First Measurement of Form Factors of the Decay Xi0->Sigma+ e- anti-nu/e

TL;DR

This paper reports the first measurement of form factor ratios in the decay Xi0 -> Sigma+ e- anti-nu/e, providing insights into weak interactions and SU(3) symmetry in hyperon decays.

Contribution

It presents the first experimental determination of key form factors for this decay, confirming SU(3)f symmetry assumptions.

Findings

Measured g1/f1 to be 1.32 with uncertainties

Results consistent with SU(3)f symmetry

Provides new data for hyperon decay form factors

Abstract

We present the first measurement of the form factor ratios g1/f1 (direct axial-vector to vector), g2/f1 (second class current) and f2/f1 (weak magnetism) for the decay Xi0 -> Sigma+ e- anti-nu/e using the KTeV (E799) beam line and detector at Fermilab. From the Sigma+ polarization measured with the decay Sigma+ -> p pi0 and the e- - anti-nu/e correlation, we measure g1/f1 to be 1.32 +0.21-0.17(stat.) +/- 0.05(syst.), assuming the SU(3)f (flavor) values for g2/f1 and f2/f1. Our results are all consistent with exact SU(3)f symmetry.