Dark Matter: Thermal Versus Non-thermal. Bhaskar Dutta. Texas A&M University

Transcription

1 Dark Matter: Thermal Versus Non-thermal Bhaskar Dutta Texas A&M University Identiication o Dark Matter with a Cross-Disciplinary Approach Madrid, May 8th, 015 1

2 Outline Thermal and Non-Thermal Dark Matter (DM) Various Features o Non-Thermal Scenarios Example o a Non-Thermal Model Distinguishing Non-Thermal Scenarios Conclusion

3 Questions Important questions: What is the origin o dark matter? Dark Energy 68% Dark Matter 7% How does it explain the dark matter content? Is there any correlation between baryon and dark matter abundance? Atoms 5% SM Consequences or: Particle Physics Models Thermal History o the Universe 3

4 Dark Matter: Thermal Production o thermal non-relativistic DM: DM DM Y Y n s n g * T s 3 Universe cools DM DM DM DM dn dt DM 3Hn DM v eq [ n DM n DM, eq ] m/t v eq 3 3 d p1d p ve ( ) 3 3 d p1d p e ( ) 6 ( E ( E E E ) / ) / T T 3 d p ( p, t ) n g nos. / 3 ( ) vol

5 Thermal Dark Matter Dark Matter content: v ~ m DM ~ 1 v reeze out T m 0 ~ DM WIMP Dark Energy 68% Dark Matter 7% v cm 3 s Weak scale physics : Atoms 5% a c ~O(10 - ) with m c ~ O(100) GeV leads to the correct relic abundance

6 Dark Matter: Thermal Suitable DM Candidate: Weakly Interacting Massive Particle (WIMP) Typical in Physics beyond the SM (LSP, LKP, ) Most Common: Neutralino (SUSY Models) Neutralino: Mixture o Wino, Higgsino and Bino smaller annihilation cross-section Larger annihilation cross-section Larger/Smaller Annihilation Problem or thermal scenario 6

7 Thermal DM 7% Status o Thermal DM Experimental constraints: ann v Gamma-rays constraints: Dwar spheroidals, Galactic center Large Crosssection is constrained ann v o : smaller than the thermal value Geringer-Sameth, Koushiappas 11, Hooper, Kelso, Queiroz, Astropart.Phys. 13 7

8 Latest result rom Planck 8

9 Dark Matter Pair Annihilation Dark matter annihilation cross-section: <sv>= a + b v a, b are constants I S wave is suppressed then the cross-section is dominated by P wave b v >>a <sv> is much smaller today compared to the reeze-out time Thermal Relic Density: At reeze-out, <sv> =3x10-6 cm 3 /s High b/a lowers the cross-section at small v (Present Epoch) For S wave domination, cross-section remains same (constant) Annihilation cross-section can be larger today compared to the Freeze-out time due to Sommereld enhancement 9

10 LHC Constraints and Status o LHC constraints on irst generation DMsquark mass + Higgs mass: Natural SUSY and dark matter [Baer, Barger, Huang, Mickelson, Mustaayev and Tata 1; Gogoladze, Nasir, Shai 1, Hall, Pinner, Ruderman, 11; Papucchi, Ruderman, Weiler 11], Higgs mass 15 GeV & Cosmological gravitino solution [Allahverdi, Dutta, Sinha 1] Higgsino dark matter Higgsino dark matter has larger annihilation cross-section Typically > 3 x 10-6 cm 3 /sec or sub-tev mass Thermal underproduction o sub-tev Higgsino Unnatural SUSY: Wino DM- Larger annihilation cross-section (or smaller wino mass) Arkani-Hamid, Gupta, Kaplan, Weiner, Zorawsky 1 10

11 LHC status Recent Higgs search results rom Atlas and CMS indicate that m h ~16 GeV in the tight MSSM window <135 GeV (1st gen.) ~ 1.7 TeV For heavy m~ q m~q, m~ g ~ t1 g ~ ~ t m~ g 1.3 TeV produced rom, 700 GeV m~ t1 produced directly, 660 GeV (special case) 1 ~e / ~ m~ t1 excluded between 110 and 80 GeV or a mass-less or or a mass dierence >100 GeV, small DM is associated with small missing energy Can lead to over production o relic abundance ~ 1 0 ~ 1 masses between 100 and 600 GeV are excluded 0 or mass-less ~ 1 or ~ 1 or or the mass dierence >50 GeV decaying into e/m Can lead to over production o relic abundance 11

12 Status o Thermal DM Thermal equilibrium above T is an assumption. T T Non-standard thermal history at is generic in some explicit UV completions o the SM. Acharya, Kumar, Bobkov, Kane, Shao 08 Acharya, Kane, Watson, Kumar 09 Allahverdi, Cicoli, Dutta, Sinha, 13 DM content will be dierent in non-standard thermal histories (i.e., i there is entropy production at ). T T Barrow 8, Kamionkowski, Turner 90 DM will be a strong probe o the thermal history ater it is discovered and a model is established. 1

13 Thermal, Non-thermal ann v : Large multicomponent/non-thermal; Small Non-thermal LHC: Investigate colorless particles, establish the model DM annihilation rom galaxy, extragalactic sources Annihilation into photons: Fermi, HAWC, H.E.S.S. Annihilation into neutrinos: IceCube Annihilation into electron-positrons: AMS 13

14 Beyond Thermal DM ann v 310 Obtaining correct relic density or : 6 cm 3 s 1 1) (thermal underproduction): ann v cm 3 s 1 Baer, Box, Summy 09 Multi-component DM (WIMP + non-wimp) Example: mixed Higgsino/axion DM ann v Zurek 13 Asymmetric DM (DM content can have large ) ) (thermal overproduction): DM rom WIMP decay Ex: Axino DM, Gravitino DM ann v cm 3 s 1 Covi, Kim, Roszkowski 99 Feng, Rajaraman, Takayama 03

15 Non-Thermal DM Dark Matter rom Moduli decay: Moduli are heavy scalar ields that acquire mass ater SUSY breaking and are gravitationally coupled to matter T r ~ The moduli decay width: 3 c m M p start oscillating when H < m t dominate the Universe beore decaying and reheating it c 1/ m M p 1/ m T r T m BBN 50 3 MeV TeV For T r <T : Non-thermal dark matter Inlation Radiation domination moduli domination Decay o moduli radiation domination. 3T r Abundance o decay products Y. 4 m. e.g., Moroi, Randall 99; Acharya, Kane, Watson 08,Randall; Kitano, Murayama, Ratz 08; Dutta, Leblond, Sinha 09; Allahverdi, Cicoli, Dutta, Sinha, 13 15

16 Dark Matter rom Moduli DM abundance min 1. First term on the RHS is the annihilation scenario Requires: th T ann Since T r < T, we need wino/higgsino DM n v DM s ann ann v v.[ n T r DM s ann obs v th v v Th T T r, Y Br DM ] Gamma-rays constraints: Dwar spheroidals, Galactic center M DM > 40 GeV, T < 30 T r T r > 70 MeV. Second term on the RHS is the branching scenario Can accommodate large and small annihilation cross-sections Bino/Wino/Higgsino are all ok Y is small to prevent the Br DM rom becoming too small (actually in realistic scenarios: Br 5 x10-3 => T r < 70MeV) (or m ~ 5 x10 6 GeV) 16

17 Dark Matter rom Moduli Decays dilutes any previous relics Thermal DM gets diluted i T r < T ~ m DM /0 ~ O(10) GeV Axionic DM gets diluted i T r < L QCD ~ 00 MeV ( a ~10 14 GeV is allowed or T r T BBN ) [Fox,Pierce,Thomas 04] Baryon asymmetry gets diluted i produced beore decay Non-thermal DM Production rom decay Annihilation scenario or T r close to T DM production with large cross-section: Wino/Higgsino Branching scenario or smaller T r (annihilation cross-section does not matter) Baryon asymmetry rom decay Cladogenesis o DM and Baryogenesis [Allaverdi, Dutta, Sinha 11] 17

18 Dark Matter rom Moduli Branching scenario solves the coincidence problem Baryon abundance in this model: n s B Y Br B Y appears in the DM abundance as well, Y ~ BR B ~ easy to satisy or baryogenesis, e (one loop actor) ~ b DM 1 m DM Y Br Y Br B DM 1 m DM Br Br B DM 1 5 W=r/r c ; r=mn For m DM ~ 5 m B, e BR B ~ BR DM n B ~ n DM The DM abundance and Baryon asymmetry are mostly saturated by Y, Brs contribute to the remaining not much particle physics uncertainty 18

19 Baryogenesis rom Moduli N W extra i N u c i X X, ' ij X d c i d c j X : SM singlet; : Color triplet, hypercharge 4/3 Baryogenesis rom decays o X, X M X or N N ~ : can be the DM candidate : Allahverdi, Dutta, Mohapatra, Sinha 1 X M N N nb nb B Y Br N s Br N : branching ratio o moduli decay to N Assuming that N produces Baryon Asymmetry e : asymmetry actor in the N decay Y ~ , <0.1, Br N ~ B = 9x

20 0 Baryogenesis From X decay Typically, e 1, is O(10 - ) or CP violating phase O(1) and l~o(1) Baryogenesis rom Moduli N N M X X M X d d X u N W c j c i ij c i i extra ' Similarly, e

21 Conditions or Models Two typical problems or moduli decay Gravitino Problem: [Endo,Hamaguchi,Takahashi 06][Nakamura,Yamaguchi 06] I m 3/ <40 TeV Gravitino decays ater the BBN m > m 3/ can lead to DM overproduction Large branching ratio o moduli into light Axions N e [Cicoli,Conlon,Quevedo 1][Higaki,Takahashi 1] 4/3 7 4 rad (1 N e ) 8 11 Current bound rom Planck+WMAP9+ACT+SPT+BAO+HST (at 95% CL) : N e =

22 Ex: NT DM in Large Volume K 3ln( T T ), Scenarios W W Ae b b at s lux Balasubramanian, Berglund, Conlon, Quevedo 05 Large volume can be obtained ater stabilization o v 3/ b 3/ np ( Tb Tb For large volume, one can have a sequestered scenario such that: 3/ vis b ) / Cicoli, Conlon, Quevedo 08 m sot m b m ( m For example, TeV scale SUSY can be obtained or: m ~ m 3/ sot 3/ b ) 10 6 m3 / ~ 10 GeV, m ~ 510 GeV, m b sot ~ 1 TeV [Detailed Mass spectra, Aparicio, Cicoli, Kippendor, Maharana, Quevedo 14 No Gravitino Problem

23 NT DM in Large Volume Scenarios Br 3 0 The decay to gauge bosons arises at one-loop level: m b m 3/ 3 m SM 3 gg ~ ln( b ) 4 M P The decay to Higgs: / Small T r H u H d 3 Z m 4 M P The decay to gauginos (and Higgsinos) is mass suppressed: m msot gg ~~ Br 1 M P Large T r LVS set up can successully accommodate non-thermal DM. Y can be quite small ~ : branching and annhilations are ok Allahverdi, Cicoli, Dutta, Sinha 13 3

24 NT DM in Large Volume Scenarios I the dominant decay mode is to gauge boson inal states decays into DM particle via 3-body: g gg ~ ~ Since g ~ BR 10 3 DM produces dark matter at the end o the decay chain The 3 body decay width larger than the -body decay width o moduli into gauginos [ g ~ g ~ is suppressed by (m gaugino /m ) compared to gg ] Y ~ (using m ~5 x 10 6 GeV) Y DM : Y BR DM ~ 10-1 m DM ~ O(100) GeV is allowed Solves the coincidence problem 4

25 DM-DR Correlation in LVS: The axionic partner o, denoted by is not eaten up by anomalous U(1) s. a a b b acquires an exponentially suppressed mass. is produced rom a b a b 1 48 DM-DR Correlation m M 3 P b decay: m ab Cicoli, Conlon, Quevedo 13 Bulk axions are ultra-relativistic and behave as DR. T r ~ 100 MeV or larger annihilation scenario a b 0 N e contribute to the eective number o neutrinos : 3 ( cvis ctot ) m 43chid N e 48 M P 7c vis ( N e N 3.04) e 5

26 DM-DR Correlation T r 1 5C 88 C vis hid g * ( T r ) 1 / 4 m m M P using N e 43 7 C C hid vis The Fermi bound is translated to constraint in N e m plane: m ~ GeV Allahverdi., Cicoli, Dutta, Sinha 14 6 m 510 N e,m : set lower bound on DM mass

27 Non-thermal Scenarios in CMSSM Suppose decays into CMSSM or T r >100 MeV scenario/annihilation scenario m>0 m<0 Large cross-section or smaller T r More Higgsino Domination T r = GeV satisies all data Apparicio, Cicoli, Dutta, Kippendor, Maharana, Muia, Quevedo, 15 7

28 Non-thermal Scenarios in CMSSM Planck Constraints 8

29 Non-thermal Scenarios in CMSSM NT h R, R 0.1 More multicomponent DM parameter space is recovered Assume: Multcomponent raction in the early epoch is same as the present epoch. More simulation work is needed Free up more parameter space or wino, Higgsino types o DM 9

30 Non-thermal Cross Sections Scenarios via Probe the DM sector directly: One interesting way: CDM pp ~ ~ jj Preselection: missing E T > 50 GeV, leading jets (j 1,j ) :p T (j 1 ),p T (j ) >30 GeV Dh(j 1, j ) > 4. and h j1 h j < 0. Optimization: Tagged jets : p T > 50 GeV, M j1j > 1500 GeV; Events with loosely identiied leptons(l = e; m ; t h ) and b-quark jets: rejected. Missing E T : optimized or dierent value o the LSP mass. Delannoy, Dutta, Gurrola, Kamon, Sinha et al 13 30

31 Non-Thermal LHC W extra i N u c i X ' ij Final states at the LHC New Particles: Heavy colored states: d c i SM Singlet: LHC signals: new colored states -spin 0- are pair produced high E T our jets in the inal states new colored states spin ½- are pair produced, high E T our jets +missing energy [via cascade decays into squarks etc] d c j X X, Distinguishing Feature: 4 high E T jets and 4 high E T jets + missing energy M X X X N M N N 31

32 Non-Thermal LHC I N is the DM candidate, i.e., m N ~ m p Monojet Dijet Dijet pair Dutta, Gao, Kamon 14 Dijet + Missing Energy 3

33 DM via Monojet at LHC Also, Mono-top, di-tops in this model Monojet Combining various observable, we can probe ann. cross-section 33

34 Direct Detection Dark Matter Candidates:, Direct detection scattering cross-section: N ~ Suppose: N ~ ~ N, c i N ~ Xu i Scatters o a quark via s-channel exchange o X N ~ is the DM particle (spin-0) For l i ~1, M x ~ 1 TeV, I N (spin ½) is DM, M N ~m p (to prevent N decay and p-decay), s N-p is cm (SI) and 10-4 cm (SD)

35 Direct Detection Neutrino loor needs to be understood! 35

36 Conclusion The origin o DM content is a big puzzle key to understand the history o the early universe Thermal DM is a very attractive scenario However, it contains certain assumptions about thermal history Alternatives with a non-standard thermal history are motivated Typically arise in UV completions Can ease the tension with tightening experimental limits Non-thermal DM arising rom moduli decay is a viable scenario can yield the correct density or large & small annihilation rates Direct, Indirect detection and LHC experimental results in tandem will probe the origin o DM Need: simulation studies o multicomponent DM and understanding the neutrino loor

37 Extra: DM-DR Correlation Decay to visible sector mainly produces gauge bosons and Higgs: gg K SM ~ 4 ZH u H b b d 3 m P M h.c. gg a b a H u H d b Z m 4 M P 3 tot H u H d a b a b Bound rom Planck+WMAP9+ACT+SPT+BAO+HST at 95% N e N e 1 Z 3 We get a lower bound on T r 37

38 Extra: DM-DR Correlation Abundance o DM particles produced rom decay: Y n s 3T 4m r Br : Branching scenario Z 3, m ~ GeV T r O( GeV ) Y 10 6 Br n s n s obs : Branching scenario does not work Small annihilation cross-sections will be hard to accommodate Avoiding excess o DR within LVS preers Annihilation scenario Higgsino-type DM. 38

39 T r T Extra: DM-DR Correlation Obtaining the correct relic density in Annihilation scenario needs: 3 10 v ann 6 ann cm v 3 s 1 Assuming S-wave annihilation, which is valid or the Higgsinotype DM, is directly constrained by Fermi. For Higgsino-type DM, using the b inal state, the bound reads: T ~ m 0 m 40 GeV 1 T r (18 GeV ) GeV m Upper bound on T r gets bounded rom below v ann 39

40 Extra: Model Examples: can be a visible sector ield S (moduli is a hidden sector ield) W s hsx X 1 m s S W=W s +W N,X m s ~ O(1) TeV, m X ~ O(10) TeV, m N ~ O(0.5) TeV S Decay + DM Annihilation or no annihilation works BR DM ~ 10-6 Y s =(3/4)T r /m s ~ 10-4 n DM /s ~ Allahverdi, Dutta, Sinha, 13 40