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The direct CP violation parameter Re(epsilon'/epsilon) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. The 2001 running period was devoted to collecting additional data under varied conditions compared to earlier years (1997-1999). The new data yield the result: Re(epsilon'/epsilon) = (13.7 +/- 3.1) x 10(-4). Combining this result with that published from the 1997, 98 and 99 data, an overall value of Re(epsilon'/epsilon) = (14.7 +/- 2.2) x 10(-4) is obtained from the NA48 experiment. (C) 2002 Elsevier Science B.V. All rights reserved

0370-2693r99r$ -see front matter q 1999 Elsevier Science B.V. All rights reserved.Ž . PII: S 0 3 7 0 -2 6 9 3 9 9 0 1 0 3 0 -8 ( ) V. Fanti et al.r Physics Letters B 465 1999 335-348 336 A.

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The beam and detector, used for the NA48 experiment, devoted to the measurement of Re(epsilon'/epsilon) and for the NA48/1 experiment on rare KS and neutral hyperon decays, are described

The two{jet invariant mass spectrum as measured in the UA2 experiment is used to search for additional heavy vector bosons decaying to two{jets. The mass of an additional W boson that couples to fermions with a V + A form is constrained to be greater than 261 GeV to the 90% condence level. A limit on the production cross section of additional W and Z bosons is given as a function of the boson mass. A limit on the production of excited quarks is also given as a function of the excited quark mass.

The decay rate of K L → π 0 γγ has been measured with the NA48 detector at the CERN SPS. A total of 2558 K L → π 0 γγ candidates have been observed with a residual background of 3.2%. The branching ratio is determined to be (1.36 ± 0.03 (stat) ± 0.03 (syst) ± 0.03 (norm) ) × 10 −6 and the vector coupling constant a v = −0.46 ± 0.03 (stat) ± 0.04 (syst) . This result suggests that the CP-violation effects are dominating in the K L → π 0 e + e − decay. An upper limit for the K L → π 0 γγ decay rate in the two photon mass region m γγ < m π 0 is also given.