P. Langacker ICHEP2004 (8/16/04) Low Energy Electroweak Precision Tests Perspective –Motivations –Precision program WNC experiments Universality EDMs, g-2 FCNC

P. Langacker ICHEP2004 (8/16/04)

Motivations WNC, Z, W established SU(2) X U(1) SM Z pole most precise (0.1%) and excluded many BSM scenarios However, Z pole is blind or less sensitive to many types of new physics (Z’, SUSY loops, RPV, new operators, exotics, leptoquarks, LED) Running sin 2  W (new physics) Precision low energy WNC (few percent) still important FCNC, g-2, EDMs complementary to WNC, Z pole and collider

P. Langacker ICHEP2004 (8/16/04) A Heavy Z’? Strings, GUTs, LED, DSB, Little Higgs (best motivated after SUSY) Solution to  problem Highly nonstandard Higgs (doublet-singlet mixing) and neutralino sectors Chiral exotics Electroweak baryogenesis Cold dark matter Family nonuniversality: tree level contribution to rare B decays

P. Langacker ICHEP2004 (8/16/04)

Weak Neutral Current below the Z-pole Z-pole insensitive to effects not directly involving Z Loop effects from new physics: (  /  )(M/M new ) 2 (Shufang Su) –muon g-2: M=m ,  new  2x10 -9,  exp < –  -decay,  -decay: M=m W,  new  10 -3,  exp  –parity-violating electron scattering: M=m W,  new  Q W e,p  1-4 sin 2  W  0.1 –Also, suppression Q W e,p  1-4 sin 2  W  0.1

P. Langacker ICHEP2004 (8/16/04) (Shufang Su)

P. Langacker ICHEP2004 (8/16/04) RPV 95% CL MSSMloop Kurylov, Ramsey-Musolf, Su (2003)

P. Langacker ICHEP2004 (8/16/04) SLAC E158 Moller Scattering e - e - polarization asymmetry, P = 85% I + II prelim:  s 2 = Compositeness scale: 10 TeV; Z’ ~0.8 TeV Run III (summer 04): (Kolomensky talk on E158 website) (Run I)

P. Langacker ICHEP2004 (8/16/04)

Q weak (Jlab)  s 2 ~ Complementary to Moller Form factors can be measured

P. Langacker ICHEP2004 (8/16/04) Atomic Parity Violation Very sensitive to Z’, leptoquarks, RPV Washington: thallium (optical rotation) 1%, but theory 2.7% Boulder: cesium (Stark) –Q W = (48) (SM: (3)) –“turbulent 2 yr” (Breit, vacuum pol.,  Z vertex, nuclear skin) –Anapole: discrepancy with nuclear physics expectations Future –Paris cesium- may become competitive –Berkeley: Yb isotopes (wave functions cancel, but nuclear radius; reduced sensitivity to new physics) –Washington: Ba + ions (0.1% may be possible) –KVI: Ra + considered

P. Langacker ICHEP2004 (8/16/04) NuTeV NC/CC; and -bar 3  discrepancy in R N

P. Langacker ICHEP2004 (8/16/04) Beyond standard model strained –Not SUSY loops or RPV –Hard to fit leptoquark –Designer Z’ possible –Mixing of  - heavy + more miracles Radiation from final lepton in cc (needs checking) NLO QCD: suppressed by sin 4  W but may be important –New analysis very important Nuclear effects unlikely 30% s-sbar asymmetry possible (controversial) 5% isospin breaking possible, but naively expect 0.5% –NOMAD, Q weak, other JLAB

P. Langacker ICHEP2004 (8/16/04) NOMAD     e oscillations Deep inelastic scattering (CC and NC) Expect 1% sin 2  W

P. Langacker ICHEP2004 (8/16/04) Outlook NOMAD Q WEAK Possible APV Possible reactor e -bar, in conjunction with oscillation experiment (  s 2 W ~0.001) Near detectors for long baseline? Neutrino factory?

P. Langacker ICHEP2004 (8/16/04) CKM Universality |V ud | 2 + |V us | 2 + |V ub | 2 ~ |V ud | 2 + |V us | 2  1 –  –PDG 2002:  = ± –New physics? Constrains  heavy explanations of NuTeV –Problem in V ud ? Superallowed: |V ud |=0.9740(5), many checks Neutron: (16) (common structure- independent rad corr) Pion beta decay: (39) (new) –Problem in V us ?

P. Langacker ICHEP2004 (8/16/04) PDG value mainly from old K e3. Radiative corrections? New BNL865 K +, KTEV K L, KLOE K S consistent with  =0. Not CERN NA48. Also hyperon decay data (theory errors) (C. Quigg)

P. Langacker ICHEP2004 (8/16/04)

The BNL g-2 experiment

P. Langacker ICHEP2004 (8/16/04)

Discrepancy between e + e - and  decay New e + e - data Work on isospin violation Hadronic light by light If real discrepancy then SUSY with large tan  and low masses is possibility: tan  /(M SUSY /100 GeV) 2 ~2 Proposal to improve experimental error by 2 Can theory error keep up?

P. Langacker ICHEP2004 (8/16/04) Electric Dipole Moments New probe of T (CP) violation New phases needed for baryogenesis EDMs small in SM, large in most BSM, e.g. SUSY MSSM: 62 new real parameters and 43 new phases –Universal soft breaking => two new phases   A = arg(A * m 1/2 ),  B = arg(B *  m 1/2 )  (300 GeV/m) 2 sin  A,B < T S d P

Electron EDM in various SM extensions not renormalizable  loop diagrams  e e Experimental limit: |d e | < 1.6  e  cm Physics model|d e | Standard Model~ e·cm Left-right symmetric e·cm Lepton flavor- changing e·cm Multi-Higgs e·cm Technicolor e·cm Supersymmetry< e·cm B. Regan, E. Commins, C. Schmidt, D. DeMille, PRL 88, (2002) Models assume new physics at ~100 GeV & CP-violating phases ~1 (D. DeMille)

P. Langacker ICHEP2004 (8/16/04)

n (ILL,PNPI)Hg (Seattle)Tl (Berkeley) EDM <7  <2  <1  dndn 7   dede 15    QCD 4    q/l, SUSY 1    x q/l, LR 1     Higgs 3/tan  0.4/tan  0.3/tan  Current status of ALL EDM searches Best limits on “natural” parameters from 3 complementary experiments: (D. DeMille)

P. Langacker ICHEP2004 (8/16/04) A new generation of electron EDM searches GroupSystemAdvantagesProjected gain D. Weiss (Penn St.)Trapped CsLong coherence~100 D. Heinzen (Texas)Trapped CLong coherence~100 H. Gould (LBL)Cs fountainLong coherence? L. Hunter (Amherst)GdIGHuge S/N100? S. Lamoreaux (LANL)GGGHuge S/N100?-100,000? E. Hinds (Imperial)YbF beamInternal E-field2-? D. DeMille (Yale)PbO* cellInternal E-field100-10,000? E. Cornell (JILA)trapped HBr + Int. E + long T?? N. Shafer-Ray (Okla.)trapped PbFInt. E + long T?? (D. DeMille)

P. Langacker ICHEP2004 (8/16/04) Flavor Violation Lepton flavor almost conserved in SM (up to m ) Violated in SUSY, multi-Higgs, heavy, leptoquark, non-universal Z’, compositeness MECO (BNL): (  N->eN)/(  N-> N) to 2 x –Sensitive to many BSM –SINDRUM: 6.1 x –Future: PRIME at PRISM: also,  ->e  at PSI: (2 orders) Rare B, K decays? E.g., B->  K s (Belle, not BaBar),  K; K ->  -bar (Tree level Z’ vs SM and SUSY loops.)

P. Langacker ICHEP2004 (8/16/04)

TWIST Measure  decay electron spectrum/angular distribution precisely Sensitive to new couplings, including RHC (eg, W R ) 2 x in 05/06 Left/Right Mixing constraints – Anticipated TWIST Sensitivity Mixing angle 

P. Langacker ICHEP2004 (8/16/04) Summary Intellectual prospects in high energy physics have never been higher Theoretical opportunities for standard model of everything, but must make connections Experimental exploration of TeV scale and beyond Collider searches: LHC is likely to be a rich but complicated discovery machine Precision, rare/suppressed, neutrino experiments will give complementary constraints 10 yr ago: almost every extension of SM yields neutrino masses/mixings at some level Now: almost every extension of SM yields EDMs, FCNC at some level, and may be other surprises