Related papers: New limit on fundamental weak-interaction paramete…
The electromagnetic structure of the nucleon can be determined from the scattering of electrons off a nucleon target. However, to study its axial structure, neutrino beams are required. The results from these experiments should be…
In the Standard Model, the charged current of the weak interaction is governed by a unitary quark mixing matrix that also leads to CP violation. Measurement of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements is essential to searches for…
A new analysis of hyperon semi-leptonic decay data is presented, based on simple and general arguments for an SU(3)-breaking structure of the couplings involved. The results obtained are compatible with those of earlier investigations and…
Unitarity along with precision measurements of sin2\beta, V_{us} and V_{cb} allows one to find a lower bound V_{ub}\geq 0.0035 which, on using the recently measured angle \alpha of the unitarity triangle, translates to V_{ub}= 0.0035\pm…
We review the status of hyperon semileptonic decays. The central issue is the $V_{us}$ element of the CKM matrix, where we obtain $V_{us}=0.2250 (27)$. This value is of similar precision, but higher, than the one derived from $K_{l3}$, and…
The success of the quantum level predictions of the Standard Model on the $Z$ boson properties, on $\mw$ and on $\mt$, which makes use of the muon lifetime as an input, implies a stringent constraint on new physics contributions to the…
The experimental determination of V_{ud} from neutron beta decay requires accurate values of the neutron lifetime and the ratio of the weak axial-vector to vector coupling constants of the nucleon. The latter is derived from measurements of…
We reconsider several current bounds on the variation of the fine-structure constant in models where all gauge and Yukawa couplings vary in an interdependent manner, as would be expected in unified theories. In particular, we re-examine the…
The value of the V_{ud} matrix element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix can be derived from nuclear superallowed beta decays, neutron decay, and pion beta decay. We survey current world data for all three. Today, the most…
Quantum weakdynamics (QWD) as an SU(3)_I gauge theory with the Theta vacuum term is considered to be the unification of the electroweak interaction as an SU(2)_L x U(1)_Y gauge theory. The grand unification of SU(3)_I x SU(3)_C beyond the…
We review the current status of precision measurements in allowed nuclear beta decay, including neutron decay, with emphasis on their potential to look for new physics beyond the standard electroweak model. The experimental results are…
We review the hypothesis of the conserved vector current (CVC) within the Standard Model. In addition to the classic tests, such as pion beta decay and neutrino scattering, we mention recent tests involving LEP data. As well as providing a…
In presenting an up-to-date account of the experimental knowledge of the CKM matrix, special emphasis is placed on the exceptional degree of consistency shown by the current Standard Model determination of the unitarity triangle; some…
Till the middle of 2004 it appeared that the unitarity relation Vud^2+Vus^2+Vub^2=1 might not hold at the 2.3sigma level. At that time, however, Vus was inferred from old experimental data. Since then, a large experimental and theoretical…
The standard model weak interactions can be described by four-fermion V-A operators at low energies. New physics at the TeV scale can, however, generate the other Lorentz structures. In this talk, we review the constraints on such…
We present constraints on the CKM parameter gamma=arg(Vub*) formed within the framework of SU(3) symmetry and based on charmless hadronic B decays to K*+- pi-+ and other pseudoscalar-vector final states. For strong phases of O(10 degrees),…
The beta-decay Q_EC-values of the superallowed beta emitters 26m-Al, 42-Sc and 46-V have been measured with a Penning trap to a relative precision of better than 8x10^-9. Our result for 46-V, 7052.72(31) keV, confirms a recent measurement…
We present the full description of a measurement of the branching ratios for the beta-decay of 38Ca. This decay includes five allowed 0+ --> 1+ branches and a superallowed 0+ --> 0+ one. With our new result for the latter, we determine its…
The renormalization of the weak charge-changing hadronic current as a function of the reaction energy release is studied at the nucleonic level. We have calculated the average quenching factors for each type of current (vector, axial vector…
The limits on time-reversal invariant tensor-type weak currents from nuclear and neutron $\beta$ decays are evaluated including most recent experimental data. We find that $ -0.14 \times 10^{-2} < (C_T + C^\prime_T)/C_A < 1.4 \times 10^{-2}…