Neutral Currents in BEBC -
The experiment WA21

Content

  1. Personal Remarks
  2. IT Environment
  3. Experiment WA21
  4. The Beam Line
  5. The Detectors
  6. Events in BEBC
  7. Analysis of Events
  8. Extracting the Neutral Current Couplings
  9. Neutral Current Events
  10. Results, Sources, and Appendix

Personal Remarks

During my physics studies at the University of Bonn from 1979 to 1985, I had the chance to work for about one year at the European Particle Physics Lab CERN close to Geneva/Swiss. During those exciting years [source] the exchange particles of the weak charged (CC) W+, W- and weak neutral current (NC) Z0 were found by the collaboration UA1 (and UA2) under leadership of Carlo Rubbia.

At that time, CERN's SPS (Super Proton Synchrotron) was in operation, providing beams with energies of 400-450 GeV (that was the same energy rate of the initial LHC runs, believed to produce the doomsday).

As young Associate, I was participating in the experiment WA21 which used the Big European Bubble Chamber BEBC to investigate the interaction of high energy (anti-) neutrinos with protons (hydrogen).

In addition, I did some research at the FNAL 15' bubble chamber at Fermilab/Chicago.

The Big European Bubble Chamber BEBC equipped with the surrounding External Muon Identifier EMI [CERN]

The BEBC bubble chamber and the facilities were also used by other collaborations, in particular

IT environment

Regarding the IT environment back in 1980, CERN used still IBM mainframes for data-storage and editing purposes (with Wylbur) running MVS. Rather, the data exploration was done on a CDC (Cyber) 'Supercomputer' facilitating the NOS/BE operating system with astonishing 1000K real memory (and no virtual memory at all) but with 60 bit words (instead of 32 bit elsewhere). It turned out, that the effective word-size for scientific calculations on the additionally favoured IBM's VM/HPO operating system was only 28 bit for floating-point variables ...

LEP Control Room at the Prevessin site in 1989 [CERN]

However, in the IT (officially called DD: Data Department) backyards of CERN the revolution took place: The first Apple's where introduced, DEC came up with their VAX (and the Virtual Memory System VMS) while their PDP computers were largely used for data acquisition. I followed a presentation of the first commercial Unix stations: Sun's Sparcstation 1. Not to forget about Tim Berners-Lee, inventing the Web, while the physicist's community at CERN was still using IBM's Script instead of Donalds Knuth's TEX ...

In order to use these resources efficiently, it needed some genius. The analysis package HBOOK was invented by René Brun and Julius Zoll (who passed by in 2003) brought out the famous Hydra and Patchy package (and later Zebra). Not to forget about the supporting IT team indispensable for every operation, namely Hans Klein and Luc Pape.

Michael Goossens was introduced by Julius Zoll to us in order to study a function based memory manager (for Zebra) and was provissionally placed in Julius' small cubical in the TC batiment. While Michael's memory manager was never realized because of intrinsic performance problems, he became active supporter of TeX.


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