The first year of the LHC and Theory. G.G.Ross, Krakow, December 09

Transcription

1 The first year of the LHC and Theory G.G.Ross, Krakow, December 09

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3 The LHC a discovery machine The gauge sector : new gauge bosons? The maber sector : new quarks and leptons? The scalar sector : the hierarchy problem and BSM Technicolour, SUSY, Xtra dimensions, LiBle Higgs

4 What can be found in the first year? Interesting cross sections Higgs

5 The (SM) Higgs search Higgs particle (scalar, spin 0) H LHC search Tevatron Run II Preliminary, L= fb -1 fb 1 95% CL Limit/SM 10 LEP Exclusion Expected Observed!1! Expected!2! Expected Tevatron Exclusion 1 SM March 5, m H (GeV/c 2 ) p p q q H q q W W... Tevatron competton

6 What can be found in the first year? Interesting cross sections Susy 4 th family Z Technihadrons Higgs

7 A new gauge boson? Extension of the SM gauge symmetry quite likely U (1)', SU (2) R, SO(10), E 6, SU (3) family,... Minimal Z models SU (3) SU (2) U (1) U (1)' Only SM fermions + RH neutrinos Flavour blind couplings, no anomalies

8 SU (3) SU (2) U (1) U (1)' Higgs doublet, H, and singlet, φ Choose basis to eliminate kinetic mixing term F µν F ' µ (at one scale) SO(2) rotation - U(1) 1 decouples from φ Rescaling U (1) 1 coupling H charge =+1 U(1) 1 U (1) Y SU (3) SU (2) U (1) Y U (1) z Mass term: Appelquist, Dobrescu, Hopper

9 Anomaly cancellaton and fermion mass terms: L NC = eaj EM + g Z ( ZJ Z + Z ' J z ' ) 3 independent parameters J z ' = (g Y / g Z )J Y + (g BL / g Z )J B L g Z, g BL, M Z ' c.f. specific models

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11 Salvioni, Villadora, Zwirner

12 Salvioni, Villadora, Zwirner

13 Salvioni, Villadora, Zwirner

14 Family dependent couplings : Salvioni, Strumia, Villadora, Zwirner

15 ?

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20 The scalar sector : the hierarchy problem and BSM Technicolour, SUSY, Xtra dimensions, LiBle Higgs

21 Supersymmetry? Susy SUSY mass scale?

22 The (LiBle) Hierarchy problem M Higgs, MW,Z M Planck, MGUT,... CMSSM: Gravity mediated SUSY breaking R parity m, m, A, tan β, sgn(µ) 0 1/ GeV (SM ) ( ) m q i M 2 Z = 2 a 0 m a 1/ 2 m 1/ 2 + µ 2 Fine tuning 2, Mi 2

23 Fine tuning measure Δ( ρ) = δρ 2 M Z 2 M Z ρ, Δ = Max Δ( ρ) max ρ Ellis et al., Barbieri, Giudice CMSSM S.Cassel, D.Ghilencea, GGR

24 Fine tuning measure Δ( ρ) = δρ 2 M Z 2 M Z ρ, Δ = Max Δ( ρ) max ρ Barbieri, Giudice S.Cassel, D.Ghilencea, GGR

25 SUSY parameters

26 SUSY parameters LHC s = 10(14)TeV L = 10 fb 1 m g 1.9(2.4)TeV Δ = 120(180) s = 10TeV L = 10 pb 1 m g 0.6TeV Δ = 14 Higgs search most sensitve

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28 lible hierarchy problem already severe But not all parameter space probed yet

29 Nonuniversal gaugino masses d 16π 2 dt m 2 =3( 2 y H u t 2 2 (m Hu + m 2 Q3 + m 2 ) + 2 a u 3 t 2 ) 6g 2 2 M g 2 M New focus point: cancellation between M 3 and M 2 contributions if M 2 2 M 3 2 at M SUSY Natural ratos? e.g.: GUT: SU(5) : Φ N ( 24 24) symm = ; SO(10) : ( 45 45) symm = String: ( 3 + δ GS ) :( 1+ δ GS ) : δ GS (also mixed moduli anomaly)

30 D.Horton,GGR Characteristic signals: M 1 : M 2 : M 3 = 0.5η 1 :1: 2.7η 3, light Higgsino µ 200GeV M 1/ 2

31 Supersymmetric Higgs search h bb dominant decay mode in MSSM h AA can dominate in extensions of the MSSM, e.g. NMSSM Dermisek, Gunion

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33 Supersymmetric Higgs search h bb dominant decay mode in MSSM h AA can dominate in extensions of the MSSM, e.g. NMSSM A τ + τ, cc, gg h 4τ, 4c, 4g, 2τ 2c, 2τ 2g, 2c2g, bb ( ) would not have been seen at LEP

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35 LHC search pp µ + µ X gg a µ + µ For s = 10(7)TeV, reduced by factor 0.8(0.6) 5σ discovery: 200(300) pb 1 Dermisek, Gunion

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37 LHC SUSY search m q m g 400GeV σ i 10 5 fb! p p t t c t t Z Z } Invisible Dark ma2er? But E T signals will take some time to confirm...not in 1st run? Baer, Barger, Lesser, Tata

38 MulT muon + jets signals with no missing energy requirement 10TeV CM energy is 5 current energy reach Signal v/s background

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43 Technicolour EW symmetry broken by technicolour condensate Must be non QCD like to avoid FCNC and satsfy precision tests(?) Walking TC allows larger quark and technipion masses Technivector mesons, ρt, ω T expected to be narrow and easily visible

44 D.Schaich

45 Summary LHC run at 10TeV with fb 1 will probe new physics: 4 th family M 300GeV Higgs enhancement Z ' M 1TeV Z ' e+ e,µ + µ,... Technicolour M 400GeV (?) SUSY M GeV Even without E T multimuon + jet signals provide viable SUSY signals Light Higgs, nonstandard decays detectable

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47 Further mass and spin measurement methods being devised to deal with P T and M.

48 Gokhan Unel, CERN workshop 2009

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