Ft value of the mirror nucleus 19 Ne

Transcription

1 Ft value of the mirror nucleus 19 Ne S. Triambak June 17, 2009

2 Why is 19 Ne interesting? Second-class and scalar interactions Right-handed interactions SU(2) L SU(2) R U(1) Jackson, Treiman and Wyld (1957) d 4 Γ de edω edω ν Measured A β values: A β = ± a p 1+a e p ν m βν E ee ν +b e F E e + J [ J p A e p β E e + B ν ν E ν = ± b = ± c For the case of 19 Ne: + D ] pe pν E ee ν Define mixing ratio λ = C AM GT C V M F [ ] Ft R = = 1 [ 1 + λ 2 (1 + ] y2 ) 2 (1 + x 2 ) Ft 19 Ne x δ ζ; y δ + ζ. a F.P. Calaprice, S.J. Freedman et al., Phys. Rev. Lett. 35, 1566 (1975). b D.F. Schreiber, Ph.D. thesis, Princeton University (1983). c G.L. Jones, Ph.D. thesis, Princeton University (1996).

3 Why is 19 Ne interesting? Second-class and scalar interactions Right-handed interactions SU(2) L SU(2) R U(1) Jackson, Treiman and Wyld (1957) d 4 Γ de edω edω ν Measured A β values: A β = ± a p 1+a e p ν m βν E ee ν +b e F E e + J [ J p A e p β E e + B ν ν E ν = ± b = ± c For the case of 19 Ne: + D ] pe pν E ee ν Define mixing ratio λ = C AM GT C V M F [ ] Ft R = = 1 [ 1 + λ 2 (1 + ] y2 ) 2 (1 + x 2 ) Ft 19 Ne x δ ζ; y δ + ζ. a F.P. Calaprice, S.J. Freedman et al., Phys. Rev. Lett. 35, 1566 (1975). b D.F. Schreiber, Ph.D. thesis, Princeton University (1983). c G.L. Jones, Ph.D. thesis, Princeton University (1996).

4 Why is 19 Ne interesting? Second-class and scalar interactions Right-handed interactions SU(2) L SU(2) R U(1) Jackson, Treiman and Wyld (1957) d 4 Γ de edω edω ν Measured A β values: A β = ± a p 1+a e p ν m βν E ee ν +b e F E e + J [ J p A e p β E e + B ν ν E ν = ± b = ± c For the case of 19 Ne: + D ] pe pν E ee ν Define mixing ratio λ = C AM GT C V M F [ ] Ft R = = 1 [ 1 + λ 2 (1 + ] y2 ) 2 (1 + x 2 ) Ft 19 Ne x δ ζ; y δ + ζ. a F.P. Calaprice, S.J. Freedman et al., Phys. Rev. Lett. 35, 1566 (1975). b D.F. Schreiber, Ph.D. thesis, Princeton University (1983). c G.L. Jones, Ph.D. thesis, Princeton University (1996).

5 Why is 19 Ne interesting? Second-class and scalar interactions Right-handed interactions SU(2) L SU(2) R U(1) Jackson, Treiman and Wyld (1957) d 4 Γ de edω edω ν Measured A β values: A β = ± a p 1+a e p ν m βν E ee ν +b e F E e + J [ J p A e p β E e + B ν ν E ν = ± b = ± c For the case of 19 Ne: + D ] pe pν E ee ν Define mixing ratio λ = C AM GT C V M F [ ] Ft R = = 1 [ 1 + λ 2 (1 + ] y2 ) 2 (1 + x 2 ) Ft 19 Ne x δ ζ; y δ + ζ. a F.P. Calaprice, S.J. Freedman et al., Phys. Rev. Lett. 35, 1566 (1975). b D.F. Schreiber, Ph.D. thesis, Princeton University (1983). c G.L. Jones, Ph.D. thesis, Princeton University (1996).

6 Why is 19 Ne interesting? Second-class and scalar interactions Right-handed interactions SU(2) L SU(2) R U(1) Jackson, Treiman and Wyld (1957) d 4 Γ de edω edω ν Measured A β values: A β = ± a p 1+a e p ν m βν E ee ν +b e F E e + J [ J p A e p β E e + B ν ν E ν = ± b = ± c For the case of 19 Ne: + D ] pe pν E ee ν Define mixing ratio λ = C AM GT C V M F [ ] Ft R = = 1 [ 1 + λ 2 (1 + ] y2 ) 2 (1 + x 2 ) Ft 19 Ne x δ ζ; y δ + ζ. a F.P. Calaprice, S.J. Freedman et al., Phys. Rev. Lett. 35, 1566 (1975). b D.F. Schreiber, Ph.D. thesis, Princeton University (1983). c G.L. Jones, Ph.D. thesis, Princeton University (1996).

7 The case of 19 Ne Ft( 19 Ne) = ± 3.2 s d t 1/2 known to 0.2%, we aim to measure it to 0.01%. Fractional uncertainties of each contribution: d N. Severijns, M. Tandecki et al., Phys. Rev. C. 78, (2008)

8 The case of 19 Ne Limits on scalar currents: 3090 Ft [s] Z of daughter For purely Fermi and GT decays, a F = 1 and a GT = 1/3 For purely V A, b F b F me E e = 0 Ft Ft 0 [1 b F ]

9 The case of 19 Ne Limits on scalar currents: 3090 Ft [s] Z of daughter For purely Fermi and GT decays, a F = 1 and a GT = 1/3 For purely V A, b F b F me E e = 0 Ft Ft 0 [1 b F ]

10 The case of 19 Ne Limits on scalar currents: 3090 C S /C V = (13) Ft [s] Z of daughter For purely Fermi and GT decays, a F = 1 and a GT = 1/3 For purely V A, b F b F me E e = 0 Ft Ft 0 [1 b F ]

11 The case of 19 Ne Limits on scalar currents: C S /C V = (13) Ft [s] Z of daughter For purely Fermi and GT decays, a F = 1 and a GT = 1/3 For purely V A, b F b F me E e = 0 Ft Ft 0 [1 b F ]

12 The case of 19 Ne Limits on scalar currents: 3090 C S /C V = (5) Ft [s] Z of daughter For purely Fermi and GT decays, a F = 1 and a GT = 1/3 For purely V A, b F b F me E e = 0 Ft Ft 0 [1 b F ]

13 The 8π Array at TRIUMF 1/2 + Al + mylar tape 19 Ne 0.004% 3/ Plastic scintillator 19 Ne beam 0.01% 5/2 + 1/ % 1/ F Pb shielding Compton suppressed Ge detector 8π array: HPGe + SCEPTAR (plastic) + DANTE (BaF 2 ) + PACES (Si) Previous half-life measurements at ISAC GPS (β counting using gas counter): 26 Na, 62 Ga, 26 Al m Gamma-ray method: 26 Na, 18 Ne New program for precision half-life measurements in TRIUMF when GPS or γ-rays can not be used.

14 Preliminary results for the half-life Taken data in both MCS mode and the regular mode at 8π Self-imposed dead times in the range from 2 20µs Implant time 1 second, count time 300 seconds Rates kept at around 1-4 khz per detector Counts Time (1 s/ch)

15 Preliminary results for the half-life An example with the 6µs deadtime case χ 2 /287 = 0.8 Counts Time (1s/ch)

16 Preliminary results for the half-life Continue testing systematics (especially rate-dependence) A better than 0.5% determination of the dead time will make a competitive T 1/2 measurement. A better than 0.2% dead time measurement will be ideal (in the 0.01% regime).

17 Branching Ratio