[Shape-univ] INTEGRAL/SPI: first 511keV-photograph of dark matter halo?

[Bartosz Lew]

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.