Quarks and Leptons as Fundamental Particles

716 Pages·1979·17.208 MB·English

by  H. Mitter (auth.), Paul Urban (eds.)

N
W
Fig. 72. PLUTO: (preliminary) invariant mass distribution ~
of the hadronic system for single-tag two-photon
events.
Acta Physica Austriaca
Supplementum XXI
Proceedings of the
XVIII. Internationale Universitatswochen fur Kerophysik 1979
der Karl-Franzens-Universitat Graz
at Schladming (Steiermark, Austria)
28th February-10th March 1979
Sponsored by
Bundesministerium fijr Wissensdlaft und ForsdlUng
Steiermarkische Landesregierung
CERN (European Organization for Nuclear Research)
ICTP (International Centre for Theoretical "Physics)
Sektion Industrie der Kammer der
Gewerblichen Wirtsdlaft fijr Steiermark
1979
Springer-Verlag
Wien New York
Quarks and Leptons
as Fundamental Particles
Edited by Paul Urban, Graz
With 184 Figures
1979
Springer-Verlag
Wien New York
Organizing Committee
Chairman
Prof. Dr. H. Mitter
Ordinarius am Institut fur Theoretische Physik
der Universitat Graz
Committee Members
Dr. L. Mathelitsm
Dr. W. Plessas
Dr. H. Zankel
Secretary
M. Krautilik
This worJt is subject to copyright.
All rights are reserved, whether the whole or part of the material is concerned,
specifically those of translation, reprinting, re-use of illustrations, broadcasting,
reproduction by photocopying machine or similar means, and storage in data banks.
© 1979 by Springer-VerlaglWien
Softcover reprint of the hardcover 1 st edition 1979
Library of Congress Cataloging in Publication Data. Intemationale Universitlitswocnen fur
Kemphysik der Karl-Franzens-Universitlit Graz, 18th, Scnladming, Austria, 1979. Quarks and
leptons as fundamental particles. (Acta physica Austriaca : Supplementum ; 21.) "Proceedings of the
XVIII. Intemationale Universitlitswocnen fur Kernphysik 1979 der Karl-Franzens-Universitlit Graz
at Scnladming (Steiermark, Austria), 28th February-10th Marcn 1979; sponsored by
Bundesministerium fUr Wissenscnafl: undForscnung ••• ret a1.]." 1. Quarks-Congresses. 2. Leptons
(Nuclear physics)-Congresses. I. Urban, Paul Oskar, 1905-. II. Austria. Bundesministerium fur
Wissenscnafl: und Forscnung. III. Title. IV. Series. QC793.5.Q2522I57. 1979.539.7'211.79-23328
ISSN 0065-1559
ISBN-13:978-3-7091-8576-6 e-ISBN-13:978-3-7091-8574-2
DOl: 10.1007/978-3-7091-8574-2
CONTENTS
MITTER, H., Opening Address.......................... 1
MORPURGO, G., Lectures on Quarks..................... 5
FLUGGE, G., Recent Experiments at DESY .......•.•••.•• 81
KRAMMER, M. and KRASEMANN, H., Quarkonia ...........•• 259
CHAN HONG-MO, ~·1anifestations of Colour in
Hadron Spectroscopy ....•.....•...••..•.....•• 351
JOOS, H., Introduction to Quark Confinement
in QCD....................................... 407
PASCHOS, E.A., Some Current Issues in
Gauge Theories ....•.••.•••..........•.•...•.• 485
GENZ, H., Strong and Electromagnetic Decays
of the New Particles .........•......•...•..•• 559
ELLIS, J., Grand Unified Theories •••.•.........•..••• 619
VAN HOVE, L., The Quark Recombination Mechanism
in Multi-Hadron Production •.................. 621
KAJANTIE, K., Tests of QCD in Two-Photon
Processes in Very High Energy
+ -
e e Collisions.............................. 663
PIETSCHMANN, H., Summary............................. 709
Acta Physica Austriaca, Suppl. XXI, 1--4 (1979)
© by Springer-Verlag 1979
OPENING ADDRESS
by
H. MITTER
Institut fUr Theoretische Physik
Universitat Graz
This year's subject is "Quarks and Leptons as
Fundamental Particles". You are all familiar with the
enthusiasm, with which theorists working in high-energy
physics follow the recent development in unifying the
world of particles and their interactions. So it was
probably no surprise to you that we have chosen this
title for our school. Since I personally have become
more sceptical against enthusiasm with increasing age
(one could also say, the burnt child abhors the fire) ,
I had even liked to put a question mark at the end of
the title: then, however, the majority of the theorists
would probably have disagreed. Enthusiasm is human, may
be some amount of it is even necessary for any progress.
So let us be enthusiastic until our friends in the ex
perimental department get us down to earth again. In the
past they did that, at least. In the last two years they
seem to work in the opposite direction. Perhaps it is
worthwile to remember, how the whole development started.
At the beginning there was probably the PEN club: of
Acta Physica Austriaca, Suppl. XXI
2
course, not the wellknown group of more or less well
known poets, but a more silent, almost secret group of
physicists, who believed, that three sPin-~ fields
(~roton, ~lectron, ~eutrino) should suffice for a
description of weak and electromagnetic interactions.
The bosonic glue fields could always be imagined as a
kind of "bound-state field". During the further
development these ideas took concrete form (through
the Salam-Weinberg model, for instance) the gauge
approach showed to be essential, generalizations were
found (the number of constituents was increased), new
leptons were discovered in due course. At the same time
the idea of quarks as fundamental constituents of the
hadronic world has gained ground slowly but steadily.
The colour degree of freedom was added, QeD came up
and opened the way to further unification, in which we
consider now quarks and leptons as building blocks. Of
course, we have now to live with at least 12 (maybe
with 18) quarks and a considerable number of leptons:
in order to give a name to our club we would need a
good part of the whole alphabet and it seems really
worth-while to look,how good the basis for our enthusiasm
is and where we stand.
In order to do this, we have tried to select a
number of subjects, which should give an account both
of the speculative and the phenomenological side of
the recent development. We were lucky to find a con
siderable number of excellent and expert speakers so
that the presentation will be a balanced one. The only
slight disbalance, which I can see, is that quarks will
appear in the lectures perhaps more frequently than
leptons. Since most of the latter objects are with us
3
for a long time, it seems, however, not quite un
justified to devote less attention to old friends and
more to foreigners, to these elusive quarks, which we
first were all anxious to see, whereas now many of us
would be happy if they were not found at all. (An
Austrian expression on confined quarks would be: Sachen
gibts, die gibts gar nicht = things exist which don't
even exist!) Two or three years ago it was just to say
that weak and electromagnetic interactions are "ahead"
of the strong ones as far as basic understanding is
concerned. Meanwhile the situation has started to change.
By the end of our school we shall see, how this race
stands now.
As always we have also included lectures on
experimental results in our field, in order to keep
track of the solid ground of all speculations. This
time we shall be confronted with the most recent
results obtained in Hamburg with the new storage
rings. If our experimental friends have worked as
hard as usual, these will be very interesting results.
A number of seminars will complete the program.
They will give some of the participants the possibility
to discuss their recent results and ideas with their
colleagues. A new achievement, which we tryout for the
first time this year, are the Stammtische, where our
speakers and other interested people may meet in the
evening in order to discuss special problems inside
(and outside) physics.
This is all what I want to say about the program.
You have already started to tryout your ability in
4
solving problems of classical mechanics, I mean motion
with more or less friction on curved trajectories in a
gravitational field, and I want to encourage you to
continue, even if you have the impression that the
Planai has to be treated as a statistical ensemble.
All the organizers of the school wish you a pleasant
stay here in Schladming. We hope that you enjoy both
the school and the environment.
Acta Physica Austriaca, Suppl. XXI, 5-80 (1979)
by Springer-Verlag 1979
@
+
LECTURES ON QUARKS
by
G. MORPURGO
Istituto di Fisica de11'Universita di Genova
Istituto Naziona1e di Fisica Nuc1eare,
Sezione di Genova
Via1e Benedetto XV, 1-16132 Genova
CONTENTS
LECTURE I: SOME RECENT RESULTS OF THE STATIC QUARK
MODEL
1. INTRODUCTION
2. THE MAGNETIC MOMENTS OF THE BARYONS AND THE
V-+Py TRANSITIONS
3. THE MAGNETIC MOMENTS AND THE MASSES OF THE
CONSTITUENT QUARKS
4. THE CHROMOSTATIC POTENTIAL AND THE DETER
MINATION OF rnn/rnA FROM THE E - A MASS
DIFFERENCE
+
Lect)lres given at the
XVIII. Internationa1e Universitatswochen fur Kern
physik, Sch1adrning, Austria, February 28 - March 10,1979.