Search results for "neutral kaon"
showing 6 items of 6 documents
Measurement of the radiative K-e3 branching ratio
2005
We present a measurement of the relative branching ratio of the decay KL -> pi e nu gamma (Ke3gamma) with respect to KL-> pi e nu (gamma) (Ke3+Ke3gamma) decay. The result is based on observation of 19 000 Ke3gamma and 5.6 x 10^6 Ke3 decays. The value of the branching ratio is Br(Ke3gamma, Egamma^*>30 MeV,theta(e,gamma)^*>20^o)/Br(Ke3)= (0.964+-0.008+0.011-0.009)%. This result agrees with theoretical predictions but is at variance with a recently published result.
Search for direct CP violation in the decays K-+/- -> 3 pi(+/-)
2006
Abstract We report a measurement of the direct CP violation asymmetry parameter A g in charged kaon decays K ± → π ± π + π − by the NA48/2 experiment at the CERN SPS. The experiment has been designed not to be limited by systematics in the asymmetry measurement. Using 1.67 × 10 9 such decays collected during the 2003 run, the charge asymmetry in the Dalitz plot linear slope parameter g has been measured to be A g = ( 1.7 ± 2.9 ) × 10 −4 . The precision of the result is limited by the statistics used.
Tuning and test of fragmentation models based on identified particles and precision event shape data
1996
Event shape and charged particle inclusive distributions are measured using 750000 decays of the $Z$ to hadrons from the DELPHI detector at LEP. These precise data allow a decisive confrontation with models of the hadronization process. Improved tunings of the JETSET ARIADNE and HERWIG parton shower models and the JETSET matrix element model are obtained by fitting the models to these DELPHI data as well as to identified particle distributions from all LEP experiments. The description of the data distributions by the models is critically reviewed with special importance attributed to identified particles.
Direct test of time reversal symmetry in the entangled neutral kaon system at a phi-factory
2013
We present a novel method to perform a direct T (time reversal) symmetry test in the neutral kaon system, independent of any CP and/or CPT symmetry tests. This is based on the comparison of suitable transition probabilities, where the required interchange of in out states for a given process is obtained exploiting the Einstein-Podolski-Rosen correlations of neutral kaon pairs produced at a phi-factory. In the time distribution between the two decays, we compare a reference transition like the one defined by the time-ordered decays (l(-), pi pi) with the T-conjugated one defined by (3 pi(0), l(+)). With the use of this and other T-conjugated comparisons, the KLOE-2 experiment at DA Phi NE co…
Measurement of the quadratic slope parameter in the K-L -> 3 pi(0) decay Dalitz plot
2001
A value of (-6.1 +- 0.9_{stat} +- 0.5_{syst})*10^{-3} is obtained for the quadratic slope parameter h in the K_L -> 3\pi^0 decay Dalitz plot at the NA48 experiment at the CERN SPS. The result is based on 14.7*10^6 fully reconstructed K_L -> 3\pi^0 -> 6\gamma decays. This is the most precise measurement of any of the Dalitz plot slope parameters in the charged and neutral kaon decays so far.
Can future observation of the living partner post-tag the past decayed state in entangled neutral K mesons?
2019
Entangled neutral K mesons allow for the study of their correlated dynamics at interference and decoherence times not accessible in any other system. We find novel quantum phenomena associated to a correlation in time between the two partners: The past state of the first decayed kaon, when it was entangled before its decay, is post-tagged by the result and the time of the future observation of the second decay channel. This surprising "from future to past"effect is fully observable and leads to the unique experimental tag of the KS state, an unsolved problem since the discovery of CP violation.