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Precision mass measurements for fundamental studies Tommi Eronen Max-Planck-Institut für Kernphysik Heidelberg, Germany
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Outline Penning trap mass spectrometry – Q = m parent – m daughter Masses for CKM unitarity tests... – Superallowed beta decay – Mirror beta decay Masses for neutrino studies.. – Double beta decay – Double electron capture – Tritium Q-value
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Penning Trap Mass Spectrometry Cyclotron frequency Penning trap eigenfrequencies INVARIANCE THEOREM SIDEBAND FREQUENCY
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TOF-ICR method For nuclei having T 1/2 > 10 ms
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A/q doublets! Q-value measurements – Special – mass doublets, e.g. 76 Ge vs 76 Se – cancellation of systematic errors – 10x better accuracy achieved – Typical: q=1e, B=7T, m=100u with 10 -9 precision -> m = 100 eV Absolute mass measurements – 10 -7..8
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Q EC values of superallowed beta emitters
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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 Q EC 5 ) – t partial half-life t 1/2 /b
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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 transitions contribute
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Superallowed beta emitters - Q EC Bold: Contributes to world average value (13) Why so many JYFL points? -Simultaneous production -No chemical selection
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Most recent Q EC from JYFLTRAP 10 C, 34 Ar, 38 Ca, (revisited 46 V) T. Eronen et al., Phys. Rev. C 83, 055501 (2011)
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Ft values The influence of JYFLTRAP Q EC value measurements.
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Ft-value error budget Most precise From J.C. Hardy, I.S. Towner, Phys. Rev. C 79, 055502 (2009)
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Different C Towner & Hardy, PRC 77, 025501 (2008). Satula et al., PRL 106, 132502 (2011). Liang et al., PRC 79, 064316 (2009).
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Standard Model is still ok? Top-row unitarity requirement: Courtesy of J.C. Hardy With H&T corrections
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Superallowed outlook Q EC values: 14 O, heavier A > 62 Branching ratios of T=-1 nuclei Half-lives Theoretical corrections ( C ) A > 62
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Q EC values of mirror decays
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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
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Error contributions
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V ud from different sources
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Mirror decays – TODO F/GT ratios; LPC-trap, MOTs, WITCH-trap... R V theoretical calculations NS - C measurements of heavy isotopes + theory Measurements of t 1/2, BR and Q EC
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Precision mass measurements for neutrino physics Double decay Double electron capture Tritium Q-value for KATRIN spectrometer
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Double beta decays Double decay ( ) and double-electron capture (2EC) – two-neutrino mode (2 ) and (2 2EC) – neutrinoless mode (0 ) and (0 2EC) Observation would prove that is a Majorana particle Conservation of total lepton number breaks Effective Majorana neutrino mass from half-life
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double-electron-capture nuclides double-beta-decay nuclides
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Penning trap Q-value harvest... SMILETRAP JYFLTRAP SHIPTRAP LEBIT TRIGATRAP Canadian PT ISOLTRAP FSU
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Detection of 0 2 is (huge) background 76 Ge – Heidelberg-Moscow claim – GERDA, MAJORANA experiments T 1/2 ≈10 19 y T 1/2 >10 25 y Penning trap mass spectrometry: Energy of the endpoint! Energy of the endpoint!
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Heidelberg-Moscow 76 Ge GERDA has some news soon...
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Neutrinoless double-electron capture Predicted half-lives very long, > 10 26 y, not seen yet Resonant enhancement! From Penning trap mass spectrometry! KK, KL, LL,..
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0 + to 0 + transitions between nuclear ground states
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|M| =3 for 0 + → 0 + T 1/2 (0 + →0 + ) ~ 3 10 24 y for |m 2EC |=1 eV multiple-resonance phenomena in 156 Dy S. Eliseev et al., PRC 84, 012501R (2011)
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Tritium beta decay: Neutrino with mass: – Endpoint shifted – Spectrum shape changed Current knowledge: Tritium ( 3 H) Q-value
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KATRIN experiment
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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
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T -3 H Q-value measurements THe-trap 2014 (?)
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New technique for Penning trap mass spectrometry Phase-Imaging motion detection Measure motion revolutions in the trap – For + and - – 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->)
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position-sensitive detector Penning trap Phase imaging B 2D delay-line MCP
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PI-ICR method 36 Eliseev et al., PRL 110, 082501 (2013)
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37 On the Way to Mass Measurements
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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
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Thank you for your attention!
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