1. Saxon Fest:A Celebration Beams and Bubble Chambers The World of Baryon Physics R.J.Cashmore Brasenose College and Dept of Physics Oxford 30-May-08DHS_Glasgow1

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 30-May-08DHS_Glasgow2

3. Manchester Grammar School u Very able and conscientious u No games player,secretary of Philosophical Society,trombonist u Apart from a scholar.. Very sound commoner u Paid 30 shillings to enter and ……. u Awarded a Brackenbury Open Scholarship 30-May-08DHS_Glasgow3

4. Balliol College u Took Prelims in March 63 … cost 5 pounds u Thereby avoiding exams for 3 years u Jenkyns Prize 1965 u Scott Prize 1966 u Travelling Scholarship to NERC Canada Where he was ‘most impressed by the vastness’,studied laser interferometry,and found ‘the Canadians most friendly’ 30-May-08DHS_Glasgow4

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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 30-May-08DHS_Glasgow6

7. Why the Topic ? u Kirz anomaly ….. pi pi mass bump that changed with incident beam energy (In fact Norman Booth had also been implicated in this debate) u Was it an I=J=0 pipi resonance? An S wave resonance? u Was it due to a baryon resonance? A P11 nucleon resonance? 30-May-08DHS_Glasgow7

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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) 30-May-08DHS_Glasgow9

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12. Computers u PDP 8 to record all the measurements and produce mountains of paper tape u KDF 9 to read the tapes and reconstruct and kinematically fit the reactions 30-May-08DHS_Glasgow12

13. Graduate Students Activities u Designed and tuned the beams u Scanned and measured the film u Processed all the results u Developed New Analyses u Wrote the paper All chasing the energy dependence of phase of the pipi s-wave interaction 30-May-08DHS_Glasgow13

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 30-May-08DHS_Glasgow14

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

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

17. 30-May-08DHS_Glasgow17 + u 2/3 d -1/3 s -1/3 The u,d and s quarks

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

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

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 30-May-08DHS_Glasgow20

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22. OXFORD at that TIME 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) 30-May-08DHS_Glasgow22

23. 30-May-08DHS_Glasgow23 The Particles of the Standard Model ()  e ~0.0 MeV 0 e 0.5 MeV -1 e e ()   ~0.0 MeV 0 e 0.1 GeV -1 e  ()   ~0.0 MeV 0 e 1.8 GeV -1 e  () 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 Leptons Quarks

24. In Conclusion It has been great having you and Margaret as friends It has been great working with you over these many years 30-May-08DHS_Glasgow24

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