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##### Sub Z Supersymmetry

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**M.J. Ramsey-Musolf**Sub Z Supersymmetry Precision Electroweak Studies in Nuclear Physics**NSAC Long Range Plan**• What is the structure of the nucleon? • What is the structure of nucleonic matter? • What are the properties of hot nuclear matter? • What is the nuclear microphysics of the universe? • What is to be the new Standard Model? Neutrino physics Precision measurements: -decay, -decay, parity violating electron scattering, EDM’s… What can they teach us about the new Standard Model?**TheStandard Modelof particle physics is a triumph of late**20th century physics • It provides a unified framework for 3 of 4 (known) forces of nature in context of renormalizable gauge theory**TheStandard Modelof particle physics is a triumph of late**20th century physics • Utilizes a simple & elegant symmetry principle to organize what we’ve observed**TheStandard Modelof particle physics is a triumph of late**20th century physics • Utilizes a simple & elegant symmetry principle to organize what we’ve observed Scaling violations in DIS Asymptotic freedom R(e+e-) Heavy quark systems Drell-Yan Strong (QCD)**TheStandard Modelof particle physics is a triumph of late**20th century physics • Utilizes a simple & elegant symmetry principle to organize what we’ve observed “Maximal” parity violation Conserved Vector Current CP-Violation in K, B mesons Quark flavor mixing Lepton universality….. Electroweak (=weak + QED)**TheStandard Modelof particle physics is a triumph of late**20th century physics • Most of its predictions have been confirmed Parity violation in neutral current processes: deep inelastic scattering, atomic transitions**sin2qW**The Standard Modelof particle physics is a triumph of late 20th century physics • Most of its predictions have been confirmed Jl0 Jlg JlY JlZ Neutral currents mix**Not yet!**TheStandard Modelof particle physics is a triumph of late 20th century physics • Most of its predictions have been confirmed • W, Z0 • 3rd fermion generation (CP violation, anomaly) • Higgs boson New particles should be found**Large Hadron Collider**Ultra cold neutrons LANSCE, SNS, NIST CERN We need anew Standard Model Two frontiers in the search Collider experiments (pp, e+e-, etc) at higher energies (E >> MZ) Indirect searches at lower energies (E < MZ) but high precision Particle, nuclear & atomic physics High energy physics**Precision measurements**• “Forbidden processes” • Weak decays • lepton scattering Outline SM Radiative Corrections & Precision Measurements Defects in the Standard Model An Example Scenario: Supersymmetry Low-energy Probes of Supersymmetry**Precision measurements**• “Forbidden processes” • EDM’s • 0nbb decay • m !e, m !eg… Outline SM Radiative Corrections & Precision Measurements Defects in the Standard Model An Example Scenario: Supersymmetry Low-energy Probes of Supersymmetry**TheFermi Theoryof weak decays gave a successful,**leading-order account**Fermi’s theory could incorporatehigher order QED**contributions QED radiative corrections: finite**The Fermi theory has trouble withhigher order weak**contributions Weak radiative corrections: infinite Can’t be absorbed through suitable re-definition of GFin HEFF**Re-define g**Finite All radiative corrections can be incorporated in the Standard Model with afinitenumber of terms g g g**g**g GFencodes the effects of all higher orderweak radiative corrections Drm depends on parameters of particles inside loops**g**g Comparingradiative corrections in different processes canprobeparticle spectrum Drm differs from DrZ**Comparingradiative corrections in different processes**canprobeparticle spectrum**Precision measurements predicted a range for mt**before top quark discovery • mt >> mb ! • mt is consistent with that range • It didn’t have to be that way Radiative corrections Direct Measurements Stunning SM Success Comparingradiative corrections in different processes canprobeparticle spectrum J. Ellison, UCI**Agreement with SM at level of loop effects ~ 0.1%**Global Analysis c2 per dof = 25.5 / 15 M. Grunenwald**LEP**SLD Tevatron Collider Studies R. Clare, UCR**MW**Mt Am shad Collider Studies Tevatron**“Blue Band”**Collider Studies**c2 per dof = 16.3 / 13**Global Fit: Winter 2004**II.Why a “New Standard Model”?**• There is no unification in the early SM Universe • The Fermi constant is inexplicably large • There shouldn’t be this much visible matter • There shouldn’t be this much invisible matter**Energy Scale ~ T**The early SM Universe had nounification Couplings depend on scale**Present universe**Early universe Standard Model High energy desert Weak scale Planck scale The early SM Universe had nounification**Present universe**Early universe Standard Model Gravity A “near miss” for grand unification High energy desert Weak scale Planck scale The early SM Universe had nounification**Present universe**Early universe Unification Neutrino mass Dark Matter Standard Model GF would shrink High energy desert Weak scale Planck scale The Fermi constant is too large**mWEAK ~ 250 GeV GF ~ 10-5/MP2**l The Fermi constant is too large**Smaller GF More 4He, C, O…**A smaller GF would mean disaster The Sun would burn less brightly G ~ GF2 Elemental abundances would change Tfreeze out ~ GF-2/3**Measured abundances**SM baryogenesis There is too much matter -visible & invisible - in the SM Universe Visible Matter from Big Bang Nucleosynthesis Insufficient CP violation in SM**No SM candidate**Dark Insufficient SM CP violation Visible There is too much matter -visible & invisible - in the SM Universe Invisible Matter S. Perlmutter**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**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**Fermions**Bosons sfermions gauginos Higgsinos Charginos, neutralinos SUSY may be one of the symmetries of the early Universe Supersymmetry**Present universe**Early universe Standard Model High energy desert Weak scale Planck scale Couplings unify with SUSY Supersymmetry**=0 if SUSY is exact**SUSY protectsGFfrom shrinking**c0 Lightest SUSY particle**CP Violation Unbroken phase Broken phase SUSY may help explain observed abundance of matter Cold Dark Matter Candidate Baryonic matter**SUSY Breaking**Superpartners have not been seen Theoretical models of SUSY breaking Visible World Hidden World Flavor-blind mediation SUSY must be a broken symmetry**LSM**LSM + LSUSY + Lsoft Minimal Supersymmetric Standard Model (MSSM) Lsoft gives contains 105 new parameters How is SUSY broken?**Visible Sector:**Hidden Sector: SUSY-breaking MSSM Flavor-blind mediation How is SUSY broken? Gravity-Mediated (mSUGRA)**Visible Sector:**Hidden Sector: SUSY-breaking MSSM messengers How is SUSY broken? Flavor-blind mediation Gauge-Mediated (GMSB)**ln**gaugino mass group structure increases as decreases increases faster than at the weak scale Mass evolution**Qf < 0**Qf > 0 Sfermion Mixing