Shufang Su • U. of Arizona Parity Violation and determination of sin2W Shufang Su • U. of Arizona Hall C 2006 summer workshop

Outline Determination of sin2eff Neutral current measurements - Determination of sin2eff Neutral current measurements parity violating electron scattering (PVES) ee Moller scattering (SLAC E158, Jlab 12 GeV) ep elastic scattering (Jlab Qweak) - Parity violation deep inelastic scattering (DIS-parity) atomic parity violation (APV) neutrino-nucleus deep inelastic scattering (NuTeV) probe new physics beyond SM some QCD issue Conclusion S. Su

Low energy precision measurements address questions difficult to study at high energy weak interactions (parity violation) high precision low energy experiment available - muon g-2: M=m , new  2x10-9, exp < 10-9 -decay, -decay: M=mW , new  10-3, exp  10-3 parity-violating electron scattering: M=mW , new  10-3, 1/QWe,p 10 more sensitive to new physics need exp  10-2 “easier” experiment - size of loop effects from new physics: (/)(M/Mnew)2 QWe,p  1-4 sin2W  0.1 probe new physics off the Z-resonance - sensitive to new physics not mix with Z S. Su

Møller Scattering DIS-Parity Z Møller Scattering Purely Leptonic e g Z Q-Weak (JLab) Coherent quarks in P Results in ~2008 2(2C1u+C1d) e g Z p n DIS-Parity Isoscaler quark scattering (2C1u-C1d)+Y(2C2u-C2d) e g Z Cs133 Atomic Parity Violation Coherent quarks in entire nucleus Nuclear structure uncertainties -376 C1u – 422 C1d n m W Z + Neutrino Scattering Quark scattering (from nucleus) Weak charged and neutral current difference S. Su Courtesy of P. Reimer and R. Arnold

Test of sin2W running Weak mixing angle sinW g sinW = g’ cosW = e - Weak mixing angle sinW g sinW = g’ cosW = e Jlab Moller QWe Qweak SLAC E158 NuTeV Standard Model Prediction Erler, Kurylov & Ramsey-Musolf, Phys. Rev. D 72, 073003 (2005) Cs APV DIS-parity S. Su

Precision of sin2W determination - Measurement Δsin2θW/sin2θW Δsin2θW Z-pole 0.07% 0.00016 0.5% Qw(Cs) 0.7% 0.0016 NuTeV 13.1% Qw(e)SLAC 0.5% 0.0013 2.5% Qw(e)Jlab 0.1% 0.00025 (on par with Z pole) 4% QW(p) 0.3% 0.00072 0.8% DIS-parity 0.45% 0.0011 Talk by D. Mack Talk by K. Paschke S. Su

Sensitivity to new physics scale - Ramsey-Musolf(1999) O(1) : new physics scale courtesy of Carlini Take  QWp=4% probe new physics scale comparable to LHC confirmation of LHC discovery (couplings, charges) S. Su

NC exp as a indirect probe of new physics - SM is a low energy approximation of a more fundamental theory SUSY: minimal Supersymmetric extension of SM (MSSM) each SM particle superpartner - with R-parity : loop corrections - without R-parity: tree-level contribution extra Z’ - exists in extension of SM - constraints from Z-pole observable (mix with Z) leptoquark extra-dimension … spin differ by ½ S. Su

M(ZΧ) M(ZLR) (TeV) (TeV) Misc. model sensitivities (non-SUSY) - Courtesy of D. Mack Experiment Z’ M(ZΧ) M(ZLR) (TeV) (TeV) Leptoquarks MLQ(up) MLQ(down) (TeV) (TeV) Compositeness (LL) e-q e-e (TeV) (TeV) Colliders (LEP2, CDF,Hera) .67 .80 “1.5” “1.5” 0.5% Qw(Cs) exists! 1.2 1.3 4.0 3.8 28 --- 13.1% Qw(e) .66 .34 --- --- --- 13 2.5% Qw(e) 1.5 .77 --- 29 4% Qw(p) under construction .95 .45 3.1 4.3 28 ---- scaled from R-Musolf, PRC 60 (1999), 015501 Collider limits from Erler and Langacker, hep-ph/0407097 S. Su

Moller and Qweak - A V weak charge QWf = 2gfV = 2 If3 -4Qfs2 S. Su

Moller and Qweak QWp (Qweak) QWe (SLAC) QWe (Jlab) - QWp (Qweak) QWe (SLAC) QWe (Jlab) QWe,p tree 1-4s2 -(1-4s2) QWe,p loop 0.0721 -0.0449 q2 0.03 GeV2 0.026 GeV2 0.008 GeV2 ALR -0.29 ppm -0.131 ppm -0.04 ppm exp precision 4% 13% 2.5%  sin2W 0.0007 0.0013 0.00025 clean environment: Hydrogen target theoretically clean: small hadronic uncertainties tree level  0.1  sensitive to new physics S. Su

MSSM correction to weak charge - QWf =  (2Tf3 - 4Qf  s2) + f Kurylov, Ramsey-Musolf, Su (2003) QWe and QWp correlated dominant :  (<0)  negative shift in sin2W MSSM  (QWp)SUSY / (QWp)SM < 4%,  (QWe)SUSY / (QWe)SM < 8% S. Su

R-parity violating (RPV) RPV operators contribute to QWe,p at tree level Kurylov, Ramsey-Musolf, Su (2003) RPV 95% CL MSSM loop No SUSY DM Exp constraints  decay: |Vud| = -0.00145  0.0007 APV(Cs):  QWCs = -0.0040  0.0066 Re/ :  Re/ = -0.0042  0.0033 G:  G = 0.00025  0.00188 Future 2.5% Moller QpW 4% Qweak I) Obtain 95% CL allowed region in RPV coefficients II) Evaluate  QWe and  QWp G S. Su

Correlation between QWp , QWe - Distinguish new physics Erler, Kurylov and Ramsey-Musolf (2003) exp MSSM: extra Z’: RPV SUSY leptoquark  QWp  QWe SM  0.0029 SM  0.0052 Distinguish via APV QWCs Combinations of NC exps could be used to distinguish various new physics S. Su

? Extract QWp use kinematics to simplify: at forward angle  - use kinematics to simplify: at forward angle  ? Musolf et. al., (1994) measure F(,q2) over finite range in q2, extrapolate F to small q2 existing PVES: SAMPLE, HAPPEX, G0, A4 minimize effect of F by making q2 small q2  0.03 GeV2, still enough statistics   QpW / QpW | hadronic effects  2 % S. Su

QCD correction to ep scattering - Box diagram contribution to QWP Erler, Kurylov and Ramsey-Musolf (2003) e p Z  e p W e p Z e p Z  suppression non-calculable Similar to nuclear -decay e e- n p  W  QWP 26% 3% 6% kloop » O(mW) kloop » O(mZ) QCD  kloop  O(mZ) |CW|  2 (CKM unitarity) |CZ|  2 non-perturbative using OPE (pQCD)  QWP (QCD) 0.7% 0.08% 0.65% Total theoretical uncertainty » 0.8% S. Su

DIS-parity: eD scattering Longitudinally polarized electrons on unpolarized deuterium target — Cahn and Gilman, PRD 17 1313 (1978). S. Su

Sensitivity to sin2W Large asymmetry Q2 = 3.7 GeV2, Ad = 0.0003 - Large asymmetry Q2 = 3.7 GeV2, Ad = 0.0003 “Easy experiment”  Ad/Ad = 0.8%   sin2 W/sin2W = 0.45% S. Su

Ranges of C1u, C1d, C2u, C2d - Courtesy of P. Reimer S. Su

SUSY contributions - DIS-parity S. Su

Atomic parity violation - Two approaches rotation of polarization plane of linearly polarized light apply external E field  parity forbidden atomic transition Boulder group: cesium APV 0.35% exp uncertainty wood et. Al. (1997) QW(Z,N)=(2Z+N)QWu+(Z+2N)QWd ¼ Z(1-4 sin2W)-N ¼ -N finite nuclear size nucleon substructure nuclear spin-dependent term  »  0.15% Pollock and Wieman (2001) Musolf (1994) Erler, Kurylov and Ramsey-Musolf (2003) atomic structure 1% Blundell et. al. (1990, 1992) Dzuba et. Al. (1989) reduced error 0.6% (exp + theory) via transit dipole amplitude measurement Bennett and Wieman (1999) + 2.5  deviation (2002) Breit interaction  Derevianko (2000), Dzuba et. al. (2001) Uehling potential  Johnson et. al. (2001), Milstein et. al. (2002) QED self-energy and vertex  Dzuba et. Al. (2002), Kuchiev and Flambaum (2002), Milstein et. al. (2002) QWCs (exp) = -72.69  0.48 QWCs(SM)=-73.16 agree S. Su

Sensitivity to new physics - Distinguish new physics  QW (Z,N)=(2Z+N)  QWu +(2N+Z)  QWd  QWu >0  QWd <0   QW(Z,N) / QW(Z,N) < 0.2 % for Cs MSSM exp MSSM: extra Z’:  QWCs small sizable  QWp SM  0.0029  QWe  0.0052 Erler, Kurylov and Ramsey-Musolf (2003) S. Su

Outlook -- APV Paris group: more precise Cs APV Seattle group: Ba+ APV 6S1/2  5D3/2 Berkeley group: isotope Yb APV eliminate large atomic structure theory uncertainties 0.2% uncertainties comparable to QWp in sensitivity to new physics Ramsey-Musolf(1999) S. Su

NuTeV experiment NC CC gL,R2=(uL,R)2+(dL,R)2 - NC CC gL,R2=(uL,R)2+(dL,R)2 R=-0.0033  0.0015 R=-0.0019  0.0026 - exp fit: (gLeff)2=0.30050.0014, (gReff)2=0.03100.0011 SM EW fit: (gLeff)2=0.3042, (gReff)2=0.0301 S. Su

NuTeV anomaly … exp fit (=1): sin2Won-shell = 0.2277  0.0016 SM fit to Z-pole: sin2Won-shell = 0.2227  0.00037 (3  away) To explain NuTeV anomaly nuclear shadowing Miller and Thomas (2002), Zeller et. Al. (2002), Kovalenkov, schmidt and Yang (2002) asymmetry in strange sea distribution Davidson, Forte, Gambino, Rius and Strumia (2002), Goncharov et. al. (2001) isospin symmetry breaking Bodek et. al. (1999), Zeller et. Al. (2002) QCD corrections Dobrescu and Ellis (2003), Kretzer et. al. (2003), Davidson et. al. (2002) … S. Su

New physics explanation - Difficult ! Supersymmetry:  R,   0 Kurylov, Ramsey-Musolf, Su (2003), Davidson, Forte, Gambino, Rius and Strumia (2002) Extra Z’ : family non-universal, finetuning Langacker and Plumacher (2000) Leptoquark: tune mass splitting Davidson, Forte, Gambino, Rius and Strumia (2002)  mixing with extra heavy neutrino: constraints from other observables Babu and Pati (2002), Loinaz et. al. (2003) - MSSM RPV S. Su

Conclusion precision measurements of sin2W at low energy - precision measurements of sin2W at low energy - PV ee, ep scattering (E158, Jlab Moller, Qweak) - eD DIS-parity - APV measurements - NuTeV consistency check of SM sensitive to new physics complementary to direct searches combinations of several exp  distinguish various new physics uncertainties caused by QCD - extract from experimental measurements - SM predictions S. Su

Talks in this workshop Talk in parity violation K. Paschke: DIS-parity D. Mack: Moller Parity Talk in parity violation S. Su