Dark Matter stability and boost factor from DM conversions Yu-Feng Zhou collaborators: Z.P.Liu, W.L.Guo,Y.L.Wu, C. Zhuang Institute of theoretical physics (ITP), Chinese Academy of Sciences (CAS). PRD79,055015(2009); PRD81,075014(2010) ArXiv: (PRD), work in progress The second DM/DE workshop, Nov.5, 2010

Outline Part-I: A model with dark matter stabilized by P and CP symmetries  The stability of DM  A LR model with DM stabilized by P and CP  Phenomenology: relic density & Direct detection  Dark matter decay through tiny C- breaking terms  Predictions for cosmic-ray neutrinos and diffuse gamma rays Part II: a scenario for large boost factor from DM conversion  Boost factor required by PAMELA/Fermi LAT  Boost factor from late time DM conversion  Numerical results  Simple models.

 Well known: R-parity, KK-parity, T-parity  Kadastik, Kanikel, Raidal 09 ’, Frigerio and Hambye 09 ’  Hidden sector U(1) symmetry exact U(1) Broken U(1): a massive Z ’, a scalar Symmetries for DM stability Ackerman,buckley,Carroll, Kamonkowski 08’ Feng, Tu, Yu 08’, Feng, Kaplinghat, Tu, Yu 09’ Foot etal. 10’ Pospelov, Ritz, voloshin 07’ Gpoalakrishnal,Jung,Wells 08’ Gpoalakrishnal,Lee,Wells 08’ Mambrini 10’ kinetic mixing Higgs portal kinetic mixing

 Large SU(2)_L multiplets (minimal DM)  Hidden custodial symmetry vector DM Custodial symmetry SU(2)_C keep vector bosons stable Cirelli, Fornengol, Strumia 06’ Cirelli, Strumia, Tamburini 07’ Hambye 08’

DM in minimal extensions of the SM SMScalar DM Extension to SM with scalar DM Silveira, Zee, 1985 McDondald, 1994, Burgess, Pospelov & Veldhuis, 2001 Barger,Langacker, KcCaskey, 2007 Shafi, Okada, 2009 He,Li, Tsai, 2007,2009 Left-Right ModelScalar DM Stability can be protected by P and CP Extension to LRM with scalar DM

A LR model with spontaneous P and CP violation  Gauge interaction: P- and CP-transformations Flavor contents Two bi-doublet required for spontaneous CP violation. Only one bi-doublet cannot give the correct CP phase

If P and CP are only broken spontaneously After EWSB S_D does not participate gauge Interactions, as it is gauge singlet Require that S_D does not develop a nonzero VEV  S_D a DM particle

Scalar interactions Guo, Wu, YFZ, PRD81, (2010)

DM annihilation Main annihilation channels Thermally averaged cross section & relic density

Relic density and direct detection  Parameter space from relic density  Prediction for direct detection rate one bi-doublet case two bi-doublet case Guo, Wang, Wu, YFZ, Zhuang,PRD79,055015(2009);

A special case: large Yukawa couplings to light quarks Relic density is dominated by heavy quark, not light ones DM-nucleus scattering is sensitive to light quark Yukawa couplings

DM decay through soft C-breaking terms  Including soft C-breaking term Guo, Wu, YFZ, PRD81, (2010) dominant part: C- and P-even tiny part: C-odd

 Decay through left-handed triplet can well explain the PAMELA/Fermi data Triplets with nonzero B-L number do not couple to quarks through Yukawa interactions Indirect channels WW, WZ, and ZZ suppressed by tiny triplet VEV required by neutrino masses.

Explain PAMELA data well. for all type of lepton final states. mu/tau final states favored by Fermi tau-lepton final states predict High neutrino-induced muon flux. PAMELA Fermi Guo, Wu, YFZ, PRD81, (2010) mass parameters Consider 3 cases with final states dominated by different lepton flavor

Predictions for up-going muon flux Triplets couple to neutrinos and charged-leptons with the same strength up-going muon flux can reach the current SK bound Guo, Wu, YFZ, PRD81, (2010)

Inverse Compton scattering (ICS) Final state radiation (FSI) Virtual internal bremsstrahlung (VIB) ICS FSI VIB ICS FSI VIB Diffuse gamma-rays SH-III caseLH-III case Guo, Wu, YFZ, PRD81, (2010) ICS FSI VIB

Summary of part I  We have proposed a LR model with scalar DM candidate stabilized by C and CP-symmetries.  Tiny DM particle decay is induced through adding tiny soft C-violation interactions.  the DM particle can decay trough SU(2)_L triplet scalars which couple mostly to leptons.  The model predicts large neutrino-induced muon flux for certain leptonic final states. The model also predict new sources for very high energy gamma-rays, favorably in the ~ TeV region.

Boot factor from DM conversions  Part-II Liu, YFZ, Wu, work in progress

The boost factor problem  The std. WIMP annihilation cross section is too small to account for the PAMELA/Fermi data  Positron flux  Boost factor Bergstrom, Edsjo, Zaharijas, PRL103,031103,09’

Boot factor for DM annihilation  Local clumps Via Lactea II: in subhalo? B~ 4-15,  Temperature-dependent ann. cross section Sommerfeld enhancement Resonance enhancement  Non-thermal origin of DM DM may decay rather than annihilate Possible origins of boost factor Diemand, et al, , Nature Sommerfeld, Ann. Phy 403, 257 (1931).

The Sommerfeld effect A. Sommerfeld, Annalen der Physik 403, 257 (1931). J. Hisano, S. Matsumoto and M. M. Nojiri, Phys. Rev. D 67 (2003) Phys. Rev. Lett. 92, (2004)

Constraints from relic density J. L. Feng, M. Kaplinghat and H. B. Yu, Phys. Rev. Lett. 104, (2010) Irreducible process

Constraints from relic density Other constraints Halo shape CMB, protohalo Refined analysis at freeze-out Cut-off of resonance, recoupling Force-carrier production & decay rates Kinetic decoupling Self-interaction efficiency, non-thermality J. Zavala, M. Vogelsberger and S. D. M. White, Phys. Rev. D 81, (2010) M. Kamionkowski and S. Profumo, Phys. Rev. Lett. 101, (2008) J. L. Feng, M. Kaplinghat and H. B. Yu, Phys. Rev. Lett. 104, (2010) arXiv:

Multi-component DM and the boost factor  Multi-component DM Models with hidden sectors naturally have multi-DM DM may have SUSY partners Neutrinos are already (tiny) part of DM  No boost from simply mixed thermal DM Large boost requires 1. Large annihilation cross section 2. Still the correct relic density Impossible for thermal DM ? For thermal relic

Correlated thermal evolution In the case of interacting multi-component DM  Thermal evolution for interacting DM  Two component case (s-wave) ( Kinetic equilibrium assumed )

The conversion term  The role of Keep the DM in chemical equilibrium Convert the heavy DM into the light

Stages of the thermal evolution 1.Thermal equilibrium 2.Departure from thermal equilibrium 3.Late time DM conversion when z is large Slow conversion characterized by r(z) Crossing point 4.Freeze-out after

The boost factor  Evolution of the total density  Late time evolution

Numerical results B~150 B~1000 no conversion With conversion Large boost factor if mass diff. is small

Numerical results B vs mass difference B vs relative cross sections

A simple model Add to the SM 

Cross sections & boost factor  Internal degree of freedom  cross sections  Parameter set  Cross sections  Boost factors For near resonance case, all couplings can be smaller

Summary of part II  In multi-DM models, DM conversion can significantly modify the thermal evolution of each DM component.  The relic density of the DM component may not always inversely proportional to it ’ s annihilation cross section. Through conversions from heavier DM components, the relic density of light DM can be enhanced, leading to large boost factors.  The boost is mostly temperature independent. For generic models with large conversion rate the boost fact can reach ~ Thank You !

backups

Positron signals  Diffusion eq. Background Sources from DM decay

The Sommerfeld enhancement Sommerfeld enhancement factor S: N. Arkani-Hamed, et al, Phys. Rev. D 79, (2009)

KITPC 2011 program Dark matter and new physics Sept. 21-Nov. 06, 2011 (7-week) International Coordinators: Shafi, Qaisar (Delaware), Shafi, Qaisar (Delaware), Aprile, Elena (Columbia U.) Aprile, Elena (Columbia U.) Wang, Tsz-king Henry(IOP,) Wang, Tsz-king Henry(IOP,) Wefel, John (Louisiana State U.) Wefel, John (Louisiana State U.) Matsumoto, Shigeki (IPMU), Matsumoto, Shigeki (IPMU), Su, Shu-Fang (Arizona U.) Su, Shu-Fang (Arizona U.) Geng, Chao-Qiang ( NCTS ), Geng, Chao-Qiang ( NCTS ), Local Coordinators: Bi, Xiao-Jun (IHEP) Ni, Kai-Xuan (SJTU) Yang, Chang-Geng (IHEP) Yue, Qian (Tsinghua U.) Zhou, Yu-Feng (ITP )