Outlook: Higgs, SUSY, flavor Ken-ichi Hikasa (Tohoku U.) Fourth Workshop, Origin of Mass and SUSY March 8, 2006, Epochal Tsukuba

Apology This is not designed to be a summary talk …, so no reference to most of the talks

Standard Model

SM = GHY  Three elements G: gauge H: Higgs Y: Yukawa

SM = GHY  Three elements G: gauge D  H: Higgs Y: Yukawa  All gauge interactions from D  =   + ig A   Universality: unique coupling, blindness to generations

SM = GHY  Three elements G: gauge H: Higgs  4 Y: Yukawa Symmetry breaking, W,Z masses Higgs mass term  2 : only dimensional parameter in SM (classically)  sets the weak scale

SM = GHY  Three elements G: gauge H: Higgs Y: Yukawa y f f  Fermion couplings to Higgs field give masses to quarks/leptons

SM = GHY  Three elements G: gauge D  H: Higgs Y: Yukawa  Only interaction experimentally confirmed: 2/3 of SM still to be tested

SM = GHY  Three elements G: gauge H: Higgs Y: Yukawa y ij f i f j   No ‘ universality ’ : origin of flavor difference and mixing  Most # of parameters in SM

Generation mixing u1u1 u2u2 d1d1 d2d2 If no Yukawa coupling, generation labels has no meaning

Generation mixing u1u1 u2u2 d1d1 d2d2 Charged current interactions connects ups and downs W±W±

Generation mixing Yukawa couplings breaks the generation symmetry u1u1 u2u2 d1d1 d2d2 u c d s

Generation mixing Mismatch of ups and downs gives the Cabibbo mixing u1u1 u2u2 d1d1 d2d2 u c d s CC W

Leptons If the neutrinos were massless … e 

Leptons Neutrino eigenstates can be defined only by charged current and the lepton flavors are conserved e  e 

Neutrino mass (side remark)  In SM, is made to be massless  Quark-lepton correspondence Naturally expect R & Yukawa R : gauge blind particle (hard to see)  Ultratiny mass suggests different origin  Important question: Dirac or Majorana?

Higgs sector

I weak = ½ Rule  Quark/lepton masses have to be I weak = ½  W, Z masses can have any I weak  Precision measurements: experimental evidence for I weak = ½ dominance

I weak = ½ Rule =1 to high precision  doublet vev dominance

Indirect Higgs limit M top (GeV) M W (GeV)

Direct Higgs searches  Still a long way to go, but worth pursueing

MSSM implies light Higgs

MSSM/two doublet  Large tan  region started to be excluded at Tevatron A0 +-A0 +-

Beyond SM Standard Model is not the final story

(Observational) reasons we need BSM  Gravity  Dark Matter  Dark Energy  Baryon asymmetry  CMB  Neutrino mass

(Theoretical) reasons we need BSM  No strong CP violation  Hierarchy problem?  Too many parameters?  Unification of gravity

Where to seek for BSM  New particles Energy frontier Faint interactions (can be light)  Forbidden processes baryon # violation lepton # violation lepton flavor violation (seen in oscillations, but very small)  Suppressed processes

Weak interaction processes  Superallowed t  b, c  s  CKM suppressed (tree-allowed but small) b  c, u; s  u  GIM suppressed (tree-forbidden) FCNC b  s, d; s  d Good place to look for new physics

BSM Scenarios

Supersymmetry Raison d ’ être aka excuse: Unique nontrivial extension of the Poincaré group (= Einstein ’ s relativity) weak scale: Stabilize Fermi-Planck hierarchy by cancelling loop corrections

Extra Dimensions Raison d ’ être aka excuse: Superstrings require 10 spacetime dimensions for consistency weak scale: (Originally) trading the Fermi-Planck hierarchy for large extra-dim size More recently, branes, Randall-Sundrum hierarchy, …

Extra Dimensions All SM interactions are nonrenormalizable for D>5  Couplings tend to blow up above weak scale: Strong-coupling phenomena at TeV (Technicolor-type physics) Higgsless models: Heavy W,Z recurrences should appear

And many others

Minimal Supersymmetric Standard Model

MSSM  Many parameters (>100)  New sources of flavor structure Sfermion masses (left and right) LR mixing (A term)  New sources of CP violation  LSP neutralino: good DM candidate

D-squark mass matrix One new source of flavor mixing

D-squark mass matrix Chiral substructure of sfermion mass

Vast parameter space  Most regions contradict with neutral Kaon mixing  mSUGRA, CMSSM: tiny regions in the parameter space Useful as a guideline Should not trust too much

Varied phenomenology  Different mass patterns Generally: colored > noncolored Split SUSY: scalars > gauginos Focus point: light higgsinos  Interesting alternatives Gauge mediation: stau LSP Anomaly mediation: light wino R parity violation: exotic resonances

Dark Matter

Rare b decays  In SM, b  s is much more suppressed than b  c  good place for new physics  b-s sfermion mixing can contribute to CP asymmetry

New physics effects on b  s

Sign of SUSY contributions  Extra contribution to s L  Same sign deviation for B  K and  ’ K  New mixing of s R  Opposite sign deviation for B  K and  ’ K

Consequence of possible deviation  If both K and  ’ K deviates in the same direction, new physics are in the left-handed sector (the data are old) Endo, Mishima, Yamaguchi

Lepton-flavor violation  Neutrino mass mixing: way too small effect on charged lepton FV  Supersymmetry: slepton mass matrix gives new LFV source GUT: quark mixing  lepton mixing Right-handed  new mixing source Observable effect expected in   ,   e etc.

Conclusions

 Tevatron has plunged into new luminosity frontier SM Higgs: important target to pursue MSSM/Two doublet: already started to constrain parameter space Supersymmetry, XD, etc: Don ’ t wait for LHC

Conclusions (cont ’ d)  B factories Very rich physics output Good measurements of all 3 angles Hint of new physics??  LFV: unique place to seek for BSM  Kaon physics should not be discontinued

Future LHC, ILC B physics K physics

One final remark ‘Mass-origin’ priority-area grant ends in one month, but We are still on the way!