David Leith Symposium: - PowerPoint Presentation

Slide1

David Leith Symposium: Early Years

From Scintillators to Bubble Chambers to Wire Chambers

Michel DavierLAL, Université Paris-Sud, Orsay

Michel Davier Dec.12 2014

David Leith Symposium, SLAC

1Slide2

Michel Davier Dec.12 2014David Leith Symposium, SLAC

2Caveat: t

hrough his long and productive career David worked with a very large number of collaborators (as demonstrated by the impressive list of participants at this symposium). Through this short report I will be able to mention only a few. My apologies! Slide3

The Glasgow University Cricket Team

From

Hutchesons Grammar School to Glasgow University (1959)

Michel Davier Dec.12 2014

David Leith Symposium, SLAC

3

i

n the 50’sSlide4

Graduate in the Department of Natural Philosophy at Glasgow University

Michel Davier Dec.12 2014

David Leith Symposium, SLAC4

Experiment on 

 photoproduction

on protons near

t

hreshold on the 330 MeV electron synchrotron with

a scintillator telescope

4 papers published

Thesis adviser:

Gething

Lewis

1962Slide5

Postdoc at CERN (1962-1966)

Michel Davier Dec.12 2014David Leith Symposium, SLAC5

Joined Max Ferro-Luzzi group: a good practice in scientific rigorFirst encounter with bubble chambers

Studies of K±p interactions: start of a long-standing interest of David

Productive period with 12 papers and many conference proceedings

Remarkable results on hyperon spectroscopy (early demonstrations

of SU(3) and the quark model)

First review paper with Bob Tripp, Adolf

Minten

, …

1964Slide6

David joins SLAC: physics with bubble chambers

Michel Davier Dec.12 2014David Leith Symposium, SLAC6

A young Associate ProfessorJoins Joe Ballam’s group BDavid gets involved in on-going activities…

- analysis of data taken at BNL (16 GeV

-p interactions)

- shake-down of monochromatic photon beam at SLAC

for further use with the 40” bubble chamber

b

ut soon wants to have his own line of research

 s

tarts a collaboration with Alvarez’s group at LBL

(Art Rosenfeld)

Exposures at Argonne with

pions

to improve situation

of

N phase shifts and baryon resonance spectroscopy

(hot topic then)

Very elaborate analysis developed (K matrix) with Paul

Söding

and Roger

Cashmore

First David’s student was on this work (Barbara Levi)

Very successful program with 8 papers published

1966Slide7

A KL Experiment with the SLAC 40”HBC

Michel Davier Dec.12 2014David Leith Symposium, SLAC

7David also pushed an original program with the 40” bubble chamber to study KL

interactions, with Wes Smart, Bill Johnson,…

Innovative scintillator system for TOFleading to 7 publicationsSlide8

From Bubble Chambers to Wire Chambers

Michel Davier Dec.12 2014David Leith Symposium, SLAC8

Bubble chambers are detectors with full solid angle coverage and good spatial precision but slowEvent samples with high statistics, triggered in order to access specific processes with

high sensitivity required fast electronic devices such as wire chambers

David got involved very early with such detectors, following experience gained at LBL in Perez-Mendez group

Spark chambers with

magnetostrictive

read-out were chosen

(the famous wands, magic…)

Important contributors were

Fatin

Bulos

, Harvey Lynch, and Steve WilliamsSlide9

Wire Chamber Spectrometer #1

Michel Davier Dec.12 2014David Leith Symposium, SLAC9

First experiment was on  photoproduction on nuclei with Burt Richter and Victor Perez-Mendez with his student Steve Williams

A dependence determines the N total cross section

A good warmup with spark chambersSlide10

Wire Chamber Spectrometer #2

Michel Davier Dec.12 2014David Leith Symposium, SLAC10

This second experiment was on  production by pions with Burt Richter triggered by a sharp forward peak observed in 

photoproduction.

Blair Ratcliff and Brig Williams were students on this experiment

S

ame sharp forward peak is observed in the right

helicity

combinationSlide11

Toward High Statistics Hadron Physics with Wire Chamber Spectrometers

Michel Davier Dec.12 2014David Leith Symposium, SLAC11

The  photoproduction and  experiments were a good starting point to plan for future activities

It was also a good training ground for students and postdocs

David immediately realized the power of wire chambers spectrometers to pursue more effectively his interest in hadron spectroscopy and dynamics

Very low SLAC duty cycle was a priori not favorable compared to hadron machines

But David took up the challenge!

He initiated studies for a wide-aperture apparatus

While his vision of a very large spectrometer had still to wait for a while,

a new version with a reduced scope was an important step capable

of providing unique results

Thus a new two-prong experimental program started led

by two newly appointed assistant professors in David’s group

E-75: spectroscopy with K

±

beams (Bob Carnegie)

E-85:

K

±

p

elastic scattering (MD) Slide12

The E-75/85 spectrometer #3

Michel Davier Dec.12 2014David Leith Symposium, SLAC12

13 GeV RF-separated K beam and beam instrumentation

Large aperture magnet 1.8 T

13 magnetostrictive chambers

Proportional chambers

Large segmented Cerenkov counterSlide13

E-75 : K± interactions at 13 GeV

Michel Davier Dec.12 2014David Leith Symposium, SLAC

13

A rich program of strange meson spectroscopy

Discovery of two 1

+

states: K

1

(1270)

K, K

2

(1400)K*

through PWA

Deck

K

1

K

1

K

2

K

2

Deck

Evidence for a 0



state at 1400 MeV (?)

Dynamics of 2-body processesSlide14

E-85 : K±/

±/p± p elastic scatteringMichel Davier Dec.12 2014

David Leith Symposium, SLAC14

Obtain the C=-1 scattering amplitude by interference with the dominant C=+1 diffractive amplitude

measure particle and antiparticle cross sections on

protons with large statistics and small systematics

D

ual absorptive model

:

cross over moves to

smaller t at higher energies

1mm spacing MWPCSlide15

New ideas and detector construction

Michel Davier Dec.12 2014David Leith Symposium, SLAC15

During this period David was constantly thinking of new ideas for developing the best detectors and equipment to achieve the physics goalsThe list of the projects he has initiated, pushed through and published is impressive:

- wedge scintillator with high spatial precision - online

Vidicon scanning system for bubble chambers - large aperture Cerenkov

hodoscope

- new digitizing and memory system for wire spark chambers

- versatile high resolution beam position monitor

- TOF trigger system for the 40” HBC

- adaptable geometry low mass

hodoscopes

using cathode readout PC

A good technical team to realize the projects: Al

Kilert

, Bob Friday, Don

McShirley

,

Ken Mauro, Bill Walsh…Slide16

Moving on to LASS (some personal memories)

Michel Davier Dec.12 2014David Leith Symposium, SLAC16

LASS concept and physics studies started even before 1970 (with George Luste)The story of the LASS adventure will be told by Bill Dunwoodie

I had the chance to participate in lively meetings in David’s office (with tables

somewhat crowded by preprints) in the technical design phase

I was impressed by David’s strong leadership, yet in a friendly atmosphere,

and his concerns over many detailed aspects (ex. discussion with John Alcorn

about safety issues in case of a quench of the large solenoid: Boeing 747)

Another occasion I still vividly remember is a (AEC, ERDA?) review in Fall 1974

where David presented the status of the project and I was given the task to

justify our interest in hadron spectroscopy. I used the quark model as an obvious

framework, but was challenged by the reviewers on the basis that the SPEAR

results had already disproved the model. Then came November 1974…Slide17

Friendships

Michel Davier Dec.12 2014David Leith Symposium, SLAC17

David created a unique friendly atmosphere in group BSo many activities going on in parallelA multinational group

David’s efficient leadership, yet leaving freedom to his

collaborators, thus fostering their creativity

Frequent occasions to meet outside the lab

- Tuesday night seminars at David’s home

- Friday night beer at the Dutch Goose

David and Doreen legendary hospitality (also unique)

Ah, Doreen’s unforgettable Xmas

S

cottish shortbread….

The famous New Year party in their house….

Slide18

Personal Friendship

Michel Davier Dec.12 2014David Leith Symposium, SLAC18

Our two families have enjoyed a good friendship for 45 yearsShared memories: citing David on another occasion

One of Doreen’s fondest memories, before her own grand-children

arrived, was daily brushing the beautiful long hair of Eve and Diane,

when their Mum and Dad had gone back to France on the death of

Francoise’s father.

My daughters Diane and Eve still remember as well

We value very much the

Leith

friendship

~ 1969

1974Slide19

Michel Davier Dec.12 2014David Leith Symposium, SLAC

19Thank you David for sharing

this very productive part of your scientific life

1984

2010

Thanks to Ewan and

Mandi

Patterson (and Doreen!), Harvey Lynch, and Jean

Deken

for some nice pictures!