SUSY Models, Dark Matter and the LHC. Bhaskar Dutta Texas A&M University

Transcription

1 SUSY odels, Dark atter and the LHC Bhaskar Dutta Texas A& University 11/7/11 Bethe Forum 11 1

2 Discovery Time We are about to enter into an era of major discovery Dark atter: we need new particles to explain the content of the universe Standard odel: we need new physics Supersymmetry solves both problems! The super-partners are distributed around 1 GeV to a few TeV LHC: directly probes TeV scale Future results from PLANCK, direct and indirect detection, rare decays etc. experiments in tandem with the LHC will confirm a model This talk: Can we establish SUSY models at the LHC? How accurately we can calculate dark matter density?

3 SUSY at the LHC Wang s talk [morning] D (or l + l -, t+t-) High P T jet [mass difference is large] Colored particles are produced and they decay finally into the weakly interacting stable particle The signal : High P T jet D The p T of jets and leptons depend on the sparticle masses which are given by models (or l + l -, t+t-) R-parity conserving jets + leptons+ t s +W s+z s+h s + missing E T 3

4 SUSY at the LHC Dilemma... 4

5 SUSY at the LHC Dilemma... 5

6 SUSY at the LHC Final states odel Parameters Calculate dark matter density Reconstruct sparticle masses, e.g., ~ Q q + l ~ L l +,3,4 ~ 1 ~ 1 + ~,, ~ Z h ll + We may not be able to solve for masses of all the sparticles from a model Solving for the SS : Very difficult 1 etc. Identifying one side is very tricky! 6

7 SUSY at the LHC We can use simpler models to understand the cascades and solve for the model parameters The best strategy: Calculate the Dark atter content Solve for the minimal model: msugra/css 4 parameters + sign: m, m 1/, A, tanb and Sign(m) The cascades can be understood in a simpler way [hopefully!] Next step: odels with more parameters or with different features, e.g., Next to minimal model (Higgs non-universality), Gaugino Non-universality (irage ediation model) etc 7

8 msugra Parameter space Focus point Coannihilation Region 1. TeV squark bound from the LHC imura, Dutta, Santoso PLB 687:5,1 The direct searches at the LHC and the Br(B s m m) measurement from LHC, Tevatron are probing the parameter space 8

9 1. Coannihilation, GUT Scale In msugra model the lightest stau seems to be naturally close to the lightest neutralino mass especially for large tanb For example, the lightest selectron mass is related to the lightest neutralino mass in terms of GUT scale parameters: m m +. 15m ~ + (37 GeV) 1/ m. 16m E c ~ 1/ Thus for m =, E ~ c becomes degenerate with at m 1/ = 37 GeV, i.e. the coannihilation region begins at m 1/ = (37-4) GeV For larger m 1/ the degeneracy is maintained by increasing m and we get a corridor in the m - m 1/ plane. 1 ~ 1 Arnowitt, Dutta, Santoso 1 The coannihilation channel occurs in most SUGRA models even with nonuniversal soft breaking. 9

10 SUSY asses Smoking Gun of CA Region g~ Typical decay chain and final states at the LHC u ~ L u Jets + t s+ missing energy Low energy taus characterize the CA region χ~ χ~1 (CD) quarks+ t s +missing energy u ~ t t 1 t However, one needs to measure the model parameters to predict the dark matter content in this scenario 1

11 SUSY at the LHC Dilemma... 11

12 SUSY asses CA Region: Final States g~ u ~ L u jtt & jt Excesses in 3 Final States: a)e miss T + 4j b)e miss T + j+t c)e miss T + b +3j Kinematical variables Example of Analysis Chart for b): χ~ u χ~1 (CD) ~ t t 1 t tt & p T(t) t = 5%, f fake = 1% for p T vis > GeV 1

13 SUSY at the LHC Dilemma... OS-LS Subtraction 13

14 Extracting One side: jtt OS-LS selection of ditaus selects the entire side χ~, but if we need to reconstruct We use the following subtraction scheme: t Bi Event Subtraction technique: BEST 14

15 BEST Dutta, Kamon, Kolev, Krislock, arxiv: [hep-ph] 15

16 What BEST Looks Like... 16

17 Top reconstruction : BEST 17

18 Kinematical Variables using a) & b) 6 equations for 5 SUSY masses peak ( ~ ~ 1 tt f1,, 1 ) Slope f(, ~ 1 ) ()peak ( ) 1 j 3 q ~ ~ ~ tt f L,, 1 ()peak j 1 4( q ~ ~ ~ t f L,,, 1 ) ()peak ( ~ ~ ) j f5 q ~ t L,,, 1 peak f ( g~,q ~ ) eff 6 L [Next page] Invert the equations to determine the masses 66 GeV [1] taus with 4 and GeV; tt & p Tt in OS-LS technique [] tt < tt endpoint ; Jets with E T > 1 GeV; jtt masses for each jet; Choose the nd large value Peak value ~ True Value q ~ L 84 GeV 18

19 pp g ~ g ~ eff a) E T miss +4j eff E T j1 +E T j +E T j3 +E T j4 + E T miss [No b jets; b ~ 5%] e.g., E T j1 > 1, E T j,3,4 > 5 No e s, m s with p T > GeV eff > 4 GeV; E T miss > max [1,. eff ] m 1/ = 335 GeV eff peak = 1 GeV m 1/ = 351 GeV eff peak = 174 GeV m 1/ = 365 GeV eff peak = 1331 GeV f ( g~,q ~ 6 L ) 19

20 Arbitrary Scale units c) E T miss +b+3j eff (b) E T j1=b +E T j +E T j3 +E T j4 + E T miss [j1 = b jet] E j1 T > 1 GeV, E j,3,4 T > 5 GeV [No e s, m s with p T > GeV] (b) eff > 4 GeV ; E miss T > max [1,. eff ] tanb = 48 eff (b)peak = 933 GeV tanb = 4 eff (b)peak = 16 GeV tanb = 3 eff (b)peak = 11 GeV eff (b)peak (GeV) (b) eff can be used to probe A and tanb measuring stop and sbottom masses without

21 D Relic Density in msugra ~h A 1 Z( m, m1/ tan b, ) [1] Established the CA region by detecting low energy t s (p T vis > GeV) [] easured 5 SUSY masses (, ~ 1, ~, q ~, g ~ ) from peak X ( m, m ) j tt peak tt peak eff peak eff, b X X X ( m ( m ( m 1/ 1/ 1/ 1/, m, m, m, tan b, A ), tan b, A [3] Determine the dark matter relic density by determining m, m 1/, tanb, and A ) ) 1

22 Determining msugra Parameters Solved by inverting the following functions: peak jtt peak tt peak eff ( b) peak eff X X X X ( m ( m ( m ( m 1/ 1/ 1/ 1/, m, m, m, m ),tan b, A ),tan b, A ) ) 1 fb -1 m m 1/ A tan b 4 1 ~h A 1 Z( m, m1/ tan b, ) 5 fb L 1 fb -1-1 h / ~ ~ 1 1 / ~ 7% (3 fb - p - p ~ ) h 6.%(3 fb 4.1%(7 fb -1-1 ) )

23 Comparison ILC analysis: 5 GeV LHC m (5 fb -1 ) We need 5fb -1 m 1/ A tan b 35 4 Arnowitt, Dutta, Kamon; PLB 5 This result was used in Baltz, Battaglia, Peskin, Wizansky 5 to extract relic density by using ILC and LHC (LCC3 point) 5 We can determine at the LHC, Arnowitt, Dutta, Kamon et al, PRL 8 3

24 mass GUT Scale Symmetry We can probe the physics at the Grand unified theory (GUT) scale ~ g ~ ~ 1 Z Log[Q] m 1/ GUT Use the masses measured at the LHC and evolve them to the GUT scale using msugra The masses ~, ~ 1, g ~ unify at the grand unified scale in the msugra model Gaugino universality test at ~15% (1 fb -1 ) Another evidence of a symmetry at the grand unifying scale! irage mediation models can be discerned 4

25 . Over-dense D Region A =, tanb = 4 m Dilaton effect creates new parameter space m 1/ Lahanas, avromatos, Nanopoulos, PLB649:83-9,7. Smoking gun signals in the region? 5

26 Reference Points m 1/ = 44 GeV; m = 471 GeV 86.8% m 1/ = 6 GeV; m = 44 GeV 77.% 6

27 m 1/ =44, m =471, tanb=4, m top =175 g~ 141 Case (a) : Higgs u u ~ L 144 E miss T > 18 GeV; N(jet) > with E T > GeV; E miss T + E j1 T + E j T > 6 GeV χ~ 341 e ~ R 5 t ~ χ~1 46 χ~1 181 h 114 Z 91 N(b) > with P T > 1 GeV;.4< R bb < 1 7

28 Determining h Solved by inverting the following functions: end point jbb peak eff ( b) peak eff ( bb) peak eff X X X X ( m ( m ( m ( m 1 / 1 / 1 / 1 /,m,m,m,m ) ), tanb, A, tanb, A ) ) 1 fb -1 m m 1 / A tanb L 1 fb -1 ~h A 1 Z( m, m1/ tan b, ) Ω ~ h / Ω ~ h ~ 15% 1 1 Dutta, Gurrola, Kamon, Krislock, Nanopoulos, Lahanas, avromatos, PRD 9 8

29 Case 3 : Focus Point/Hyperbolic Branch m, A, m, tanb q ~ l ~ Z g~ Prospects at the LHC: A few mass measurements are available: nd and 3 rd neutralinos, and gluino ~ i m 1/, m, tanb Goals: 1)technique on h )SUSY mass measurements Can we determine the dark matter content? 9

30 m m b b b b b b b b s c s s c c c s s c c c s s c s W Z W Z W Z W Z W Z W Z W Z W Z Μ ~ m m b b b b b b b b s c s s c c c s s c c c s s c s W Z W Z W Z W Z W Z W Z W Z W Z Μ ~ A 4x4 (m 1/, m, tanb ) g ~ 1 1 ~ ~ D ~ ~ D - h ) tan ( 1 1 b m,, m Z h / ~ 3 3

31 Focus Point: Leptons Large m sfermions are heavy m =355 GeV; m 1/ =3 GeV; A =; tanß=1 ; μ> Direct three-body decays ~ n ~ 1 + leptons Edges give m(~ ~ n)-m( 1) Tovey, PPC 7 ~ ~ 1 ll ~ 3 ~ 1 ll ATLAS 3 fb -1 Z ll Parameter Without cuts Exp. value 1 68± ± ± Preliminary Similar analysis: Error (-1)~.5 GeV G. oortgat-pick 7 31

32 h Determination m.7% m tanb ~ 31% tanb m m 1/ 1/ 5. 6% h h ~ 8% Dutta, Flanagan, Kamon, Krislock, to appear LHC Goal: D 1 and D 31 at 1-% and gluino mass at 5% 3

33 Case 4 : Non-U SUGRA Nature may not be so kind Our studies have been done based on a minimal scenario(= msugra) Let s consider a non-universal scenario: Higgs nonuniversality: m Hu, m Hd m (most plausible extension) easy to explain the D content: 1) Reduce m or ) heavy Higgs/pseudoscalar (A) resonance Case 1 steps: 1) Reduce Higgs coupling parameter, m, by increasing m Hu, ore annihilation (less abundance) correct values of h ) Find smoking gun signals Technique to calculate h m m Hu m [ tan d (1 + ), m m (1 + b - u u Hd (1 + D For low and intermediate tanb... ) ] m d ), +... Where D <.3 33

34 Reference Point h =.11 Testing msugra and Extensions 34

35 BEST and SUSY Dilemma In this scenario we have W s in the final states: 35

36 End Point Techniques with BEST N jet > 4, p T > 3 E T j1, > 1, E T miss > 18 E T miss + E T j1 + E T j > 6 No e s, m s with p T > 5 Significance improves 5 times with BEST 36

37 Extraction of odel Parameters Utilizing the characteristic decays, we can create some observables to determine our model parameters Dutta, Kamon, Kolev, Krislock, Oh, Phys.Rev. D8 (1)

38 Relic Density 38

39 Case 5 : irage ediation Soft masses: oduli mediation + anomaly mediation 39

40 irage ediation Choi, Falkowski, Nilles, Olechowski, Pokorski; Choi, Jeong, Okumura 4

41 irage ediation 41

42 irage ediation B. Dutta, T. Kamon, A. Krislock, K. Sinha, K. Wang, 11 4

43 irage ediation Dark matter allowed regions: 1. Stop Coannihilation. Stau Coannihilation 3. Higgsino domination 4. Wino domination 5. Pseudo scalar Higgs resonance Two main goals: Gaugino unification, D requirements 43

44 irage ediation One typical stau-neutralino coannihilation point 44

45 irage ediation 45

46 irage ediation 46

47 irage ediation 47

48 irage ediation 48

49 irage ediation 49

50 irage ediation 5

51 irage ediation Two t s in the final states: decays of ~ tt~ tt~ 1 1 P T (algebraic mean value) =(P Tmax +P Tmin )/ 51

52 irage ediation Two t s in the final states: decays of ~ tt~ tt~ 1 1 P T (absolute difference value) = (P tmax -P Tmin ) / These two new p T variables are important in the regions where Tau p T are comparable 5

53 irage ediation 53

54 irage ediation Collecting the observables: P T_diff (m t1, m, m 1 ); P T_diff (m t1, m, m 1 ); m tt (m t1, m, m 1 ); Determines m t1, m, m 1 jtt (m sq, m 1 ); eff (m gluino, m 1 ) Determines squark and gluino masses 54

55 irage ediation fb -1 55

56 irage ediation We have moduli mediation plus anomaly mediation Using observables like: eff, tt, P t, jtt, it is possible to reconstruct the gaugino masses to check the gaugino unification scale Input from the experimental measurements Dutta, Kamon, Sinha, Wang, to appear ~ 1 ~ g 1 fb -1 Values of the masses at the GUT scale 56

57 irage ediation Typical stop-neutralino coannihilation region 57

58 irage ediation 58

59 irage ediation 59

60 irage ediation 6

61 irage ediation

62 Conclusion Signature contains missing energy (R parity conserving) many jets and leptons : Discovering SUSY should not be a problem! Once SUSY is discovered, attempts will be made to measure the sparticle masses (highly non trivial!), establish the model and make connection between particle physics and cosmology Different cosmologically motivated regions of the SUGRA models have distinct signatures. Use the signatures and BEST to construct a decision tree It is possible to determine model parameters and the relic density based on the LHC measurements non-universal model parameters (Higgs nonuniversality)----can be determined irage mediation models? ----Can be determined 6