You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Extending to higher mass values with gas filling<br />
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany<br />
PONT d‘Avignon, 21-25 April 2008, Avignon, France<br />
<strong>Axion</strong>-photon transition probability<br />
⎛ g<br />
γB<br />
2<br />
a ⎞<br />
⎛<br />
⎞<br />
= ⎜ ⎟<br />
2 qL<br />
Pa<br />
→γ<br />
sin<br />
⎜<br />
⎟ ⎝<br />
q<br />
⎠<br />
⎝<br />
2<br />
⎠ <strong>Axion</strong>-photon momentum transfer<br />
m<br />
2<br />
m<br />
2<br />
a − γ<br />
q<br />
=<br />
2E<br />
Transition suppressed for qL ≳ 1<br />
Gas filling: Give photons a refractive<br />
mass to restore full transition strength<br />
(~ MSW effect)<br />
2<br />
4<br />
πα<br />
m<br />
γ =<br />
n<br />
e<br />
(n m<br />
e electron density)<br />
e<br />
Z<br />
m<br />
γ<br />
=<br />
28.9 eV<br />
ρ<br />
Gas<br />
A<br />
He 4 vapour pressure at 1.8 K<br />
ρ<br />
≈<br />
0 .2<br />
×<br />
10<br />
−<br />
3 g<br />
cm<br />
−<br />
3<br />
m γ<br />
=<br />
0.26<br />
eV
Change language