For all of you that suddenly awaken at night (in a cold sweat) because you forgot your SM particle masses, make sure to check out the PDG page for a refresher.
One can explain the birefringence seen in the quasar polarizations as a photon / axion coupling constant (see equation 9 of astro-ph/0607294 a very interesting paper which references the 355 quasar paper Dorigo talks about). The coupling constant works out to be 3.8 x 10^-6/GeV. The Fermi coupling constant is 1.16637 x 10^{-5}/GeV^2. To get a dimensionless constant from them compute:
(1.17 x 10^-5) /(3.8 x 10^-6)^2 = 810000 = (3.1^6)^2
In other words, the ratio of the coupling constants is reasonably close to a power of 729, at least compared to 729. To fix it exactly, and to make a prediction of the p/a coupling constant, one puts 729^2 = 531441 and gets a photon / axion coupling constant of 4.6 x 10^-6, probably within measurement error of the value reported above.
5 comments:
Hee, hee! Good to see you blogging, kneemo.
kneemo, the dark purple on black is a bit difficult to read. Nice colour scheme, though.
The PDG data are shot through with unusual coincidences with powers of 27. My latest commentary on this is here.
Blue looks much better. Thanks.
One can explain the birefringence seen in the quasar polarizations as a photon / axion coupling constant (see equation 9 of astro-ph/0607294 a very interesting paper which references the 355 quasar paper Dorigo talks about). The coupling constant works out to be 3.8 x 10^-6/GeV. The Fermi coupling constant is 1.16637 x 10^{-5}/GeV^2. To get a dimensionless constant from them compute:
(1.17 x 10^-5) /(3.8 x 10^-6)^2 = 810000 = (3.1^6)^2
In other words, the ratio of the coupling constants is reasonably close to a power of 729, at least compared to 729. To fix it exactly, and to make a prediction of the p/a coupling constant, one puts 729^2 = 531441 and gets a photon / axion coupling constant of 4.6 x 10^-6, probably within measurement error of the value reported above.
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