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Hidden Charged Dark Matter

Hidden Charged Dark Matter. Hai-Bo Yu University of California, Irvine Talk given at PHENO 05/11/2009. Jonathan L. Feng, Huitzu Tu and HBY JCAP 0810:043,2008. arXiv:0808.2318 [hep-ph] Jonathan L. Feng, Huitzu Tu, Manoj Kaplinghat and HBY, coming soon. Outline.

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Hidden Charged Dark Matter

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  1. Hidden Charged Dark Matter Hai-Bo Yu University of California, Irvine Talk given at PHENO 05/11/2009 Jonathan L. Feng, Huitzu Tu and HBY JCAP 0810:043,2008. arXiv:0808.2318 [hep-ph] Jonathan L. Feng, Huitzu Tu, Manoj Kaplinghat and HBY, coming soon.

  2. Outline • Motivation: Hidden charged dark matter from WIMPless model. • Cosmology and constraints of hidden charged dark matter • Small structure formation . • Bound state formation in the early Universe. • Primordial halo (z~200): Sommerfeld enhanced annihilation. • Galaxy (z~0): shape of dark matter halo and long range force. • Summary

  3. Hidden sectors • ~20% of total mass is dark. • But what do we really know about dark matter? ---Gravitational , No EM, Tight constraint of strong interaction. ---Dark matter could be SM neutral, i.e. hidden. • Hidden sector dark matter? ---WIMP miracle? ---Connect to hierarchy problem? ---prediction?

  4. WIMPless Miracle • the ratio is important • SUSY partner mass of GMSB • The ratio is determined solely by the SUSY breaking factor Feng, Kumar (2008) Model building and thermal history of hidden sectors, see Feng, Tu and Yu (2008) One can rescale (mx, gx) simultaneously while keep the ratio unchanged.

  5. Hidden charged dark matter from WIMPless DM model Feng, Tu and Yu (2008) • The model is anomaly-free, and chiral. We take SM-like gauge group SU(3)×SU(2)×U(1) for hidden sector. Unbroken hidden U(1)EM. • The model has one generation of matter field and is flavor-free. • All Yukawa couplings are order 1 and the model has only one scale mx with slight mass splittings. • Dark matter is hidden CHARGED!

  6. Thermal relics in hidden sectors

  7. Effects of long-range self-interactions • Small structure formation. • DM particles may form bound state. • Enhanced annihilation in primordial halos. • Galaxy shape and bullet cluster.

  8. Matter power spectrum and the smallest halo masses Feng, Tu, Kaplinghat and Yu (2009). • Small structure formation for hidden charged dark matter: • No Problem!

  9. Bound state formation (Sommerfeld enhanced annihilation) • For the Galactic Halo, the bound state formation rate is order magnitude 10^(-31) per second. • For the early Universe, we need to make sure For dark mass smaller than a few TeV, the bound state formation rate is much smaller than expansion rate. Feng, Tu, Kaplinghat and Yu (2009).

  10. Enhanced annihilation in the primordial halos (redshift~200) • Sommerfeld enhancement: if there is long range attraction force between two particles, the annihilation cross section will be enhanced. • This enhancement is not important in very early Universe.

  11. Small velocity dispersion in primordial halos (redshift~200) • Protohalos have masses around • Protohalos collapse to • The velocity dispersion is • Annihilation cross section is strongly enhanced due to the small velocity dispersion.

  12. Bounds from CMB • The annihilation generate photons. However it does not distort the CMB spectrum because it is hidden. • The total relics are SAFE from the bound state formation and Sommerfeld enhanced annihilation. Feng, Tu, Kaplinghat and Yu (2009).

  13. Galaxy Shape and Bullet Cluster • Scattering due to the Coulomb interaction • The cross section has 1/v dependence. For galaxy V~10^(-3) , a huge factor! DM has collision. • However observations suggest that DM is effectively collisionless. The collision of DM cause the more spherical halo. • Galactic dynamics. Demanding the relaxation time is larger than the age of Univerise. • Bullet cluster. Demanding that fraction of particle loss be no greater than 30%.

  14. Feng, Tu, Kaplinghat and Yu (2009). • Galactic dynamics and bullet clusters in fact allow hidden charged dark matter, and the allowed parameter space is quite reasonable. • Typically for DM particle mass 100GeV, the hidden fine structure constant should be smaller than ~0.0001 to satisfy the bound. The lower mass limit can reach ~1GeV for hidden charged DM naturally. See also L. Ackerman, M. R. Buckley, S. M. Carroll and M. Kamionkowski (2008)

  15. Summary Hidden charged DM is well motivated in WIMPless framework. • Small structure formation. • Bound state formation and Sommerfeld ehanced annihilation. • Galatic dynamics. • Bullet cluster. Hidden charged dark matter is allowed !

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