Probing Supersymmetry with Neutral Current Scattering Experiments Shufang Su • U. of Arizona

Sub-Z precision measurements neutral current scattering heavy quark physics CP violation, EDM Rare K-decay, CKM unitarity muon g-2 lepton flavor violation … polarized ee scattering (SLAC E158) polarized ep scattering (JLab Qweak) neutrino-nucleus scattering (NuTeV) A. Kurylov, M. Ramsey-Musolf, SS S. Su LOOPFESTIII

Outline motivation parity-violating electron scattering experiments radiative corrections to weak charge QW analysis of SUSY contributions to QW MSSM contributions RPV analysis distinguish various new physics / SUSY NuTeV experiment conclusion S. Su LOOPFESTIII

Motivation high precision low energy experiment available - 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/Qe,pW 10 more sensitive to new physics need exp  10-2 “easier” experiment indirect+direct: complementary information consistency test of theory at loop level size of loop effects from new physics: (/)(M/Mnew)2 Qe,pW  1-4 sin2W  0.1 probe new physics off the Z-resonance - sensitive to new physics not mix with Z S. Su LOOPFESTIII

Test of sin2W running sin2W(0) - sin2W(mZ2) = +0.007 QCsw: agree Q2=0 NuTeV: +3 Q2=20 (GeV)2 parity-violating electron scattering (PVES) ee Moller scattering (SLAC) QeW ep elastic scattering (J-lab) QpW - -  sin2W  0.0007 at Q2=0.03 (GeV)2 clean environment: Hydrogen target theoretically clean: small hadronic uncertainties tree level  0.1  sensitive to new physics S. Su LOOPFESTIII

Goal Develop consistency checks for theories of new physics - Develop consistency checks for theories of new physics using the low energy precision measurements minimal Supersymmetric extension of SM (MSSM) SUSY: most promising candidate for new physics solution to Hierarchy problem gauge coupling unification provide a natural electroweak symmetry breaking dark matter candidate ? (PVES) with R-parity : loop corrections without R-parity: tree-level contribution low-energy precision measurements PVES: weak charge QeW , QpW , ( QCsW ) - NuTeV: R() - S. Su LOOPFESTIII

Weak charge QW A N+-N- ALR  QfW N++N- V geA = Ie3 weak charge QfW = 2gfV = 2 If3 -4Qfs2 ep Qweak exp QpW ee Moller exp QeW Qe,pW tree 1-4s2 -(1-4s2) Qe,pW loop 0.0721 -0.0449 exp precision 4% 8%  sin2W 0.0007 0.0009 SM running 10  8  QCsW :  sin2W = 0.0021 NuTeV:  sin2W = 0.0016 S. Su LOOPFESTIII

General structure of radiative corrections to QfW - Including radiative corrections: QfW =  (2If3 - 4  Qf s2) + f , : universal, f: depend on fermion species  = 1+SM+SUSY,  = 1+SM+SUSY, f= fSM+fSUSY correction to muon life time  S. Su LOOPFESTIII

Radiative contributions - QfW =  (2If3 - 4  Qf s2) + f correction to , G and mZs2  f S. Su LOOPFESTIII

MSSM particle contents - Spin differ by 1/2 SM particle superpartner mass parameter mqL2,  mqR2,  mqLR2  mlL2,  mlR2,  mlLR2  , tan=vu/vd M3 M2 M1 S. Su LOOPFESTIII

One loop SUSY contributions to PVES - gauge boson self-energies external leg corrections vertex corrections box diagrams S. Su LOOPFESTIII

50 GeV < mq, ml, M1,2,  < 1000 GeV Numerical analysis - Model-independent analysis MSSM parameter range: random scan 50 GeV < mq, ml, M1,2,  < 1000 GeV 1.4 < tan < 60 ~ hard to impose bounds on certain MSSM parameter show the possible range of MSSM corrections impose exp search limit on SUSY particles impose S-T 95% CL constraints impose g-2 constraints (2nd slepton LR mixing) S. Su LOOPFESTIII

Correction to weak charge - QfW =  (2Tf3 - 4Qf  s2) + f QeW and QpW correlated dominant :  (<0)  negative shift in sin2W  (QpW)SUSY / (QpW)SM < 4%,  (QeW)SUSY / (QeW)SM < 8% S. Su LOOPFESTIII

Dominant contributions - QfW =  (2Tf3 - 4Qf  s2) + f non-universal corrections vertex + wavefunction : cancel box diagrams numerically suppressed  contribution suppressed by (1-4 s2) dominant contribution from   (<0)  negative shift in sin2W S. Su LOOPFESTIII

R-parity General MSSM, including B,L-violating operators ijk ’ijk dangerous  introduce proton decay R-parity SM particle: even superparticle: odd stable LSP as dark matter candidate RPV: only look at L-violating operator S. Su LOOPFESTIII

R-parity violating (RPV) RPV operators contribute to Qe,pW at tree level RPV 95% CL MSSM loop 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 QpW No SUSY dark matter I) Obtain 95% CL allowed region in RPV coefficients II) Evaluate  QWe and  QWp G S. Su LOOPFESTIII

Correlation between QpW and QeW -  QW (Z,N)=(2Z+N)  QuW +(2N+Z)  QdW  QuW >0  QdW <0 SUSY correction to heavy nuclei QW   QW(Z,N) / QW(Z,N) < 0.2 % for Cs Distinguish new physics MSSM: extra Z’: leptoquark: RPV SUSY  QpW  QeW  QCsW small sizable S. Su LOOPFESTIII

Additional PV electron scattering ideas - Czarnecki, Marciano， Erler et al.  N deep inelastic Linear Collider e-e- DIS-Parity, JLab sin2W DIS-Parity, SLAC APV e+e- LEP, SLD SLAC E158 (ee) JLab Moller (ee) JLab Q-Weak (ep) (GeV) S. Su LOOPFESTIII

NuTeV experiment NC CC wrong-sign contribution! R=-0.0033  0.0015 Davidson et. al., JHEP 02, 037, 2002 MSSM (N  X) (N  l-(+)X) R()  - (-) R=-0.0033  0.0015 R=-0.0019  0.0026 - S. Su LOOPFESTIII

R-parity violating (RPV) RPV operators contribute to R() at tree level NC either wrong sign or too small hard to explain NuTeV deviation CC S. Su LOOPFESTIII

Conclusion Parity-violating ee and ep scattering could be used to test SM and probe new physics MSSM contribution to QeW and QpW is 8% and 4%  1 exp need higher exp precision to constrain SUSY correlation between QeW and QpW distinguish various new physics distinguish various SUSY scenario whether dark matter is SUSY particle ? SUSY contribution to NuTeV result MSSM with R-parity: wrong sign /small negative gluino contribution: size constrained by other considerations hard to explain NuTeV in RPV SUSY is not responsible for the NuTeV deviation other new physics ? hadronic effects ? S. Su LOOPFESTIII