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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?
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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