14 research outputs found
Semileptonic Hyperon Decays
We review the status of hyperon semileptonic decays. The central issue is the
element of the CKM matrix, where we obtain . This
value is of similar precision, but higher, than the one derived from ,
and in better agreement with the unitarity requirement,
. We find that the Cabibbo model gives an
excellent fit of the existing form factor data on baryon beta decays ( for 3 degrees of freedom) with , , and no indication of flavour-SU(3)-breaking effects. We
indicate the need of more experimental and theoretical work, both on hyperon
beta decays and on decays.Comment: 37 pages, 8 figures, 4 tables, Final version of this material is
scheduled to appear in the Annual Review of Nuclear and Particle Science Vol.
5
Semileptonic Hyperon Decays and CKM Unitarity
Using a technique that is not subject to first-order SU(3) symmetry breaking
effects, we determine the element of the CKM matrix from data on
semileptonic hyperon decays. We obtain =0.2250(27). This value is of
similar precision to the one derived from , but higher and in better
agreement with the unitarity requirement, .Comment: 3 pages, 1 tabl
Measurement of the form factors of charged kaon semileptonic decays
International audienceA measurement of the form factors of charged kaon semileptonic decays is presented, based on 4.4 × 10K → πeν (K ) and 2.3 × 10K → πμ±ν (K ) decays collected in 2004 by the NA48/2 experiment. The results are obtained with improved precision as compared to earlier measurements. The combination of measurements in the K and K modes is also presented