Introduction to the Beyond the Standard Model session

Transcription

1 Introduction to the Beyond the Standard Model session JJC 2014 Dec. 11th 2014 Samuel Calvet

2 Outline Why do we need Beyond the Standard Model (BSM) theories? BSM theories on the market : their predictions/particles SuperSYmetry, Extra-dimensions, compositness,... 2

3 Why do we need BSM theories? 2 reasons (among others) that drive searches at HC? 3

4 Dark matter Astrophysical observations in contradiction w/ the theories Rotation of galaxies needs extra mass Cluster of galaxies: Same velocity issue Gravitational lensing Bullet cluster. Observed Prediction 4

5 Dark matter Astrophysical observations in contradiction w/ the theories Rotation of galaxies needs extra mass Cluster of galaxies: Same velocity issue Gravitational lensing Bullet cluster. Observed Prediction Need of neutral particles weakly interacting (dark matter) 5

6 Naturalness Higgs mass modified by quantum corrections H Λ: scale of new physic H t H If: Λ is large (up to Planck scale to include the gravity?) No ultra precise cancellation of terms ( fine tuning) arge mh 6

7 Naturalness Higgs mass modified by quantum corrections H Λ: scale of new physic H t H If: Λ is large (up to Planck scale to include the gravity?) No ultra precise cancellation of terms ( fine tuning) arge mh Observation : mh125gev light! Not natural! 7

8 Solving naturalness issue Main ideas to solve the naturalness issue: No ultra precise cancellation of terms ( fine tuning) Λ can be large (up to Planck scale to include the gravity?) New symmetry Each correction balanced by another (new) one Protects mh H t supersymmetry 8

9 Solving naturalness issue Main ideas to solve the naturalness issue: No ultra precise cancellation of terms ( fine tuning) Λ can be large (up to Planck scale to include the gravity?) New symmetry New spatial dimensions Bring the Planck scale to lower value Λ is small 9

10 Solving naturalness issue Main ideas to solve the naturalness issue: No ultra precise cancellation of terms ( fine tuning) Λ can be large (up to Planck scale to include the gravity?) New symmetry New spatial dimensions Higgs boson is not the SM one Higgs is a composite particle at scale Λ naturalness issue disappears 10

11 Solving naturalness issue Main ideas to solve the naturalness issue: No ultra precise cancellation of terms ( fine tuning) Λ can be large (up to Planck scale to include the gravity?) New symmetry New spatial dimensions Have to appear at the TeV scale to be efficient Higgs boson is not the SM one 11

12 Supersymmetry 12

13 Supersymmetry Add new symmetry: fermion boson ( )( )( ) u c t g d s b ur cr tr W± dr sr br Z S=1 ( )( )( ) e h e H er R R A S=1/2 ( )( )( ) u d c s t b u R dr cr s t R br R ( )( )( ) H± S=0 e e er R R S=0 g ± W Z S=1/2 h H A ± H S=1/2 Extended Higgs sector 13

14 Supersymmetry Add new symmetry: fermion boson ( )( )( ) cancellation of radiative corrections u c t g d s b ur cr tr W± dr sr br Z S=1 ( )( )( ) e h e H er R R A S=1/2 ( )( )( ) u d c s t b u R dr cr s t R br R ( )( )( ) H± S=0 e e er R R S=0 g ± W Z S=1/2 h H A ± H S=1/2 Extended Higgs sector 14

15 Supersymmetry Add new symmetry: fermion boson ( )( )( ) cancellation of radiative corrections u c t g d s b ur cr tr W± dr sr br Z S=1 ( )( )( ) e h e H er R R A S=1/2 H± S=0 ( )( )( ) u d c s t b u R dr cr s t R br R t2 ( )( )( ) e e er R R S=0 heavy light t 1 g ± W Z S=1/2 h H A ± H S=1/2 Add a pinch of mixing 15

16 Supersymmetry Add new symmetry: fermion boson ( )( )( ) cancellation of radiative corrections u c t g d s b ur cr tr W± dr sr br Z S=1 ( )( )( ) e h e H er R R A S=1/2 H± S=0 ( )( )( ) u d c s t b t2 u R dr cr s t R br t 1 R ( )( )( ) e e er R R S=0 g ± W Z S=1/2 h H A ± H S=1/2 Add a pinch of mixing 16

17 Supersymmetry Add new symmetry: fermion boson ( )( )( ) cancellation of radiative corrections u c t g d s b ur cr tr W± dr sr br Z S=1 ( )( )( ) e h e H er R R A S=1/2 H± S=0 ( )( )( ) u d c s t b u R dr cr s t R br R ( )( )( ) e e er R R S=0 t2 t 1 g ± W Z S=1/2 h H A ± H χ±1 χ±2 χ01 χ02 χ03 χ04 S=1/2 S=1/2 Add a pinch of mixing 17

18 Supersymmetry: R-parity R=(-1)+3B+2J /B: leptonic/baryoni number, J:spin +1 for SM particles -1 for SuSy particles R-parity: Assumed prefect or weakly violated (to preserve proton lifetime) SuSy particle produced by pair SM, R=1 SuSy, R=-1 SM SM, R=1 R=1 SuSy, R=-1 18

19 Supersymmetry: R-parity R=(-1)+3B+2J /B: leptonic/baryoni number, J:spin +1 for SM particles -1 for SuSy particles R-parity: Assumed prefect or weakly violated (to preserve proton lifetime) SuSy particle produced by pair ightest SuSy particle (SP) is stable Dark matter candidate SM, R=1 SuSy, R=-1 SM SM, R=1 SuSy, R=-1 R=1 SuSy, R=-1 SuSy, R=-1 SM, R=1 19

20 Breaking SuSy Super-partners not yet observed heavier than SM partners SuSy has to be broken By an unknown mechanism Introduces many free parameters Phenomenological assumptions to express results (msugra, MSSM, nmssm, pmssm, ) or Simplified models: branching ratio=100% decouple other sparticles 20

21 A rich phenomenology A simple example 2 b + missing energy 21

22 A rich phenomenology A more complex one t t t t 22

23 A rich phenomenology A more complex one t t t t 23

24 A rich phenomenology A more complex one t t t t 24

25 A rich phenomenology A more complex one t t t t 25

26 Extra-dimensions Nice ref: M. Besancon, Moriond EW 2010 Models & signatures of extra dimensions at the HC 26

27 Kaluza Klein excitations Add a space-dimension (y) y Flat (ie factorisable): ds2=gμνdxμdxν μ,ν=0, 1, 2, 3,... D Our 4-d world 27

28 Kaluza Klein excitations Compactification Add a space-dimension (y) y y Flat (ie factorisable): ds2=gμνdxμdxν μ,ν=0, 1, 2, 3,... D Our 4-d world R Our 4-d world 28

29 Kaluza Klein excitations Compactification Add a space-dimension (y) y y Flat (ie factorisable): ds2=gμνdxμdxν μ,ν=0, 1, 2, 3,... D Our 4-d world R Our 4-d world Fourier mode expansion Φ(x,y)=ΣkΦ(k)(x)eiky/R Assume some fields can propagate along y Kaluza Klein (KK) excitations mk2=m02+k2/r2 Momentum in new dimensions mass 4-D (Kaluza Klein resonance) 29

30 Kaluza Klein excitations Compactification Add a space-dimension (y) y y Flat (ie factorisable): ds2=gμνdxμdxν Our 4-d world μ,ν=0, 1, 2, 3,... D R Our 4-d world y Fourier mode expansion Wrapped: ds =a(y) (gμνdx dx ) + dy 2 μ ν Φ(x,y)=ΣkΦ(k)(x)eiky/R 2 μ,ν=0, 1, 2, 3 Our 4-d world Assume some fields can propagate along y Kaluza Klein (KK) excitations mk2=m02+k2/r2 Momentum in new dimensions mass 4-D (Kaluza Klein resonance) 30

31 Adding extradimensions... A lot of room to play... ADD TeV-1 mued RS1 Bulk RS Topology Flat Flat Flat Wrapped Wrapped N extradim Propagating fields Graviton Vector boson (V) V, fermions Graviton Everything apart Higgs... 31

32 ADD (Arkani-Hamed, Dimopoulos and Dvali) n compactified flat extra-dimensions Only grativity propagates in the bulk Dilution of the gravity Planck mass in 4+nD R Our 4-d world Planck mass in 4D If MPl=1TeV (to address the hierarchy problem): n=1 R=1010km n=2 R=1mm n=3 R=1nm arge R, but gravity not yet probed at these scales!... 32

33 ADD signatures at colliders arge R states close to each other (ΔmeV) continuum s-channel q q KK graviton in final states detected Missing Energy Gamma+MET 33

34 TeV-1 / mued 5D flat bulk R No gravity included Our 4-d world TeV-1: R=O(TeV-1) gauge bosons in the bulk Z', W', gkk 1st, 2nd 3rd, modes well separated Minimal Universal Extra-Dimensions All the SM fields in the bulk Assume momentum conservation in the bulk KK-parity Similar effect than R-parity (pair production of 1st mode, dark matter candidate) 34

35 Randal Sundrum (RS) y Wrapped compacted 5D ds2=e-2krθ (gμνdxμdxν) + Rdθ2 (θ [0,π], kmpl) Wrap factor Our 4-d world Wrap generates vevo(tev) on a brane from Planck scale on another brane Fix hierarchy problem Graviton near Planck brane GKK near TeV brane 35

36 Randal Sundrum (RS) Minimal RS (RS1): Only gravity propagates in bulk Well separated (ΔmTeV) KK gravitons Democratic couplings A Oliveira arxiv:

37 Randal Sundrum (RS) Minimal RS (RS1): Only gravity propagates in bulk Well separated (ΔmTeV) KK gravitons Democratic couplings Bulk RS: Higgs localized on/near TeV brane Other fields in bulk KK resonances 1st and 2nd generations : Planck brane 3rd generation: TeV brane A Oliveira arxiv: large Yukawa Prediction of Vector-like quark (see next slides) 37

38 Compositness 38

39 Compositness Assume new Strong sector (QCD-like) at TeV-scale SO(5) SO(4) + 4 Goldstone bosons (=Higgs doublet) Higgs boson is composite (like pion in QCD) Consequences: Fix naturalness issue agrangian modified as: Stolen to A. Pomarol (SM: a=b=c=1) 39

40 Compositness: consequence SM without Higgs No unitarity at high energy SM with Higgs: unitarity recovered Figures stolen to A. Pomarol 40

41 Compositness: consequence If the Higgs is (partially) composite: Need extra states: Figures stolen to A. Pomarol Also predicts Vector-ike Quarks (VQ) 41

42 Vector-ike Quark (VQ) Predicted by many theories Extra-dimension, Compositness, Grand Unified Theory, Vector-like? 42

43 Vector-ike Quark (VQ) Predicted by many theories Extra-dimension, Compositness, Grand Unified Theory, Vector-like?. Panizzi 43

44 Vector-ike Quark (VQ) Predicted by many theories Extra-dimension, Compositness, Grand Unified Theory, Vector-like?. Panizzi 44

45 VQ VQ mix with SM quarks and interact through Yukawa interactions Various incarnation possible:. Panizzi 45

46 Searching for VQ Production / decay 46

47 Searching for VQ Production / decay 47

48 Searching for VQ Production / decay 48

49 Searching for VQ Production / decay 49

50 Searching for VQ Production / decay 50

51 Conclusion ots of models on the market trying to address dark matter naturalness Of course, I could not present many other models many other problems (ν mass,...) Hors-Série Beyond SM Higgs t H Un avenir pour le TeVatron? 51

52 Backup 52

53 Top-quark mass Important parameter of the SM (meta-)stability of the Higgs field? arger mtop larger corrections M et ast ab il i ty ty Our vacuum St ab i li Energy of empty space vev Exotic vacuum 53