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Nuclear Physics and the New Standard Model M.J. Ramsey-Musolf Quick Time™ a nd a TIFF ( Un compr ess ed ) de co mp res sor ar e n eed ed to s ee this pic tur e. Wisconsin-Madison NPAC Theoretical Nuclear, Particle, Astrophysics & Cosmology http://www.physics.wisc.edu/groups/particle-theory/ Taiwan , June 2008 The Big Picture The Nuclear next physics decade studies presents ofNP ns & with a historic fundamental opportunity symmetries to buildplayed on thisan legacy essential in developing role in developing the “new & Standard confirming Model” the Standard Model Fifty years of PV in nuclear physics The Our value role has of our been contribution broadly will be broadly recognized recognized within and outside beyond the NP field Solar ns & the neutrino revolution 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 ! Outline I. Overview & Motivation II. Illustrative Scenario: Supersymmetry III. Neutrinos: Lepton Number & n 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, ePrint: hep-ph/0612057Model” • “Low energy tests of the weak interaction”, J. Erler & M. J. Ramsey-Musolf , Prog.Part.Nucl.Phys.54:351 442, 2005, ePrint: hep-ph/0404291 Plus many references therein… I. Motivation • Why New Symmetries ? • Why Low Energy Probes ? Fundamental Symmetries & Cosmic History Electroweak symmetry breaking: Higgs ? Beyond the SM SM symmetry (broken) Fundamental Symmetries & Cosmic History 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 • Big Bang Nucleosynthesis (BBN) & light element abundances • Weak interactions in stars & solar burning •Standard Supernovae & neutron Model puzzles stars Standard Model successes Fundamental Symmetries & Cosmic History Electroweak symmetry breaking: Higgs ? • Non-zero vacuum expectation value of neutral Higgs breaks electroweak sym and gives mass: • Where is the Higgs particle? Puzzles the St’d Model may or may not solve: SU(3)c x SU(2)L x U(1)Y U(1)EM How is electroweak symmetry broken? How do elementary particles getsuccesses mass ? • Is Standard there more Model than puzzles Standard Model one? Fundamental Symmetries & Cosmic History Electroweak symmetry Puzzles the Standard Model can’t solve breaking: Higgs ? 1. 2. 3. 4. Origin of matter Unification & gravity Weak scale stability Neutrinos Beyond the SM What are the symmetries (forces) of the early universe beyond those of the SM? SM symmetry (broken) Fundamental Symmetries & Cosmic History Electroweak symmetry breaking: Higgs ? Baryogenesis: When? CPV? SUSY? Neutrinos? WIMPy D.M.: Related to baryogenesis? “New gravity”? Lorentz violation? Grav baryogen ? • C: Charge Conjugation ? • P: Parity Beyond the SM SM symmetry (broken) Cosmic Energy Budget Fundamental Symmetries & Cosmic History Early universe Present universe Unification? Use gauge coupling energydependence look back in time Standard Model 4 2 gi Weak scale e e() g g() High energy desert log10 ( / 0 Energy ) Scale ~ T Planck scale Fundamental Symmetries & Cosmic History Early universe Present universe Standard Model 4 for A “near miss” 2 grand unification g Gravity i Is there unification? What new forces are responsible ? Weak scale High energy desert log10 ( / 0 ) Planck scale Fundamental Symmetries & Cosmic History Early universe 2 GF ~ 1 Muniverse Present WEAK Weak Int Rates: Solar burning Element abundances Standard Model 4 Weak scale 2 gi unstable: Why is GF so large? Weak scale Unification Neutrino mass Origin of matter High energy desert log10 ( / 0 ) Planck scale 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 Indirect searches at (pp, e+e-, etc) at higher lower energies (E < MZ) energies (E >> MZ) but high precision Large Hadron Collider Ultra cold neutrons CERN High energy physics LANSCE, NIST, SNS, ILL Particle, nuclear & atomic physics Precision Probes of New Symmetries Electroweak symmetry New Symmetries breaking:LHC: Higgs energy? frontier 1. 2. 3. 4. Origin of Matter Unification & gravity Weak scale stability Neutrinos ? n ne ˜ n W ˜0 ˜ e QuickT ime™ and a T IFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF(Uncompressed) decompressor are needed to see this picture. Qu ickT ime ™ a nd a TIF F (U nco mpre sse d) de com pres sor are nee ded to s ee th is pi cture . Quic kTime™ and a TIFF (Uncompres sed) dec ompressor ar e needed to see this picture. Low-energy: precision frontier Beyond the SM Qui ckT ime™ and a T IFF (Uncompressed) decompressor are needed to see this picture. SM symmetry (broken) Precision & Energy Frontiers Direct Measurements Radiative corrections Precision Probing Fundamental Frontier: • Precision measurements Symmetries beyond predicted for scale mt GFZ a range • Precision ~ Mass 1 r r quark Z theGSM: before top discovery F • Look for pattern from a low• mUse mb ! t >> precision variety of measurements t b W Z Z W energy measurements • mt is consistent with that •to Identify probe virtual effects t complementarity t range with symmetries of new collider & searches • Itcompare didn’t have tocollider be that with way • Special role: SM results suppressed processes 0 0 Stunning SM Success J. Ellison, UCI Precision, low energy measurements can probe for new symmetries in the desert Precision ~ Mass Scale O M NEW SM O M˜ NEW 2 M=m ~ 2 x 10-9 M=MW exp ~ 1 x 10-9 ~ 10-3 Interpretability • Precise, reliable SM predictions • Comparison of a variety of observables • Special cases: SM-forbidden or suppressed processes II. Illustrative Case: SUSY • Why Supersymmetry ? • Key Features of SUSY Couplings unify with SUSY Early universe Present universe Standard Model 4 2 gi Supersymmetry High energy desert Weak scale log10 ( / 0 ) Planck scale GF is Too Large 2 GF g 1 2 2 2 8MW 2 WEAK GF ~ 10-5/MP2 NEW H0 m 2 l 2 h H0 l WEAK ~ 250 GeV 2 WEAK 2 WEAK ~ M2 SUSY protects GF NEW H0 ˜ NEW H0 H0 H0 2 WEAK 2 ~ M M log terms 2 ˜ =0 if SUSY is exact GF & the “hierarchy problem” SUSY Relation: Quadratic divergence ~ UV2 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 t˜ H SUSY: a candidate symmetry of the early Universe • Unify all forces 3 of 4 • Protect GF from shrinking Yes • Produce all the matter that exists Maybe so • Account for neutrino properties Maybe • Give self-consistent quantum gravity Probably necessary Minimal Supersymmetric No new coupling constants Two Higgs vevs Standard Model (MSSM) Supersymmetric HiggsSupersymmetry mass, Fermions Bosons e L,R , q L,R e˜ L,R , q˜ L,R gauginos ˜ , Z˜ , ˜, g ˜ W W , Z , , g Higgsinos ˜ ,H ˜ H u d sfermions H u, H d 0 ˜ ˜ ˜ ˜ ˜ ˜ W, Z ,, Hu, d , Charginos, neutralinos SUSY and R Parity If nature conserves PR PR 1 3(BL) 1 2S vertices have even number of superpartners Consequences 0 ˜ Lightest SUSY particle is stable viable dark matter candidate Proton is stable Superpartners appear only in loops “Superpotential” : a convenient way to derive supersymmetric interactions by R-Parity Violation taking derivatives w.r.t. scalar fields (RPV) WRPV = lijk LiLjEk + lijk LiQjDk +/i LiHu + lijkUiDjDk B=1 proton decay: Set lijk =0 Li, Qi SU(2)L doublets Ei, Ui, Di SU(2)L singlets L=1 Four-fermion Operators ne e l12k e˜ Rk q˜ Lj l1j1 l12k n e d l1j1 e d L=1 L=1 12 k l12 k 2 2 ˜eRk 4 2GF M / 1j 1 / 2 ij i l 4 2GF Mq2˜ j L SUSY must be a broken symmetry Superpartners have not been seen M e˜ me M q˜ mq M ˜ MW ,Z , How is SUSY broken? Theoretical models of SUSY breaking SUSY Breaking Visible World Hidden World Flavor-blind mediation MSSM SUSY Breaking One solution: af ~ Yf Superpartners have not been seen Theoretical models of SUSY breaking Gaugino mass Triscalar interactions Sfermion mass ~ 100 new parameters 40 new CPV phases Flavor mixing parameters How is SUSY broken? O(1) CPV phases & flavor mixing ruled out by expt: “SUSY CP” & “SUSY flavor” problems MSSM: SUSY Breaking Models I Visible Sector: Hidden Sector: SUSY-breaking MSSM Flavor-blind mediation Gravity-Mediated (mSUGRA) ˜ , g˜ W˜ , Z˜ , H f˜ f˜ M1 / 2 M 2 0 Hu Hd f˜ A0 b0 MSSM: SUSY Breaking Models II Visible Sector: Hidden Sector: SUSY-breaking MSSM Flavor-blind mediation Gauge-Mediated (GMSB) f˜ ˜ , g˜ W˜ , Z˜ , M1 / 2 messengers a 4 W,Z,... a M Ca 4 2 0 2 A0 0 b0 0 MSSM: SUSY Breaking Models III Visible Sector: Hidden Sector: SUSY-breaking MSSM Flavor-blind mediation Parameter evolution: mass 2 dM ˜f dt 3 ˜ a C M a Mq˜ M˜ ˜f a 2 a1 at the weak scale Gaugino-Higgsino Mixing Chargino T << TEW Mass Matrix N11B MC = BINO T ~TEW : scattering ~ ~ of H,W from CPV N N H N H W d 14 u m 213cos M 12 2 background field W mW 2 sin WINO T << TEW : mixing ~ ~ ~ of H,W to ~, HIGGSINO Neutralino Mass Matrix M1 MN = 0 0 -mZ cos sin qW mZ cos cos qW M2 mZ sin sin qW -mZ sin sin qW -mZ cos sin qW mZ cos cos qW 0 - mZ sin sin qW -mZ sin sin qW - 0 Relic Abundance of SUSY DM T << TEW : mixing ~ ~ ~ of H,W to ~, Neutralino Mass Matrix M1 MN = 0 0 -mZ cos sin qW mZ cos cos qW M2 mZ sin sin qW -mZ sin sin qW -mZ cos sin qW mZ cos cos qW 0 - mZ sin sin qW -mZ sin sin qW - 0 N11B N12W N13HdN14Hu BINO ˜ 10 t t˜ ˜ 10 + res t WINO HIGGSINO ~10 ~ 0 , ~ i ~10 W,Z + coannihilation j W,Z Sfermion Mixing Sfermion mass matrix ˜ 2˜ M fL 2 ˆ M 2 M LR 2 M LR 2 ˜ ˜ M f R m f ( t an A f ) M m f ( cot A f ) 2 LR T ~TEW : scattering ~ ~ of fL, fR from background field T << TEW : mixing ~ ~ ~ ~ of fL, fR to f1, f2 Qf < 0 Qf > 0 Test “Superpotential” : a convenient way to derive supersymmetric interactions by taking derivatives w.r.t. scalar fields ~ 100 new parameters 40 new CPV phases Flavor mixing parameters No new coupling constants Two Higgs vevs ˜ NEW H0 NEW H Higgs mass, Supersymmetric 0 H0 H0 Neutral Current Interactions II Neutral current l+f --> l+f at one loop: Normalization: Normalize to G: Remove r QuickTime™ and a decompressor are needed to see this picture. Vector & axial vector couplings: Weak mixing: Vertex & ext leg QuickTime™ and a decompressor are needed to see this picture. The parameter: Weak mixing: Can impose constraints from global fits to EWPO via S,T,U-dependence of these quantities