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:1008.4479 (PRD),

work in progress

The second DM/DE workshop, Nov.5, 2010

Outline

 

Part-I: by P and CP symmetries



A model with dark matter stabilized

The stability of DM   A LR model with DM stabilized by P and CP Phenomenology: relic density & Direct detection  

Part II: from DM conversion



a scenario for large boost factor

Boost factor required by PAMELA/Fermi LAT    Dark matter decay through tiny C- breaking terms Predictions for cosmic-ray neutrinos and diffuse gamma rays Boost factor from late time DM conversion Numerical results Simple models .

Symmetries for DM stability

 

Well known: R-parity, KK-parity, T-parity Kadastik, Kanikel, Raidal 09 ’ , Frigerio and Hambye 09

’ 

Hidden sector U(1) symmetry

 exact U(1)

Ackerman,buckley,Carroll, Kamonkowski 08’ Feng, Tu, Yu 08’, Feng, Kaplinghat, Tu, Yu 09’ Foot etal. 10’

 kinetic mixing Broken U(1): a massive Z ’ , a scalar

Pospelov, Ritz, voloshin 07’ Gpoalakrishnal,Jung,Wells 08’ Gpoalakrishnal,Lee,Wells 08’ Mambrini 10’

Higgs portal kinetic mixing



Large SU(2)_L multiplets (minimal DM) Cirelli, Fornengol, Strumia 06’ Cirelli, Strumia, Tamburini 07’



Hidden custodial symmetry vector DM

Custodial symmetry SU(2)_C keep vector bosons stable

Hambye 08’

DM in minimal extensions of the SM

Extension to SM with scalar DM

SM Scalar DM

Silveira, Zee, 1985 McDondald, 1994, Burgess, Pospelov & Veldhuis, 2001 Barger,Langacker, KcCaskey, 2007 Shafi, Okada, 2009 He,Li, Tsai, 2007,2009 Extension to LRM with scalar DM

Left-Right Model Scalar DM

Stability can be protected by P and CP

A LR model with spontaneous P and CP violation  Gauge interaction: Flavor contents  

Two bi-doublet required for spontaneous CP violation.

Only one bi-doublet cannot give the correct CP phase

P- and CP-transformations

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, PRD81,075014 (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

Guo, Wu, YFZ, PRD81,075014 (2010)

 Including soft C-breaking term

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.

mass parameters Guo, Wu, YFZ, PRD81,075014 (2010) Consider 3 cases with final states dominated by different lepton flavor PAMELA

  

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

.

Fermi

Predictions for up-going muon flux

Triplets couple to neutrinos and charged-leptons with the same strength

Guo, Wu, YFZ, PRD81,075014 (2010)

up-going muon flux can reach the current SK bound

Diffuse gamma-rays

LH-III case

Inverse Compton scattering ( ICS ) ICS FSI VIB Final state radiation ( FSI )

SH-III case

ICS FSI VIB Virtual internal bremsstrahlung ( VIB ) ICS FSI VIB ICS FSI VIB Guo, Wu, YFZ, PRD81,075014 (2010)

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.



Part-II Boot factor from DM conversions

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

Bergstrom, Edsjo, Zaharijas, PRL103,031103,09’

 Boost factor

Possible origins of boost factor

Boot factor for DM annihilation  Local clumps Via Lactea II: in subhalo? B~ 4-15,

Diemand, et al, 0805.1244, Nature

 Temperature-dependent ann. cross section  Sommerfeld enhancement

Sommerfeld, Ann. Phy 403, 257 (1931).

  Resonance enhancement Non-thermal origin of DM DM may decay rather than annihilate

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, 031303 (2004 )

Constraints from relic density

J. L. Feng, M. Kaplinghat and H. B. Yu, Phys. Rev. Lett. 104, 151301 (2010)

Irreducible process

Constraints from relic density J. L. Feng, M. Kaplinghat and H. B. Yu, Phys. Rev. Lett. 104, 151301 (2010) arXiv:1005.4678

Refined analysis at freeze-out

• • Cut-off of resonance, recoupling • Force-carrier production & decay rates Kinetic decoupling • Self-interaction efficiency, non-thermality

Other constraints

•Halo shape •CMB, protohalo J. Zavala, M. Vogelsberger and S. D. M. White, Phys. Rev. D 81, 083502 (2010) M. Kamionkowski and S. Profumo, Phys. Rev. Lett. 101,261301 (2008)

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 For thermal relic

Large boost requires

1.

Large annihilation cross section 2. Still the correct relic density Impossible for thermal DM ?

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

Large boost factor if mass diff. is small

B~150 With conversion no conversion B~1000

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  Parameter set  cross sections  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 ~100-1000. Thank You !

backups

Positron signals

 Diffusion eq.

Sources from DM decay Background

The Sommerfeld enhancement

N. Arkani-Hamed, et al, Phys. Rev. D 79, 015014(2009) Sommerfeld enhancement factor S:

KITPC 2011 program

Dark matter and new physics

Sept. 21-Nov. 06, 2011 (7-week)

International Coordinators:

       Shafi, Qaisar Aprile, Elena (Delaware), (Columbia U.) Wang, Tsz-king Henry(IOP, ) Wefel, John (Louisiana State U.) Matsumoto, Shigeki Su, Shu-Fang (IPMU), (Arizona U.) Geng, Chao-Qiang ( NCTS ),

Local Coordinators:

     Bi, Xiao-Jun (IHEP) Ni, Kai-Xuan (SJTU) Yang, Chang-Geng Yue, Qian (IHEP) (Tsinghua U.) Zhou, Yu-Feng (ITP )