Introduction to the Beyond the Standard Model session

Transcription

1 Introduction to the Beyond the Standard Model session JRJC 2015 Nov. 19th 2015 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 Cf Talk by Antje 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 Cf Talk by Antje 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 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 e er R R S=1/2 ( )( )( ) u d c s t b u R dr cr s t R br R ( )( )( ) e e er R R g ± W Z S=1/2 S=0 13

14 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 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 ( )( )( ) 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 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 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 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 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 17

18 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 χ±1 χ±2 χ01 χ02 χ03 χ04 S=1/2 S=1/2 Add a pinch of mixing 18

19 Supersymmetry: R-parity R=(-1)+3B+2J /B: leptonic/baryonic 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 19

20 Supersymmetry: R-parity R=(-1)+3B+2J /B: leptonic/baryonic 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 20

21 Breaking SuSy Super-partners not yet observed heavier than SM partners SuSy has to be broken Unknown mechanism Introduces many free parameters Phenomenological assumptions to express results (msugra, MSSM, nmssm, pmssm, ) or Simplified models: branching ratio=100% decouple other sparticles 21

22 A rich phenomenology A simple example 2 b + missing energy 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 A rich phenomenology A more complex one t t t t 26

27 SuSy : summary Addresses naturalness & dark matter Very rich phenomenology A lot of free parameters Difficult to kill Baptiste's talk 27

28 SuSy : summary Addresses naturalness & dark matter Very rich phenomenology A lot of free parameters Difficult to kill Baptiste's talk 28

29 Extra-dimensions Nice ref: M. Besancon, Moriond EW 2010 Models & signatures of extra dimensions at the HC 29

30 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 30

31 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 31

32 Kaluza Klein excitations Compactification Add a space-dimension (y) y y Flat (ie factorisable): ds2=gμνdxμdxν μ,ν=0, 1, 2, 3,... D R Our 4-d world Our 4-d world Fourier mode expansion Φ(x,y)=ΣkΦ(k)(x)eiky/R Kaluza Klein (KK) excitations Assume some fields can propagate along y mk2=m02+k2/r2 Momentum in new dimensions mass 4-D (Kaluza Klein resonance) 32

33 Kaluza Klein excitations Compactification Add a space-dimension (y) y y Flat (ie factorisable): ds2=gμνdxμdxν μ,ν=0, 1, 2, 3,... D R Our 4-d world Our 4-d world y Fourier mode expansion Φ(x,y)=ΣkΦ(k)(x)eiky/R Warped: ds2=a(y) (gμνdxμdxν) + dy2 μ,ν=0, 1, 2, 3 Our 4-d world Kaluza Klein (KK) excitations Assume some fields can propagate along y mk2=m02+k2/r2 Momentum in new dimensions mass 4-D (Kaluza Klein resonance) 33

34 Adding extradimensions... A lot of room to play... ADD mued RS1 Bulk RS Topology Flat Flat Warped Warped N extradim Propagating fields Graviton V, fermions Graviton Everything apart Higgs... 34

35 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... Gravity probed down to 0.1mm 35

36 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 36

37 UED Universal Extra-Dimensions R No gravity included All the SM fields in the bulk Our 4-d world Assume momentum conservation in the bulk KK-parity = (-1)KK Similar effect than R-parity (pair production of 1st mode, dark matter candidate) SM, KK=0 KK=1 SM, R=1 KK=2 KK=1 KK=1 SM, KK=0 KK=1 SM, R=1 KK=1 KK=1 KK=1 KK=0 37

38 Randall Sundrum (RS) y Warped compacted 5D ds2=e-2kry (gμνdxμdxν) + R2dy2 (θ [0,π], kmpl) Warp factor Our 4-d world Warp generates vevo(tev) on a brane from Planck scale on another brane 38

39 Randall Sundrum (RS) y Warped compacted 5D ds2=e-2kry (gμνdxμdxν) + R2dy2 (θ [0,π], kmpl) Warp factor Our 4-d world Warp generates vevo(tev) on a brane from Planck scale on another brane Bulk RS Higgs localized on/near TeV brane Fix hierarchy problem 39

40 Randall Sundrum (RS) y Warped compacted 5D ds2=e-2kry (gμνdxμdxν) + R2dy2 (θ [0,π], kmpl) Warp factor Our 4-d world Warp generates vevo(tev) on a brane from Planck scale on another brane Bulk RS Higgs localized on/near TeV brane Fix hierarchy problem 1st and 2nd generations : Planck brane 3rd generation: TeV brane large Yukawa large 3rd gen. mass 40

41 Randall Sundrum (RS) y Warped compacted 5D ds2=e-2kry (gμνdxμdxν) + R2dy2 (θ [0,π], kmpl) Warp factor Our 4-d world Warp generates vevo(tev) on a brane from Planck scale on another brane Bulk RS Higgs localized on/near TeV brane Fix hierarchy problem 1st and 2nd generations : Planck brane 3rd generation: TeV brane large Yukawa large 3rd gen. mass Fields in bulk KK resonances Prediction of Vector-like quark (see next slides) 41

42 Extra-dimensions... Various kinds of models addressing different issues Topology ADD mued Bulk RS Propagating fields Graviton V, fermions Addresses... Flat Flat N extradim 2 1 Warped 1 Everything apart Higgs Naturalness Naturalness Dark matter... Kirill's talk 42

43 Compositness 43

44 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) 44

45 Compositness: consequence SM without Higgs Cf Philipp Pigard's talk No unitarity at high energy SM with Higgs: unitarity recovered Figures stolen to A. Pomarol 45

46 Compositness: consequence If the Higgs is (partially) composite: Need extra states: Figures stolen to A. Pomarol Also predicts Vector-ike Quarks (VQ) 46

47 Vector-ike Quark (VQ) Predicted by many theories Extra-dimension, Compositness, Grand Unified Theory, Vector-like? 47

48 Vector-ike Quark (VQ) Predicted by many theories Extra-dimension, Compositness, Grand Unified Theory, Vector-like?. Panizzi 48

49 Vector-ike Quark (VQ) Predicted by many theories Extra-dimension, Compositness, Grand Unified Theory, Vector-like?. Panizzi 49

50 VQ VQ mix with SM quarks and interact through Yukawa interactions Various incarnation possible:. Panizzi 50

51 Searching for VQ Production / decay 51

52 Searching for VQ Production / decay 52

53 Searching for VQ Production / decay 53

54 Searching for VQ Production / decay 54

55 Searching for VQ Production / decay Cf Romain's talk 55

56 Conclusion ots of models on the market trying to address dark matter naturalness Hors-Série Beyond SM Higgs t H Of course, I could not present many other models many other problems (ν mass,...) Un avenir pour le TeVatron? 56

57 Backup 57

58 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 58