Saxon Fest:A Celebration

1. Saxon Fest:A Celebration Beams and Bubble Chambers The World of Baryon Physics R.J.Cashmore Brasenose College and Dept of Physics Oxford DHS_Glasgow

2. A Brief CV Born 27 Oct 1945 Education Manchester Grammar School 1956 - 63 Balliol College Oxford 1963 - 68 Employment JRF Jesus College 1968 - 70 RA Columbia University 1970 - 73 SO,PSO RAL 1973 - 90 Kelvin Prof at Glasgow Univ. 1990 - 2008 Honours FRSE 1993 FRAS 2005 OBE 2005 DHS_Glasgow

3. Manchester Grammar School • Very able and conscientious • No games player,secretary of Philosophical Society,trombonist • Apart from a scholar .. Very sound commoner • Paid 30 shillings to enter and ……. • Awarded a Brackenbury Open Scholarship DHS_Glasgow

4. Balliol College • Took Prelims in March 63 … cost 5 pounds • Thereby avoiding exams for 3 years • Jenkyns Prize 1965 • Scott Prize 1966 • Travelling Scholarship to NERC Canada Where he was ‘most impressed by the vastness’,studied laser interferometry,and found ‘the Canadians most friendly’ DHS_Glasgow

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6. Research Thesis Oct 1969 ‘A Study of Elementary Particle Interactions using the Bubble Chamber Technique’ Pi- Proton -> Pi Pi Nucleon at 456/505/552 Mev/c Thesis Adviser John Mulvey ( & Willie Chinowsky) Acknowledges DHW for pleasure of working in NPL Balliol for occasional support and Scanning Girls for their support DHS_Glasgow

7. Why the Topic ? • Kirz anomaly ….. pi pi mass bump that changed with incident beam energy (In fact Norman Booth had also been implicated in this debate) • Was it an I=J=0 pipi resonance? An S wave resonance? • Was it due to a baryon resonance? A P11 nucleon resonance? DHS_Glasgow

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9. The BUBBLE CHAMBER and the BEAMS Beams 456/505/552 MeV/c 400/590/660/740 MeV/c Needed clever design to get rid of electrons Saclay 80cms hydrogen chamber used at RAL (NIMROD) and SACLAY (SATURNE) DHS_Glasgow

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12. Computers • PDP 8 to record all the measurements and produce mountains of paper tape • KDF 9 to read the tapes and reconstruct and kinematically fit the reactions DHS_Glasgow

13. Graduate Students Activities • Designed and tuned the beams • Scanned and measured the film • Processed all the results • Developed New Analyses • Wrote the paper All chasing the energy dependence of phase of the pipi s-wave interaction DHS_Glasgow

14. Baryon Resonances Only the ground state multiplets and a few beyond were known In fact piN,pipiN final states were to pave the way for the spectrum we now know SU(3) and SU(6) structures existed Baryons qqq and Mesons q-anti q DHS_Glasgow

15. p n 0 - + 0 - 0 The Baryon Octet +

16. The Baryon Decuplet - + 0 ++ - + 0 + - 0 -

17. The u,d and s quarks u 2/3 d -1/3 + s -1/3 DHS_Glasgow

18. p n 0 - + 0 - 0 u,d,s quark structures udd uud + dds uus uds dss uss

19. u,d,s quark structures - + 0 ++ uuu ddd uud udd - + 0 uss uus uds + - 0 uss dss - sss

20. Baryon Resonances Only the ground state multiplets and a few beyond were known In fact piN,pipiN final states were to pave the way for the spectrum we now know SU(3) and SU(6) structures existed Baryons qqq and Mesons q-anti q DHS_Glasgow

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22. OXFORD at that TIME Dick Dalitz ,the father of ‘real’ quarks, was the ‘great man’ The language was quarks and no one else in the world believed in them until DIS(1969) and PSI’s(1974) DHS_Glasgow

23. The Particles of the Standard Model ( ) ( ) ( ) e ~0.0 MeV0 e 0.5 MeV-1 e e  ~0.0 MeV0 e 0.1 GeV-1 e   ~0.0 MeV0 e 1.8 GeV -1 e  Leptons ( ) ( ) ( ) uuu 5.0 MeV+2/3 e 10.5 MeV-1/3 e ddd ccc 1.3 GeV+2/3 e 0.2 GeV-1/3 e sss ttt 0.175 TeV+2/3 e 4.3 GeV-1/3 e bbb Quarks DHS_Glasgow

24. In Conclusion It has been great having you and Margaret as friends It has been great working with you over these many years DHS_Glasgow

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