Baryon Destruction by Asymmetric Dark Matter

Transcription

1 Baryon Destruction by Asymmetric Dark Matter Hooman Davoudiasl Brookhaven National Laboratory Based on: H. D., D. E. Morrissey, K. Sigurdson, and S. Tulin Phys.Rev.Lett. 105 (010) 11304, arxiv: [hep-ph] arxiv: [hep-ph] INFO 11, July 18-, Santa Fe, NM

2 Introduction DM: no SM candidate, unknown origin Visible matter: baryons (p, n) - Asymmetry: B 0, negligible cosmic anti-matter - Baryogenesis, Sakharov s conditions (i) B/ (ii) C/, CP/ (iii) / - Most likely requires new physics Observations: ρ DM 5ρ visible - Seemingly unrelated sectors - Suggests common asymmetric origin

3 Asymmetric Dark Matter Typically two broad classes (I) Charge asymmetry chemical equilibration Transfer operator O T connects two sectors. Charges freeze in after O T decouples (II) Equal and opposite DM and visible sector charges ( B=0) Hylogenesis ( hyle = matter) Non-equilibrium dynamics generates asymmetries Transfer operators remain decoupled to avoid washout In this talk, we will focus on option (II), hylogenesis.

4 A Concrete Model of Hylogenesis Basic idea HD, D. Morrissey, K. Sigurdson, S. Tulin, 010 Visible and hidden sectors charged under generalized B Non-thermal production of heavy fermions X, X; B(X)=+1 Quarks and DM couplings to X preserve B CP violation in X, X quarks, anti-quarks B(q) 0 CPT: X, X DM, anti-dm B(DM)= B(q) DM, quarks decoupled to avoid washout: typically low reheat temperature Symmetric populations annihilated efficiently n DM n visible Implications Nucleon destruction via inelastic scattering from DM: DM masses close to m N 1 GeV Induced Nucleon Decay (IND)

5 More Details: Dirac fermions X a, a=1,, Ψ, complex scalar Φ, B(X a )= [B(Ψ)+B(Φ)]=+1 m Ψ m Φ <m p + m e, m p m e < m Ψ + m Φ (Stability) X a couples to quarks via the neutron portal (dim-6) and DM (Yukawa): L λ a i jk M (X a,l dk R)(u i Rd j R )+ζ a(x a,l Ψ L + X a,r Ψ R )Φ+H.C. Visible baryon asymmetry: X 1 u d d Y X X 1 Φ u d d ε = 1 [ Γ(X1 udd) Γ( X 1 ūd d) ] m5 X 1 Im[λ1 λ ζ 1 ζ ] Γ X1 56π 3 ζ 1 M 4 m X U(1), Ψ,Φ charges ±e, kinetic mixing with U(1) Y : (κ/)b µν Z µν GeV-scale Z coupling to SM c W κ Q em e: Ψ, Φ thermalization, annihilation Example: Ψ Ψ Z Z σv = e 4 16π 1 m Ψ ( ) e 1 m Z /m Ψ ( cm 3 4 ( 3GeV /s) 0.05 m Ψ ) M. Pospelov, A. Ritz, M. Voloshin, 007

6 This proposal shares some elements with previous discussions, e.g.: Kitano, Low, hep-ph/ , hep-ph/050311; Farrar, Zaharijas, hep-ph/ ; Agashe, Servant, hep-ph/041154; Kaplan, Luty, Zurek, arxiv: [hep-ph]; An, Chen, Mohapatra, Zhang, arxiv: [hep-ph]; Allahverdi, Dutta, Sinha, arxiv: [hep-ph]. Some recent works on similar topics, e.g.: Shelton, Zurek, arxiv: [hep-ph]; Haba, Matsumoto, arxiv: [hep-ph]; Buckley, Randall, arxiv: [hep-ph]; M. Blennow, B. Dasgupta, E. Fernandez-Martinez, N. Rius, arxiv: [hep-ph]]; Hall, March-Russell, West, arxiv: [hep-ph]; Allahverdi, Dutta, Sinha, arxiv: [hepph]; Bell, Petraki, Shoemaker, Volkas, arxiv: [hep-ph]; Graesser, Shoemaker, Vecchi, arxiv: [hep-ph].

7 IND and Effective Nucleon Lifetime HD, D. Morrissey, K. Sigurdson, S. Tulin, 011 ΦN ΨM, ΨN Φ M p,n π,k,η p,n π,k,η n,σ 0,Λ 0 Ψ,Φ Φ, Ψ Ψ,Φ Φ, Ψ IND mimics standard nucleon decay (SND) N meson ν. Transfer operator O T cu i R d j R dk R Ψ R Φ+H.C., [c]= 3 L int = i c i O i ; I(O i )=(1/,0,1) O 1 = ε αβ γ Φ(u α R dβ R )(dγ R Ψ R) O = 1 6 ε αβ γ Φ[(d α R sβ R )(uγ R Ψ R)+(s α R uβ R )(dγ R Ψ R) (u α R dβ R )(sγ R Ψ R)] O 3 = 1 ε αβ γ Φ[(d α R s β R )(uγ R Ψ R) (s α Ru β R )(dγ R Ψ R)] L int = Tr(cO) c c 6 + c c 1 c 6 c c, O i j 1 ε αβγ ε jkl (q α Rk qβ Rl )(qγ ir Ψ R)Φ

8 SU(3) L SU(3) R chiral Lagrangian: L IND = β Tr[cξ (B R Ψ R )Φξ] M. Claudson, M. Wise, L. Hall, 198 ξ exp(im/ f), M = η 6 + π 0 π + K + π 6 η π 0 K K 0 K 0 3 η, B= Λ Σ0 Σ + p Λ0 6 Σ0 n Ξ Ξ 0 Σ 3 Λ0 f 140 MeV, β = 0.010(6) GeV 3 (Lattice) Y. Aoki et al., RBC-UKQCD Collaboration, 008 p meson 1 GeV, hence 1/ f expansion yields only order-of-magnitude estimate. Decay mode p SND M p IND M [up] pind M [down] τsnd N N π 460 < τ SND p bound ( 10 3 yr) > 0.16 [A], τ SND n N K 340 < τp SND > 3 [C], τn SND N η 310 < τn SND > 1.58 [B] [A] Soudan, 000; [B] IMB-3, 1999; [C] Super-Kamiokande, 005 > 1.1 [B] > 1.3 [C] ( ) 6 ( ) 6 ( ) (σv) IND cm 3 ΛIND /s τ N 10 3 ΛIND ρ DM yr 1 TeV 1 TeV 0.3 GeV/cm 3 Λ IND c i 1/3 IND meson kinematics different from standard nucleon decay; effect on bounds.

9 Search for Nucleon Decay Signals p K + ν, n K 0 ν Super-Kamiokande (water Čerenkov detector). (a) K + π + π 0 and K + µ + (+ prompt γ) - SND: K + below Čerenkov threshold, β < 0.75, decay at rest. - IND: except for up-scattering near threshold, β > 0.75, not all stopped. (b) K 0 S π0 π 0 4γ and K 0 S π+ π. - SND: 4 e-like rings and µ-like rings, respectively, 00 MeV< p K 0 < 500 MeV. - IND: boost can cause 4 rings to overlap, but π + π signal may be better.

10 p π + ν Soudan (iron tracking calorimeter). - Single π+ track, consistent with m π or m µ. - Initial 140 MeV< p π + < 40 MeV, visible endpoint decays (π + µ + e). - Simulations: On average half of initial p π + lost in iron nucleus. - IND: higher p π +; may help with atmospheric ν background. - Open questions: momentum loss in iron and possible nuclear fragmentation. n π 0 ν, n ην IMB-3 (water Čerenkov detector). - IND: Photons could overlap for π 0 γγ; better prospects for η γγ.

11 Dotted (dashed) lines NΦ ΨM (NΨ Φ M); c i =TeV 3 Σv IND cm 3 s p Π n Π 0 Σv IND cm 3 s n Η m GeV m GeV Σv IND cm 3 s p K O p K O 3 Σv IND cm 3 s n K 0 O n K 0 O m GeV m GeV Gray regions: Super-Kamiokande bounds for up-scattering near thershold: p K + for β K + < 0.75 (below Čerenkov threshold). n K 0 for 00 MeV< p K 0 < 500 MeV.

12 Collider Signals Monojet (mono t/b) from the neutron portal: q i q j q k X 1, Focus on the lighter X 1 X and L λ M (X L s R)(u R d R )+ζ XΨΦ+H.C., q(p 1 )q (p ) q (p 3 ) Ψ(p 4 )Φ (p 5 ) M = 3 3 λ ζ M 1 q m x+iγ x m x (p1 p ) [ (p 3 q)(p 4 q) (q m X )(p 3 p 4 ) ] ; λ ζ M m x q m +iγ x xm x (p1 p 3 ) [ (p q)(p 4 q) (q m X )(p p 4 ) ] ; s-like t-like q=(p 4 + p 5 )=(p 1 + p p 3 ); Γ x = ζ m X /16π Enhancement near X pole, but m X < M (hylogenesis): loss of effective theory. Mimic UV phyisics by boson exchange with mass M and width Γ=CM, C = 1/5, 1/50. λ M λ ŝ M + i ŝγ ; λ M λ ˆt M,

13 Tevatron; λ = 1 and ζ = 0.7 Cuts: p T > 80 GeV, η <1.0; efficiency factor: 40% Dotted line: Tevatron σ limit CDF collaboration 008 J. Goodman, M. Ibe, A. Rajaraman, W. Shepherd, T. Tait, H.-B. Yu, σ (fb) m x = 0.75 M, Γ = M/50 m x = 0.75 M, Γ = M/5 m x = 1.50 M, Γ = M/50 m x = 1.50 M, Γ = M/ M (GeV)

14 LHC, s=14 TeV; λ = 1 and ζ = 0.7 Cuts: p T > 500 GeV, η <3.; efficiency factor: 85% S/ B>5 for Ldt = 1,100 fb 1 L. Vacavant, I. Hinchliffe, 001 J. Goodman, M. Ibe, A. Rajaraman, W. Shepherd, T. Tait, H.-B. Yu, 010 σ (fb) m x = 0.75 M, Γ = M/50 m x = 0.75 M, Γ= M/5 m x = 1.50 M, Γ = M/50 m x = 1.50 M, Γ = M/ M (GeV)

15 LHC sensitivity to M = 1 4 TeV. IND in nucleon decay searches: M 1 TeV. IND and collider mono-jet signals correlated. Hylogenesis may also go through heavy quark flavors. M 1 TeV mono-top or mono-bottom signals: sd X t,... Recent work on mono-top signals at the LHC: J. Andrea, B. Fuks, F. Maltoni, arxiv: [hep-ph] J. kamenik, J. Zupan, arxiv: [hep-ph].

16 IND in Astrophysical Environments Hylogenesis: DM-DM annihilation very suppressed (B). In stars: capture followed by IND ΨN Φ M. Capture: assume σp SI = cm, σn SI = 0 (Z couples to charge). Consistent with CRESST, CDMS, and CoGeNT for m<3 GeV. ( ) Z ( σ0 SI =( cm µn ) ( ) e ( κ ) ( ) 0.1GeV 4 ) A GeV m Z Hylogenesis possible for σ SI cm. (σv) ann = 10 5 cm 3 /s. For IND, assume two cases: (1) (σv) IND = cm 3 /s (large) ; () (σv) IND = 0 (small)

17 Capture and Annihilation in Stars Once captured, DM is quickly thermalized, collect within Evolution governed by ( 9Tc r i,th = 4πGρ c m i ) 1/ dn Ψ dt dn Ψ dt dn Φ dt dn Φ dt = C Ψ A Ψ N Ψ N Ψ B ΨN Ψ = A Ψ N Ψ N Ψ + ε Ψ B ΦN Φ = C Φ A Φ N Φ N Φ B Φ N Φ = A Φ N Φ N Φ + ε Φ B Ψ N Ψ C i capture rate, A i annihilation rate, B i IND rate A i (σv) i,ann / ( 4πr 3 i,th /3 ) ; B i (σv) i,ind (ρ c /m n ) Probability of anti-dm produced by IND to be captured: ε i

18 Neutron Stars C i s 1( ρ DM E. g., I. Goldman, S. Nussinov, 1989 )( )( 5GeV 0km/s GeV/cm 3 m Ψ +m Φ v f = min { 1,(x p σ p + x n σ n )/( cm ) } ) f x p = 0.1, NS optically thick for (Ψ, Φ) with σ SI p = cm r i,th (140cm) ( T c ) ( ) 1/ 1/ ( ) 3GeV / kg/m K m i ρ c NASA/CXC/SAO First case: (σv) IND = cm 3 /s Steady state for t > 10 7 s. Neutron star heating likely unobservable. E. g., A.Lavallaz, M. Fairbairn, 010 Destroyed baryons negligible unless ρ DM GeV/cm 3. N N N N 10 5 N t s

19 Second case: (σv) IND = 0 After 10 Gyr (ρ DM /GeVcm 3 ) DM particles. Self-gravitation: N i N sel f ρ c m i (4πr 3 i,th /3) ( 3GeV m i ) 5/ ( ) 3/ ( Tc kg/m K Larger than number for local DM densities (3 10 GeV/cm 3 )min{1, cm 3 s 1 /(σv) IND }. Black hole formation Fermions (degeneracy pressure): N i N f crit ( 8πMPl m i ) ρ c ( 3GeV m i ) 3 ( ) Bosons (zero-point pressure): N i Ncrit b 8πMPl 10 ( ) 37 3GeV m i m i M Pl = 8π/G GeV With U(1) present, black hole formation unlikely: Pressure among Φ population for m Z (m Φ M Pl )1/3 and e m Φ /M Pl. Charge neutrality: N > N f crit (overcome degeneracy) with ρ DM > GeV/cm 3! ) 1/

20 White Dwarfs Mainly carbon and oxygen. Supported by degeneracy pressure of electrons. M = 0.7M, R=0.01R, ρ c = 10 9 kg/m 3, and T c = 10 7 K WD optically thick for σ SI p = cm ( f p = 1, f n = 0): ( )( )( )( )( ) R M C Ψ,Φ = ( s 1 ρhdm 5GeV 70km/s ) 0.01R 0.7M GeV/cm 3 m Ψ + m Φ v ( ) 3GeV 1/ ( ) 1/ ( r i,th ( Tc 10 9 kg/m 3 cm) 10 7 K m i ρ c ) 1/ IND: steady state with N Ψ,Φ and N Ψ,Φ (Destroyed baryons over Hubble time negligible for ρ DM GeV/cm 3 ) Main effect heating with rate (m Ψ + m Φ + m N )C Ψ,Φ. Bounds on σ SI p inconclusive (globular cluster DM density). Cool WD within dwarf spheroidal galaxies good probe. D. Hooper, D. Spolyar, A. Vallinotto, N. Gnedin, 010 Small IND: no significant effect unless N i N sel f, N f crit (ρ DM GeV/cm 3 ).

21 The Sun Sun optically thin for σ SI p = cm. IND products Ψ,Φ escape. ( )( )( ) ( ) 5GeV C i ( s 1 ρ DM 70km/s σp SI ) m Ψ + m Φ 0.3GeV/cm 3 v cm [ ] x H +(1.1)x He (1+ f n / f p ) m r He m r p ( ) 3GeV 1/ ( ) r i,th ( T 1/ ( c kg/m 3 cm) K Evaporation important for the Sun: A. Gould, 1987; D. Hooper, F. Petriello, K. Zurek, M. Kamionkowski, 008 m i ( ) E i 10 [ 3.5(m σ SI i/gev) 4] p cm s 1. ρ c ) 1/ NSSDC/NASA For fiducial parameters and m DM <.4 GeV, evaporation more important than IND. Steady state after yr with N i < ; negligible effect on main sequence stars. Neutrinos from IND below threshold of telescopes such as IceCube.

22 Conclusions Data: DM and atoms have similar energy densities; suggests common origin. Hylogenesis: DM and baryons generated by asymmetry; no net cosmic B. - DM can destroy nucleons through inelastic scattering processes. - Signals in nucleon decay experiments, at colliders, and from astrophysics. - If hidden and visible sectors coupled through TeV-scale physics Nucleon decay signal correlated with mono-jets at colliders (LHC). - Mono-top/bottom signals at colliders are generally present in Hylogenesis. - Astrophysics does not yield severe constraints. Nature of DM unknown novel approaches to detection important.