OMC rates in different nuclei related to 2β-decay.

K.Ya. Gromov, D.R. Zinatulina, C. Briançon, V.G. Egorov, A.V. Klinskih, R.V. Vasiliev, M.V.Shirchenko,I. Yutlandov, C. Petitjean.

MATRIX elements workshop, Dresden, Germany30.07.10

A, Z

A, Z+2

A, Z+1

Virtual transition( Left leg )

Virtual transition( Right leg )

A,Z (p,n)

(n,p)-like(n,p)-likecharge-charge-

-exchange-exchangereactionsreactions

Ordinary MuonOrdinary Muon Capture (OMC)Capture (OMC)

Electron Capture: e- + (A,Z) (A, Z-1) + e

Q ~ me 0.5 MeV

Muon Capture: - + (A,Z) (A, Z-1) +

Q ~ m 100 MeV

A, Z

A, Z+2

A, Z+1

n

A-1, Z+1

Target:

A+1, Z+2

A+1, Z+1

n

OMC OMC

2β-decay 2β-exp’ts μ-capture Status

76GeGerda

Majorana 76Se 2004

48Ca TGV, NEMO3 48Ti 2002

106Cd TGV 106Cd 2004

82SeNEMO3,

SuperNEMO82Kr 2006

100Mo NEMO3 100Ru −

116Cd NEMO3 116Sn 2002

150Nd SuperNEMO 150Sm 2002, 2006

Candidates for 2β decay and status of μ-capture:

Setup (solid target)Setup (solid target)

PSI,2006

Setup (gas target)Setup (gas target)

321 CCCstop Vessel walls Vessel walls plastic scintillator plastic scintillator

C3C3

Entrance window Entrance window C1 C1

& C2& C2

PSI, 2006

Distribution of N (E, t):

Time evolution (method)Time evolution (method)

The fragment number (each fragment corresponds to 10 ns time period)The fragment number (each fragment corresponds to 10 ns time period)

Muon life-time in Kr isotopesMuon life-time in Kr isotopes

0 100 200 300 400 500 600 700 800

10

100

1000

10000

100000

82Kr : 244 .8

276 .0

84Kr : 408.2

86Kr : 345.2

ns

yiel

d

Our results for Kr and Sm:

Isotope Eγ, keV Life-time, ns λc, 1/μs

82Kr(isotopic-enriched)

244.8276.0649.8

142.89 ± 0.60142.57 ± 0.33143.53 ± 1.67

6.54 ± 0.056.56 ± 0.016.51 ± 0.08

84Kr (57%) 408.2 160.14 ± 2.71 5.79 ± 0.10

86Kr (17.3%) 345.2 173.50 ± 2.57 5.31 ± 0.09

150Sm(isotopic-enriched)

114.3198.9287.2

82.83 ± 0.2482.65 ± 0.6683.12 ± 1.02

11.62 ± 0.0311.64 ± 0.0911.58 ± 0.14

Distribution of N (E, t)

What do we observe?What do we observe?

Prompt muonic X-rays (cascade) - Prompt spectrumgive us: identification, normalization, and isotopic shifts.

Delayed γ-rays following μ-capture - Delayed spectrumgive us: identification and partial rates

-(Background) -uncorrelated to muon capture- Uncorrelated spectrumgive us: identification, calibration and isotopic yields.

Delayed

Pr ompt

100 200 300 400 500 600 700 800 900

1000

10000

100000

1000000 U ncor r elat ed

Spectra with Kr:Spectra with Kr:

6

1

2

3

4

5

S

P

D

K-series

MuonicMuonic

X -raysX -rays

Normalization: Number of Incoming muons ~~ sum of KX-lines

Isotopic shift in Cd:

K(106Cd)

K(106Cd)

A, Z

A, Z+2

A, Z+1

n

A-1, Z+1

Target:

OMC OMC

Detector efficiency:

10 100 1000 10000

0.001

0.010

0.100

1.000

10.000

Small detector with Be window High-volume

detector

E[keV]

eff‘cy

48Sc

252.35If

Ii

Extraction of partial rates

mX

if

I

II

*252

iI - Intensity of gamma line incoming to level 252.35 keV

fI - Intensity of gamma line outgoing from level 252.35 keV

mXI -The sum of intensities mu-X-rays K-series.

- Enrichment of our target.

1+

3216.1

1-, 2- 2670.3

2+

3149.9

2783.3

2190.46

2275.48

622.64

1142.57

1401.69

1891.06

130.945+

3+

4+ 252.35

2+

2–

3-

3+

2+

2517.3

2640.1

1+

1, 2-

06+

2811.21, 2, 3

3056.51+

3301.9

3026.2

2980.81+

2,3

<3

48Sc

<3

~ 7.37%

(0.24 ± 0.04) %

(1.10 ± 0.06) %

(0.35 ± 0.09) %

(0.40 ± 0.03) %

(0.37 ± 0.04) %

(0.47 ± 0.07) %

< 0.31 %

< 0.0004 %

(0.11 ± 0.05) %

(0.35 ± 0.08) %

< 1.55 %

<1.25%

<0.194 %

<0.194 %

E_level, keV

Partial rates (experiment)

Charge-excharge reactions

0 6+ T1/2= 43.67 h

130.94 5+ < 0.31

252.35 4+

622.64 3+ < 1.25 high

1142.57 2+ < 1.55

1401.69 2- medium

1891.06 3- 0.11 ± 0.05

2190.46 3+ < 0.0004

2275.48 2+ 0.47 ± 0.07 medium

2517.3 1+ 0.35 ± 0.08 high

2640.1 1, 2- 0.37 ± 0.04

2670.3 1-, 2- < 0.194

2783.3 2+ 0.40 ± 0.03

2811.2 1, 2, 3

2980.8 1+ 0.35 ± 0.09

3026.2 2, 3 1.10 ± 0.06

3056.5 1+ 0.24 ± 0.04 medium

3149.9 1+ < 0.194

Partial ratesPartial rates for for 4848Sc (% per Sc (% per μμ-stop)-stop)

E_level, keV

Partial ratesE_level,

keVPartial rates

E_level, keV

Partial rates

44.4 (1)+ T1/2=1.8*10-6

sec457.3 (2;3) 745.0 (1+;2+) 0.25

86.8 (1)+ 471.0 (2) - 0.05 751.8 (0 - ;1;2) 0.35

120.3 (1)+ < 0.3 479.3 (2÷5) - 0.43 756.6 (0+;3+) 0.24

122.2 (1) - 0.2 499.6 (1;2+) 0.93 774.4 (1;2;3+) 0.21

165.0 (3) - < 0.5 505.2 (2;3)+ 0.23 785.8 < 3 > 0.12

203.5 (0;1)+ < 0.07 508.7 (2÷6) - 0.27 793.6 (1;2;3)+ 0.19

211.1 (4) - < 0.2 517.6 (1;2+) 0.22 802.4 (1 -;2 -;3+) 0.16

264.8 (1;2)+ 579.6 (1 -;2;3+) 1.18 863.3 (1;2;3)+ ~0.25

280.3 (1;2)+ < 0.1 544.0 (2;3) - 0.36 893.2 (1 -;2 -;3+) 0.21

286.0 (3;4) - ~0.3 550.4 (1;2 -) 0.11 909.1 (1;2)+ 2.5

292.6 (2;3;4) < 0.05 553.5 (1;2;3) 924.7 (< 3) - 0.22

300.5 (2;3) 1.13 610.0 (1;2;3+) 0.63 935.4 < 3 0.21

308.3 (2)+ < 0.05 624.6 < 4 < 0.3 939.7 (1;2;3) 0.31

328.5 (3;4) 0.08 628.7 (1;2;3 -) ~0.23 958.4 < 3 0.12

352.4 (3) - 0.05 637.2 (1+;2+) 0.15 971.0 < 3 ~0.06

363.9 (1;2 -) 0.26 640.1 (1 -;2 -) 0.17 985.5 (1;2;3)+ 0.20

366.3 (2÷5) 0.05 669.1 (1+;2+) ~0.6 1013.8 < 3 0.31

377.4 (2÷5) 681.1 (1÷4) 0.31 1026.2 (1;2)+ ~0.9

401.8 (1;2)+ 0.38 703.2 (1÷4) ~0.3 1034.2 (1;2;3)+ 0.12

436.8 (1;2;3) - 0.26 734.4 (< 4) - 0.07 1064.5 (1+;2+) 0.21

447.2 (1;2)+ 0.43 741.5 < 3 0.47

Partial ratesPartial rates for for 7676As (% per As (% per μμ-stop)-stop)

Decay of the nuclei produced in OMCDecay of the nuclei produced in OMC

n

OMC

2n

A, ZTarget:

aγ

aγ

aγ

aβ-

aβ-

aβ-

pZAZA

nZAZA

nZAZA

ZAZA

11

10

10

)2,1(),(

2)1,2(),(

)1,1(),(

)1,(),(

76As76As75As75As

74As74As

Uncorrelated spectrum measured with the Uncorrelated spectrum measured with the 7676Se targetSe target

Isotopes yields for Isotopes yields for 150150Sm:Sm:

A, A, ElementElement

Type of Type of decaydecay

TT1/21/2 λλii//101044, c , c -1-1

150 Pm g.s β- 2.68 h. 145

149* Pm IT 240.2 35 μs 180

149 Pm g.s β- 53.1 h 293

148* Pm IT 61.3 41.3 d 10.0

148* Pm IS β- 41.3 d 21

148 Pm g.s β- 5.37 d 77

149 Nd g.s β- 1.73 h <78

Conclusions and plans:

OMC presently  seems to be a bit off the main stream of physicsBut: it can provide important information about the high-q component of the weak nuclear response, i.e. it is relevant for the neutrinoless double beta decay (here in particular the 2- and 3+ states)

Further: the connection between mucap and double beta decay has been fully worked out theoretically (Suhonen et al)

Several double beta decay nuclei (48Ti, 76Se, 82Kr, 106Ag, 150Sm) have been studied in mu-cap by our group and results are consistent with chargex and  also complementary to chargex

The analyses are difficult and require a strong concerted effort(level scheme of 150Pm is unknown, difficult spectrum of 82Kr with many lines which including different isotopes in this reaction)

New and forceful initiatives are needed to advance the field --  the initiative of Prof. Ejiri is very much appreciated!!

Thank you for your attention!

Conclusion   1)           Mucap presently  seems to be a bit off the main stream of physics 2)           But: it can provide important information about the high-q component

of the weak nuclear response, i.e. it is relevant for the neutrinoless double beta decay (here in particular the 2- and 3+ states)

3)           Further: the connection between mucap and double beta decay has been fully worked out theoretically (Suhonen et al)

4)           several double beta decay nuclei (48-Ti, 76Se, 82Kr, 106Ag, 116Sn, 150Sm) have been studied in mucap by our group and results are consistent with chargex and  also complementary to chargex.

5)           The analyses are difficult and require a strong concerted effort 6)           New and forceful initiatives are needed to advance the field --  the

initiative of Prof. Ejiri is very much appreciated!!   

here are my thoughts about mu-capture1) mucap tells us what states respond to the weak interaction at high momentum transfer2) the information gives  us a way to connect these states to hadronic interaction and may be allow to find some common scaling between mucap and chargex3) strong interaction  processes in chargex are complicated and contain components which are not relevant for weka interaction -- may be mucap can tell us more about the selectivity of the excitation in chargex