Third Workshop on Grand Unification: University of North Carolina, Chapel Hill April 15–17, 1982

378 Pages·1982·6.79 MB·English

by  S. L. Glashow (auth.)

Progress in Physics
No.6
Edited by
A. Jaffe and
D. RueUe
Springer Science+Business Media, LLC
Third Workshop
on Grand Unification
University of North Carolina,
Chapel Hill
April15 -17, 1982
Paul H. Frampton,
Sheldon L. Glashow, and
Hendrik van Dam, editors
1982 Springer Science+Business Media, LLC
Editors:
Paul H. Frampton and Hendrik van Dam
Institute of Field Physics
Department of Physics and Astronomy
University of North Carolina
Chapel Hill, NC 27514
Sheldon L. Glashow
Lyman Laboratory of Physics
Harvard University
Cambridge, MA 02138
Library of Congress Cataloging in Publication Data
Workshop of Grand Unification (3rd : 1982 :
University of North Carolina, Chapel Hill)
Third Workahop on Grand Unification, University of
North Carolina, Chapel Hill, April 15-17, 1982.
(progress in physics ; no. 6)
1. Grand unified theories (Nuclear physics)-
Congresses. 1. Frampton, Paul H. II. Van Dam, H.
III. Glashow, Sheldon L. IV. Title. V. Series:
Progress in physics (Boston, Mass.) ; v. 6.
QCT94.6.G7W67 1982 539.7'54 82-17717
CIP - Kurztitelaufnahme der Deutschen Bibliothek
Workshop on Grand Unification:
... Workshop on Grand Unification. - Boston; Basel;
Stuttgart ; Birkhauser
3. University of North Carolina, Chapel Hill, April
15 - 17,1982. - 1Q82.
(Progress in Phvsics: No. 6)
NE Universitv of North Carolina (Chauel Hill): GT
AII rights reserved. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted,
in any form or by any means, electronic, mechanica1,
photocopying, record ing or otherwise, without prior
permission of the copyright owner.
© Springer Science+Business Media New York 1982
Originally published by Birkhiiuser Boston, Inc. in 1982
Softcover reprint of the hardcover lst edition 1982
ISBN 978-0-8176-3105-5 ISBN 978-1-4612-5800-1 (eBook)
DOI 10.1007/978-1-4612-5800-1
TABLE OF CONTENTS
EDITORS' INTRODUCTION ••••••••••••••••••••••••••••• vii
Paul H. Frampton, Sheldon L. Glashow,
Hendrik van Dam
MAGNETIC MONOPOLES ABOUT US •••••••••••••••••••••••
Sheldon L. Glashow
GUD: GIANT UNDERGROUND TRACK-DETECTOR,
A PROJECT FOR THE GRAN SASSO LABORATORy........... 7
Guido De Zorzi
GAUGE SYMMETRY BREAKING WHICH PRESERVES
SUPERSYMMETRY..................................... 22
Paul H. Frampton
THE UCI MOBILE NEUTRINO OSCILLATION EXPERIMENT •••• 30
Henry W. Sobel
SUPERSYMMETRY AT ORDINARY ENERGy •••••••••••••••••• 42
Burt A. Ovrut
THE KAMIOKA PROTON DECAY EXPERIMENT ••••••••••••••• 56
-PRESENT STATUS-
Kasuke Takahashi
GEOMETRIC HIERARCHy ••••••••••••••••••••••••••••••• 72
Savas Dimopoulos
THE HOMES TAKE SPECTROMETER
A ONE-MILE DEEP 1400-TON LIQUID SCINTILLATION
NUCLEON DECAY DETECTOR............................ 89
Richard I. Steinberg
COMPLEX ANOMALY-FREE REPRESENTATIONS
FOR GRAND UNIFICATION ••••••••••••••••••••••••••••• 105
Kyungsik Kang
NUCLEON DECAY EXPERIMENT AT KOLAR GOLD FIELDS ••••• 119
S. Miyake and V. S. Narasimham
FROM FLUX QUANTIZATION TO MAGNETIC MONOPOLES •••••• 131
BIas Cabrera
COMPOSITE/FUNDAMENTAL HIGGS MESON ••••••••••••••••• 158
Howard Georgi
SEARCH FOR PROTON DECAY - THE HPW
DEEP UNDERGROUND WATER CERENKOV DETECTOR •••••••••• 174
Robert Morse
vi
SUPERSYMMETRY, GRAND UNIFICATION
AND PROTON DECAy •••••••••••••••••••••••••••••••••• 191
Serge Rudaz
NEUTRINO OSCILLATION EXPERIMENTS
AT ACCELERATORS ••••••••••••••••••••••••••••••••••• 206
Herbert Chen
COSMOLOGICAL CONSTRAINTS ON WITTEN'S
HIERARCHY MECHANISM ••••••••••••••••••••••••••••••• 222
So-Young Pi
THE LEPTON ASYMMETRY OF THE UNIVERSE •••••••••••••• 231
Paul Langacker
STATUS OF THE IRVINE-MICHIGAN-BROOKHAVEN
NUCLEON DECAY SEARCH •••••••••••••••••••••••••••••• 236
William R. Kropp
FRACTIONALLY-CHARGED COLOR SINGLETS ••••••••••••••• 249
Michael T. Vaughn
NEUTRINO MASSES FROM e
END-PO I NT MEAS UREME NT S • • • • • • • • • • • • • • • • • • • • • • • • • • •• 258
John J. Simpson
NEUTRINO WEIGHT WATCHING •••••••••••••••••••••••••• 269
Alvaro de Rujula
PLANNING FOR THE NEXT GENERATION OF PROTON DECAY
EXPERIMENTS IN THE UNITED STATES •••••••••••••••••• 289
David S. Ayres
RECENT DEVELOPMENTS OF THE INVISIBLE AXION •••••••• 305
Jihn E. Kim
NEUTRON ANTINEUTRON CONVERSION EXPERIMENTS •••••••• 322
Herbert L. Anderson
MASS OF THE t-QUARK ••••••••••••••••••••••••••••••• 348
Sandip Pakvasa
THE MONT-BLANC FINE GRAIN EXPERIMENT ON NUCLEON
STABILITy ••••••••••••••••••••••••••••••••••••••••• 356
Donald Cundy
WHERE IS SUPERSYMMETRY BROKEN? ••••••••••••••••••• 359
Steven Weinberg
ORGANIZING COMMITTEE 369
LIST OF PARTICIPANTS 370
..................................................
PROGRAM 374
EDITORS' INTRODUCTION
This workshop held at the University of North Carolina was in the
series which started with meetings in the University of New Hampshire
(April 1980) and the University of Michigan (April 1981). More than
one hundred participants congregated in the Carolina Inn in April 1982
to discuss the status of grand unified theories and their connection to
experiment. The spring foliage of Chapel Hill provided a beautiful
back-drop to this Third Workshop on Grand Unification. As mentioned in
the first talk herein, these three workshops have heard of indications,
respectively, of neutrino oscillations, proton decay and a magnetic
monopole. Since all three experimental reports remain unconfirmed,
grand unifiers must wait expectantly and patiently.
These proceedings preserve faithfully the ordering of the workshop
talks which followed the tradition of alternation between theory and
experiment. Only our introduction will segregate them.
The experimental presentations mainly concerned proton decay and
massive neutrinos.
Four U.S. proton decay experiments were reported: the Brookhaven
Irvine-Michigan experiment in the Morton Salt Mine at Fairport Harbor,
Ohio was described by WILLIAM KROPP, and ROBERT MORSE represented the
Harvard-Purdue-Wisconsin group in the Silver King Mine, Utah. The
Homestake Mine, South Dakota and Soudan Mine, Minnesota, experiments
were reported respectively by RICHARD STEINBERG and DAVID AYRES, the
latter providing also a survey of future U.S. experiments.
Equally intensive are the proton decay searches abroad. European
experiments were discussed by GUIDO DE ZORZI from the Gran Sasso Labo
ratory and by DONALD CUNDY of the Hont Blanc tunnel collaboration. The
Japanese Kamioka proposal was covered in a talk by KASUKE TAKAHASHI.
The only experiment with actual candidates for proton decay events is
that in the Kolar Gold Mine, India, a Japanese-Indian collaboration
which was represented in Chapel Hill by SABURO MIYAKE and V.S.
NARASIMHAN.
vii
viii
On massive neutrinos, ALVARO DE RUJULA described the progress at
CERN in measuring radiative electron capture; JOHN SIMPSON surveyed
critically other end-point determinations of neutrino mass; HERBERT
CHEN reviewed accelerator searches for neutrino oscillations; and
HENRY SOBEL reported on a new movable detector installation at the
Savannah River reactor facility.
In addition, there were two experimental talks concerning respec
tively neutron-antineutron conversion and a magnetic monopole search.
The talk on neutron-antineutron oscillation this year was by HERBERT
ANDERSON who emphasized the efforts at Los Alamos National Laboratory.
Finally, on experiment, BLAS CABRERA described a magnetic monopole
search at Stanford, including one impressive event suggestive of a
monopole with one Dirac unit of charge.
We turn now to the theoretical contributions to the workshop.
Possible origins for the monopole flux indicated by the Stanford
result were provided by SHELDON GLASHOW who favored a cloud of
monopoles in solar orbit fed by slow evaporation of monopoles from the
Sun.
A novel approach to the gauge hierarchy problem was provided by
HOWARD GEORGI. Recent work on the invisible axion solution of the
strong CP puzzle was surveyed by JIHN KIM. A prediction for the top
quark mass was made by SANDIP PAKVASA.
MICHAEL VAUGHN constructed grand unified theories containing
fractionally-charged leptons or hadrons. KYUNGSIK KANG built complex
anomaly-free SU(N) representations. The cosmological lepton number was
discussed by PAUL LANGACKER.
The most popular theoretical topic this year was undoubtedly super
symmetry which paradoxically combines strong theoretical appeal with,
as yet, absolutely no empirical basis. PAUL FRAMPTON analyzed the group
theory of gauge group breaking while retaining super symmetry unbroken.
A review of supersymmetric electroweak models was made by BURT OVRUT.
An ambitious supersymmetric attempt to derive both the Planck scale and
the electroweak scale from one input mass was made by SAVAS DIMOPOULOS.
Implications of super symmetry for the lifetime and decay branching
ratios of the proton were explained by SERGE RUDAZ. SO-YOUNG PI
studied the cosmology of a mass hierarchy generated in a supersymrnetric
gauge theory.
The general question of at what mass scale super symmetry is broken
was addressed by STEVEN WEINBERG. He argued against preserving super-
ix
symmetry down to the electroweak scale, and imposed cosmological
bounds on the allowed higher energy scales of super symmetry breaking.
He also suggested how gravity can distinguish between degenerate super
symmetric vacua having different residual gauge symmetries, and pointed
to cosmological difficulties that would arise if super symmetry were
broken below about 1013 GeV.
The experimental and theoretical speakers provided the partici
pants with a clear overall picture of the current status of grand
unification. Quite apart from the speakers' program, many other par
ticipants made valuable contributions to informal discussions.
We acknowledge financial support by grants from the U.S. Depart
ment of Energy and the National Science Foundation, as well as from the
University of North Carolina.
Thanks are due to MAURICE GOLDHABER for his after-dinner speech,
to TOM KEPHART for help with the workshop and these proceedings, and to
DEBBIE WILSON who acted as workshop secretary.
May 1982 P.H. Frampton
S.L. Glashow
H. van Dam
MAGNETIC MONOPOLES ABOUT US
S.L. Glashow
Lyman Laboratory of Physics
Harvard University
In the first of these workshops, indications of neutrino oscilla
tions were reported. In the second, candidate nucleon-decay events
were shown. In this third workshop, we have heard of the Valentine's
Day monopole. What is left for future workshops? Perhaps we will have
axions next year, and neutron-antineutron oscillations the year after.
The magnetic monopole was invented by Paul Dirac half a century
ago, and it is one of his only unverified predictions. Today, its
existence is one of the few predictions of grand unified theories,
along with proton decay and the great desert. Perhaps, by the time
these notes are published, the existence of magnetic monopoles will be
confirmed.
Blas Cabrera reports the observation of one monopole candidate
(with the Dirac value of magnetic charge 2eg ; hc) passing through a
20 cm2 superconducting loop during half a year. The most likely value
2
for the flux of monopoles upon the Earth is O.l/cm yr (2n sr). This is
a very large flux. If monopoles were to accumulate on the Earth's
surface, we would expect to find many of them per gram of terrestrial
material. We do not. But today's monopole is supposed to be very
maSSL. ve, -1016 GeV. The force of surface gravity amounts to -0.1 eV/Ao ,
and is sufficient to propel a heavy monopole through the solid Earth.
If all the ambient monopoles have fallen into the Earth's core, then
27
there are now 3 xlO monopoles inside the Earth. This is impossible.
A far smaller number of monopoles is sufficient to poison the geomag
netic dynamo. Either the Cabrera flux is wrong, or the ambient
monopoles must pass through the Earth so readily as to almost never be
trapped within it.
Incident monopoles have been searched for with particle detectors.
1