physics of 0 + → 0 +  transitions recent experimental efforts world data on 0 + → 0 + decay future studies Bertram Blank, CEN Bordeaux-GradignanISOLDE WS, february 2007

SM is theory which describes electro-weak interaction BUT: parameters have to be determined experimentally e.g. masses, coupling constants, mixing angles, etc. nuclear  decay is weak process and may allow for determination of these parameters 5 different couplings possible due to Lorentz invariance: - scalar coupling (S) - vector coupling (V) - tensor coupling (T) - axial-vector coupling (A) - pseudo-scalar coupling (P)  decay: mainly vector and axial-vector  V-A theory weak contribution from other coupling??  scalar, tensor coupling determination of vector coupling constant: 0 +  0 +, n decay,  decay determination of axial-vector coupling constant: neutron decay SM is theory which describes electro-weak interaction BUT: parameters have to be determined experimentally e.g. masses, coupling constants, mixing angles, etc. nuclear  decay is weak process and may allow for determination of these parameters 5 different couplings possible due to Lorentz invariance: - scalar coupling (S) - vector coupling (V) - tensor coupling (T) - axial-vector coupling (A) - pseudo-scalar coupling (P)  decay: mainly vector and axial-vector  V-A theory weak contribution from other coupling??  scalar, tensor coupling determination of vector coupling constant: 0 +  0 +, n decay,  decay determination of axial-vector coupling constant: neutron decay

2 F 2 V M g K ft  2 GT 2 A M g + in general: for 0 +  0 + transitions: only vector current due to selection rules experimental quantities: masses of parent and daughter, half-life, branching ratio K / (hc) 6 = (12) * GeV -4 s = constant, 2 = T(T+1) - T zi T zf g v can be determined, V ud = g v / g F, quark-mixing matrix element one high-precision measurement would be enough BUT….. 2 F 2 V M g K ft   f(Q ec ) * T 1/2 / BR

electromagnetic interactions: e.g. positron - protons, positron - electrons  radiative correction  R →  R ’ isospin impurity: binding energy difference, configuration mixing  Coulomb correction  c =  c1 +  c2 nuclear structure dependent radiative correction  NS if these effects corrected: constant ft value  constant vector current hypothesis (CVC)  determination of g v via Ft value:  many ft values are needed to test CVC and theoretical corrections from g v :  determination of V ud matrix element of CKM quark mixing matrix V ud = g v / g F Ft = ft (1 +  R ’ ) (1 –  c +  NS ) = = constant K 2 F 2 V M g (1 +  R )

Jaus & Rasche, 1987

Towner & Hardy, 2005

overall precision: Ft = ( ± 1.2) s  4 *  single measurements: < f: f(Q EC 5 ) →  Q < 2 * → < 1keV T 1/2 :  T < BR:  BR < theoretical corrections:  C,  R ~ 1% → < 10% 9 “classical” cases

Q value measurements at JYFLTRAP: 62 Ga T. Eronen et al., 2006 Q EC = ( ± 0.54) keV

half-life measurement at GSI: half-life measurement at JYFL: G. Canchel et al., 2005 T 1/2 = ( ± 0.15) ms B. Blank et al., 2004 T 1/2 = ( ± 0.04) ms

branching ratio measurement at JYFL: A. Bey et al., 2007 BR = ( ± 0.026) % 2  511- e + e  954 – 62 Ga 1388 – 62 Ga 2228 – 62 Ga

62 Ga 31 (0 +,T=1) 62 Zn 32 (0 +,T=1)  + Fermi Analog. (sa) %  + Fermi Nonanalog. < 0.014%  + Gamow-Teller ~ 0.022% (8)% 0.025(7)% 0.014(5)% 0.022(7)% New Ft value for 62 Ga

Q value measurements at ISOLTRAP: e.g. 38 Ca half-life measurements at ISOLDE using REXTRAP: e.g. 38 Ca S. George et al., 2007 B. Blank et al., 2007 T 1/2 = (450.0±1.6) ms  m = ( ±0.65) keV T 1/2 = (450.0  1.6) ms

A longitudinal Penning trap filled with Ne as buffer gas EE Accumulation CoolingEjection – TOF selection Buffer gas cooling Superconducting magnet 3T PNe ~10 -4 mbar in the trapping area

Q value measurements at ISOLTRAP: e.g. 38 Ca half-life measurements at ISOLDE using REXTRAP: e.g. 38 Ca S. George et al., 2007 B. Blank et al., 2007 T 1/2 = (450.0±1.6) ms  m = ( ±0.65) keV T 1/2 = (450.0  1.6) ms

branching-ratio measurement: 22 Mg half-life measurement: 34 Ar other measurements: 62 Ga J. Hardy et al., 2003 V. Iacob et al., 2006 BR = (53.15 ± 0.12) % T 1/2 = (843.8 ± 0.4) ms

branching-ratio measurement: 62 Ga other measurements: 18 Ne, 74 Rb B. Hyland et al., 2006 BR = ( ± 0.011) %

14 O T 1/2 Leuven, Auckland, Berkeley Q EC Auckland 18 Ne T 1/2 TRIUMF Q EC ISOLDE 22 Mg T 1/2, BRTexas A&M Q EC CPT Argonne, ISOLDE 26 Si Q EC JYFL 26 Al m Q EC JYFL 34 Ar T 1/2, BRTexas A&M Q EC ISOLDE 38 CaQ EC, T 12 ISOLDE Q EC MSU 38 K m T 1/2 Auckland 42 ScQ EC JYFL 42 TiQ EC JYFL 46 VQ EC JYFL, CPT Argonne 50 MnQ EC JYFL T 1/2 Auckland 62 Ga T 1/2, BR GSI, JYFL, TRIUMF, Texas A&M Q EC JYFL 74 Rb T 1/2,BRTRIUMF, ISOLDE Q EC ISOLDE

= ( ± 1.2) s  g v = (4)  V ud = (4)

CVC accepted measurement of ft test  c -  NS from theoretical models

ft value + QED corrections ft value with all corrections  Ft  nuclear corrections seem to be okey, but they have large uncertainties  new calculations needed + measurements for nuclei with large corrections ft (1 +  R ’ ) (1 –  c +  NS )

coupling of quark weak eigen states to mass eigen states in the Standard Model unitarity condition: V ud = (4) ~ 95 % V us = (21) ~ 5 % V ub = (47) ~ 0 %   V ui ² = (12) V ud 0 +  0 +  decays: (4) neutron decay: (20)  Part. Data Group (2004) (Serebrov et al. (2005) not included) pion beta decay: (30)  larger uncertainty V us K X decays + form factor  Leutwyler-Roos (1984)  Cirigliano et al. (2005) deviation to unitarity V ud nuclear 0 +  0 + neutron pdg 04 neutron Se 05 V us K decay: pdg04 ~ 2  ok K: all results ~ 1  ok ~ 2  the situation today  Severijns, Beck, Naviliat-Cuncic, 2006

limit on induced scalar currents: f s = (130) or |fs|  limit for fundamental scalar current: |Cs / Cv |  limit for Fierz interference term: b F = (26) Ft = limits on right-handed currents: <  < (90% C.L.) W 1 = W L cos  - W R sin  W 2 = W L sin  + W R cos  unitarity of first column of CKM matrix:  V id = (54)  best limits from all approaches Ft value for f s =  K 2 G F 2 V ud 2 (1 +  V R ) 1 (1 + ) Hardy & Towner, 2005

uncertainty on : (35) s  (12) s ==>> 30 % due to more and more precise exp. data Fierz term : (30)  (26) ==>> strongly reduced value due to better exp. data V ud : (10)  (4) ==>> slight change, factor 2.5 unitarity test of first row of CKM matrix:  V ui = (21)   V ui = (12)==>> change mainly due to V us, improved precision from Ft unitarity test of first column of CKM matrix:   V id = (54) ==>> not evaluated in 1990 right-handed currents:  Re(a lr ) = (6) ==>> not evaluated in 1990

T z = -1 nuclei: 10 C, 18 Ne, 22 Mg, 26 Si, 30 S, 34 Ar, 38 Ca, 42 Ti - major problems: T 1/2 of daughter nuclei BR with precision of → absolute  efficiency with < → knowledge of source strength - solutions: trap-assisted spectroscopy for half-life measurements high-precision efficiency calibration of single-crystal Germanium ion counting → experiments on separators like MARS (Texas A&M), LISE3 (GANIL), TR  MP (KVI) T z = 0 nuclei: 66 As, 70 Br, 78 Y, 82 Nb, 86 Tc, …, 98 In - major problem: production rates, for some isomers, excited 0 + states - solution: future facilities like EURISOL, maybe SPIRAL2, ISOLDE theoretical corrections: - new approaches needed for nuclear corrections - higher-order calculations for QED corrections

half-life of 38 Ca at ISOLDE half-life of 26 Si at JYFL half-life of 42 Ti at JYFL or at KVI calibration of a HP germanium - branching ratio of 10 C, 26 Si, 38 Ca, 42 Ti

interesting physics case with strong implications beyond nuclear physics lively field with world-wide activities high-intensity beams of nuclei of interest are already available trap-assisted spectroscopy becomes more and more important, ISOLDE is a very good place LISE3/GANIL and TRI  P/KVI could be a prominent place for new branching ratio measurements in Europe: ISOLDE, JYFL, LISE3, TRI  P, LIRAT/DESIR can play an important role

Q value measurements at ISOLTRAP: e.g. 38 Ca half-life measurements at ISOLDE: e.g. 38 Ca other measurements: 18 Ne, 22 Mg, 34 Ar, 74 Rb S. George et al., 2007 B. Blank et al., 2007 T 1/2 = (451.8±1.6) ms

Q value measurements at MSU trap: 38 Ca G. Bollen et al., 2006  m = 280 eV

Q value measurements at JYFLTRAP: e.g. 62 Ga half-life and branching-ratio measurements: other measurements: 26 Al m, 26 Si, 42 Ti, 42 Sc m, 46 V, 50 Mn G. Canchel et al., 2005 A. Bey et al., 2007 T. Eronen et al., 2006 T 1/2 = ( ± 0.15) ms Q EC = ( ± 0.54) keV

Q value measurements at CPT at Argonne: 46 V other measurements: 22 Mg G. Savard et al., 2005

half-life measurement: 62 Ga branching-ratio measurement: 62 Ga B. Blank et al., 2004 G. Savard et al. T 1/2 = ( ± 0.04) ms

half-life measurement: 14 O M. Gaelens et al., 2001 T 1/2 = ( ± 0.049) s

half-life measurement: 50 Mn other measurements: 14 O, 38 K m P.H. Barker et al., 2006 T 1/2 = ( ± 0.14) ms

half-life measurement: 14 O J.T. Burke et al., 2006 T 1/2 = ( ± 0.052) s

half-life measurements: - only nuclei without “daughter half-life problem” e.g. 10 C, 14 O, 18 Ne, 30 S, ….. 66 As, 70 Br ?? on LIRAT2 or SIRa branching ratio measurements - top candidates: 18 Ne, 26 Si, 38 Ca, where half-life and Q EC are measured production rates at LISE3: 18 Ne: 6000pps with 3  A of 20 Ne, 100% pure 26 Si: 3000pps with 3  A of 32 S, 100% pure 38 Ca: 2500pps with 3  A of 40 Ca, 100% pure - others which are feasible: 10 C, 14 O, 22 Mg, 30 S, 34 Ar, ( 42 Ti)

integration of decay time spectrum to yield source strength (a few percent error) intensity of  rays (statistical and systematic error)  branching ratios with large error bars (~ 1%) acceptable for very small branching ratios

Primary beam SISSI target spectrometer LISE3 : degrader Be Wien filter