Present status of  -decay studies… …in nuclear mirror transitions Oscar Naviliat-Cuncic National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy Michigan State University

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Scope and outline 1. Definitions 2. Status of the strength of the weak interaction in  -decay 3. Recent results and plans: - spectroscopic quantities - theory - decay correlations 4. Summary Stress the role of  -decay experiments in mirror nuclei to test the structure of the weak interaction. Review recent results in theory and experiments and describe future plans to improve the determination of the weak strength in mirror transitions.

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Nuclear mirror transitions J , T=1/2 Q EC BR t 1/2 Super-allowed transitions between isobaric analogue states within T=1/2 doublets. Occur in mirror nuclei, between states with same spins and parities. Involve the vector (V) and axial (A) components of the weak interaction (in SM) neutrons protons Many candidates (Z=N+1) All   (except n and 3 H) In practice: a dozen Z = N+1 Z max ≈ 40-45

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Strength of the weak interaction Pure leptonicSemi-leptonic (non strange) Semi-leptonic (strange) WW d e ee dd uu u np WW ee e   g g WW s dd uu u  p e ee GF  g2GF  g2 G V = G F cos  C G  = G F sin  C  C  13°)  C (Cabibbo angle)

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Generalization to three quark generations The Cabibbo scheme was generalized to 3 generations of quarks by Kobayashi and Maskawa. Mass eigenstates Weak eigenstates Cabibbo-Kobayashi-Maskawa (CKM) matrix V ud = cos  C

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Determination of V ud Pure leptonicSemi-leptonic (non strange) WW du WW   ggV ud Compare the  -decay rate of a (simple) system made out of u and d quarks with the muon decay rate. (at tree level)

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Vud from mirror transitions |V ud | = (17) Dominated by experimental errors O. N-C and N. Severijns, PRL102 (2009) K : constant G F : Fermi constant g V = 1 (if CVC holds)  R : SM radiative correction

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Status of V ud values

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Error budget on Ft-values N. Severijns and O.N-C, Annu. Rev. Nucl. Part. Sci. 61 (2011) 23 Errors dominated by those on mixing ratio,  X ≡ never measured

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Spectroscopic quantities J , T=1/2 Q EC BR t 1/2 Example: 19 Ne half-life (s) ParentObservableGroup(s)/Lab nucleus 19 Ne t 1/2 TRIUMF GANIL 21 Na t 1/2 29 P t 1/2 31 S t 1/2 BR Q EC JYFL 37 K t 1/2 39 Ca t 1/2 TRIUMF: S. Triambak et al. PRL109 (2012) KVI: (PRELIMINARY) L. Broussard, PhD thesis, Duke University, 2012 GANIL: (PRELIMINARY) P. Ujic, F. de Oliveira Santos, priv. com. Similar to 0 + →0 + transitions Precision: 2.8×10 -4 New proposal at GANIL to go below the level

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Theoretical corrections (T=1/2) SM-WS: N.Severijns et al., PRC 78 (2008) DFT-Skyrme: W. Satula et al., arXiv: v2 Negligible impact on Ft -value at the present level of precision.

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Measurements of correlations “Mixing ratio” J pepe J pvpv pepe pvpv Beta asymmetry Neutrino asymmetry  angular correlation ParentObservableGroup(s)/Lab nucleus 19 Ne a 21 Na  A NSCL) 23 Mg( A NSCL) 35 Ar a 37 K a, A, B TRIUMF  A NSCL) Next talk (Dan Ashery)

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Measuring principle Production of radioactive nuclei Separate, slowing down cool, bunch Trapping ions and measure TOF of recoils relative to  pvpv pepe p R  p e  p v  LPCTrap setup at GANIL

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Beam manipulation 6 He + 19 Ne + 35 Ar + E kin : 10 keV 100 eV-1 eV 1 keV 100 eV 0 eV RFQ Pulsed cavities Paul trap  E 20 eV 1 eV 0.10 eV Overall efficiency: ~1% at 200 ms duty cycle

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation LPCTrap and detectors recoil Deduce  correlation from detection of recoil ions in coincidence with  particles. Continuous injection/extraction of ion bunches into the Paul trap Measure energy and position of  particles Measure TOF and position of recoil ions Over-determination of decay kinematics Register trap RF phase at decay time Measure extracted ions for each filling Paul trap

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation A short digression through 6 He decay 3x He /s  E~20 10 keV emittance: 80  mm.mrad (cooling/bunching) (Setup ) The only trap for measurement of a with 6 He + ions operational since 2006! Reached (  a/a) stat < 0.3 % (2010 run) Goal (  a/a) ~ 0.1 % seems feasible with new setup Old detection setup: short TOF base

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation 6 He results TOF spectrum of recoiling ion Proof of principle… X. Fléchard et al., PRL101 (2008) …data analysis X. Fléchard et al., JPG 38 (2011) (highlight 2011) (already been “2nd best”)

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation A funny systematic effect 6 He + 6 Li 2+ Sudden change of central potential 6 Li 2+ 6 Li 3+ Shake-off excited (gs) Different charge states are affected differently by the RF field. Potential distortion of TOF spectrum. Separate charge states by TOF

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Shake-off measurement 6 Li 2+ 6 Li 3+ Nov (P so ) exp = 2.348(35)% C. Couratin et al., PRL 108 (2012) Confirm systematic effect on TOF due to shake-off is negligible. Have a new little peak which is useless for extracting a and has no real physical interest. How to turn something useless into something fun ? 6 Li 2+ 6 Li 3+ excited (gs) (P su + P so = 1) Final n state in 6 Li 2+ (P so ) QM = 1 -  = % Ideal experimental conditions to illustrate elementary QM calculations (sudden approximation in Hydrogen like systems)… just fun (…and the referees loved it!) QM exercise

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Measurements in mirror transitions 35 Ar (test: June 2011; run: June 2012) Precision expected  a/a ~ 0.3 % Analysis under way 19 Ne (proposal accepted; run: 2013) Precision goal  a ~ 0.3 % Only “universal” trap so far to measure a. Can measure a from any separated/cooled beam produced at SPIRAL (new program with alkalis) The only existing device that can measure charge state distributions following  -decay of ions.

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Future plans Implantation tape station Multi Reflection TOF Mass Spectometer Main RFQ Small RFQ ("rebuncher") New chamber Improvement of total efficiency by a factor ~ 10

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Measurement of relative  -asymmetry J J J’ Mixed GT Decay rate P cancels A GT exactly known In practice: The  measured in singles include also the contribution from GT branch Geometrical cuts (energy, angle) at target and detectors enter as a ratio (MC) J pepe Beta asymmetry

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Selection of candidates J J J’ Mixed GT 21 Na 23 Mg 37 K Optical pumping scheme; relaxation?… Control of nuclear polarization via GT transition Experimental constraints for measurements of A  Mirror transition

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Polarized low energy beam: BECOLA 77K Cooler/buncher Laser Charge exchange cell Polarization by optical pumping 60 keV beam P. Mantica & K. Minamisono BECOLA = BEam COoling and LAser Soectroscopy  detectors  array 2T magnets

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Statistical estimates 21 Na 23 Mg 37 K Q EC (keV) E  (keV) B  (%) T 1/2 (s) A SM  SM  A/A (10 -3 ) Assumptions: 10 5 s -1 low energy beam; = 10%; 2x2  spectrometer; 8 CsI(Tl) modules; 5 days continuous running. Dominated by statistics in the GT branch

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Summary For the studies of the weak interaction, neutron and nuclear mirror decays probe the same physics. (neutron decay is the simplest mirror transition). Nuclear mirror transitions have shown to provide competitive inputs within the SM (V ud ). Much activity has been triggered to improve the data for the determination of V ud from mirror transitions. Precision measurements of  decay correlations in nuclear mirror transitions can contribute to the improved determination of SM parameters and the search for new physics. …/…

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation In memory of Stuart Freedman The trace of Stuart is also behind the study of mirror transitions, and in particular in the measurements of correlations. …and in unpublished documents

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation In memory of Stuart Freedman NSF proposal (circa ~1996) Another example among elegant experiments/ideas by Stuart. It will be a nice tribute if we succeed to measure at least one candidate with sufficient precision. →

(J. Torres-García) X Latin American Symposium on Nuclear Physics and Applications December 2-6, 2013 Universidad de la Republica Montevideo, Uruguay R. Donangelo (chair) G. Gonzalez-Sprinberg (UdelaR) O. Naviliat-Cuncic (MSU) C. Salgado (Jlab) Nuclear reactions and phases of nuclear matter -- Nuclear and particle astrophysics -- Fundamental symmetries and neutrinos -- Nuclear instrumentation and applications

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Impact from asymmetry measurements N. Severijns and O.N-C, Annu. Rev. Nucl. Part. Sci. 61 (2011) 23 Arrows indicate impact from  A/A = 0.2%. X ≡ never measured

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Corrections 1. Recoil effect: change in the central potential due to recoil 6 He + 6 Li 2+  P so = ( E R )% (E R ) max = 1.4 keV 2. Duration of central potential variation (~ s )  P so =  0.02%  = 2.322% (corrections are small)

FUNTRAP workshop, Rehovot, December 2-6, Michigan State University National Science Foundation Ionization after beta decay processTheo 1 Theo 2 Exp 3 single ionization10.5(1.5) (2) double ionization (7) The simplest system so far for which theo./exp. comparisons were available 1. A. Winther Dan. Mat. Fys. Medd. 27(1952)1 2. L. Wauters and N. Vaeck PRC 53(1996) T.A. Carlson et al. PR 129(1963) He 6 Li +