Neutrino Nuclear Responses for ββ ν & Charge Exchange Reactions. Hiro Ejiri RCNP Osaka & CTU Praha

Transcription

1 Neutrino Nuclear Responses for ββ ν & Charge Exchange Reactions Hiro Ejiri RCNP Osaka & CTU Praha

2 Nuclear responses (matrix elements) for ββ ν and charge exchange reactions H. Ejiri, Phys. Report 338 (2000) 265. H. Ejiri, J. Phys. Soc. Japan, 74 (2005) H. Ejiri, Progress in Particle and Nuclear Physics, 64 (2010) A view from the Ejiri-weekend house

3 H3 Nuclear matrix element for ββ Sensitivity of m ν = k [M 0ν ] -1 [N ββ /B] -1/4 in case of B>>1 1. M 0ν =<ττσσh(r)> is crucial for extracting m ν, CP phases, for designing exps. M 0ν 30% leads to N ββ detector 1/3 2. Sensitive to nuclear structures, τ σ corr., pp-correlation, effective g A, short-range correlation. 3. Extremely small, 10-2 M SP, 10-4 M GR 4. 2νββ J π =1, 0νββ J π =1+,2-,3+, 6 for virtual ν q ~ 0.2 GeV Suhonen

4 スライド 3 H3 Ejiri, 2009/07/25

5 Model calculation Suhonen Dresden2010 A without shape change look good, but factor 2 in M 0ν gives 16 in detector volume

6 2ββ Μ 2νββ Μ 2νββ matrix element 1/m e νββ matrix element 1/m e E(2+ initial) / E(2+ final) Ca Nd Nd Cd Zr Mo Mo E(2+ initial) / E(2+ final) Te Xe Te Se Ge M 2ν decrease as change of initial to final nuclear shapes near closed shell M 2ν with single lowest state is large due to the small denominator The ratio of the 1 st excited state E ~deformation/shape/rigidness. Xe predicted >> observed

7 FSQP: Fermi Surface Quasi Particle Model GTR> M 2ν (EXP) and M 2ν (FSQP) k 0.1 ββ M 2ν (FSQP) M 2νββ = Σ k M β km b k /Δ k =Σ k (g eff A) 2( m ij ) 2 V n U p V p U n /Δ k 0.01 g eff A from β,ec exp. for M β km b k H. Ejiri et al. J. Phys. Soc. Japan Lett. 65 (1996) 7. Η. Ejiri J. Phys. Soc. Japan, 78 (2009) No 7. H. Ejiri Prog. Nuclear Particle Physics, M 2ν (EXP) /m e 136 Xe M= FSQP T 1/2 = y T 1/2 > y (g eff A) 2 ~ (0.25) 2 = 0.05 T 0ν ~ (g eff A) 4 = 0.002

8 Nuclear τσ responses for ν in β &ββ τ, τσ Nuclear weak responses ββ ν, solar-ν, supernova ν Fermi- Isospin τ GT Spin Ispspin τσ ν e e e p, 3 He n,t n W p n γ n n π,ρ p β-decay, e capture ν-probe from J-PARC γ-capture, e scattering γ from Spring-8, HIGS CXR 3 He,t t, 3 He d, 2 He N RCNP, MSU, KVI

9 2. Charge exchange reactions at RCNP for ββ ν. A view from the Ejiri-Yokohama

10 CXR:Charge exchange reactions for τσ ν-weak responses RCNP ( 3 He,t) ( 7 Li, 7 Be), MSU (t, 3 He), KVI (d, 2 He) E/A~0.2 GeV, LargeV(τσ), small V 0 I. Start 1995 for ββ & solar-ν (Akimune, Ejiri, Fujiwara et al) II ΔE ~10-4, Freckers Ejiri, Zegers et al. Ge, Se, Mo, Te, Xe V(weak) V(strong), non-central V, distortion, multi-step, etc. CER q-dependence and EC/β rates are used to get weak responses

11 Neutrino response Project ββ and astro-neutrinos with 2 -, weak 1 +, CER, DCXR, ν e, β 3 He,t RCNP ΔE/E = 0.03/450 e ν, β + d, 2 He RCNP LAS (Δφ=240mr, Δθ=125 mr, Δp=±15% ΔE/E = x /200)

12 One state in FSQP, 100 Mo Ejiri et al (1997) Mi = 0.56 Frekers Zegers Ejiri et al, (2009) M i = 0.57, agree with 1997 data Frekers RCNP GTR> M i = 0.57 k ββ M 1 = 0.11 m e -1, agree with M 2ν = 0.09 (EL) 0.12(NEMO) M f = 0.55 β decay

13 FSQP QP states at Fermi surface Case I Only one 1 + state 96 Zr, 100 Mo, 116 Cd. (g7/2 g9/2) 150 Nd (h9/2,h11/2) j 1 = l-1/2 J 1 = l+1/2 V p U n Case II states 76 Ge, 82 Se, 128,130 Te, V p U n

14 (d, 2 He) Freckers ( 3 He,t) B(GT + ) = 0.3 Ex (MeV) B(GT - ) = 0.18 T Fascination: With this 1 level only: (2 νββ) = (2.2 ± 0.3) 10 years calc. 19 1/ 2 T (2 νββ = (2.2 ± 0.4) 10 years (NEMO3-result) exp. 19 1/ 2

15 Frekers Again!! an anticorrelation of strength (very similar to 48 Ca)!!!!!!! some B(GT) in the bckgnd An effect of the difference of deformation?? 76Se: oblate (β 2 ~ 0.2) 76Ge: moderately oblate/ prolate (β 2 ~ 0.1)

16 Frekers triplet of states: 0.044, 0.082, 0.12 MeV Correlate states within the expmtl resolution

17 Effective g A (g A ) 2 ~ 0.5 g A ~ 0.7 Nuclear medium effect g A ~ 1 (p,n) Frekers B(GT) and [ g A ] 2 =B(GT)/3(N-Z) B(GT)/3(N-Z) B(GT) A Mass number g eef (1 + )=0.24, where 0.33 by GR shift and 0.7 by medium effect, likewise for 2-

18 Frekers MeV One or several low-lying 1+ states of [g7/2 g9/2] etc One or several low-lying 2- states of [h11/2 g7/2] etc. These contribute to 2νββ and 0νββ processes

19 Nuclear Matrix elements from 0 + to 1 + and 2-10 J=1+ GT M(EXP) β - β J=2 [σ ry 1 ] M(EXP) 10-3 β β+ M(GT EXP) β - and β Mass number A Mass number M(1+) ~ 0.4 M(2 - )~ g eff =M(1+)/M(SQP) ~0.25 g eff =(M(2-)/M(SQP) ~ 0.15 M 0ν =<ττσσh>, with h~ R/ r 1 -r 2, = R/[2<r> 3 ] M i M f,, Use exp. M i ~g eff M QP, M QP = <r> <τσy 1 > U V M 0ν ~ 0.01 for the lowest 2 - state, sum ~ 0.02, while QRPA ~ 0.8 with g eff ~ 1 (~0.02 with g eff ~ 0.15) GR?

20 DCXR /10 de/tof 11 B(pp) 13 C 1/2- n n 11 Li(nn) p p 13 O 3/2-11 Li Takahisa Ejiri et al., Preliminary 881MeV(80MeV/A),50nA/electric,7mg/cm2(13C)

21 Photon γ H. Ejiri, Czech J. Physics, 56 (2006) Neutral current responses 2. Isospin rotation for charged current responses via IAS <f g M β i> = g/e (2T) 1/2 <f em γ I> E1 and M1 γ P γ (L) azymuthal distribution Spring-8 Τ,Tz-1 γ β γ N P HiGS Albert, Hiro, Mitzi, Τ =ΙΑS γ T,Tz=6,6 Β Τ,Τz=5,5 β ββ Τ,Τz=6,6 Τ,Τz=5,5 Α Τ,Τz-1 H. Ejiri PRL 21 68, H. Ejiri PR 38 78

22 Nuclear β + weak responses by μ-capture and Exp. σ(μ, Nn γ) H. Ejiri Proc. e-γ conference Sendai 1972 Nn,γ τ+σ Y 1 GR b ββ μ capture β + b No of n and b γ & their E give the strength distribution. Calibrate by p/α captures. MUSIC RCNP 10 7 /s100na 1. Large atomic cross section, capture probability ~ 1 2. E up to 100 MeV, p ~ 100 MeV/c, and l~1-2 H. Ejiri, et al, NP. 305 (1978) 167

23 Remarks The mountain log cottage at Tateshina

24 Requirements for source-detectors for IH mev Mass sensitivities & nuclear sensitivity T 0ν = <m ν > 2 S N <m ν > = S N -1/2 (N eff ) -1/2 δ 1/2 S N =k [M 0ν ] 2 (G ον /0.01A ), Ν eff = ε 0ν N t y, δ ~(BN) 1/2 ββ-sources nuclear sensitivity S N -1/2 ~ 10 mev, M 0ν ~ 3, G 0ν ~ /y,, Q ββ ~3MeV A = 40~90 % Production ~ 0.1 t /y Note N 0 = N/A ton if A=10-90% Detector sensitivity (N eff ) -1/2 δ 1/2 ~ 2 Detector = Source ε 0ν ~0.7 N ~ 1.5 t y δ~3, ΔE ~ 5 kev, BG: B~5 /t y Detector Source ε 0ν ~0.2 N ~ 5 t y δ~3, ΔE ~ 100 kev, BG:B~5 /t y

25 Nuclear sensitivity S N for ββ-mass T 0ν = <m ν > 2 S N <m ν > = S N -1/2 (N eff ) -1/2 δ 1/2 S N = [65 mev] -2 [M 0ν ] 2 (G/0.01A ) G in /y M 0ν =3 136 Xe Isotope 136 G 0ν Q ββ S N B C D 130 Te Mo* Mo Se Ge G in Q ββ in MeV S in 10-3 /mev 2

26 Neutrino mass sensitivities for 76 Ge, 82 Se, 100 Mo, 130 Te CUORE B=33), MOOM-PS(B=10), MOOM-PL B=7), GERDA(B=20) mev CUORE TeO 2 MOON PS ZnMoO 4 MOON PL Se 130 C D GERDA Ge (Majorana) 76 ε 0ν =1 B=0 0 IH C m ν (N=1 t y) D m ν (N=5 t y) t y=ton yaer 150 Nd for the deformed excited state and less-deformed ground state if ~40%

27 Concluding remarks 1. Neutrino nuclear responses (M 0ν ) are crucial for 0νββ. Calculated values are very small and sensitive to nuclear parameters. 2. Experimental inputs such as 2νββ, β EC & charge exchange 1 +, 2 - and transfer reactions, etc are indispensable to get effective g A, β- strengths for intermediate states, deformation effects, and p-h vacancy effects and others to help/verify calculations. 3. Charge exchange reactions (CER) with RCNP 3 He, d and MSU t probes, the NewSUBARU/HIGS γ probes, the RCNP μ probes and J- PARC ν probes in future are used for studying ν responses. 4. The 2νββ matrix elements are reproduced by FSQM. Extension to the 0νββ matrix elements is of great interest. 5. PS MOON(ZnMoO4) with 5keV, PSA/PS is most powerful for IH. 6. Coordinated/collaboration efforts for high-sensitivity 0νββ exps. and theoretical and experimental evaluations of M 0ν are of vital importance for QD- IH ν-mass 0νββ studies.

28 Thanks for your attention A view from the mountain log cabin at Tateshina