Electric Dipole Moments: A Look Beyond the Standard Model

Transcription

1 Electric Dipole Moments: A Look Beyond the Standard Model M.J. Ramsey-Musolf U Mass Amherst PSI Symmetries Workshop October 016! 1

2 Outline I. The BSM context II. Electric dipole moments III. EDM complementarity IV. Outlook V. Back up slides: challenges for hadronic & nuclear structure theory

3 I. The BSM Context 3

4 EDMs & SM Physics d n ~ (10-16 e cm) x θ QCD + d n CKM 4

5 EDMs & SM Physics d n ~ (10-16 e cm) x θ QCD + d n CKM d n CKM = (1 6) x 10-3 e cm C. Seng arxiv:

6 EDMs & BSM Physics d ~ (10-16 e cm) x (υ / Λ) x sinφ x y f F 6

7 EDMs & BSM Physics d ~ (10-16 e cm) x (υ / Λ) x sinφ x y f F CPV Phase: large enough for baryogenesis? 7

8 EDMs & BSM Physics d ~ (10-16 e cm) x (υ / Λ) x sinφ x y f F BSM mass scale: TeV? Much higher? 8

9 EDMs & BSM Physics d ~ (10-16 e cm) x (υ / Λ) x sinφ x y f F BSM dynamics: perturbative? Strongly coupled? 9

10 EDMs & BSM Physics d ~ (10-16 e cm) x (υ / Λ) x sinφ x y f F BSM dynamics: perturbative? Strongly coupled? Hadronic & atomic systems: reliable SM calc s? 10

11 EDMs & BSM Physics d ~ (10-16 e cm) x (υ / Λ) x sinφ x y f F Need information from at least three frontiers 11

12 EDMs & BSM Physics d ~ (10-16 e cm) x (υ / Λ) x sinφ x y f F Need information from at least three frontiers Baryon asymmetry Cosmic Frontier High energy collisions Energy Frontier EDMs Intensity Frontier 1

13 The Origin of Matter Baryons Cosmic Energy Budget Dark Matter 7 % 5 % 68 % Dark Energy Explaining the origin, identity, and relative fractions of the cosmic energy budget is one of the most compelling motivations for physics beyond the Standard Model 13

14 The Origin of Matter Baryons Cosmic Energy Budget Dark Matter 7 % 5 % EDMs 68 % Dark Energy Explaining the origin, identity, and relative fractions of the cosmic energy budget is one of the most compelling motivations for physics beyond the Standard Model 14

15 Ingredients for Baryogenesis Scenarios: leptogenesis, EW baryogenesis, Afflek- Dine, asymmetric DM, cold baryogenesis, postsphaleron baryogenesis Testable Standard Model BSM B violation (sphalerons) C & CP violation EDM Out-of-equilibrium or CPT violation 15

16 Electroweak Baryogenesis Was Y B generated in conjunction with electroweak symmetry-breaking? 16

17 BSM Physics: Where Does it Live? BSM? SUSY, LNV, extended Higgs sector Mass Scale M W BSM? Sterile ν s, axions, dark U(1) Coupling 17

18 Low-Energy / High-Energy Interplay Discovery Diagnostic Low energy High energy 18

19 Low-Energy / High-Energy Interplay Discovery Diagnostic? Low energy High energy 19

20 II. EDMs 0

21 EDMs: New CPV? System Limit (e cm) * SM CKM CPV BSM SM CPV 199 Hg ThO n 7.4 x x 10-9 ** 3.3 x background well 10 below new CPV expectations 10 New expts: 10 to 10 3 more sensitive 10-6 CPV needed for BAU? * 95% CL ** e - equivalent 1

22 EDMs: New CPV? System 199 Hg ThO n Limit (e cm) * 7.4 x x 10-9 ** 3.3 x 10-6 SM CKM CPV BSM SM CPV background well 10 below new CPV expectations 10 New expts: 10 to 10 3 more sensitive 10-6 CPV needed for BAU? * 95% CL ** e - equivalent Mass Scale Sensitivity ψ e ϕ ϕ γ sinφ CP ~ 1! M > 5000 GeV M < 500 GeV! sinφ CP < 10 -

23 EDMs: New CPV? System Limit (e cm) * SM CKM CPV BSM SM CPV 199 Hg ThO n 7.4 x x 10-9 ** 3.3 x background well 10 below new CPV expectations 10 New expts: 10 to 10 3 more sensitive 10-6 CPV needed for BAU? * 95% CL ** e - equivalent neutron proton & nuclei atoms Not shown: muon ~ 100 x better sensitivity 3

24 Why Multiple Systems? 4

25 Why Multiple Systems? Multiple sources & multiple scales 5

26 EDM Interpretation & Multiple Scales Baryon Asymmetry Early universe CPV BSM CPV SUSY, GUTs, Extra Dim Collider Searches Particle spectrum; also scalars for baryon asym? Energy Scale QCD Matrix Elements d n, g πnn, Expt Nuclear & atomic MEs Schiff moment, other P- & T-odd moments, e-nucleus CPV 6

27 Effective Operators: The Bridge + 7

28 EDM Interpretation & Multiple Scales Baryon Asymmetry Early universe CPV BSM CPV SUSY, GUTs, Extra Dim Collider Searches Particle spectrum; also scalars for baryon asym d= 6 Effective Operators: CPV Sources fermion EDM, quark chromo EDM, 3 gluon, 4 fermion Energy Scale QCD Matrix Elements d n, g πnn, Expt Nuclear & atomic MEs Schiff moment, other P- & T-odd moments, e-nucleus CPV 8

29 Wilson Coefficients: Summary δ f fermion EDM (3) ~ δ q quark CEDM () C G ~ 3 gluon (1) C quqd non-leptonic () C lequ, ledq semi-leptonic (3) C ϕud induced 4f (1) 1 total + θ light flavors only (e,u,d) 9 9

30 Wilson Coefficients: Summary δ f fermion EDM (3) ~ δ q quark CEDM () C G ~ 3 gluon (1) C quqd non-leptonic () C lequ, ledq semi-leptonic (3) C ϕud induced 4f (1) 1 total + θ light flavors only (e,u,d) Complementary searches needed 30 30

31 BSM Origins EDM: γff CEDM: gff Weinberg ggg: MSSM LRSM RS Four fermion ϕ udhh d L u L W + ϕ u R d R 31

32 III. EDM Complementarity CPV in an extended scalar sector (HDM): Higgs portal CPV Weak scale baryogenesis (MSSM) Model-independent 3

33 The Higgs Portal 33

34 Portals & Early Universe Standard Model Hidden Sector New CPV? 34

35 this symmetry general haveunder a di erent expression another basistoobtained by the transformatio ethough CPV complex phases will thatinare invariant a rephasing of theinscalar fields. 0 totaking a basis where the vacuum expectation value (vev) of the j = UY jk transformation L U(1) k. For example, complex: while that associated with the neutral component of is in general For future purposes,+we emphasize U = p that the value, of is not invariant. ( 1 1 H1+ H Inoue, R-M, Zhang: tan = v / v1,0 the,minimization conditions in the(5) Hk0 and A0k directions give us the, Denoting = p1 (v1 + H 0 + ia0 ) p1 (v + H 0+ ia ) 1 1 thetransformation (1) corresponds to i i Higgs Portal CPV m11 = 1v cos +( )v sin Re(m1 e ) tan + Re( 5e )v sin GeV, v1 = v1 and v = v ei. It is apparent that in0 general the relative $ +0( 3. +denotes m = v sin Re(m1 ei ) cot + Re( 5 ei )v cos (3 4 )v cos 1 CPV & HDM: Type I & II λ6,7 = 0 for simplicity lobal rephasing transformation i i Im(m e ) = v sin cos Im( 5 e ). We then take the Higgs i potential to have the1form 0 j (6) j = e j, h given the complex i parameters From the last equation, it is clear that the phase can be solved1 for 1 = the ( useful, ( to )express + 3 ( this )( ) +in terms however, 1) + 4 ( 1 of )(the 5 ( 1 ) + h.c. 1 1condition 1k): + e redefined tovabsorb 1global phases n h i o 0 m sin( sin( 0 i( 1 ) 1 i( 1 ) 1). 1 (4 (m1 ) = e m1m, 11 ( 15 = e m1 ( 1 5,) + h.c. + m ( ) 1.) = 5 v1 v(7) 1) + In the limit that the to small but that rephasing will be appropriate for our later phenomeno k are l is unchanged. It is then straightforward observe thatnon-vanishing there exist two could contribute work, only the scalar loop to C and eventually to EDMs. representative diagram is shown in 1 The complex coefficientseq. in (1) the potential are m1 and 5. In general, the presence of Athe then implies 1 term, in conjunctio the right panel of Fig. 1. It is proportional to with the Z -conserving quartic interactions, will induce other Z -breaking quartic operators at one-loop order. Simp Im( v1 v ) =magnitude m1 v1 v5 vproportional sin 1 v. 5 m1with 5 EWSB power counting implies that the responding coefficients are finite to m1 k /(16 (A10) ). Give 1 = Arg (m ), 1 m1 5 1, term. our attention Zrelated 1 CPV the 1/16 suppression, we restrict toabove thequantity tree-level -breaking bilinear the in Eq. (13), the is indeed to vthe unique source in the model. will Using relation 5 1 v = Arg (m )v v. (8) 1 1 fermionic loops do not contribute because the physical The charge Higgs and quark the structure 5 1 m1a rephasingcouplings It is instructive to identify the CPV complex phases that are invariant under of thehave scalar fields. T proportional to the corresponding CKM element. As a result, the coefficients Cij are purely real and C ij are purely that end, we perform an SU()Limaginary. U(1)YThey transformation to dipole a basis where theof vacuum expectation value (vev) of th contribute to magnetic moments instead EDMs. so that there exists only one independent CPV phase in the theory after EWSB. neutral component of 1 is real while that associated with the neutral component of is in general complex: A special case arises when 1 = 0. In this case, Eq. (1) implies that + M at the electroweak scale without the Z symmetry flavor violation, flavor H1+ is to assume minimal H sin( ) = 0 5 v1 v0 sin(, = m1p1 studies., ), (5 not discuss this possibility, but refer [13 15] for recent phenomenological = to p (v + H + ia ) (v + H + ia ) /H + or H p H+ H+ where v = v1 + v = 46 GeV, v1 = v1 and v = v ei. It is apparent that in general denotes the relativ 1 m 1 ± H0 H phase of v and v1. Under the global rephasingw transformation cos =. f the couplings m1 f j =e i j 0f j, W+ 5 v1 v H0 H10 H1+ (6 When the right-hand side is less than 1, has solutions two solutions of equal 35 magnitude and op to the presence of spontaneous CPV (SCPV) [17, 18]: and sponding phases 5 can be redefined to absorb the global FIG. 1: Left: quark or lepton EDM from W ± H exchange and CPV Higgs interactions. Right: a scalar loop contribution a as the upper loop of the left panel. to 1 Wµ B µ e ective operator, which then contributes to EDM 0 i( 1 ) 01 i( m 1 m1 1 ) 1 (m1 ) = e m arccos, (7 5 =e = 5±,. = ±1 v v v cos sin The gauge invariant contributions to EDM from this class 5 1 of diagrams have 5been calculated recently in [4], a

36 Future Reach: Higgs Portal CPV CPV & HDM: Type II illustration λ 6,7 = 0 for simplicity Hg ThO n Ra Present Future: Future: d n x 0.1 d n x 0.01 d A (Hg) x 0.1 d A (Hg) x 0.1 sin α b : CPV scalar mixing d ThO x 0.1 d A (Ra) [10-7 e cm] d ThO x 0.1 d A (Ra) Inoue, R-M, Zhang:

37 Higgs Portal CPV: EDMs & LHC CPV & HDM: Type II illustration λ 6,7 = 0 for simplicity Hg ThO n Ra LHC Current Dawson et al: M h = 400 GeV Present Future: Future: d n x 0.1 d n x 0.01 d A (Hg) x 0.1 d A (Hg) x 0.1 sin α b : CPV scalar mixing d ThO x 0.1 d A (Ra) [10-7 e cm] d ThO x 0.1 d A (Ra) Inoue, R-M, Zhang:

38 Higgs Portal CPV: EDMs & LHC CPV & HDM: Type II illustration λ 6,7 = 0 for simplicity Hg ThO n Ra LHC Future? Dawson et al: M h = 400 GeV Present Future: Future: d n x 0.1 d n x 0.01 d A (Hg) x 0.1 d A (Hg) x 0.1 sin α b : CPV scalar mixing d ThO x 0.1 d A (Ra) [10-7 e cm] d ThO x 0.1 d A (Ra) Inoue, R-M, Zhang:

39 Higgs Portal CPV: EDMs & LHC CPV & HDM: Type II illustration λ6,7 = 0 for simplicity Current dn LHC 100 fb-1 Hg LHC 300 fb-1 ThO Run II n Ra Chen, Li, RM preliminary Mh = 550 GeV FIG. 10: Current and prospective future constraints from electron EDM (blue), neutron EDM (green), Mercury EDM (red) and Future: FirstFuture: row: type-i model; Second row: type-ii model. The model parameters used are the same as Fig. 6. Central values of the hadronic and nuclear matrix elements are used. Left: Combined current dn and x 0.1 dn xorder 0.01 limits. Middle: combined future limits if the Mercury neutron EDMs are both improved by one of magnitude. Also shown are the future constraints if electron EDM is improved by another order of magnitude (in blue dashed curves). Right: da(hg) 0.1 combined future limits if the Mercury and neutron EDMs areximproved by one and two orders of dmagnitude, respectively. A(Hg) x 0.1 Present Radium (yellow) in flavor conserving HDMs. d x 0.1 d x 0.1 ThO ThO sin αb : CPVthere is guidance from naı ve dimensional matrix elements, analysis, which takes into account the chiral structures of -7 e cm] d (Ra) [10 d (Ra) A A scalar mixing the operators in question. However, the precise value of matrix elements involving quark CEDMs and the Weinberg three-gluon operator are only known to about an order of magnitude, and dimensional analysis does not tell us39 the Inoue, R-M, Zhang: signs of the matrix elements. We highlight two places where these uncertainties can change our results. In Figs. 7 and 8, we see that the Weinberg three-gluon operator is always subdominant as a contribution to the neutron and mercury EDMs. It is possible, though, that the actual matrix element may be an order of magnitude

40 Low-Energy / High-Energy Interplay Higgs Portal CPV Discovery Diagnostic? Low energy High energy 40

41 Was the baryon asymmetry produced during electroweak symmetry-breaking? EDMs provide most powerful probe of CPV Phase transition! Separate talk 41

42 EDMs & EW Baryogenesis: MSSM Neutron EDM Compatible with observed BAU Next generation d n sin(µm 1 b * ) d n = 10-7 e cm d n = 10-8 e cm Compressed spectrum (stealthy SUSY) Li, Profumo, RM

43 EDMs & EW Baryogenesis: MSSM Electron EDM Compatible with observed BAU d e = 10-8 e cm ThO Limit sin(µm 1 b * ) d e = 10-9 e cm Compressed spectrum (stealthy SUSY) Next generation d e? Li, Profumo, RM

44 EDMs & EW Baryogenesis: MSSM Compatible with observed BAU d e = 10-8 e cm ACME: ThO sin(µm 1 b * ) d n = 10-7 e cm sin(µm 1 b * ) d e = 10-9 e cm d n = 10-8 e cm Next gen d e Next gen d n Li, Profumo, RM Compressed spectrum (stealthy SUSY) Next gen lepton collider 44 44

45 Two-Step EW Baryogenesis 45

46 EWSB: The Scalar Potential From Nature What was the thermal history of EWSB? 46

47 EWSB: The Scalar Potential From Nature What was the thermal history of EWSB? 47

48 Scalar Potential: Thermal History Single-Step EWSB Constrained by experiment, but not the only possibility 48

49 Two-Step EW Baryogenesis H j St d Model Scalar Sector j 1 <φ 0 > φ BSM Scalar Sector: at least one SU() L non-singlet plus possibly gauge singlets ( partially secluded sector ) Conventional one step EWSB Two step EWSB BSM CPV in φ H interactions: baryogenesis during step 1 Inoue, Ovanesyan, R-M: ; Patel & R-M: ; Blinov, Kozaczuk, Morrissey:

50 Two-Step EW Baryogenesis Two cases: (A) δ S = 0 (B) δ Σ =0 Y B Present d e Future d n Future d p? No EDM constraints Inoue, Ovanesyan, R-M:

51 CPV for EWBG EDM Theoretical creativity EDM EWBG 51

52 Wilson Coefficients: Model Independent δ f fermion EDM (3) ~ δ q quark CEDM () C G ~ 3 gluon (1) C quqd non-leptonic () C lequ, ledq semi-leptonic (3) C ϕud induced 4f (1) 1 total + θ light flavors only (e,u,d) 5 5

53 Global Analysis: Input Chupp & R-M:

54 Paramagnetic Systems: Two Sources e Electron EDM γ e N e γ (Scalar q) x (PS e - ) N e Tl, YbF, ThO 54

55 Paramagnetic Systems: Two Sources e Electron EDM γ Chupp & R-M: e N e γ p (Scalar q) x (PS e - ) N e > (1.5 TeV) p sin CPV Electron EDM (global) > (1300 TeV) p sin CPV C S (global) Tl, YbF, ThO LHC accessible? 55

56 IV. Outlook Searches for permanent EDMs of atoms, molecules, hadrons and nuclei provide powerful probes of BSM physics at the TeV scale and above and constitute important tests of weak scale baryogenesis Studies on complementary systems is essential for first finding and then disentangling new CPV There exists a rich interplay between EDM searches and the quest to discover BSM physics at the Energy and Cosmic frontiers The advancing experimental sensitivity challenges hadronic structure theory to aim for an unprecedented level of reliability & model building to envision new pathways for baryogenesis 56

57 V. Theoretical Challenges 57

58 Hadronic Matrix Elements Hadronic Matrix Elements Engel, R-M, van Kolck 13 58

59 Hadronic Matrix Elements (CEDM) Engel, R-M, van Kolck 13 59

60 Nuclear Matrix Elements Engel, R-M, van Kolck 13 60

61 Had & Nuc Uncertainties CPV & HDM: Type II illustration λ 6,7 = 0 for simplicity Present sin α b : CPV scalar mixing Inoue, R-M, Zhang:

62 Had & Nuc Uncertainties CPV & HDM: Type II illustration λ 6,7 = 0 for simplicity Range of hadronic matrix elements Range of nuclear matrix elements Present sin α b : CPV scalar mixing Inoue, R-M, Zhang:

63 Had & Nuc Uncertainties CPV & HDM: Type II illustration λ 6,7 = 0 for simplicity Range of hadronic matrix elements Range of nuclear matrix elements Present Challenge for Theory sin α b : CPV scalar mixing Inoue, R-M, Zhang:

64 Symmetries & Cosmic History BSM Physics? EW Symmetry Breaking: Higgs Standard Model Universe s s 10-5 s ~ 1 m 380k yr QCD: q+g! n,p QCD: n+p! nuclei Astro: stars, galaxies,.. 64

65 Symmetries & Cosmic History? EW Symmetry Breaking: Higgs Baryogenesis: When? Standard CPV? SUSY? Model Neutrinos? Universe s s 10-5 s ~ 1 m 380k yr QCD: q+g! n,p QCD: n+p! nuclei Astro: stars, galaxies,.. 65

66 Symmetries & Cosmic History? EW Symmetry Breaking: Higgs Baryogenesis: When? Standard CPV? SUSY? Model Neutrinos? Universe Leptogenesis: look for ingred s w/ νs: DBD, ν osc s EW Baryogenesis: testable w/ EDMs + colliders s 10-5 s ~ 1 m 380k yr QCD: q+g! n,p QCD: n+p! nuclei Astro: stars, galaxies,.. 66