Hadronic physics of EDMs Vincenzo Cirigliano Los Alamos National - - PowerPoint PPT Presentation

▶
hadronic physics of edms
SMART_READER_LITE
LIVE PREVIEW

Hadronic physics of EDMs Vincenzo Cirigliano Los Alamos National - - PowerPoint PPT Presentation

Jun 08, 2023 113 likes •590 views

ACFI EDM School November 2016 Hadronic physics of EDMs Vincenzo Cirigliano Los Alamos National Laboratory 1 Lecture VII outline Status of hadronic matrix elements Lattice QCD: results and prospects Impact on phenomenology and the

slide-1
SLIDE 1

1

Hadronic physics of EDMs

Vincenzo Cirigliano Los Alamos National Laboratory

ACFI EDM School November 2016

slide-2
SLIDE 2

2

Lecture VII outline

  • Status of hadronic matrix elements
  • Lattice QCD: results and prospects
  • Impact on phenomenology and the need for improvement
slide-3
SLIDE 3

3

Status of hadronic matrix elements

slide-4
SLIDE 4

4

Going from quark & gluons to hadrons

RG EVOLUTION

(perturbative)

MATRIX ELEMENTS

(non-perturbative)

Multi-scale problem: need RG evolution of effective couplings & hadronic / nuclear / molecular calculations of matrix elements

slide-5
SLIDE 5

5

Going from quark & gluons to hadrons

RG EVOLUTION

(perturbative)

MATRIX ELEMENTS

(non-perturbative)

Matrix element uncertainties strongly dilute constraining and model-discriminating power of impressive experimental searches

slide-6
SLIDE 6

6

  • At scale E ~ 1 GeV, find a handful of leading CPV dim=6 operators

Electric and chromo-electric dipoles of fermions Gluon chromo-EDM (Weinberg operator) Semileptonic and 4-quark

Going from quark & gluons to hadrons

slide-7
SLIDE 7

6

  • At scale E ~ 1 GeV, find a handful of leading CPV dim=6 operators

Electric and chromo-electric dipoles of fermions Gluon chromo-EDM (Weinberg operator) Semileptonic and 4-quark

Going from quark & gluons to hadrons

  • The above quark-gluon operators induce π,N CPV operators
  • Effective Lagrangian can be constructed according to chiral

transformation properties of each quark-gluon operator

  • Power counting in q/mn, mπ /mn → identify leading effects

Great work on this by the Arizona-Groningen and Bonn-Julich groups: see 1505.06272 and 1412.5471 for recent reviews

slide-8
SLIDE 8

7

CPV at the hadronic level

T

  • odd P-odd pion-

nucleon couplings Short-distance contribution to nucleon EDM Short-range 4N and 2N2e coupling

  • Leading pion-nucleon CPV interactions characterized by few LECs
slide-9
SLIDE 9

8

CPV at the hadronic level

  • Leading pion-nucleon CPV interactions characterized by few LECs
  • All hadronic EDMs are expressed in terms of these LECs:

Nucleon EDM dN

+ ...

slide-10
SLIDE 10

9

CPV at the hadronic level

  • Leading pion-nucleon CPV interactions characterized by few LECs
  • All hadronic EDMs are expressed in terms of these LECs:

Nucleon EDM dN

Isovector and isoscalar anomalous magnetic moments

Seng et al 1401.5366

slide-11
SLIDE 11

10

CPV at the hadronic level

  • Leading pion-nucleon CPV interactions characterized by few LECs
  • All hadronic EDMs are expressed in terms of these LECs:

Nuclear EDMs

See Lecture VIII by Emanuele Mereghetti CP violation in current and potential

slide-12
SLIDE 12

11

CPV at the hadronic level

  • Leading pion-nucleon CPV interactions characterized by few LECs
  • All hadronic EDMs are expressed in terms of these LECs:
  • To connect to new physics, need to calculate LECs in terms of short-

distance coefficients (most methods give directly dn and not dn) _

slide-13
SLIDE 13

12

CPV at the hadronic level

  • Leading pion-nucleon CPV interactions characterized by few LECs
  • All hadronic EDMs are expressed in terms of these LECs:

Non-perturbative approaches to low-energy QCD:

  • QCD sum rules, Dyson-Schwinger, vacuum saturation, quark

model, …, naive dimensional analysis

  • Lattice QCD — challenging but systematically improvable
slide-14
SLIDE 14
  • Consider nucleon-nucleon correlation function in presence of CP-

violating operators

13

QCD sum rules: methodology

  • Compute in two ways (and match)
  • perator product expansion at quark level

(perturbative factors and operator condensates)

  • phenomenological representation in terms of

hadronic poles and matrix elements

Product of three quark fields with quantum number of the nucleon

  • Some difficulties: excited states, unknown condensates, …

Pospelov-Ritz hep-ph/0504231 and refs therein

slide-15
SLIDE 15

14

Lattice QCD methodology

L a

  • Discretize space-time into a finite euclidean lattice →

perform Monte Carlo evaluation of correlation functions in Feynman’s path integral → extract matrix elements

  • Statistical uncertainty
  • “Systematic” uncertainty: renormalization; excited states;

(a, mq, V) → (0, (mq)phys ,∞)

Oiq

n

n

×

Isolate the neutron e-Mnτ Project on the neutron e-Mnτ

slide-16
SLIDE 16

15

Status: neutron EDM

  • Nucleon EDMs from BSM operators:

Dependence on other operators (4-quarks, etc) discussed in Engel, Ramsey-Musolf, van Kolck 1303.2371

slide-17
SLIDE 17

16

Status: neutron EDM

QCD Sum Rules (50%) QCD Sum Rules + NDA (~100%)

μ=1 GeV

  • Matching with QCD sum rules: 50% → 200% uncertainties
  • Here Lattice QCD can play a major role

Pospelov-Ritz hep-ph/0504231 and refs therein

  • Nucleon EDMs from BSM operators:
slide-18
SLIDE 18

17

Status: nuclear EDMs

  • πNN couplings: O(1) uncertainties (from QCD sum rules)

Pospelov-Ritz hep-ph/0504231 and refs therein — larger ranges quoted in Engel, Ramsey-Musolf, van Kolck 1303.2371

slide-19
SLIDE 19

17

Status: nuclear EDMs

199Hg, 129Xe, 225Ra

  • Diamagnetic atoms: O(1) uncertainties from nuclear structure

Engel, Ramsey-Musolf, van Kolck 1303.2371, and references therein

  • πNN couplings: O(1) uncertainties (from QCD sum rules)

Pospelov-Ritz hep-ph/0504231 and refs therein — larger ranges quoted in Engel, Ramsey-Musolf, van Kolck 1303.2371

slide-20
SLIDE 20

18

Lattice QCD: results and prospects

L a

slide-21
SLIDE 21

19

Matrix elements with lattice QCD

  • Nucleon EDMs
  • Pion-nucleon CP-odd couplings
  • Major role for lattice QCD: systematically improvable calculations

N N γ N N π

slide-22
SLIDE 22

20

Matrix elements with lattice QCD

  • Nucleon EDMs
  • Pion-nucleon CP-odd couplings
  • Major role for lattice QCD: systematically improvable calculations

RECENT PROGRESS (LANL+ UW): will discuss in a moment

slide-23
SLIDE 23

21

Matrix elements with lattice QCD

  • Nucleon EDMs
  • Pion-nucleon CP-odd couplings
  • Major role for lattice QCD: systematically improvable calculations

WORK IN PROGRESS (LANL, BNL-UConn)

Exploit chiral symmetry, relate to mass shifts induced by chromo-magnetic operator

(A. Walker-Loud)

Renormalization in RI-SMOM and exploratory study of signal

slide-24
SLIDE 24

22

Matrix elements with lattice QCD

  • Nucleon EDMs
  • Pion-nucleon CP-odd couplings
  • Major role for lattice QCD: systematically improvable calculations

FUTURE

slide-25
SLIDE 25

23

dn,p from quark EDMs

  • Quarks directly couple to photon in CP-odd way
  • Problem “factorizes”: need tensor charge of the nucleon

** Use

slide-26
SLIDE 26

24

Tensor charges in lattice QCD

  • Features of this calculation:
  • Included disconnected diagrams (small)

“Disconnected” “Connected”

Bhattacharya, VC, Gupta, Lin, Yoon, Phys. Rev. Lett. 115 (2015) 212002 [1506.04196]

slide-27
SLIDE 27

24

Tensor charges in lattice QCD

  • Features of this calculation:
  • Included disconnected diagrams (small)

“Disconnected” “Connected”

Bhattacharya, VC, Gupta, Lin, Yoon, Phys. Rev. Lett. 115 (2015) 212002 [1506.04196]

  • Studied excited state

contamination

tins - tsep/2

slide-28
SLIDE 28

24

Tensor charges in lattice QCD

  • Features of this calculation:
  • Included disconnected diagrams (small)

“Disconnected” “Connected”

Bhattacharya, VC, Gupta, Lin, Yoon, Phys. Rev. Lett. 115 (2015) 212002 [1506.04196]

  • Simultaneous fit in mq, a, V (9 ensembles)
  • Studied excited state

contamination

tins - tsep/2

slide-29
SLIDE 29

25

Simultaneous fit in a, Mπ, MπL

* Yellow (a=0.12 fm), green(a= 0.09 fm), blue (a=0.06 fm); squares (Mπ = 310 MeV), diamonds & triangles (Mπ = 220 MeV), circles (Mπ = 130 MeV) MS @ 2 GeV

slide-30
SLIDE 30

26

Comparisons

QCD SUM RULES TRANSVERSITY

(gT)u (gT)d

μ=? μ=2GeV μ=1GeV μ=3.2GeV μ=2GeV

LQCD (our work)

  • Smaller uncertainty: 50% to 10% + scale/scheme dependence
  • Smaller central values: dn “less sensitive” to new physics in dq

Widely used in BSM studies of neutron EDM

slide-31
SLIDE 31

27

dn,p from quark CEDMs

Requires 4-point function:

Bhattacharya, VC, Gupta, Mereghetti, Yoon, 1502.07325

  • T. Bhattacharya,

VC, R. Gupta, E. Mereghetti, B. Yoon, Proceedings of Science LATTICE 2015 (2016) 238

  • First steps toward extracting neutron EDM from correlation function

Chromo EDM insertion

slide-32
SLIDE 32

28

Impact on phenomenology & the need for improvement

slide-33
SLIDE 33
  • Hadronic uncertainties strongly dilute constraining and model-

discriminating power of impressive experimental searches

  • Next:
  • discuss impact of hadronic uncertainties on some selected models
  • show benefits of improved matrix elements in one scenario

29

Why do we care?

slide-34
SLIDE 34

30

Impact on 2HDM

slide-35
SLIDE 35

31

Impact on CPV Higgs couplings

  • Leading operator affects both Higgs production and decay and EDMs

θ′ θ′ θ′

E.g.: Gluon Fusion at LHC

θ′

nEDM via quark chromo-EDM (→ qEDM and Weinberg)

Y.-T. Chien,VC, W. Dekens, J. de Vries, E. Mereghetti, JHEP 1602 (2016) 011 [1510.00725]

slide-36
SLIDE 36

31

Impact on CPV Higgs couplings

  • Leading operator affects both Higgs production and decay and EDMs

θ′ θ′ θ′

E.g.: Gluon Fusion at LHC

θ′

nEDM via quark chromo-EDM (→ qEDM and Weinberg)

Y.-T. Chien,VC, W. Dekens, J. de Vries, E. Mereghetti, JHEP 1602 (2016) 011 [1510.00725]

Bounds on at the scale Λ = 1TeV Range Central

slide-37
SLIDE 37

31

Impact on CPV Higgs couplings

  • Leading operator affects both Higgs production and decay and EDMs

θ′ θ′ θ′

E.g.: Gluon Fusion at LHC

θ′

nEDM via quark chromo-EDM (→ qEDM and Weinberg)

Y.-T. Chien,VC, W. Dekens, J. de Vries, E. Mereghetti, JHEP 1602 (2016) 011 [1510.00725]

Bounds on at the scale Λ = 1TeV Range Central

  • Central: EDMs leave little room for observable deviation at LHC run 2
  • Range: 199Hg bounds disappears, n bound much weaker
slide-38
SLIDE 38
  • Matrix elements determine the difference between life and

death of a model

32

Impact on testing baryogenesis

Compatible with baryon asymmetry Next generation neutron EDM

Li, Profumo, Ramsey-Musolf 2009-10

These “constant EDM lines” shift due to hadronic uncertainties!

slide-39
SLIDE 39

33

Impact on split-SUSY

  • “Split-SUSY”: retain gauge coupling unification and DM candidate
  • Higgs mass at ~125 GeV points to PeV-scale super-partners

Arkani-Hamed, Dimopoulos 2004, Giudice, Romanino 2004, Arkani-Hamed et al 2012, …

_ _

1 TeV 103 TeV Gauginos (M1,2,3) Higgsino (μ) Squarks, sleptons (mf)

~

EDMs among a handful

  • f observables capable of

probing such high scales Same CPV phase controls de, dn

slide-40
SLIDE 40

34

Both de and dn within reach of current searches for M2, μ <10 TeV

sin(ϕ2)=1 tan(β)=1

Current limit from ThO (ACME) Bhattacharya, VC, Gupta, Lin, Yoon 1506.04196

  • Studying the ratio dn /de with

precise matrix elements → upper bound dn<4 ×10-28 e cm

  • If you see nEDM, you will

falsify this model!

  • Model diagnosing enabled by

multiple measurements and controlled th. uncertainty

E X C L U D E D

Impact on split-SUSY

slide-41
SLIDE 41

35

Backup slides

slide-42
SLIDE 42

EDMs in split SUSY (1)

Relative importance controlled by Higgsino mass parameter |μ| Quark EDMs and chromo-EDMs Only fermion EDMs

Altmannshofer-Harnik-Zupan 1308.3653

slide-43
SLIDE 43

EDMs in split SUSY (1)

Maximal CPV phases. Squark mixings fixed at 0.3

For |μ| < 10 TeV, mq ~ 1000 TeV, same CPV phase controls de, dn

~ Altmannshofer-Harnik-Zupan 1308.3653

Current nEDM limit

Distinctive correlations?

slide-44
SLIDE 44

sin(ϕ)=1 sin(ϕ)=0.2

  • The correlation between dn and de provides an interesting

experimental test for Split SUSY (Giudice-Romanino 2004)

The thickness of the bands reflects the uncertainty in (gT)u,d,s With old results each band would be as thick as the whole plot

  • Obtain the stringent upper bound dn < 4 ×10-28 e cm:

Split SUSY scenario can be falsified by current nEDM searches

de = 8.7 ×10-29 e cm

slide-45
SLIDE 45

39

Excited state contamination

  • Large tins and tsep - tins would

isolate neutron, but weak signal

  • Calculate at different tsep, tins, and

keep one excited state in the fit tins - tsep/2

slide-46
SLIDE 46

40

Comparisons

QCD SUM RULES TRANSVERSITY

(gT)u (gT)d

μ=? μ=2GeV μ=1GeV μ=3.2GeV μ=2GeV

LQCD (our work)

gT =

  • Transversity analysis: currently large extrapolation uncertainty