UofC's CPV Group

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Model CE1337 VME Universal Pipeline TDC Module

CP Violating Rare Kaon Decay Experiment

This group primarily focuses on the measurement of the branching ratio of a very special rare kaon decay, a k-long particle decays into a neutral pion and two neutrinos (so called the "golden" mode). This decay mode provides the cleanest and best answer to the question of CP violation in elementary particle physics that the theoretical calculation (prediction) within the so called Standard Model is unambiguous and precise. Therefore no matter what the measurement result is, standard or non-standard; it will be most fascinating.

Rare Kaon Decay Mode

This experiment is designed and built to measure the "golden" mode. Our group joined E391a at KEK (Japan High Energy Accelerator Laboratory) in 2001, and is responsible to build the front-plug and back-plug calorimeters. This experiment is a pilot to get within reach of Standard Model sensitivity and also provides comprehensive background checks and understanding. Data taking will start in early 2004, and we expect many results by end of 2004. This experiment is an important step to a possible new experiment at JPARC (Japan Physics and Accelerator Research Complex, aka JHF) in 2006. This new accelerator is expected to be online in 2006. Currently a letter of intent to measure a thousand "golden" mode events has been submitted, and a formal proposal will follow soon.

The experimental pursuit of this measurement started in 1990 with a Chicago undergraduate, Greg Graham who wrote a senior thesis on the first measurement of this decay mode using data from a dedicated rare kaon decay (Experiment E799 at Fermilab, proposed in 1988, data taking in 1990-91). Since then, follow up experiment KTeV/E799-II (proposed 1993, data taking 1996-97 and 1999-2000) improved the limit with basically the same technique. The KTeV detector had the highest sensitivities for many decay modes that the current knowledge about neutral kaon decays are mostly from KTeV results.

Who are we?

GWJ
Professor Yau Wah: Project Lead
Jonathan Nix: Graduate Student
Gabriel N. Perdue: Graduate Student
Jiasen Ma: Graduate Student
Bihui Li: Undergraduate Student
Robert J. Lucero: Undergraduate Student
Sara Waters: REU Summer Student - 2005
Elizabeth Pod: Lead Engineer
To Be Hired: Incoming Postdoc