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Precision mass measurements for fundamental studies. Tommi Eronen Max-Planck-Institut für Kernphysik Heidelberg, Germany. Outline. Penning trap mass spectrometry Q = m parent – m daughter Masses for CKM unitarity tests... Superallowed beta decay Mirror beta decay - PowerPoint PPT Presentation
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Precision mass measurements for fundamental studies
Tommi EronenMax-Planck-Institut für Kernphysik
Heidelberg, Germany
Outline
• Penning trap mass spectrometry– Q = mparent – mdaughter
• Masses for CKM unitarity tests...– Superallowed beta decay– Mirror beta decay
• Masses for neutrino studies..– Double beta decay– Double electron capture– Tritium Q-value
Penning Trap Mass Spectrometry
Cyclotron frequency Penning trap eigenfrequencies
INVARIANCE THEOREM
SIDEBANDFREQUENCY
TOF-ICR methodFor nuclei having T1/2 > 10 ms
A/q doublets!
• Q-value measurements– Special – mass doublets, e.g. 76Ge vs 76Se– cancellation of systematic errors– 10x better accuracy achieved– Typical:
• q=1e, B=7T, m=100u with 10-9 precision -> Dm = 100 eV
• Absolute mass measurements – 10-7..8
QEC values of superallowedbeta emitters
Superallowed beta emitters
NEED Q-values at 100-eV level
• Decays of nuclear 0 + → 0+ states, T=1
• Pure Fermi decays• Simple decay matrix element• Characterized with an ft value
– f stat. rate function; (f QEC5)
– t partial half-life t1/2/b
Testing the Standard Model
• Corrected value:
• Corrections about 1% [Towner and Hardy, Phys. Rev. C 77, 025501 (2008)]
• Cabibbo-Kobayashi-Maskawa quark mixing matrix
• Quark-mass eigenstates to weak eigenstates
Currently 13 transitionscontribute
Superallowed beta emitters - QEC
Bold: Contributes to worldaverage value (13)
Why so many JYFL points?- Simultaneous production- No chemical selection
Most recent QEC from JYFLTRAP
• 10C, 34Ar, 38Ca, (revisited 46V)T. Eronen et al., Phys. Rev. C 83, 055501 (2011)
Ft valuesThe influence of JYFLTRAP QEC value measurements.
Ft-value error budget
Most precise
From J.C. Hardy, I.S. Towner, Phys. Rev. C 79, 055502 (2009)
Different dC
Towner & Hardy,PRC 77, 025501 (2008).Satula et al.,PRL 106, 132502 (2011).Liang et al.,PRC 79, 064316 (2009).
Standard Model is still ok?Top-row unitarity requirement:
Courtesy of J.C. Hardy
With H&T corrections
Superallowed outlook
• QEC values: 14O, heavier A > 62• Branching ratios of T=-1 nuclei• Half-lives• Theoretical corrections (DC) A > 62
QEC values of mirrordecays
• T=1/2 decays• Fermi + Gamow-
Teller– Need mixing ratio
• Currently 5 well known decays
O. Naviliat-Cuncic and N. Severijns, PRL 102, 142302 (2009)
Mirror decays
Error contributions
Vud from different sources
Mirror decays – TODO
• F/GT ratios; LPC-trap, MOTs, WITCH-trap...• DR
V theoretical calculations• dNS - dC measurements of heavy
isotopes + theory• Measurements of t1/2, BR and QEC
Precision mass measurements for neutrino physics
• Double b- decay• Double electron capture• Tritium Q-value for KATRIN spectrometer
Double beta decays• Double b- decay (bb) and double-electron capture (2EC)
– two-neutrino mode (2nbb) and (2n2EC)– neutrinoless mode (0nbb) and (0n2EC)
• Observation would prove thatn is a Majorana particle• Conservation of total lepton number breaks• Effective Majorana neutrino mass from half-life
double-electron-capture nuclides
double-beta-decay nuclides
Penning trap Q-value harvest...
SMILETRAPJYFLTRAPSHIPTRAPLEBITTRIGATRAPCanadian PTISOLTRAPFSU
Detection of 0nbb
• 2nbb is (huge) background• 76Ge
– Heidelberg-Moscow claim– GERDA, MAJORANA experiments
T1/2≈1019y T1/2>1025y
Penning trap mass spectrometry:
• Energy of the endpoint!
Heidelberg-Moscow
76Ge
GERDA has some news soon...
Neutrinoless double-electron capture
• Predicted half-lives very long, > 1026 y, not seen yet• Resonant enhancement!
From Penning trap
mass spectrometry!
KK, KL, LL, ..
0+ to 0 + transitions between nuclear ground states
• |M| =3 for 0+ → 0+
T1/2 (0+→0+) ~ 31024 y for |m2EC|=1 eV
multiple-resonance phenomena in 156Dy
S. Eliseev et al., PRC 84, 012501R (2011)
• Tritium beta decay:
• Neutrino with mass:– Endpoint shifted– Spectrum shape changed
• Current knowledge:
Tritium (3H) Q-value
KATRIN experiment
Endpoint of tritium beta spectrum
Electron neutrino mass with KATRIN:• 10x better - sensitivity 0.2 eV
Goal with Penning traps:• Improve 1.2 eV → 0.03 eV
T-3H Q-value measurements
THe-trap2014 (?)
New technique for Penning trap mass spectrometry
• Phase-Imaging motion detection• Measure motion revolutions in the trap
– For n+ and n-
– Recipe:• Excite the motion (dipolar RF E-field)• Project to magnetron motion• Count revolutions + phase of the last round
– Some x10 faster or more precise than TOF-ICR
Developed at SHIPTRAP by S. Eliseev et al. (2012->)
position-sensitive detector
Penning trap Phase imaging
B
2D delay-line MCP
PI-ICR method
36Eliseev et al., PRL 110, 082501 (2013)
37
On the Way to Mass Measurements
Summary
• Q-values from mass spectrometry for– Testing the Standard Model
• Superallowed beta decays (some cases left to measure)• Mirror decays (plenty of cases still to measure)
– Neutrino studies• Neutrinoless double beta- decay• Neutrinoless double electron capture
• New mass measurement techniques
Thank you for your attention!