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We summarize the situation regarding non-polynomial Lagrangians: I
should make the qualification that an enor mous amount of
verification is needed before the problems of renormalizability are
all sorted out, but one may ten tatively state: 1) All matrix
elements are finite for theories where the Dyson index D is less
than two. 2) For the cases when D=2 or 3, counter-terms have been
explicitly written which absorb all infinities and the theories are
renormalizable. 3) Mixed theories of polynomial and non-polynomial
fields appear to be renormalizable provided the Dyson in dices
separately and jointly fulfill renormalizability criteria. We
believe that weak interactions, chiral La grangians and Yang-Mills
theory fall into this class though detailed proofs have not yet
been constructed. 4) It seems likely that to each order in the
major coupling (and to all orders in the minor coupling}the S
matrix elements, as computed by methods outlined, satisfy the
necessary unitarity and analyticity requirements."
Soluble quantum field theory models are a rare commodity. An
infinite number of degrees of freedom and noncompact invariance
groups have a nasty habit of ex ploding in the model-makers' face.
Nevertheless, impor tant progress has recently been made in the
class of superrenormalizable relativistic theories, such as a
self-interacting boson in a two-dimensional space time [ 1]. These
results have been obtained starting with the free field and adding
the interaction in a carefully controlled way. Yet, the models
successfully studied in this way do DQ~ have an infinite field
strength renormalization, which, at least according to perturbation
theory, should appear for realistic relativistic models in
four-dimensional space time. ~2~!Y~~!9n_~g_~h~_~gg~1 The ultralocal
scalar field theories discussed in these lecture notes are likewise
motivated by relativistic theories but are based on a different
approximatiGn. This approximation formally amounts to dropping the
spatial gradient term from the Hamiltonian rather than the non
linear interaction. For a self-interacting boson field in a
space-time of (s+l) dimensions (s~l), the classical ultralocal
model Hamiltonian reads (1-1) The quantum theory of this model is
the subject of the present paper. This model differs formally from
a rela tivistic theory by the term f![Z~Cl(~)]2 d~ which, it is
hoped, can, in one or another way, be added as a pertur 229 bation
in the quantum theory. However, that still remains a problem for
the future, and we confine our remarks to . . a careful study of
the "unperturbed" model (1-1).
The equations of quantum mechanics, let alone those of quantum
field theory, are sufficiently complex to solve that various
approximation schemes are both welcome and desirable. In
applications to quantum field theory, renorm alized perturbation
theory has long been the predominant calculational tool, and it has
even tended to shape the entire conceptual outlook on such problems
as well. How ever, the apparently irreconcilable conflict between
strong interaction physics and perturbation theoretic calculations
has given way in the past few years to some fairly revolut ionary
(at least for field theory) modes of formulation and calculation.
The fires of this revolution have been fed by exact solutions of
special classical systems, [1] notably the sine-Gordon equation,
and an appreciation of the relevance of classical solutions of
nonlinear systems as starting points in quantum analyses [2]. The
soliton solutions of the classical sine-Gordon equation exhibit
extraordinary stability under scattering, but this feature is not
essential for their utility in quantum studies. Consequently, broad
studies have been made of nonlinear systems that exhibit localized,
persistent solutions, which have also frequently been termed
"solitons" (or solitary waves, or kinks) as well [31. Solitons that
have their origin in con ventional symmetries and conserved
currents (and thus are ~topological in origin) have been discussed
[4] along with those that arise from asymptotic properties of the
solution, as in the sine-Gordon model, (and thus are topo logical
in origin).
These lectures represent a condensation of a number of colloquia,
seminars and discussions held at the Institute of Theoretical
Physics of the University of Graz during the last years and
epitomize the principal lines of research undertaken by my group.
From the very beginning of my appointment at the University of Graz
in 1947 I have been concerned with the task of bringing up a
relatively small group of scientifically interested and open-minded
co-workers and of stimulating them to sound scientific research.
Since 1930 I myself have dealt with subjects of the kind treated in
these lectures, to which I was introduced by my late friend and
teacher TH. SEXL. But also as assistant and co-worker of E. FUES
and R. THIRRING I frequently worked on these problems, constantly
using new methods and lines of approach. During the last years of
the war and the first ones afterwards Ihad the fortunate
opportunity to receive many stimulating ideas and comments on my
work from A. SOMMERFELD on the occasion of my frequent visits to
Munich. Especially this last period, although partially connected
with personal difficulties and troubles of many kinds stemming from
the turbulence of lost-war readjustments, I consider to be one of
the most valuable times in my life.
These lectures concern the properties of topological charge in
gauge theories and the physical effects which have been attributed
to its existence. No introduction to this subject would be adequate
without a discussion of the original work of Belavin, Polyakov,
Schwarz, and Tyupkin [1], of the beautiful calculation by 't Hooft
[2,3], and of the occurrence of 8-vacua [4-6]. Other important
topics include recent progress on solutions of the Yang-Mills
equation of motion [7,8], and the problem of parity and
time-reversal invariance in strong interactions [9] (axions
[10,11], etc. ). In a few places, I have strayed from the
conventional line and in one important case, disagreed with it. The
im- portant remark concerns the connection between chirality and
topological charge first pointed out by 't Hooft [2]: in the
literature, the rule is repeatedly quoted with the wrong sign! If
QS is the generator for Abelian chiral transformations of massless
quarks with N flavours, the correct form of the rule is ssQs = - 2N
{topological charge} (1. 1) where ssQS means the out eigenvalue of
QS minus the in eigenvalue. The sign can be checked by consulting
the standard WKB calculation [2,3], rotating to Minkowski space,
and observing that the sum of right-handed chiralities of operators
in a Green's function equals -ssQS. The wrong sign is an automatie
consequence of a standard but incorrect derivation in which the
axial charge is misidentified.
The main task of an experimental talk at a theoreticians school
should probably be a tempering one. In this respect, e+e- physics
may have been a bad choice. The field has so rapidly developed and
dis coveries are chasing each other that much of the optimism of
theory has passed over to e+e- experimentalists. A vast amount of
experimental material arose from the simple reaction of e+e-
annihilation. I, therefore, have to limit myself to recent results
- most of them less than one year old. The paper will be organized
as follows: In the first lecture (chapter I and II) I will give - a
short introduction to e e machines and cross sections. In
particular I will discuss the total cross section an- after a short
summary on charm - concentrate on the third generation of auarks
and leptons: the heavy lepton T and the T family. In my second
lecture the various aspects of event topologies in the DORIS energy
range will be discussed, including the T decay. In the third
lecture I will then describe the new storage ring PETRA and present
first results on QED checks, total cross section, jet structure,
and two-photon processes."
On the occasion of the 50th anniversary of the discovery of the
Schrodinger equation a small symposium was organized in Vienna. It
had mainly retrospective character, where after an appreciation of
Schrodinger's scientific achievements the results were collected
which one could extract from his equation. Of course not all the
developments which originated in Schrodingers dis coveries could be
included. Instead, it was attempted to present a review of the
established predictions which follow directly from his equation.
Despite the 50 years of its existence there are always new results
of this sort being found, especially because the necessary mathe
matical methods are being developed and become known to the
physicists slowly only now .. I want to take the opportunity here
to thank the lecturers for their efforts which they put into their
excellent talks and their written versions. With their help this
volume should become a useful document on the current mathematical
art in the treatment of the Schrodinger equation. Finally it is my
pleasant obligation to thank the Bundesministerium fUr Wissenschaft
und Forschung and the Kulturamt der Gemeinde Wien for their
financial support which made it possible to honor one of the great
Austrian scientists."
The subject of this year's conference, as of the six previous
meetings, was again elementary particle physics. One of the main
topics of current interest here is the understanding of strong
interactions; some of the attempts to explain them are discuBBed at
length in these proceedings, including current algebra, Regge pole
theory and effective Lagrangians. On the other hand, the proceBses
of weak interactions, too, are not yet fully understood, especially
when strong interactions intervene, as in the radiative corrections
to weak decays. Several other aspects of elementary particle
physics are also treated in this volume, every one of them another
step towards a thorough understanding of the sub. atomic world. I
want to take this opportunity to thank all the members of my staff
for their assistance in organizing the meeting and for their help
in preparing the manuscripts. Graz, June 1968 P. Urban Contents
Urban, P. Introduction
................................................. V Nilsson, J.
Discrete Symmetries in Elementary Particle Physics ............ 1
Pietschmann, H. Semi-Leptonic Weak Decay Processes ....
............... 88 Dothan, Y. Introduction to Recent Developments
in Regge Pole Theory .... 126 Koller, K. On Feynman Diagrams wi h
Infinite Dimensional Representations of the Lorentz Group 0 (3,1)
......................................... 161 Giirsey, F. Effective
Lagrangians in Particle Physics. . . . . . . . . . . . . . . .. . .
185 . . . ."
The past meetings held under the auspices of the Austrian Ministry
of Education and the successes and benefits derived from these
lectures in former years have encouraged us to continue this year
with a survey of high energy physics. The experimental side of this
field has undergone such a great advancement that the evaluation of
huge masses of data called for the theoretical physicist to develop
new theories and to explain facts and connections which we have not
been able to clarify up to the present. In spite of the precarious
situation especially in the field of Elementary Particle Theories,
the theoretical physicist is about to summarize the present
situation and to give further impulses for thc progress of our
knowledge in nuclear physics. Thus the results of the Sixth
International Meeting in Schladming and the interest shown in it
fully justify our endeavours in this direction. In organizing the
publication of the proceedings we shall continue on the same lines
as hitherto so as to reduce delays through editing to an absolute
minimum and to offer the publication at a reasonable price. I am
again grateful for the assistance of the Springer-Verlag whose
photo mechanical method proved so successful. Nevertheless we wish
to apologize for any mistakes that might have occurred in writing
the text of formulae."
The great success of the experimental research on elementary
particles and their qualities during the last years suggests giving
a summary of the present situation also in the theoretical
description of this important branch of physics. In spite of the
precarious situation in this field of theoretical physics I believe
I can fully account for this choice and must see that the number of
participants and the general interest justify my opinion. In
organizing the proceedings it was our prime concern to reduce the
delay in editing and also keep down the price. This was possihle
only through the assistance of the Springer-Verlag who chose
photomechanical method working quicker and cheaper. Therefore we
apologize for any mistakes and errors that may occur in the text
and formulae. I am very indebted to my secretary, Miss A.
SCHMALDIENST and one of my assistants, Dr. H. KUHNELT, who did an
the typing and correcting of the manu scripts with great patience
and knowledge."
Whereas then' has been significant progress in various branches of
elementary particle physics during the last decade or so, Quantum
Electrodynamics seems to be in a somewhat stagnating phase. For
people not involved in sophisticated questions of relativistic
field theories the situation might appear as not very di(: ltinct
from the time, when Schwinger, Feynman and Dyson publishl'ld their
famous articles in the early 1950's. Only some arguments against
the possibility of a finite Quantum Electrodynamics (1953) has
caused a significant reaction and initiated a rather vehement
discussion. In connection with these questions about the
consistency of Quantum Electrodynamics there arises the problem of
the high energy behaviour of the theory, since higher and higher
energies will be available in future experiments. For these reasons
I thought it quite useful to choose Quantum Electrodynamics at high
energies as subject of this year's meetings and hope to meet the
demands of both experimental and theoretical physi cists working in
this field. Graz, October, 1965."
Weak interactions and higher symmetries are nowadays of special
importance for elementary particles theory. Lately both theoretical
and experimental physicists became more and more interested in the
subject. Because of the complicated subject and the scarce
available literature proper introductions in the subject are
tiresome. The mathematical back ground such as higher Algebra and
Grouptheory etc. cannot be applied immediately in all cases. The
third Schladming University Courses on the above subject belong to
this category. The present first supplement volume of "Acta Physica
Austriaca" contains all lectures (with literature references)
giving not only a review of the fundamentals but also discussing
recent research work. I; incerely hope that the pUblication will
find interested readers. In the last years it became customary in
physics and mathematics to arrange summer schools on subjects which
allow the experienced as well as the young scientiflt to get
quickly acquainted with special modern fields. Discussions and
private contacts make it possible for participants to touch quickly
the peripheries of the subject in question, and new research work
will be stimulated which otherwise could not be expected. Graz,
October, 1964."
The observation of the scaling properties of the structure
functions w and vw of deep inelastic electron 1 2 nucleon
scattering [1]+ has been taken by many people as an indication for
an approximate scale invariance of the world. It was pointed out by
Wilson [2], that in many field theories it is possible to assign a
dimension d to every fundamental field, which proves to be a
conserved quantum number as far as the most singular term of an
operator product expansion at small distances ((x-y) +a) is con- JJ
cerned++. Later it was shown, at the canonical level, that in many
field theories the dimension of a field seems to be a c:pod quantum
number even in the terms less singular at small (x-y) , as long as
they all belong to the strongest \l light cone singularity (i. e.
(x-y)2+a) [3]. The assumption that this type of scale invariance on
the light cone be present in the operator product ex pansion of two
electromagnetic currents has provided us with a rather natural
explanation of the observed scaling phenomena. We should like to
mention, however, that this ex planation cannot account for the
precocity with which scaling is being observed experimentally in
energy regions, in which resonances still provide prominent
contributions to the final states [4].
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