Nuclear Physics and the New Standard Model

1. Nuclear Physics and the New Standard Model M.J. Ramsey-Musolf Wisconsin-Madison NPAC Theoretical Nuclear, Particle, Astrophysics & Cosmology http://www.physics.wisc.edu/groups/particle-theory/ Taiwan , June 2008

2. 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 Nuclear physics studies of ns & fundamental symmetries played an essential role in developing & confirming the Standard Model Our role has been broadly recognized within and beyond NP The Big Picture Solar ns & the neutrino revolution Fifty years of PV in nuclear physics

3. 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 more and get involved in research !

4. Outline Overview & Motivation Illustrative Scenario: Supersymmetry Neutrinos: Lepton Number &  EDMs & the Origin of Matter Electroweak Precision Observables Weak Decays Neutral Current Processes

5. References • “Low Energy Precision Test of Supersymmetry”, M.J. Ramsey-Musolf & S. Su, Phys.Rept.456:188, 2008, e-Print: hep-ph/0612057Model” • “Low energy tests of the weak interaction”, J. Erler & M. J. Ramsey-Musolf , Prog.Part.Nucl.Phys.54:351 442, 2005, e-Print: hep-ph/0404291 Plus many references therein…

6. Motivation • Why New Symmetries ? • Why Low Energy Probes ?

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

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

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

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

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

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

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

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

15. Supersymmetry, GUT’s, extra dimensions… 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

16. Large Hadron Collider Ultra cold neutrons LANSCE, NIST, SNS, ILL CERN What are the new fundamental symmetries? 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

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

18. Probing Fundamental Symmetries beyond the SM: Use precision low-energy measurements to probe virtual effects of new symmetries & compare with collider results • 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 • Precision Frontier: • Precision ~ Mass scale • Look for pattern from a variety of measurements • Identify complementarity with collider searches • Special role: SM suppressed processes Radiative corrections Direct Measurements Stunning SM Success Precision & Energy Frontiers J. Ellison, UCI

19. Precision ~ Mass Scale M=m~ 2 x 10-9 exp ~ 1 x 10-9 M=MW ~ 10-3 Interpretability • Precise, reliable SM predictions • Comparison of a variety of observables • Special cases: SM-forbidden or suppressed processes Precision, low energy measurements can probe for new symmetries in the desert

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

21. Present universe Early universe Standard Model High energy desert Weak scale Planck scale Couplings unify with SUSY Supersymmetry

22. GF ~ 10-5/MP2 mWEAK ~ 250 GeV l GF is Too Large

23. =0 if SUSY is exact SUSY protects GF

24. GF & the “hierarchy problem” SUSY Relation: Quadratic divergence ~ UV2 cancels After EWSB:

25. c0 Lightest SUSY particle CP Violation Unbroken phase Broken phase SUSY may help explain observed abundance of matter Cold Dark Matter Candidate Baryonic matter: electroweak phase transition

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

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

28. If nature conserves vertices have even number of superpartners • Lightest SUSY particle is stable viable dark matter candidate • Proton is stable • Superpartners appear only in loops SUSY and R Parity Consequences

29. “Superpotential” : a convenient way to derive supersymmetric interactions by taking derivatives w.r.t. scalar fields Li, Qi SU(2)L doublets Ei, Ui, Di SU(2)L singlets R-Parity Violation (RPV) L=1 WRPV = ijk LiLjEk + ijk LiQjDk +/i LiHu + ijkUiDjDk B=1 proton decay: Set ijk =0

30. 12k 1j1 12k 1j1 L=1 L=1 Four-fermion Operators

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

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

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

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

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

36. M1 0 -mZ cosb sinqW mZ cosb cosqW T ~TEW : scattering of H,W from background field MN = ~ ~ mZ sinb sinqW M2 -mZ sinb sinqW 0 CPV 0 -m -mZ cosb sinqW mZ cosb cosqW -m T << TEW : mixing of H,W to c+, c0 mZ sinb sinqW -mZ sinb sinqW 0 ~ ~ ~ ~ M2 • = N11B 0 + N12W 0 + N13Hd0 + N14Hu0 MC = m T << TEW BINO WINO HIGGSINO Gaugino-Higgsino Mixing Chargino Mass Matrix Neutralino Mass Matrix

37. M1 0 -mZ cosb sinqW mZ cosb cosqW MN = mZ sinb sinqW M2 -mZ sinb sinqW 0 0 -m -mZ cosb sinqW mZ cosb cosqW -m T << TEW : mixing of H,W to c+, c0 mZ sinb sinqW -mZ sinb sinqW 0 ~ ~ ~ ~ • = N11B 0 + N12W 0 + N13Hd0 + N14Hu0 BINO WINO HIGGSINO + res + coannihilation Relic Abundance of SUSY DM Neutralino Mass Matrix

38. T ~TEW : scattering of fL, fR from background field ~ ~ T << TEW : mixing of fL, fR to f1, f2 ~ ~ Qf < 0 Qf > 0 ~ ~ Sfermion Mixing Sfermion mass matrix

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

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

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