1. US-Japan and the KTeV Research Program at Fermilab R. Tschirhart US-Japan 30th Anniversary Symposium Kona, Hawaii October 20 th 2010

2. Kaons at the TeVatron The KTeV experiment was primarily a comprehensive study of neutral kaon decays, data collected 1996-2000. The research program yielded 32 PhD theses and 50 physics publications, most notably the establishment of matter/antimatter asymmetry in particle decay amplitudes. This rich research program was largely driven by intense beams of in- flight neutral kaon decays reconstructed with a high-speed, high-resolution spectrometer. US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab

3. Context and Prejudice: Flavor Physics in the early 1990’s Neutrino mixing out of reach?? What is CP violation? Why is it so small? A new super-weak force?? The top quark is elusive…..very high mass; does it even exist? If the top quark exists and is heavy…new high mass particles can compete in virtual loops in flavor changing neutral currents. But…B meson’s are reconstructed only by the handful. K mesons can be produced in large numbers, but how can we possibly measure the rare K L   0  0 neutral mode decay with sufficient precision to search for direct matter anti-matter asymmetries?? US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab

4. Fast forward… Highlights of KTeV Science… Re(  ’/  ) = (1.66 ± 0.26)×10 -3*  L    ee     (K 0 →     ) -  (K 0 →     )  (K 0 →     ) +  (K 0 →     ) = (5.04 ± 0.22) ×10 -6 ** Matter/Antimatter asymmetry in a decay amplitude established, Superweak model excluded. Large component of this asymmetry might arise from New Physics. KTeV limited these rates to x8 and x25 the Standard model rates (10 -11 level) for the ee and  modes….fertile hunting ground for new physics models. * PDG, **J Imazoto Insert piee/pimumu plot here

5. Serendipity: Resolution of the V ud /V us /V ub non-Unitarity tension by precision measurement of K L   e decays. US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab Enrico Lunghi, LME-2010, Fermilab 2010: KTeV,BNL-865,NA48,KLOE New Physics models squeezed out beyond the 5 TeV scale 2004: |V ud | 2 +|V us | 2 +|V ub | 2 < 1 ??

6. …Our competitors and colleagues… US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab

7. Emergence of the “Flavor Problem” Why don’t we see the Terascale Physics we expect affecting the flavor physics we study today?? 4

8. KTeV was the culimanation of the high- energy in-flight program at Fermilab US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab University of Chicago Group

9. Enabling Collaboration! US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab 1996 KTeV Collaboration meeting at the University of Arizona. 75 collaborators, 32 PhD students, 50 science publications.

10. US-Japan Contributions to KTeV: Unprecedented photon calorimetry and Trigger & DAQ Beam view of K 0   0  0 in CsI calorimeter US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab

11. KTeV Pure CsI Calorimeter 3100 crystals, 1.9mx1.9m 27 X 0 deep (50cm) 90% of light has 20-nsec component Osaka group and US-J developed “collar” veto systems that cleanly defined acceptance. US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab

12. Calorimeter Readout 5-6 Stage low-gain (x3000) PMTs critical to preserve large dynamic range. Developed by Osaka, Fermilab, and UCLA (Arisaka-san) working closely with Hamamatsu. PMTs funded by US-Japan. QIE: 16-bit range-compressed charge integrating pipelined readout (9-bit resolution) operating at 53 MHz local to PMT base, developed by FNAL. US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab

13. Delivered EM-calorimetry performance better than 1% resolution over full physics energy range: Best in the field US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab

14. KTeV CsI Crystals and PMTs continuing great science in the JPARC E14 K L   0 adventure US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab JPARC PAC tour of E14 calorimeter E14 Calorimeter assembly KTeV Calorimeter assembly

15. US-Japan largely funded the visionary DAQ that was first in the field to filter out most events based on full reconstruction US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab Great science needs great throughput! Visionary effort led by Yamanaka-san and Nakaya-san

16. The US-Japan@KTeV Legacy US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab Established decay-amplitude matter-antimatter asymmetries together with our CERN colleagues. Probed many, many rare-decays that have cranked up the tension on the “flavor problem”. Substantially advanced the state of the art in precision calorimetry and data acquisition in High Energy Physics. Developed next generation leaders in flavor physics and elsewhere. Ichiro Suzuki, Seattle Mariners: ( 鈴木 一朗 ) Best player in the league- Achieved through systematic high quality team-work and leadership on the field

17. Spares US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab

18. Osaka Unviersity PhDs “Study of the Decay K L ->pi +- e -+ nu e + e - to Probe the Semileptonic K-pi Structure” by Katsushige Kotera, Osaka University, September, 2006. "CP Asymmetry in the Decay KL-> pi + pi - e + e - " by Katsumi Senyo, Osaka University, December, 1999. "Search for the Decay K L ->pi 0 mu + mu - " by Masayoshi Sadamoto, Osaka University, February 1999. "Search for the Decay K L ->pi 0 nu nu-bar" by Kazunori Hanagaki, Osaka University, August 1998. US-Japan 30th Anniversary Symposium October 20th 2010 R. Tschirhart - Fermilab