Low Energy Electroweak Precision Tests Perspective Motivations Precision

Low Energy Electroweak Precision Tests • Perspective –Motivations –Precision program • WNC experiments • Universality • EDMs, g-2 • FCNC P. Langacker ICHEP 2004 (8/16/04)

P. Langacker ICHEP 2004 (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 ICHEP 2004 (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 ICHEP 2004 (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/Mnew)2 (Shufang Su) – muon g-2: M=m , new 2 x 10 -9, exp < 10 -9 -decay, -decay: M=m. W , new 10 -3, exp 10 -3 parity-violating electron scattering: M=m. W , new 10 -3 – Also, suppression QWe, p 1 -4 sin 2 W 0. 1 – – P. Langacker ICHEP 2004 (8/16/04)

(Shufang Su) P. Langacker ICHEP 2004 (8/16/04)

RPV 95% CL MSSM loop Kurylov, Ramsey-Musolf, Su (2003) P. Langacker ICHEP 2004 (8/16/04)

SLAC E 158 Moller Scattering e-e- polarization asymmetry, P = 85% I + II prelim: Ds 2=0. 0021 Compositeness scale: 10 Te. V; Z’ ~0. 8 Te. V Run III (summer 04): 0. 0015 (Kolomensky talk on E 158 website) P. Langacker (Run I) ICHEP 2004 (8/16/04)

P. Langacker ICHEP 2004 (8/16/04)

P. Langacker ICHEP 2004 (8/16/04)

P. Langacker ICHEP 2004 (8/16/04)

Qweak (Jlab) Ds 2~0. 0007 Complementary to Moller Form factors can be measured P. Langacker ICHEP 2004 (8/16/04)

Atomic Parity Violation • Very sensitive to Z’, leptoquarks, RPV • Washington: thallium (optical rotation) 1%, but theory 2. 7% • Boulder: cesium (Stark) – QW = -72. 69(48) (SM: -73. 19(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 ICHEP 2004 (8/16/04)

Nu. Te. V NC/CC; n and n-bar 3 s discrepancy in Rn. N P. Langacker ICHEP 2004 (8/16/04)

• Beyond standard model strained – – Not SUSY loops or RPV Hard to fit leptoquark Designer Z’ possible Mixing of n- nheavy + 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, Qweak, other JLAB P. Langacker ICHEP 2004 (8/16/04)

NOMAD • n -> nt, ne oscillations • Deep inelastic scattering (CC and NC) • Expect 1% sin 2 W P. Langacker ICHEP 2004 (8/16/04)

Outlook • NOMAD • QWEAK • Possible APV • Possible reactor ne-bar, in conjunction with oscillation experiment (D s 2 W~0. 001) • Near detectors for long baseline? • Neutrino factory? P. Langacker ICHEP 2004 (8/16/04)

CKM Universality • |Vud|2 + |Vus|2 + |Vub|2 ~ |Vud|2 + |Vus|2 1 – D – PDG 2002: D = 0. 0042 ± 0. 0019 – New physics? Constrains n-nheavy explanations of Nu. Te. V – Problem in Vud? • Superallowed: |Vud|=0. 9740(5), many checks • Neutron: 0. 9745 (16) (common structureindependent rad corr) • Pion beta decay: 0. 9716(39) (new) – Problem in Vus? P. Langacker ICHEP 2004 (8/16/04)

• • PDG value mainly from old Ke 3. Radiative corrections? New BNL 865 K+, KTEV KL, KLOE KS consistent with D=0. Not CERN NA 48. Also hyperon decay data (theory errors) (C. Quigg) P. Langacker ICHEP 2004 (8/16/04)

P. Langacker ICHEP 2004 (8/16/04)

The BNL g-2 experiment

P. Langacker ICHEP 2004 (8/16/04)

P. Langacker ICHEP 2004 (8/16/04)

• Discrepancy between e+e- and t 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 /(MSUSY/100 Ge. V)2~2 • Proposal to improve experimental error by 2 • Can theory error keep up? P. Langacker ICHEP 2004 (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 d P S T – Universal soft breaking => two new phases § f. A = arg(A* m 1/2), f. B = arg(B* m 1/2) § (300 Ge. V/m)2 sin f. A, B < 10 -2 P. Langacker ICHEP 2004 (8/16/04)

Electron EDM in various SM extensions not renormalizable loop diagrams e e Physics model |de| Standard Model Left-right symmetric ~10 -41 e·cm Experimental limit: |de| < 1. 6 10 -27 e cm B. Regan, E. Commins, C. Schmidt, D. De. Mille, PRL 88, 071805 (2002) 10 -26 -10 -28 e·cm Lepton flavorchanging Multi-Higgs Technicolor 10 -26 -10 -29 e·cm Models assume new physics at ~100 Ge. V & CP-violating phases ~1 10 -27 -10 -28 e·cm 10 -27 -10 -29 e·cm (D. De. Mille) Supersymmetry < 10 -25 e·cm

P. Langacker ICHEP 2004 (8/16/04)

Current status of ALL EDM searches (D. De. Mille) Best limits on “natural” parameters from 3 complementary experiments: EDM dn n (ILL, PNPI) Hg (Seattle) Tl (Berkeley) <7 10 -26 <2 10 -28 2 10 -25 <1 10 -24 15 10 -27 1. 6 10 -27 de QCD q/l, SUSY 4 10 -10 2 10 -10 1 10 -2 2 10 -3 1 10 -2 xq/l, LR 1 10 -2 1 10 -3 3 10 -2 Higgs 3/tan 0. 4/tan 0. 3/tan P. Langacker ICHEP 2004 (8/16/04)

A new generation of electron EDM searches (D. De. Mille) Group System Advantages Projected gain D. Weiss (Penn St. ) Trapped Cs Long coherence ~100 D. Heinzen (Texas) Trapped C Long coherence ~100 H. Gould (LBL) Cs fountain Long coherence ? L. Hunter (Amherst) Gd. IG Huge S/N 100? S. Lamoreaux (LANL) GGG Huge S/N 100? -100, 000? E. Hinds (Imperial) Yb. F beam Internal E-field 2 -? D. De. Mille (Yale) Pb. O* cell Internal E-field 100 -10, 000? E. Cornell (JILA) trapped HBr+ Int. E + long T ? ? N. Shafer-Ray (Okla. ) trapped Pb. F Int. E + long T ? ? P. Langacker ICHEP 2004 (8/16/04)

Flavor Violation • Lepton flavor almost conserved in SM (up to mn) • Violated in SUSY, multi-Higgs, heavy n, leptoquark, non-universal Z’, compositeness • MECO (BNL): ( N->e. N)/( N->n. N) to 2 x 10 -17 – Sensitive to many BSM – SINDRUM: 6. 1 x 10 -16 – Future: PRIME at PRISM: 10 -18 • also, ->eg at PSI: 10 -13 (2 orders) • Rare B, K decays? E. g. , B-> f. Ks (Belle, not Ba. Bar), K; K -> n n-bar • (Tree level Z’ vs SM and SUSY loops. ) P. Langacker ICHEP 2004 (8/16/04)

P. Langacker ICHEP 2004 (8/16/04)

P. Langacker Left/Right Mixing constraints – Anticipated TWIST Sensitivity Mixing angle • Measure decay electron spectrum/angular distribution precisely • Sensitive to new couplings, including RHC (eg, WR) • 2 x 10 -4 in 05/06 TWIST ICHEP 2004 (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 Te. V 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 P. Langacker ICHEP 2004 (8/16/04)