun and the GC.
hmm, so this is about the evolution but, this is a different experiment.
However, the last i remember of the QSO abs sys alpha evolution claims they were no longer looking interesting (one of Srianand's papers is pretty convincing - look in shape-univ and/or cosmo-torun archives... :). In any case, a more precise calculation would be needed to see if these really are on the same scale or whether i've rounded off too many orders of magnitude.
well, anyway it's interesting enough to read more about over a morning coffee :))
pozdr. bartek.