Electric dipole moments of light nuclei

Transcription

1 Electric dipole moments of light nuclei In collaboration with Nodoka Yamanaka (IPN Orsay) E. Hiyama (RIKEN), T. Yamada (Kanto Gakuin Univ.), Y. Funaki (Beihang Univ.) 2017/4/24 RPP Marseille

2 CP violation of Standard model is not sufficient to explain matter/antimatter asymmetry ratio photon : matter Prediction of Standard model: Real observed data: : : 1 CP violation of standard model is in great deficit! We need new source(s) of large CP violation beyond the standard model!

3 Electric dipole moment (EDM) Electric dipole moment: Permanent polarization of internal charge of a particle. + This is what will be evaluated! - Direction: (Spin is the only vector uantity in spin ½ particle ) Interaction: Transformation properties: Under parity tr.: Under time reversal: H EDM is P-odd H EDM is CP-odd!

4 Why the nuclear EDM? Nuclear EDM is sensitive to hadron level CP violation (hadron level CP violation is generated by CP violating operator with gluons and uarks) Standard model contribution is very small : O(10-31 )e cm Nuclear EDM may enhance the CP violation through many-body effect (Cluster, deformation make the parity violation easier) NY and E. Hiyama, JHEP 02 (2016) 067. V. V. Flambaum, I. B. Khriplovich and O. P. Sushkov, Phys. Lett. B162, 213 (1985); NY and E. Hiyama, Phys. Rev. C 91, (2015). Nuclear EDM does not suffer from Schiff s screening encountered in atomic EDM (No electron to screen the nucleus) Very accurate measurement of EDM is possible using storage rings O(10-29 )e cm! Nuclear EDM is a very good probe of BSM

5 CP violating contribution from new physics CP violating processes scale as 1/MNP 2 Quark EDM, chromo-edm: γ,g t γ,g SUSY: 1-loop γ,g H 2-Higgs doublet: 2-loop CP-odd 4-uark interaction: Tree level: * Left-right sym. * Scalar exchange WL WR Weinberg operator: 2-loop diagram: * 2-Higgs doublet model * Vectorlike uark model g g g Probe BSM sectors without mixing with light uarks

6 Nuclear EDM from nucleon level CP violation e,µ EDM Paramagnetic Atom / Molecule EDM e-n int e- int Left-Right Leptouark Diamagnetic Atom EDM MQM Schiff moment N EDM N-N int (πnn int) EDM cedm - int ggg Composite models SUSY Extradimension Energy scale Nuclear EDM (or ion) θ-term Standard Model Atomic Nuclear Hadron QCD TeV observable : Observable available at experiment : Sizable dependence : Weak dependence J. S. M. Ginges, V. V. Flambaum, Phys. Rept. 397, 63 (2004).

7 Nuclear EDM from nucleon level CP violation e,µ EDM Paramagnetic Atom / Molecule EDM e-n int e- int Left-Right Leptouark Diamagnetic Atom EDM MQM Schiff moment N EDM N-N int (πnn int) EDM cedm - int ggg Composite models SUSY Extradimension Energy scale Atomic Nuclear EDM (or ion) Nuclear Hadron θ-term Need the calculation of nuclear structure: Many-body method!! QCD Standard Model TeV observable : Observable available at experiment : Sizable dependence : Weak dependence J. S. M. Ginges, V. V. Flambaum, Phys. Rept. 397, 63 (2004).

8 Nuclear EDM from nucleon level CP violation Two leading contributions to be evaluated: 1) Nucleon s intrinsic EDM: Contribution from the nucleon EDM D (Nedm) = 1 AX h [(d p + d n )+(d p d n ) i z ] 2 i=1 z i i p n p Spin expectation value (CP-even) 2) Polarization of the nucleus: Contribution from the P, CP-odd nuclear force D (pol) = e 2 AX h (1 + i z )z i i + (c.c.) i=1 EDM generated by the CP-even CP-odd mixing - +

9 Nuclear EDM from nucleon level CP violation Two leading contributions to be evaluated: 1) Nucleon s intrinsic EDM: Contribution from the nucleon EDM D (Nedm) = 1 AX h [(d p + d n )+(d p d n ) i z ] 2 i=1 z i i p n p Spin expectation value (CP-even) 2) Polarization of the nucleus: Contribution from the P, CP-odd nuclear force D (pol) = e 2 AX h (1 + i z )z i i + (c.c.) i=1 EDM generated by the CP-even CP-odd mixing - + May be enhanced by many-body effect!

10 Nuclear EDM (polarization) from CP-odd nuclear force Electric dipole operator reuires CP mixing to have finite expectation value Total hamiltonian: N N H = Hrealistic HPT N N P, CP-odd nuclear force HPT Hrealistic P, CP-even realistic nuclear force (e.g. Av18,χEFT, ) CP-odd N-N interactions mixes opposite parity states = - + s-wave p-wave polarized system Parity mixing Polarized ground state!

11 P, CP-odd nuclear force from one pion exchange P, CP-odd nuclear force : we assume one-pion exchange process N N π 2 1 m 2 NN Ni 5 N N N P, CP-odd Hamiltonian (3-types): HPT 4 important properties: Isoscalar Isotensor Isovector Coherence in nuclear scalar density : enhanced in nucleon number One-pion exchange : suppress long distance contribution Spin dependent interaction : closed shell has no EDM Derivative : contribution from the surface What is expected: Polarization effect grows in A for small nuclei May have additional enhancements with cluster, deformation,

12 What we want to do Nucleon level CPV is unknown and small : linear dependence Linear coefficients depends on the nuclear structure We want to find nuclei with large enhancement factors We must calculate the nuclear structure with nucleon level CPV Dependence of nuclear EDM on nucleon level CP violation must be written as: Unknown CP violating nuclear couplings beyond the standard model da (pol) = (aπ (0) Gπ (0) + aπ (1) Gπ (1) + aπ (2) Gπ (2) ) e fm Depends on the nuclear structure! We want to evaluate red factors and find interesting nuclei!

13 How to calculate: Gaussian expansion method A sophisticated method to calculate few-body system E. Hiyama et al., Prog. Part. Nucl. Phys. 51, 223 (2003). Basis function: lm(r) = X n X N nl C lm,k e n(r D lm,k ) 2 k Solve Schroedinger e. with variational method Successful in the benchmark calculation of 4 He binding energy H. Kamada et al., Phys. Rev. C 64, (2001). 4 He Density distribution It is applied in many subjects: Nuclei, Hypernuclei, atoms, hadrons, astrophysics, We expect accurate calculation of nuclear EDM!

14 Ab initio tests ( 2 H, 3 He) Ab initio: Solve the full many-body Schroedinger euation with realistic nuclear force. Deuteron EDM: Group Nuclear force a 0 a 1 a 2 Liu & Timmermans Liu et al., PRC 70, (2004) Av x10-2 e fm 0 GEM (our work) NY, E. Hiyama, PRC 91, (2015) Av x10-2 e fm 0 3 He EDM: Group Nuclear force a 0 a 1 a 2 Faddeev Bsaisou et al., JHEP 1503 (2015) 104 N 2 LO chiral EFT e fm e fm e fm GEM (our work) e fm e fm e fm NY, E. Hiyama, PRC 91, (2015) Av18 Ab initio results are consistent!

15 Physics of nuclear EDM: light and heavy nuclei N α N N α Core Light nuclei Heavy nuclei

16 Physics of nuclear EDM: light and heavy nuclei N α N N α Light nuclei have cluster structure Larger surface May enhance CPV effect?? Core Light nuclei Heavy nuclei

17 Setup of the cluster model We treat light nuclei in the cluster model n p N-N interaction: Av8 R. B. Wiringa et al., Phys. Rev. C 51, 38 (1995). α example of 6 Li N-α interaction: Fitted to reproduce the α-n scattering phase shift at low energy Pauli exclusion taken into account via OCM H. Kanada et al., Prog. Theor. Phys. 61, 1327 (1979). α-α interaction: Fitted to reproduce the α-α scattering phase shift at low energy Pauli exclusion taken into account via OCM A. Hasegawa and S. Nagata, Prog. Theor. Phys. 45, 1786 (1971).

18 CP-odd nuclear force with cluster (CP-odd α-n interaction) Integrate the CP-odd N-N interaction with the 4 He nucleon density (α cluster is indestructible) n 0 Gaussian approximation of density: (r) =Ae r2 b n p p n Spread : b = (1.358 fm) 2 CP-odd potential (MeV) folding extends the interaction range r(fm) V(r) V α-n (r) Only isovector CP-odd nuclear force is relevant in N-α interaction (Isoscalar and isotensor CP-odd nuclear forces cancel by folding)

19 Results EDM 129 Xe atom E. Teruya et al., to appear in PRC Y. Singh et al., PRA 89, (2014) 199 Hg atom Ban et al., PRC 82,, (2010) Y. Singh et al., PRA 91, (2015) 225 Ra atom Dobaczewski et al., PRL 94, (2005) Y. Singh et al., PRA 92, (2015) Neutron Crewther et al., PLB 88,123 (1979) Mereghetti et al., PLB 696, 97 (2011) Deuteron Liu et al., PRC 70, (2004) NY and EH, PRC 91, (2015) 3 He nucleus Bsaisou et al., JHEP 1503 (2015) 104 NY and EH, PRC 91, (2015) 6 Li nucleus NY and EH, PRC 91, (2015) isoscalar (a0) isovector (a1) isotensor (a2) 1.1x10-7 e fm 4.0x10-8 e fm 1.4x10-7 e fm 3.2x10-6 e fm -1.3x10-6 e fm 5.2x10-6 e fm e fm e fm e fm 0.01 e fm 0.01 e fm e fm e fm e fm e fm e fm 9 Be nucleus e fm NY and EH, PRC 91, (2015) 7 Li nucleus e fm e fm e fm NY, in preparation Preliminary 13 C nucleus e fm NY et al., arxiv: [nucl-th] 129 Xe nucleus N. Yoshinaga et al., PRC 89, (2014) 7.0x10-5 e fm 7.4x10-5 e fm 3.7x10-4 e fm

20 Results EDM isoscalar (a0) isovector (a1) isotensor (a2) 129 Xe atom E. Teruya et al., to appear in PRC Y. Singh et al., PRA 89, (2014) 199 Hg atom Ban et al., PRC 82,, (2010) Y. Singh et al., PRA 91, (2015) 225 Ra atom Dobaczewski et al., PRL 94, (2005) Y. Singh et al., PRA 92, (2015) Neutron Crewther et al., PLB 88,123 (1979) Mereghetti et al., PLB 696, 97 (2011) Deuteron Liu et al., PRC 70, (2004) NY and EH, PRC 91, (2015) 3 He nucleus Bsaisou et al., JHEP 1503 (2015) 104 NY and EH, PRC 91, (2015) 6 Li nucleus NY, in preparation 3.2x10-6 e fm -1.3x10-6 e fm 5.2x10-6 e fm e fm e fm e fm 0.01 e fm 0.01 e fm e fm e fm e fm e fm NY and EH, PRC 91, (2015) e fm 9 Enhanced! Be nucleus e fm NY and EH, PRC 91, (2015) 1.1x10-7 e fm 4.0x10-8 e fm 1.4x10-7 e fm 7 Li nucleus e fm e fm e fm Preliminary 13 C nucleus e fm NY et al., arxiv: [nucl-th] 129 Xe nucleus N. Yoshinaga et al., PRC 89, (2014) 7.0x10-5 e fm 7.4x10-5 e fm 3.7x10-4 e fm

21 Results EDM isoscalar (a0) isovector (a1) isotensor (a2) 129 Xe atom E. Teruya et al., to appear in PRC Y. Singh et al., PRA 89, (2014) 199 Hg atom Ban et al., PRC 82,, (2010) Y. Singh et al., PRA 91, (2015) 225 Ra atom Dobaczewski et al., PRL 94, (2005) Y. Singh et al., PRA 92, (2015) Neutron Crewther et al., PLB 88,123 (1979) Mereghetti et al., PLB 696, 97 (2011) Deuteron Liu et al., PRC 70, (2004) NY and EH, PRC 91, (2015) 3 He nucleus Bsaisou et al., JHEP 1503 (2015) 104 NY and EH, PRC 91, (2015) 6 Li nucleus NY, in preparation 3.2x10-6 e fm -1.3x10-6 e fm 5.2x10-6 e fm e fm e fm e fm 0.01 e fm 0.01 e fm e fm e fm e fm e fm NY and EH, PRC 91, (2015) e fm 9 Enhanced! Be nucleus e fm NY and EH, PRC 91, (2015) 1.1x10-7 e fm 4.0x10-8 e fm 1.4x10-7 e fm 7 Li nucleus e fm e fm e fm Preliminary 13 C nucleus Suppressed! e fm NY et al., arxiv: [nucl-th] 129 Xe nucleus N. Yoshinaga et al., PRC 89, (2014) 7.0x10-5 e fm 7.4x10-5 e fm 3.7x10-4 e fm

22 Isovector CP-odd nuclear force: a counting rule? 6 Li EDM 7 Li EDM 9 Be EDM deuteron cluster n p n 3 H cluster p n n α α α α d6li = G (1) π e fm d7li = G (1) π e fm d9be = G (1) π e fm 6 Li : 7 Li : 9 Be : a1 = Gπ (1) e fm a1 = Gπ (1) e fm a1 = Gπ (1) e fm 2 H EDM + 2 x (α-n polarization) 3 H EDM + 1 x (α-n polarization) 2 x (α-n polarization) α-n polarization : a1 = (0.005~0.007) Gπ (1) e fm

23 Predictions 10 B : 11 B : deuteron cluster n p n 3 H cluster p n α α α α 2 H EDM + 4 x (α-n polarization) 3 H EDM + 2 x (α-n polarization) d10b 0.03 Gπ (1) e fm d11b 0.02 Gπ (1) e fm

24 Nuclear EDM of heavier nuclei? EDM of larger nuclei is larger? n da = (A/4) x (α-n polarization)?? α α α (Simple shell model picture) No! Large nuclei have configuration mixing Ψ = EDM of large nuclei is uenched due to destructive interference of the spin of valence nucleon(s). e.g. 129 Xe EDM : d129xe Gπ (1) e fm N. Yoshinaga, K. Higashiyama, R. Arai and E. Teruya, Phys. Rev. C 89, (2014).

25 Sensitivity to new physics beyond standard model If the EDM of light nuclei can be measured at O(10-29 )e cm: Supersymmetric model: Can probe 10 TeV scale SUSY breaking F γ,g F L χ, g F R Models with 4-uark interactions: Can probe PeV scale physics (Left-right symmetric model, ) BSM particle Models with Barr-Zee type diagrams: γ, g Can probe TeV scale physics f (Higgs doublet models, RPV SUSY, ) F ν F γ, g EDM is an attractive observable in the search for BSM physics!

26 Summary Summary: We have studied the EDM of several light nuclei in the cluster model: can unveil beyond TeV scale BSM with future experiments? Enhancement due to many-body effect is suggested for EDM of light nuclei. Heavy nuclei are not more sensitive than light nuclei due to the configuration mixing (exception may be the octuple deformed or easily deformable nuclei). Future subjects: Evaluation of the effective CP-odd interactions reuired. Further study of EDM of light nuclei: -> EDM of 10 B, 11 B, 19 F? We are waiting for experiments!

27 Advertisement Please also see: N. Yamanaka, B. K. Sahoo, N. Yoshinaga, T. Sato, K. Asahi and B. P. Das, Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms, European Physical Journal A 53, 54 (2017) arxiv: [nucl-th]. N. Yamanaka, Review of the electric dipole moment of light nuclei, International Journal of Modern Physics E 26, (2017) arxiv: [nucl-th]. N. Yamanaka, Analysis of the Electric Dipole Moment in the R-parity Violating Supersymmetric Standard Model, Springer, EDM Physics is reviewed!!

28 End

29 Backup slides

30 EDM of charged particles using storage rings Rotating particles in a storage ring feel very strong central effective electric field The spin precession of the charged particle can be measured if magnetic moment is kept collinear to the particle momentum. (strong electric field normal to the precession plane) Measurements of the EDMs of muon, proton, deuteron, 3 He are planned. Prospective sensitivity: O(10-29 ) e cm!! EDM of light nuclei is accurately measurable!

31 Flow of EDM calculation of Gaussian expansion method 1) Prepare interaction hamiltonian Realistic nuclear force + CP-odd nuclear force (nonrela.) 2) Set Gaussian basis Choose Gaussian basis with geometric series of range parameters Repeat to find the lowest binding energy (variational method) 3) Calculate matrix elements in the gaussian basis Integral is simple due to the gaussian basis 4) Diagonalization Becomes exponentially difficult with growing nucleon number (A) 5) Calculation of observables (EDM) D (pol) = e 2 AX h (1 + i z )z i i + (c.c.) i=1

32 EDM from physics beyond Standard model EDM operator in relativistic field theory: dimension five-5 operator i 2 d µ F µ 5 d E Nonrela. lim. EDM is generated by CP violating interactions. Can be calculated using Feynman diagrams: BSM particles γ BSM particles CPV int. γ CPV int. CPV int. W γ γ,g,e,e,e,e g 1-loop diagram (e.g. SUSY) 2-loop diagram (e.g. 2-Higgs models) 3-loop diagram (e.g. Standard model) EDM receives very small contribution from SM, whereas BSM new physics may contribute with low loop level : EDM is a very good probe of BSM new physics!

33 EDM of composite systems The EDM are usually measured in composite systems (neutron, atoms, ) The EDM of composite systems is not only generated by the EDM of the components, but also by CP violating many-body interactions. n + p p - EDM of constituents CP-odd many-body interaction Example of QCD level many-body interactions inducing neutron EDM: g g g g uark chromo-edm Weinberg operator P, CP-odd 4-uark interaction Note : Effect of CPV many-body interaction may be enhanced!

34 Orthogonality condition model (OCM) Simple way to include the effect of antisymmetrization (Pauli exclusion) in cluster model N-α interaction: Repulsion of the 0s state: X V Pauli = lim f(r )ih f (r 0!1 ) f=0s λ α-α interaction: Repulsion of the 0s, 1s, 0d states. V Pauli = lim!1 X λ f=0s,1s,0d f(r )ih f (r 0 ) In our calculation, we have taken λ ~ 10 4 MeV S. Saito, Prog. Theor. Phys. 41, 705 (1969); V. I. Kukulin et al., Nucl. Phys. A 586, 151 (1995).