The 'LASS' Program where LASS equals E-135, LASS and SLD

The beginning In 1975/6 Sharon Traweek and Henry Abarbanel encouraged me to be in contact with several Japanese groups who might be interested in collaborating on strong interaction spectroscopy studies. This led to a meeting with Ryo Kajikawa, of Nagoya University and the start of a long personal friendship, and of a productive scientific collaboration. Nagoya applied to JSPS for support, and Shiro Suzuki visited SLAC. Thus began the US/ Japan basis for the “LASS” program. Prof.Nishikawa pushed the formation of the Japan/US collaboration in HEP, and supported the Nagoya group’s role on the LASS experiment as part of that activity. Shiro Suzuki came to SLAC as KEK/Mombusho ACO, and as resident senior leader of the Japanese group.

SLAC hosted two activities under the early Japan/US program – a series of bubble chamber experiments, and the LASS activity. Joe Ballam made the decision – a very wise, generous and impactful one – to hire a series of young Japanese scientists, into short term appointments, using the lab resources offset by the Japan/US investment at SLAC. This program had over 30 Japanese visitors working on the experiments through the period 1979 to 1999, with 18 post docs and graduate students working long term at SLAC, in these visiting appointments. Around 1990 such temporary positions - a important bridge between graduate student status and regular employment as faculty or staff on research - became established in Japan. The SLAC temporary positions were a very important precedent/exemplar.

From those times, and from this program, there were 10 graduate students from Japan working at SLAC, from Nagoya University and from Tohoku University, who finished their PhD studies and graduated - and of that group 7 are now working in research at Japanese universities or laboratories. There were 15 young Japanese who held these temporary positions at SLAC, and of these 12 now are faculty or staff in Japanese universities or laboratories. Nineteen of the young Japanese who worked on this program are now active in Japanese HEP. This is an impressive deliverable from our international, collaborative activity. I believe it ranks in equal importance to the science that was carried out.

The LASS experiment established the full excitation spectrum of both orbital and radial light quark meson states. Most completely in the strange meson sector, but also in the strangeonium sector.

Examples of direct impact on B physics analysis Analysis of D +  K -  + e + e

Japanese role in the SLD experiment By this time, the Nagoya group were joined by people from Tohoku. Prof. Haruo Yuta brought his group to join the Nagoya activity in the SLAC program, working now on the SLD experiment while still partici- pating in LASS data analysis. The “Ballam plan”, (of lab temporary staff positions), still continued supporting senior resident scientists, and a new set of temporary SLAC scientist appointments. The impressive table of those from Japan who played a part in these activities, displays both the past, and the current placement of the young Japanese scientists. These Japanese groups helped design and build the CRID particle identification system, and the important CCD vertex detector of the SLD detector, run the experiment through its data taking, and participate in the data analysis.

SLD science activities - # Precise measurements of A(b) and A(LR) at the Z mass # Measurement of alpha-s at the Z mass # Measurement of R(b) at the Z mass # Precise measurement of b fragmentation in Z decays # A test of flavor independence in strong interactions These were all “TOP CITE” publications (i. e. greater than 50 citations per paper)

Conclusion # strong, productive science program, with ‘hands-on’ learning of designing and building detector instrumentation, running large HEP experiments ‘24/7’, and giving attention to development of the software to support both the data production, and the data analysis of the resulting data. # the data and the results from LASS provided a broad, empirical foundation on the detailed spectroscopy of light quark meson systems, with particular emphasis on the strange quark. # the SLD experiment introduced new kinds of detector technology, and with the polarized beams of the high energy collider allowed precision measurements that challenged the SM story for heavy quark couplings.

Conclusions (continued) # development of human resources that are now an important part of ongoing basic research manpower in Japan. Nineteen professors and staff, now engaged in HEP research within Japan. # a great number of very good friends from the originating community of Japan/US, some of whom are no longer with us, but who enriched our community, and enabled the creation and sustainability of the program we are celebrating in this symposium. I am thankful for this rich set of very important friends that came into my life only through this Japan/US program.

THE end

The magnitude, (a), and the phase, (b), of the S-wave and P-wave amplitudes in the mass region below 1.84 GeV/c 2.