Sub Z0 Supersymmetry

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Sub Z0 Supersymmetry
Precision Electroweak Physics Below the Z0 Pole
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Fundamental Symmetries Cosmic History

• What were the fundamental symmetries that
  governed the microphysics of the early universe?

The (broken) symmetries of the Standard Model of
particle physics work remarkably well at late
times, but they leave many unsolved puzzles
pertaining to the early universe

• What insights can low energy (E ltlt MZ)
  precision electroweak studies provide?

New forces and their symmetries generally imply
the existence of new particles. Looking for their
footprints in low energy processes can yield
important clues about their character
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Fundamental Symmetries Cosmic History
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Fundamental Symmetries Cosmic History
It provides a unified framework for understanding
3 of the 4 (known) forces of nature in the
present universe
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Fundamental Symmetries Cosmic History
It utilizes a simple and elegant symmetry
principle
SU(3)c x SU(2)L x U(1)Y
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Fundamental Symmetries Cosmic History
It utilizes a simple and elegant symmetry
principle
SU(3)c x SU(2)L x U(1)Y
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Fundamental Symmetries Cosmic History
It utilizes a simple and elegant symmetry
principle
SU(3)c x SU(2)L x U(1)Y
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Fundamental Symmetries Cosmic History
Most of its predictions have been confirmed
Parity violation in neutral current interactions
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Fundamental Symmetries Cosmic History
Most of its predictions have been confirmed
New particles should be found
How is electroweak symmetry broken?
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Fundamental Symmetries Cosmic History
It gives a microscopic basis for understanding
astrophysical observations
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Fundamental Symmetries Cosmic History
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We need a new Standard Model
Two frontiers in the search
Collider experiments (pp, ee-, etc) at higher
energies (E gtgt MZ)
Indirect searches at lower energies (E lt MZ) but
high precision
Particle, nuclear atomic physics
High energy physics
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Outline

1. SM Radiative Corrections Precision Measurements
2. Defects in the Standard Model
3. An Alternative Supersymmetry
4. Low-energy Probes of Supersymmetry

New
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I. Radiative Corrections Precision Measurements
in the SM
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Weak Decays Fermi Theory
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Fermi Theory QED Corrections
QED radiative corrections finite
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Fermi Theorys Stumbling Block Higher Order
(Virtual) Weak Effects
Weak radiative corrections infinite
Cant be absorbed through suitable re-definition
of GF in HEFF
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The Standard Model (renormalizable) Control of
Virtual Weak Corrections
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, UCI
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Global Analysis
c2 per dof 25.5 / 15
Agreement with SM at level of loop effects 0.1
M. Grunenwald
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II. Why a New Standard Model?

• There is no unification in the early SM Universe
• The Fermi constant is inexplicably large
• There shouldnt be this much visible matter
• There shouldnt be this much invisible matter

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The early SM Universe had no unification
Couplings depend on scale
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The early SM Universe had no unification
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The early SM Universe had no unification
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The Fermi constant is too large
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The Fermi constant is too large
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A smaller GF ,a different cosmos
The Sun would burn less brightly
G GF2
Elemental abundances would change
Tfreeze out GF-2/3
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There is too little matter - visible invisible
- in the SM Universe
Visible Matter from Big Bang Nucleosynthesis CMB
Insufficient CP violation in SM
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There is too little matter - visible invisible
- in the SM Universe
Invisible Matter
S. Perlmutter
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There must have been additional symmetries in the
earlier Universe to

• Unify all forces
• Protect GF from shrinking
• Produce all the matter that exists

• Account for neutrino properties
• Give self-consistent quantum gravity

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III. Supersymmetry

• Unify all forces
• Protect GF from shrinking
• Produce all the matter that exists

3 of 4 Yes Maybe so

• Account for neutrino properties
• Give self-consistent quantum gravity

Maybe Probably necessary
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SUSY a candidate symmetry of the early Universe
Supersymmetry
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SUSY and R Parity
Consequences
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Couplings unify with SUSY
Supersymmetry
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SUSY protects GF from shrinking
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SUSY may help explain observed abundance of matter
Cold Dark Matter Candidate
Baryonic matter electroweak phase transition
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SUSY must be a broken symmetry
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IV. Low Energy Probes of SUSY

• J Erler (UNAM)
• V Cirigliano (Caltech)
• C Lee (INT)
• S Su (Arizona)
• S Tulin (Caltech)
• S Profumo (Caltech)
• A Kurylov

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Precision, low energy measurements can probe for
new symmetries in the desert
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Weak decays
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Weak decays
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Weak decays
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Weak decays SUSY
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SUSY Radiative Corrections
Drm
Propagator
Box
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Weak decays SUSY
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CKM Summary PDG04
UCNA
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CKM Summary New Vus tn ?
New tn !!
UCNA
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Probing SUSY with Lepton Scattering
Parity-Violating electron scattering
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Probing SUSY with Lepton Scattering
Neutrino-nucleus deep inelastic scattering
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Neutral currents mix
Weak mixing depends on scale
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Weak Mixing Angle Scale Dependence
Czarnecki, Marciano Erler, Kurylov, MR-M
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SUSY Radiative Corrections
Propagator
Box
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Comparing Qwe and QWp
SUSY loops
Kurylov, Su, MR-M
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Comparing Qwe and QWp
??? SUSY dark matter
?? -gt e??e
Kurylov, Su, MR-M
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Comparing Qwe and QWp

• Can be a diagnostic tool to determine whether or
  not
• the early Universe was supersymmetric
• there is supersymmetric dark matter

The weak charges can serve a similar diagnostic
purpose for other models for high energy
symmetries, such as left-right symmetry, grand
unified theories with extra U(1) groups, etc.
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Additional PV electron scattering ideas
Czarnecki, Marciano Erler et al.
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What is the origin of baryonic matter ?
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EDM Probes of SUSY CP Violation
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Present n-EDM limit

Proposed n-EDM limit


Matter-Antimatter Asymmetry in the Universe
?
M. Pendlebury B. Filippone
Riotto Carena et al. Lee, Cirigliano, R-M,
Tulin
n-EDM has killed more theories than any other
single experiment
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EDMs Baryogenesis
Sakharov Criteria

• B violation
• C CP violation
• Nonequilibrium dynamics

Sakharov, 1967
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SUSY Baryogenesis
90s Cohen, Kaplan, Nelson
Joyce, Prokopec, Turok
Unbroken phase
CP Violation
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EDM constraints SUSY CPV
Different choices for SUSY parameters
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EDM constraints SUSY CPV
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Conclusions

• The Standard Model is triumph of 20th century
  physics, but we know it is far from a complete
  theory

Lack of unification, size of the Fermi constant,
abundance of matter, neutrino mass, gravity,

• Supersymmetry is a leading candidate theory that
  might address many of these SM shortcomings

Future high-energy collider experiments may
discover it

• Precision measurements in particle, nuclear, and
  atomic physics at energies below MZ can provide
  important indirect information about what form of
  SUSY - if any - is viable

Weak decays, lepton scattering, electric dipole
moments
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Conclusions

• The interface between high-energy collider
  physics and precision low-energy physics
  involves a rich and stimulating synergy
  between many sub-fields of physics

Sub-Z0 A working group on precision
electroweak physics below the
Z-pole http//krl.caltech.edu/subZ