matrix elements workshop, dresden, germany 30 . 07 . 10
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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
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