Nuclear Physics and the New Standard Model M.J. Ramsey-Musolf Wisconsin-Madison NPAC Theoretical Nuclear, Particle, Astrophysics & Cosmology Taiwan, June 2008

The Big Picture Fifty years of PV in nuclear physics Nuclear physics studies of s & fundamental symmetries played an essential role in developing & confirming the Standard Model Our role has been broadly recognized within and beyond NP Solar s & the neutrino revolution The next decade presents NP with a historic opportunity to build on this legacy in developing the “new Standard Model” The value of our contribution will be broadly recognized outside the field

Goals Show how studies of fundamental symmetries & neutrinos in nuclear physics can complement high energy searches for the “new Standard Model” Introduce some of the basic ideas & theoretical machinery, but leave details to your future reading Describe recent progress & open problems Encourage you to learn moreand get involved in research !

Outline I.Overview & Motivation II.Illustrative Scenario: Supersymmetry III.Neutrinos: Lepton Number &  IV.EDMs & the Origin of Matter V.Electroweak Precision Observables VI.Weak Decays VII. Neutral Current Processes

References “ Low Energy Precision Test of Supersymmetry”, M.J. Ramsey-Musolf & S. Su, Phys.Rept.456:188, 2008, e- Print: hep-ph/ Model ” “ Low energy tests of the weak interaction”, J. Erler & M. J. Ramsey-Musolf, Prog.Part.Nucl.Phys.54: , 2005, e- Print: hep-ph/ Plus many references therein…

Why New Symmetries ? Why Low Energy Probes ? I.Motivation

Fundamental Symmetries & Cosmic History Beyond the SMSM symmetry (broken) Electroweak symmetry breaking: Higgs ?

Fundamental Symmetries & Cosmic History Standard Model puzzlesStandard Model successes to explain the microphysics of the present universe It utilizes a simple and elegant symmetry principle SU(3) c x SU(2) L x U(1) Y Big Bang Nucleosynthesis (BBN) & light element abundances Weak interactions in stars & solar burning Supernovae & neutron stars

Fundamental Symmetries & Cosmic History Standard Model puzzlesStandard Model successes How is electroweak symmetry broken? How do elementary particles get mass ? Puzzles the St’d Model may or may not solve: SU(3) c x SU(2) L x U(1) Y Electroweak symmetry breaking: Higgs ? U(1) EM Non-zero vacuum expectation value of neutral Higgs breaks electroweak sym and gives mass: Where is the Higgs particle? Is there more than one?

Fundamental Symmetries & Cosmic History Beyond the SMSM symmetry (broken) Electroweak symmetry breaking: Higgs ? Puzzles the Standard Model can’t solve 1.Origin of matter 2.Unification & gravity 3.Weak scale stability 4.Neutrinos What are the symmetries (forces) of the early universe beyond those of the SM?

Fundamental Symmetries & Cosmic History Beyond the SMSM symmetry (broken) Electroweak symmetry breaking: Higgs ? Cosmic Energy Budget ? Baryogenesis: When? CPV? SUSY? Neutrinos? WIMPy D.M.: Related to baryogenesis? “New gravity”? Lorentz violation? Grav baryogen ? C: Charge Conjugation P: Parity

Standard Model Present universe Early universe Weak scalePlanck scale High energy desert Fundamental Symmetries & Cosmic History Unification? Use gauge coupling energy- dependence look back in time Energy Scale ~ T

Standard Model Present universe Early universe Weak scalePlanck scale High energy desert Gravity Fundamental Symmetries & Cosmic History A “near miss” for grand unification Is there unification? What new forces are responsible ?

Standard Model Present universe Early universe Planck scale High energy desert Weak scale Weak scale unstable: Why is G F so large? Unification Neutrino mass Origin of matter Fundamental Symmetries & Cosmic History Weak Int Rates : Solar burning Element abundances

There must have been additional symmetries in the earlier Universe to Unify all matter, space, & time Stabilize the weak scale Produce all the matter that exists Account for neutrino properties Give self-consistent quantum gravity Supersymmetry, GUT’s, extra dimensions…

What are the new fundamental symmetries? Two frontiers in the search Collider experiments (pp, e + e -, etc) at higher energies (E >> M Z ) Indirect searches at lower energies (E < M Z ) but high precision High energy physics Particle, nuclear & atomic physics CERNUltra cold neutronsLarge Hadron ColliderLANSCE, NIST, SNS, ILL

Precision Probes of New Symmetries Beyond the SMSM symmetry (broken) Electroweak symmetry breaking: Higgs ? New Symmetries 1.Origin of Matter 2.Unification & gravity 3.Weak scale stability 4.Neutrinos ? LHC: energy frontier Low-energy: precision frontier

Precision & Energy Frontiers Radiative corrections Direct Measurements Stunning SM Success J. Ellison, UCI Precision measurements predicted a range for m t before top quark discovery m t >> m b ! m t is consistent with that range It didn’t have to be that way Probing Fundamental Symmetries beyond the SM: Use precision low- energy measurements to probe virtual effects of new symmetries & compare with collider results Precision Frontier: Precision ~ Mass scale Look for pattern from a variety of measurements Identify complementarity with collider searches Special role: SM suppressed processes

Precision, low energy measurements can probe for new symmetries in the desert Precision ~ Mass Scale M=m   ~ 2 x  exp ~ 1 x M=M W  ~ Interpretability Precise, reliable SM predictions Comparison of a variety of observables Special cases: SM-forbidden or suppressed processes

Why Supersymmetry ? Key Features of SUSY II. Illustrative Case: SUSY

Standard Model Present universe Early universe Weak scalePlanck scale Couplings unify with SUSY Supersymmetry High energy desert

G F is Too Large G F ~ /M P 2  WEAK ~ 250 GeV

SUSY protects G F =0 if SUSY is exact

G F & the “hierarchy problem” SUSY Relation: Quadratic divergence ~  UV 2 cancels After EWSB:

SUSY may help explain observed abundance of matter Cold Dark Matter Candidate  0 Lightest SUSY particle Baryonic matter: electroweak phase transition Unbroken phase Broken phase CP Violation

SUSY: a candidate symmetry of the early Universe Unify all forces Protect G F from shrinking Produce all the matter that exists Account for neutrino properties Give self-consistent quantum gravity 3 of 4 Yes Maybe so Maybe Probably necessary

Minimal Supersymmetric Standard Model (MSSM) Supersymmetry Charginos, neutralinos FermionsBosons sfermions gauginos Higgsinos No new coupling constants Two Higgs vevs Supersymmetric Higgs mass, 

SUSY and R Parity If nature conservesvertices have even number of superpartners Consequences  Lightest SUSY particle is stable viable dark matter candidate  Proton is stable  Superpartners appear only in loops

W RPV = ijk L i L j E k +  ijk L i Q j D k +  / i L i H u +  ijk U i D j D k  L=1  B=1 L i, Q i E i, U i, D i SU(2) L doublets SU(2) L singlets proton decay: Set  ijk =0 R-Parity Violation (RPV) “Superpotential” : a convenient way to derive supersymmetric interactions by taking derivatives w.r.t. scalar fields

Four-fermion Operators 12k  1j1  L=1

SUSY must be a broken symmetry Visible World Hidden World Flavor-blind mediation SUSY Breaking Superpartners have not been seen Theoretical models of SUSY breaking How is SUSY broken?

MSSM SUSY Breaking Superpartners have not been seen Theoretical models of SUSY breaking How is SUSY broken? ~ 100 new parameters 40 new CPV phases Flavor mixing parameters Gaugino mass Sfermion mass Triscalar interactions O(1) CPV phases & flavor mixing ruled out by expt: “SUSY CP” & “SUSY flavor” problems One solution: a f ~ Y f

MSSM: SUSY Breaking Models I Flavor-blind mediation Visible Sector: Hidden Sector: SUSY-breaking MSSM Gravity-Mediated (mSUGRA)

MSSM: SUSY Breaking Models II Flavor-blind mediation Visible Sector: Hidden Sector: SUSY-breaking MSSM Gauge-Mediated (GMSB) messengers

MSSM: SUSY Breaking Models III Flavor-blind mediation Visible Sector: Hidden Sector: SUSY-breaking MSSM Parameter evolution: mass at the weak scale

Gaugino-Higgsino Mixing Neutralino Mass Matrix M1M1 -- M2M2 -m Z cos  sin  W m Z cos  cos  W m Z sin  sin  W -m Z sin  sin  W - -m Z cos  sin  W m Z cos  cos  W m Z sin  sin  W -m Z sin  sin  W M N = Chargino Mass Matrix M2M2  M C = T << T EW : mixing of H,W to     ~~ ~~ T ~T EW : scattering of H,W from background field ~~ CPV   B    W    H d    H u   BINOWINOHIGGSINO T << T EW

Relic Abundance of SUSY DM Neutralino Mass Matrix M1M1 -- M2M2 -m Z cos  sin  W m Z cos  cos  W m Z sin  sin  W -m Z sin  sin  W - -m Z cos  sin  W m Z cos  cos  W m Z sin  sin  W -m Z sin  sin  W M N = T << T EW : mixing of H,W to     ~~ ~~   B    W    H d    H u   BINOWINOHIGGSINO + res+ coannihilation

Sfermion Mixing Sfermion mass matrix Q f < 0 Q f > 0 T << T EW : mixing of f L, f R to f 1, f 2 ~~~~ T ~T EW : scattering of f L, f R from background field ~~

Test No new coupling constants Two Higgs vevs Supersymmetric Higgs mass,  ~ 100 new parameters 40 new CPV phases Flavor mixing parameters “Superpotential” : a convenient way to derive supersymmetric interactions by taking derivatives w.r.t. scalar fields

Neutral Current Interactions II Neutral current l+f --> l+f at one loop: Normalization: Vector & axial vector couplings: Normalize to G  : Remove  r  Weak mixing: Vertex & ext leg

The  parameter: Weak mixing: Can impose constraints from global fits to EWPO via S,T,U-dependence of these quantities