Sub Z0 Supersymmetry

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Sub Z0 Supersymmetry
Precision Electroweak Physics Below the Z0 Pole
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Outline

• Precision measurements radiative corrections

The Standard Model SUSY

• Charged Current Universality

Is SUSY-breaking flavor neutral ?

• Neutral currents

Is there SUSY dark matter ?

• Some QCD Issues

How well do we know the Standard Model
predictions ?
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I. Radiative Corrections Precision
Measurements SM SUSY
Why we love the Standard Model
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The Fermi theory of weak decays
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The Fermi theory and QED corrections
QED radiative corrections finite
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The Fermi theory and higher order weak
contributions
Weak radiative corrections infinite
Cant be absorbed through suitable re-definition
of GF in HEFF
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All radiative corrections can be incorporated in
the Standard Model with a finite number of terms
g
g
g
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GF encodes the effects of all higher order weak
radiative corrections
Drm depends on parameters of particles inside
loops
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Comparing radiative corrections in different
processes can probe particle spectrum
Drm differs from DrZ
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Comparing radiative corrections in different
processes can probe particle spectrum
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Comparing radiative corrections in different
processes can probe particle spectrum
J. Ellison, UCR
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Can we place analogous constraints on new physics
using low-energy precision measurements ?
This talk SUSY
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Minimal Supersymmetric Standard Model (MSSM)
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Minimal Supersymmetric Standard Model (MSSM)
Lsoft gives
contains 105 new parameters
How is SUSY broken?
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The Fermi constant is too large
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SUSY protects GF from shrinking
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How is SUSY broken?
Gravity-Mediated (mSUGRA)
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How is SUSY broken?
Flavor-blind mediation
Gauge-Mediated (GMSB)
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Mass evolution
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Sfermion Mixing
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MSSM and R Parity
Matter Parity An exact symmetry of the SM
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MSSM and R Parity
Consequences
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Precision Measurements SUSY Sensitivity
Muon (g-2) Weak processes
Mm? ????????? 2 x 10-9 ??exp 1 x
10-9 MMW ? 10-3
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II. Charged Current Processes

• Is SUSY-breaking mediation flavor blind?

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Charged Current (non) Universality
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Fermi Constants, Contd
SUSY
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Fermi Constants, Contd
CKM Unitarity

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SM
Data SM
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SUSY Radiative Corrections
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SUSY Radiative Corrections
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Vertex Corrections (Dominant)
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Other Inputs
1. Muon (g-2)
Size of error bar crucial
2. W Mass
3. Superpartner Masses
Start analysis with collider lower bounds and
vary later
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Model-independent Analysis
Usual approaches
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Model Independent Analysis
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Model Independent Analysis
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Model Independent Analysis
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CC (non) universality the MSSM
Data appeared to conflict with MSSM models
having flavor-blind SUSY-breaking mediation
Possible resolutions

• MSUSY gt TeV
• 2. Hadronic effects in SM predictions
• 3. Something is wrong with expt
• 4. New models of SUSY-breaking
• 5. Go beyond the MSSM

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Ke3 decays recent developments
V. Cirigliano
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Ke3 decays current status
G. Isidori, CKM 2005
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Ke3 decays current status
G. Isidori, CKM 2005
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CC (non) universality the MSSM
Data appeared to conflict with MSSM models
having flavor-blind SUSY-breaking mediation
Possible resolutions

• MSUSY gt TeV
• 2. Hadronic effects in SM predictions
• 3. Something is wrong with expt
• 4. New models of SUSY-breaking
• 5. Go beyond the MSSM

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III. Neutral Current Processes

• Is there SUSY dark matter?

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Weak Neutral Currents at Low Energies
Parity-violating electron scattering
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Weak Charges
QWp 1 - 4 sin2?W 0.1 QWe -1 4
sin2?W -0.1
Need ? few percent to probe SUSY
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Weak Mixing Angle Scale Dependence
Czarnecki, Marciano Erler. Kurylov, MR-M
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QW and SUSY Radiative Corrections
Tree Level
Radiative Corrections
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Universal corrections
muon decay
gauge boson propagators
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Oblique Parameters
SM fit only No SUSY effects
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Parameter Space Scan
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Comparing Qwe and QWp
SUSY loops
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Correlated Radiative Corrections
total
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Correlated Radiative Corrections
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R-Parity Violation (RPV)
?L1
WRPV ?ijk LiLjEk ??ijk LiQjDk ?/i LiHu
???ijkUiDjDk
?B1
proton decay Set ???ijk 0
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Four-fermion Operators
?L1
?L1
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Corrections to Weak Charges
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Other Constraints

1. CKM unitarity
2. ?l2 decays
3. ?-GF-MZ-MW relation
4. Cesium atomic PV

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Other constraints, contd.
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Comparing Qwe and QWp
?? -gt e??e
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Comparing Qwe and QWp
Erler, Kurylov, R-M
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Additional PV electron scattering ideas
Czarnecki, Marciano Erler et al.
SLAC E158 (ee)
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Comparing AdDIS and Qwp,e
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Comparing Qwe and QWp
Kurylov, R-M, Su
??? SUSY dark matter
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Weak Mixing Angle Scale Dependence
Czarnecki, Marciano Erler, Kurylov, MR-M
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Weak Neutral Currents at Low Energies
?-Nucleus Deep Inelastic Scattering
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?-Nucleus DIS, Contd.
Cross section ratios
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NuTeV-SM Discrepancy
Paschos-Wolfenstein Relation
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?-Nucleus DIS SUSY Loop Corrections
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RPV Effects
unconstrained elsewhere
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?-Nucleus DIS RPV Effects
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?-Nucleus DIS RPV Effects
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Neutral Currents Summary

• Comparison of weak charges may allow one to
  distinguish between SUSY with or without R
  parity conservation
• Test for viability of SUSY dark matter,
  solution to the charged current problem, and
  Majorana character of the neutrino
• SUSY presently cannot account for the NuTeV
  anomaly
• Hadronic physics in the SM or more exotic new
  physics scenario responsible

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IV. Interpretation issues

• Do we have QCD under sufficient control?

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Interpretation of precision measurements
How well do we now the SM predictions? Some QCD
issues
Proton Weak Charge
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Interpretation of precision measurements
How well do we now the SM predictions? Some QCD
issues
Proton Weak Charge
FP(Q2, ? -gt 0) Q2
Use ?PT to extrapolate in small Q2 domain and
current PV experiments to determine LECs
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QCD Effects in QWP
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Box graphs, contd.
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pQCD Corrections
Integrand
Hadronic tensor
Contract with k?
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Box graphs, contd.
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Neutron ?-decay
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Higher Twist Pollution
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Higher Twist Pollution
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Interpretation QCD Issues

• QCD effects in electroweak radiative corrections
  not problematic for QWp, ?l2-decays, but more
  of concern for neutron ?-decay, (g-2)?
• Future study of C?W, C?Z on the lattice
• Form factors in Ke3 decays (Vus)
• ?PT at O(p6)
• ?N Deep inelastic scattering
• PDFs isospin, shadowing
• Deep inelastic scattering
• Higher twist

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Conclusions

• Precision electroweak measurements below the
  Z-pole can provide important clues about the
  structure of the new Standard Model
• Comparison of a variety of measurements is
  essential
• Charged current processes provide a window on
  the mechanism of SUSY-breaking mediation at
  very high energy scales
• ?-decay, ?l2-decays, ?-decay, Ke3-decay
• Neutral current measurements may allow one to
  test the viability of SUSY dark matter
• PV ep, ee, eA scattering, ?N deep inelastic
  scattering
• Theoretical control of QCD uncertainties is
  crucial
• Future QCD-electroweak theory synergy

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References

• A. Kurylov, MR-M, S. Su, Phys. Rev. D68 035008
  (2003)
• A. Kurylov, J. Erler, MR-M, Phys. Rev. D68
  016006 (2003)
• A. Kurylov, MR-M, S. Su, Nucl. Phys. B667, 321
  (2003)
• A. Kurylov, MR-M, S. Su, Phys. Lett. B582, 222
  (2003)
• A. Kurylov MR-M, Phys. Rev. Lett. 88 071804
  (2002)
• MR-M, Phys. Rev. D 62 056009 (2000)