9,901 research outputs found
Outlook on Neutrino Physics
Some of the hot topics in neutrino physics are discussed, with particular
emphasis on neutrino oscillations. After proposing credibility criteria for
assessing various claimed effects, particular stress is laid on the solar
neutrino deficit, which seems unlikely to have an astrophysical explanation.
Comments are also made on the possibility of atmospheric neutrino oscillations
and on the LSND experiment, as well as cosmological aspects of neutrinos and
neutralinos. Several of the central issues in neutrino physics may be resolved
by the new generation of experiments now underway, such as CHORUS, NOMAD and
Superkamiokande, and in preparation, such as SNO and a new round of
accelerator- and reactor-based neutrino-oscillation experiments. At the end,
there is a brief review of ways in which present and future CERN experiments
may be able to contribute to answering outstanding questions in neutrino
physics.Comment: 27 pages, LaTex, uses sprocl.sty, Invited Talk presented at the
conclusion of the Neutrino 96 Conference, Helsinki, June 199
Theoretical Summary: 1999 Electroweak Session of the Rencontres de Moriond
The following aspects of the electroweak interactions are discussed, based on
presentations here: the status of the Standard Model, CP violation, neutrino
masses and oscillations, supersymmetry and models in extra dimensions, and
future projects. Particular emphasis is laid on the tests of CP and CPT by KTeV
and CPLEAR, on the problems of degenerate neutrinos, on supersymmetric dark
matter, on future long-baseline neutrino beams, and on muon storage rings that
may be used as neutrino factories.Comment: 25 LaTeX pages, 5 eps figures, Invited talk presented at the 1999
Electroweak Session of the Rencontres de Morion
Prospects for Future Collider Physics
One item on the agenda of future colliders is certain to be the Higgs boson.
What is it trying to tell us? The primary objective of any future collider must
surely be to identify physics beyond the Standard Model, and supersymmetry is
one of the most studied options. it Is supersymmetry waiting for us and, if so,
can LHC Run 2 find it? The big surprise from the initial 13-TeV LHC data has
been the appearance of a possible signal for a new boson X with a mass ~750
GeV. What are the prospects for future colliders if the X(750) exists? One of
the most intriguing possibilities in electroweak physics would be the discovery
of non-perturbative phenomena. What are the prospects for observing sphalerons
at the LHC or a future collider?Comment: 17 pages, 14 figures, contribution to the Hong Kong UST IAS Programme
and Conference on High-Energy Physics, based largely on personal research
with various collaborator
The Physics Landscape after the Higgs Discovery at the LHC
What is the Higgs boson telling us? What else is there, maybe supersymmetry
and/or dark matter? How do we find it? These are now the big questions in
collider physics that I discuss in this talk, from a personal point of view.Comment: Invited plenary talk at SILAFAE 2014, Medell\'in, Colombia, 12 pages,
21 figure
Limits of the Standard Model
Supersymmetry is one of the most plausible extensions of the Standard Model,
since it is well motivated by the hierarchy problem, supported by measurements
of the gauge coupling strengths, consistent with the suggestion from precision
electroweak data that the Higgs boson may be relatively light, and provides a
ready-made candidate for astrophysical cold dark matter. In the first lecture,
constraints on supersymmetric models are reviewed, the problems of fine-tuning
the electroweak scale and the dark matter density are discussed, and a number
of benchmark scenarios are proposed. Then the prospects for discovering and
measuring supersymmetry at the LHC, linear colliders and in non-accelerator
experiments are presented. In the second lecture, the evidence for neutrino
oscillations is recalled, and the parameter space of the seesaw model is
explained. It is shown how these parameters may be explored in a supersymmetric
model via the flavour-changing decays and electric dipole moments of charged
leptons. It is shown that leptogenesis does not relate the baryon asymmetry of
the Universe directly to CP violation in neutrino oscillations. Finally,
possible CERN projects beyond the LHC are mentioned.Comment: Lectures given at the PSI Summer School, Zuoz, August 2002, 40 pages,
28 figures, uses axodraw.sty, cernrep.cls (included
Supersymmetry for Alp Hikers
These lectures provide a phenomenological introduction to supersymmetry,
concentrating on the minimal supersymmetric extension of the Standard Model
(MSSM). In the first lecture, motivations are provided for thinking that
supersymmetry might appear at the TeV scale, including the naturalness of the
mass hierarchy, gauge unification and the probable mass of the Higgs boson. In
the second lecture, simple globally supersymmetric field theories are
introduced, with the emphasis on features important for model-building.
Supersymmetry breaking and local supersymmetry (supergravity) are introduced in
the third lecture, and the structure of sparticle mass matrices and mixing are
reviewed. Finally, the available experimental and cosmological constraints on
MSSM parameters are discussed and combined in the fourth lecture, and the
prospects for discovering supersymmetry in future experiments are previewed.Comment: 45 pages, 19 figures, Lectures at the European School of High-Energy
Physics, Beatenberg, Switzerland, 26 Aug - 8 Sept 200
Looking Back at the First Decade of 21st-Century High-Energy Physics
On the occasion of the Tenth Conference on String Phenomenology in 2011, I
review the dramatic progress since 2002 in experimental tests of fundamental
theoretical ideas. These include the discovery of (probably fermionic) extra
dimensions at the LHC, the discovery of dark matter particles, observations of
charged-lepton flavour violation, the debut of quantum gravity phenomenology
and the emergence of space-time from the string soup.Comment: 18 pages, 16 eps figures, uses ws-procs9x6.cls (included
Higgs Physics
These lectures review the background to Higgs physics, its current status
following the discovery of a/the Higgs boson at the LHC, models of Higgs
physics beyond the Standard Model and prospects for Higgs studies in future
runs of the LHC and at possible future colliders.Comment: 52 pages, 45 figures, Lectures presented at the ESHEP 2013 School of
High-Energy Physics, to appear as part of the proceedings in a CERN Yellow
Repor
Theory Summary and Prospects
This talk reviews some of the theoretical progress and outstanding issues in
QCD, flavour physics, Higgs and electroweak physics and the search for physics
beyond the Standard Model at the Tevatron and the LHC, and previews some
physics possibilities for future runs of the LHC and proposed future hadron
colliders.Comment: 14 pages, 7 figures, Presented at the Second Annual Conference on
Large Hadron Collider Physics Columbia University, New York, U.S.A June 2-7,
201
Cosmic Connections
A National Research Council study on connecting quarks with the cosmos has
recently posed a number of the more important open questions at the interface
between particle physics and cosmology. These questions include the nature of
dark matter and dark energy, how the Universe began, modifications to gravity,
the effects of neutrinos on the Universe, how cosmic accelerators work, and
whether there are new states of matter at high density and pressure. These
questions are discussed in the context of the talks presented at this Summer
Institute.Comment: Closing Lecture at the 31st SLAC Summer Institute, July 2003: PSN
TF07, 18 pages latex, uses ssi.sty (included
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