Kaons: Review and Outlook

This article presents a review of recent results and an outlook of kaon physics. After enjoying a renaissance, the discipline is now becoming and endangered species. Action will be needed to keep kaon physics at the heart of future FPCP meetings.Comment: 9 pages, 5 figures, conference proceedings "Flavor Physics & CP Violation Conference, Vancouver, 2006

Towards results on direct CP violation in kaon decays from the CERN-SPS experiment NA48

The NA48 experiment aims to measure the direct CP violation parameter $\Re(\epsilon'/\epsilon)$ using the method of the double ratio with a precision of $2 \times 10^{-4}$. The experiment has collected data during 1997 and during 1998 and plans to produce a result based on the 1997 statistics soon. The status of the analysis and the perspectives for the future are outlined in this paper

NA62/P-326 Status Report

In this document a report on the 2007 activities of the NA62/P-326 Collaboration is given, including a summary of the data taking activities related to the measurement of the RK ratio and the progress on the R&D activities for the K+ --> pi+ nu nubar experiment

The NA48 LKr calorimeter digitizer electronics chain

The 13 500 channels of the NA48 liquid-krypton electromagnetic calorimeter readout electronics were put into operation in 1997. The digitizer electronics employs a new gain switching technique that expands the dynamic range of a standard 10-bit ADC to 14 bits at 40 MHz sampling rate employing a custom-developed integrated circuit (KRYPTON). The KRYPTON has been fabricated in 1.2 μm BiCMOS technology and was successfully developed together with industry on a short timescale. The performance and the experience from the first year of the operation of the liquid-krypton calorimeter electronics will also be briefly discussed

Measurement of the decay rate and the parameter αK* of the decay KL → μμγ

The rate of the decay of the neutral K meson into KL0 → μμγ has been measured with the NA48 detector at the CERN SPS. A total of 59 events has been observed with an estimated background of 14 events. The overall Kaon flux was determined to be 1.2 × 109. This observation corresponds to a branching ratio of (3.4 ± 0.6stat ± 0.4sys × 10-7. Using this branching ratio the parameter αK* describing the relative strength of the two contributing amplitudes to this decay, through intermediate pseudoscalar or vectorlike mesons, was measured to be αK* = -0.04+-0.21+0.24

The NA48 LKr calorimeter readout electronics

The NA48 experiment at the CERN SPS accelerator is making a measurement of the direct CP violation parameter $\epsilon'/\epsilon$ by comparing the four rates of decay of $K_{S}$ and $K_{L}$ into $2\pi^{0}$ and $\pi^{+}\pi^{-}$. To reconstruct the decays into $2\pi^{0}$ the information from the almost 13500 channels of a quasi-homogeneous liquid krypton electromagnetic calorimeter is used. The readout electronics of the calorimeter has been designed to provide a dynamic range from a few MeV to about 50 GeV energy deposition per cell, and to sustain a high rate of incident particles. The system is made by cold charge preamplifiers (working at 120 degrees K), low-noise fast shapers followed by digitizer electronics at 40 MHz sampling rate that employs a gain switching technique to expand the dynamic range, where the gain can be selected for each sample individually (i.e. every 25 ns). To reduce the amount of data collected the system contains a zero suppression circuit based on halo expansion

Space charge in ionization detectors and the NA48 electromagnetic calorimeter

The subject of space charge due to positive ions slowly moving in parallel plate ionization chambers is considered. A model for the degradation of the detector response is developed, with particular emphasis on electromagnetic calorimeters. The topics discussed include: (a) the stationary and (b) the time dependent cases; (c) the limit of very large space charge; (d) the electric field dependence of the electron drift velocity; (e) the effect of longitudinal development of showers; (f) the behavior of the average reductions of response and (g) the non-uniformity of response for different positions of the shower axis inside the cell defined by the electrodes. The NA48 calorimeter is used as application and for comparison of results