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-

E. Abouzaid, M. Arenton, A. R. Barker, L. Bellantoni, A. Bellavance, E. Blucher, G. J. Bock, E. Cheu, R. Coleman, M. D. Corcoran, G. Corti, B. Cox, A. R. Erwin, C. O. Escobar, A. Glazov, A. Golossanov, R. A. Gomes, P. Gouffon, K. Hanagaki, Y. B. HsiungH. Huang, D. A. Jensen, R. Kessler, K. Kotera, A. Ledovskoy, P. L. McBride, E. Monnier, K. S. Nelson, H. Nguyen, R. Niclasen, H. Ping, X. R. Qi, E. J. Ramberg, R. E. Ray, M. Ronquest, E. Santos, J. Shields, W. Slater, D. Smith, N. Solomey, E. C. Swallow, P. A. Toale, R. Tschirhart, C. Velissaris, Y. W. Wah, J. Wang, H. B. White, J. Whitmore, M. Wilking, B. Winstein, R. Winston, E. T. Worchester, M. Worchester, T. Yamanaka, E. D. Zimmerman, R. F. Zukanovich

Research output: Contribution to journalArticle

22 Scopus citations

Abstract

Using the complete KTeV data set of 5241 candidate KL→π+π-e+e- decays (including an estimated background of 204±14 events), we have measured the coupling gCR=0.163±0.014(stat)±0.023(syst) of the CP conserving charge radius process and from it determined a K0 charge radius of rK02 =[-0.077±0.007(stat)±0.011(syst)]fm2. We have determined a first experimental upper limit of 0.04 (90% C.L.) for the ratio |gE1||gM1| of the couplings for the E1 and M1 direct photon emission processes. We also report the measurement of |gM1| including a vector form factor |g M1|(1+a1/a2(Mρ2- MK2)+2MKEγ*), where |g M1|=1.11±0.12(stat)±0.08(syst) and a1/a2=[-0.744±0.027(stat)±0.032(syst)]GeV2/c2. Finally, a CP-violating asymmetry of [13.6±1.4(stat)±1.5(syst)]% in the CP and T odd angle between the decay planes of the e+e- and π+π- pairs in the KL center of mass is reported.

Original languageEnglish (US)
Article number101801
JournalPhysical review letters
Volume96
Issue number10
DOIs
StatePublished - Mar 23 2006

    Fingerprint

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Abouzaid, E., Arenton, M., Barker, A. R., Bellantoni, L., Bellavance, A., Blucher, E., Bock, G. J., Cheu, E., Coleman, R., Corcoran, M. D., Corti, G., Cox, B., Erwin, A. R., Escobar, C. O., Glazov, A., Golossanov, A., Gomes, R. A., Gouffon, P., Hanagaki, K., ... Zukanovich, R. F. (2006). 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-. Physical review letters, 96(10), [101801]. https://doi.org/10.1103/PhysRevLett.96.101801