Measurement of the K0 charge radius and a CP-violating asymmetry and a search for CP-violating E1 direct photon emission in the rare decay KL→π+π-e+e-

Using the complete KTeV data set of 5241 candidate K-L ->pi(+)pi(-)e(+)e(-) decays (including an estimated background of 204 +/- 14 events), we have measured the coupling g(CR)=0.163 +/- 0.014(stat)+/- 0.023(syst) of the CP conserving charge radius process and from it determined a K-0 charge radius of < r(K)(02)>=[-0.077 +/- 0.007(stat)+/- 0.011(syst)]fm(2). We have determined a first experimental upper limit of 0.04 (90% C.L.) for the ratio parallel to g(E1)parallel to/parallel to g(M1)parallel to of the couplings for the E1 and M1 direct photon emission processes. We also report the measurement of parallel to g(M1)parallel to including a vector form factor parallel to g(M1)parallel to(1+a(1)/a(2)/(M-rho(2)-M-K(2))+2M(K)E(gamma+)), where parallel to g(M1)parallel to=1.11 +/- 0.12(stat)+/- 0.08(syst) and a(1)/a(2)=[-0.744 +/- 0.027(stat)+/- 0.032(syst)] GeV2/c(2). Finally, a CP-violating asymmetry of [13.6 +/- 1.4(stat)+/- 1.5(syst)]% in the CP and T odd angle phi between the decay planes of the e(+)e(-) and pi(+)pi(-) pairs in the K-L center of mass is reported.