 asymmetry parameter measurements in nuclear  -decay as a probe for non-Standard Model physics K.U.Leuven, Univ. Bonn, NPI Rez (Prague), ISOLDE CERN - INTC 15 November 2004 N. Severijns

STRUCTURE OF THE WEAK INTERACTION IN NUCLEAR BETA DECAY  general Lorentz invariant 4-fermion interaction Fermi, 1933 : 4-fermion interaction Lee & Yang, 1956; Wu et al., 1957 : parity violation with i = Scalar, Vector, Tensor, Axial vector, Pseudoscalar and coupling constants C i defining properties of the interaction types

In the Standard Model : * C V = 1 (CVC) * C A = ( g A /g V = (6) from n-decay ) * C V ’ = C V & C A ’ = C A (maximal P-violation) * C S = C S ’ = C T = C T ’ = C P = C P ’  0 (only V- and A-currents) experimental upper limits: (neutron and nuclear  -decay) * no time reversal violation (except for the CP-violation described by the phase in the CKM quark-mixing matrix) from: N. Severijns, M. Beck, O. Naviliat-Cuncic, Rev. Mod. Phys., accepted

Limits (95 % CL) on possible new bosons for S- and T-interactions, from high-energies: mass limit for H ± (charged Higgs) : > 79.3 GeV (LEP-ALEPH) mass limit for leptoquarks : > 242 GeV (from pair production; combined CDF-D0) : > 298 GeV (from single production; ZEUS) Limits for f T from K ± decay [Particle Data group, Phys. Lett. B592 (2004) 1 ] : |f T / f + | = 0.012(23) from K ± e3 decay  |f T / f + | < (95% C.L.) |f T / f + | = 0.001(7) from K ±  3 decay  |f T / f + | < (95% C.L.)

J    -asymmetry for a pure Gamow-Teller transition : ( assuming maximal P-violation and T-invariance for V- and A-interactions) < Im (C T +C’ T )/C A < (90% CL) from 8 PSI, R. Huber et al., PRL 90 (2003)  A/A = 0.01  (for  m/E e  0.5) Re [(C T +C T ’) / C A ] < (95% CL) recoil corr. (induced form factors)  (see below) ; radiative corrections  A GT independent of nuclear matrix elements

Low Temperature Nuclear NICOLE cf. IS349 – IS381

1. Absolute measurements 2. Relative measurements from Geant and experimental data

First case: 114 In 1 +  0 + pure GT E 0 = 1.99 MeV log ft = 4.473(5) E  = 1.70 – 1.85 MeV N. Severijns, submitted for publication  (  m/E = 0.210) < Re (C T +C’ T )/C A < 0.08 (90% CL) ( best precision for A for a fast pure GT transition to date ! )

IsotopetransitionE endpoint (keV)  endpoint A GT log ft recoil correction *) P 10 mK type of meas. 79 Kr  +, 1/2 -  3/ (12)54 85m Kr  -, 1/2 -  3/ (6)61 79 Kr/ 85m Kr (5) rel. 67 Cu  -, 3/2 -  5/ (3)76 abs. 82g Br  -, 5 -  (8)-0.004(2)87 abs. 83 Br  -, 3/2 -  1/ (4)-0.005(3)98 abs. Proposal *) due to weak magnetism and induced tensor form factors if  A/A = 0.01  | Re (C T +C’ T )/C A |< 0.02 to 0.04 (90% CL)

Other experiments 1.Leuven - A GT 60 Co and 133 Xe, with LTNO and 15 T external magnetic field instead of hyperfine field ( I.S. Kraev, N. Severijns et al., in preparation ) 2.Los Alamos - A GT 82 Rb in MOT atom trap;  m/E = 0.13 ( S.G. Crane et al., Phys. Rev. Lett. 86 (2001) D.J. Vieira et al., Hyp.Int. 127 (2000) 387 ) 3.LPC-Caen (O. Naviliat et al) - a GT 6 He in Paul ion trap ( P. Delahaye al., Hyp.Int. 132 (2001) 479 ) All experiments are aiming at a precision of 0.5% to 1% !

Beam shifts purpose 79 Kr2A GT 85m Kr8A GT 67 Cu1A GT 68 Cu4 implantation quality 82g Br1A GT 83 Br10A GT 82 Sr1 calibrate Geant 118 Te (or 118 Xe )1 calibrate Geant Total = 28 Beam time request

Note: effect of recoil terms (induced form factors) b, g M : weak magnetism c, g A : Gamow-Teller d, g T : induced tensor