Physics Beyond the Standard Model Electric Dipole Moments
Physics Beyond the Standard Model & Electric Dipole Moments Viewer Discretion Advised William J. Marciano January 24, 2015 1
Today Many Elementary Particles! SU(3)Cx. SU(2)Lx. U(1)Y Standard Model 8 gluons + W±, Z, gauge bosons (spin 1) 3 generations of quarks & leptons (mix->CP violation) e, e, u, d , , c, s , , t, b (mt/m >1013!!) (spin ½) Scalar Doublet: S±, S 0, h source of mass The End? Is that all there is? New Particles? Interactions? Supersymmetry - Something Else Multi-Higgs (2 doublets? ) (Singlet? ) * Heavy (Vector-like) Leptons etc. 2
Early LHC “Lessons” • SM Higgs Scalar Exists!: m. H=125 -126 Ge. V Great Discovery but reopens old Issues. λΦ 4 theory: Alone Trivial, Quadratic Divergences, Vacuum stability… Higgs Properties become a primary goal Branching Ratios (Couplings), Precision! Anomalies Loop Induced BR(H γγ ) ≈ BR(H γγ ) SM (W&t) Anomalous? Two Higgs Doublet Mixing (Inoue, Ramsey-Musolf, Zhang) New CP Violation Sources? Implications for edms! de, dn, dp 3
S & T Constraints Gauge Boson Self-Energy Loops Experimental Averages sin 2 W(m. Z)MS= 0. 23125(15) & m. W = 80. 385(15)Ge. V Standard Model + S & T sin 2 W(m. Z)MS= 0. 23124(6)[1+0. 016 S-0. 011 T] m. W = 80. 362(6)Ge. V[1 -0. 0036 S+0. 0056 T] S≈0. 7 T (from Z pole sin 2 W(m. Z)MS= 0. 23125(15)) S=0. 07(8) T=0. 10(11) ΔNdoublets=2(2) Very Little room available for “New Physics” Severely Constrains: New Dynamics (Technicolor), 4 th Generation, SUSY, Z’’ (mixing)… 4
Is the Higgs Mechanism Fundamental or Dynamical? Is there just a single Higgs doublet? Several? h=0++ Remnant Predicted – Higgs Boson, Others h, A, H±… h coupling to particles proportional to their masses W, Z, t, b, τ large… c, s, μ potentially observable e, u, d very small (undetectable? ) edms maybe only window! 5
Baryogenesis: NB-NBbar/Nγ ≈10 -10 1957 - Parity Violation in Weak Interactions (Maximal!) Lee & Yang Why is nature left-handed (Chiral)? 1964 - CP Violation Discovered in Kaon Decays 1967 Sakharov Conditions: 1) Baryon Number Violation 2) CP Violation (strong source) 3) Non-Equilibrium 1 st Order Phase Transition *(Leptogenesis – Very Early Universe Alternative) 6
Dirac 1918 -48 Chiral Phase Confusion 1950 Purcell & Ramsey Speculate P may be violated Begin search for neutron edm T (CP) violation also needed for edms! P & T Violation EDMs for all particles with spin CKM CP Violation unobservably small edms EDMs: Window to Early Universe CP Violation! Window to CP Violating Higgs Physics “New Physics” Source of CP Violation Needed! Supersymmetry Leading Candidate (Not observed at LHC yet! Some MSSM Tension!) Higgs Physics? True God Particle! 7
Some Current Dipole Moments fermion afexp e 0. 00115965218073(28) p 1. 792847356(23) n -1. 9130427(5) |dfexp| e-cm <1 x 10 -28 (from Mol. ) <8 x 10 -25 (from d. Hg) <3 x 10 -26 electron & neutron bounds (Very Powerful BSM Constraints) Griffith, Swallows, Loftus, Romalis, Heckel & Fortson PRL 102, 101601 (2009) • d. Hg <3. 1 x 10 -29 e-cm Further factor 3 -5 Hg Improvement Expected! 8
Great Future Expectations • dn 10 -27 -10 -28 e-cm Neutron Spallation/Reactor Sources • de 10 -30 e-cm or better! • dp & d. D 10 -28 -10 -29 e-cm Storage Ring Proposal (BNL/COSY) Pave the way for a new generation of storage ring experiments dp, d. D, d(3 He), d(radioactive nuclei), d Several orders of magnitude improvement expected 9
Higgs (125 -126 Ge. V) Discovery & Properties • ATLAS and CMS Experiments have strong evidence for a • Higgs (spin 0) new particle with mass 125 -126 Ge. V Expected Higgs SM Properties 10
• 5 sigma SM evidence/experiment presented (July 4, 2012) > 1, 000 H already produced at the LHC! gluon + gluon H through top quark loop H γγ ≈ Roughly SM Expectation H ZZ*(virtual) 4 leptons H WW* 4 leptons (includes Neutrinos) H τ +τ H bb Early ATLAS & CMS fluctuations? Other decays e, u, d expected to be unobservabley small FNAL Tevatron strong hints of HW &HZ (3 sigma) with H bb (as expected) 11
W Loop Contribution to H γγ 12
Br(H γγ ) ≈ 1. 5 x expectations (early) How can you enhance H γγ ? Beyond SM Leave SM glue +glue H at SM Rate (top loop) Multi-Higgs mixing, SUSY Loops, … Scenarios New Heavy Fermion Loops (Not Colored) Leptons Problem: if SM like HDLSR Br(H γγ ) reduction! W & top loops have opposite sign *Popular Solution – New Heavy (O(125 Ge. V)) Vector-Like Leptons L-R Doublets & Singlets SU(2)Lx. U(1)Y Invariant Masses + HDS couplings Mixing Potential opposite sign contribution to H γγ 13
14
Vector-like Heavy Leptons Dark Variant Davoudiasl, Lee &WJM • Example: A Possible Dark Sector Two Left Handed Doublets (Ni 0, Ei-))L i=1, 2 Two Right-Handed Doublets (Ni 0, Ei-)R Dark Charges ± 1 Four Left Handed Singlets N j. L, Ej. L j=3, 4 Four Right Handed Singlets Nj. R, Ej. R Dark Charges ± 1 Gauge Invariant Mass Terms + Higgs Couplings Mixing All interactions vector-like under SU(2)Lx. U(1)Yx. U(1)d 4 Charged & 3 Neutral Leptons Unstable Lightest Neutral: Potential Stable Dark Matter? 15
Example H γγ vs edms Mc. Keen, Pospelov & Ritz; Voloshin H γγ Dim. 5 Operator (Scalar Analog of Dipole Moments) a. HFμνFμν + b. H*FμνFμν (*Fμν=Fμν dual =1/2εμναβFαβ) second term violates P & T (much like edm) New Source of CP Violation! Higgs pseudoscalar Coupling tanϕH γγ = b/a Γ(H γγ ) α a 2 +b 2 Could the Higgs violate CP? Source of Baryogenesis? Measure γγ planes of polarizaton (Voloshin) Max. at θ=ϕH γγ = b/a (instead of 0) Very Difficult, particularly for b<<a 16
Charged Leptons: H γγ Loops Increase or Decrease Br(H γγ )? Could Violate CP! (M. Voloshin) induce edms! (Mc. Keen, Pospelov, Ritz) Also give rise to γ–Zd kinetic mixing If gd≈e ε≈α/2π≈10 -3 solves gμ-2 problem for 20 Me. V<m. Zd<50 Me. V (Experimental Range) 17
CP Violating higgs 2 loop (Mc. Keen, Pospelov, Ritz) 18
2 loop dipole moment sources: Mc. Keen, Pospelov, Ritz earlier Huber, Pospelov, Ritz 19
Two Loop Higgs Contribution to Fermion Dipole Moments Barr-Zee, Bjorken-Weinberg (μ eγ) 20
2 Loop 2 HD edm diagrams: Inoue, Ramsey-Musolf, Zhang 21
2 Higgs Doublet electron edm: from Inoue, Ramsey-Musolf, Zhang 22
2 loop 2 HD neutron edn: from Inoue, Ramsey-Musolf, Zhang 23
af vs df (very roughly) • Two loop Higgs contribution: aμ(H)≈fewx 10 -11 a e(H)≈5 x 10 -16 Unobservably Small! Two Loop Higgs contribution: de(H) ≈ 10 -26 sinϕ e-cm |dn(H)|≈|dp(H)|≈3 x 10 -26 sinϕe-cm Already de bound implies sinϕ≤ 0. 1 (smaller? ) CP violation in H γγ sin 2ϕ≤ 0. 01 Unlikely to be observable, but edm experiments can Explore down to sinϕ≈O(10 -3) ! Unique! 24
Very Rough de, dp & dn Relationship Constituent Quark Model: dn=4/3 dd-1/3 du dp=4/3 du-1/3 dd 2 loop Higgs induced edms: Hγ du≈ -dd couplings mf. Qf du = -⅔(mu/me)de dp≈ -dn≈ -(10 mu/9 me)de≈-3 de (very rough) Lattice Calculation Would Be Useful 25
dp not “just” complementary to dn Window to “New Physics” Baryogenesis! (why do we exist? ) Potential � sensitivity an order of magnitude better than dn! Probes New Physics(NP) at (1 Te. V/ NP)2 tan NP 10 -7! or for NP~O(1) NP~3000 Te. V! (well beyond LHC) Paves the way for a new generation of storage ring experiments dp d. D, d(3 He), d(radioactive nuclei), d 26
Physics Reach of dp~10 -29 e-cm dp 0. 01(mp/ NP)2 tan NPe/2 mp 10 -22(1 Te. V/ NP)2 tan NPe-cm If NP is of O(1), NP~3000 Te. V Probed! If NP~O(1 Te. V), NP~10 -7 Probed! Unique Capabilities! 27
Complex Formalism: FD=F 2+i. F 3 Hdipole=-1/2[FDf. L f. R+FD*f. R f. L]F FD=|FD|ei f. R, L=(1± 5)/2 f |FD|=(F 22+F 32)1/2, tan =F 3/F 2 tan = Relative Degree of CP Violation egs. |tan e |SM 10 -24 |tan n|SM 10 -20 Can be removed by a chiral rotation? f exp(i 5 /2) f (Dirac Confusion) No, not if it makes the mass mf complex (EDM = relative phase!) 28
Future Expectations • dn 10 -27 -10 -28 e-cm Spallation Neutron Sources • dp & d. D 10 -28 -10 -29 e-cm Storage Ring Proposal (BNL/COSY) Probes New Physics(NP) at (1 Te. V/ NP)2 tan NP 10 -7! for NP~O(1) NP~3000 Te. V! (well beyond LHC) Paves the way for a new generation of storage ring experiments dp, d. D, d(3 He), d(radioactive nuclei), d • de 10 -30 e-cm or better! • d 10 -24 e-cm Storage Ring Proposal 29
dp & dn Relationship Constituent Quark Model: dn=4/3 dd-1/3 du dp=4/3 du-1/3 dd Roughly 1/4<|dp/dn|<4 Similar Magnitudes Isovector (dp-dn)/2 or Isoscalar (dp+dn)/2? Need both dn & dp dd & du (Relationship? ) (Deuteron edm more sensitive to isoscalar) QCD leading effect (roughly) isovector ( PT) dn=-dp~3. 6 x 10 -16 QCDe-cm 30
Currently: dn | QCD|<10 -10! Future: 10 -12 dp at 10 -29 e-cm explores QCD<10 -13 If a non-zero dn is discovered, the first thing we want to do is know dp Opposite sign? Isovector, QCD Interpretation or Higgs (2 loop) Example: naïve dp=-dn Same Sign? Isoscalar, QCD Unlikely Primary Source More Likely: strangeness, gluonic, susy… dn, dp, d. D…de all needed! 31
H γγ Dim. 5 Operator a. HFμνFμν + b. H*FμνFμν (*Fμν=Fμν dual =1/2εμναβFαβ) second term violates P & T New Source of CP Violation! Higgs pseudoscalar Coupling tanϕH γγ = b/a Γ(H γγ ) α a 2 +b 2 Could the Higgs violate CP? Window to Baryogenesis? Measure γγ planes of polarizaton (Voloshin) Max. at θ=ϕH γγ = b/a (instead of 0) Very Difficult, particularly for b<<a 32
EDM 2 loop sources: Mc. Keen, Pospelov, Ritz earlier Huber, Pospelov, Ritz 33
General Two Loop Higgs Contribution to Fermion Dipole Moments 34
Outlook EDMs may soon be discovered: de, dn, dp…d. D Magnitudes of ≈ 10 -27 -10 -28 expected for Baryogenesis Atomic, Molecular, Neutron, Storage Ring (All important) CP violation in 2 HD Model & H γγ (Contemporary topics) Uniquely explored by 2 loop edms! May be our only window to Hee, Huu and Hdd couplings Guided by experiment: H γγ (H τ+τ−) etc. Updates Anxiously Anticipated! In the end, the Higgs may be central to our and the matter dominated universe! Truly the God Particle existence 35
- Slides: 35