A new limit on the CP violating decay K-S -> 3 pi(0) with the KLOE experiment
2013 (English)In: Physics Letters B, ISSN 0370-2693, Vol. 723, no 1-3, 54-60 p.Article in journal (Refereed) Published
We have carried out a new direct search for the CP violating decay K-S -> 3 pi(0) with 1.7 fb(-1) of e(+)e(-) collisions collected by the KLOE detector at the Phi-factory DA Phi NE. We have searched for this decay in a sample of about 5.9 x 10(8) KSKL events tagging the K-S by means of the K-L interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake K-S tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of K-S -> 2 pi(0) events in the same sample, we set the upper limit on BR(K-S -> 3 pi(0)) <= 2.6 x 10(-8) at 90% C.L., five times lower than the previous limit. We also set the upper limit on the eta(000) parameter, vertical bar eta(000)vertical bar <= 0.0088 at 90% C.L., improving by a factor two the latest direct measurement. (c) 2013 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
2013. Vol. 723, no 1-3, 54-60 p.
e(+)e(-) collisions, DA Phi NE, KLOE, Rare K-S decays, CP, CPT
IdentifiersURN: urn:nbn:se:uu:diva-204113DOI: 10.1016/j.physletb.2013.05.008ISI: 000320206500006OAI: oai:DiVA.org:uu-204113DiVA: diva2:637784