26,286 research outputs found
Charge assignments in multiple-U(1) gauge theories
We discuss the choice of gauge field basis in multiple-U(1) gauge theories.
We find that there is a preferred basis, specified by the charge orthogonality
condition, in which the U(1) gauge fields do not mix under one-loop
renormalization group running.Comment: 7 pages, LaTe
Narrow Technihadron Production at the First Muon Collider
In modern technicolor models, there exist very narrow spin-zero and spin-one
neutral technihadrons---, and ---with masses of a
few 100 GeV. The large coupling of to , the direct
coupling of and to the photon and , and the superb
energy resolution of the First Muon Collider may make it possible to resolve
these technihadrons and produce them at extraordinarily large rates.Comment: 11 pages, latex, including 2 postscript figure
CAFÉ - Changes around Food Experience - impact of reduced contact with food on social engagement and wellbeing of older women
Open educational resources and widening participation in higher education: innovations and lessons from open universities
This paper, which references a European Lifelong Learning project under the Erasmus Virtual Campus programme, briefly reviews the role of open educational resources, open and distance learning and widening participation within European higher education. It also examines and analyses policies and practices from various European open universities, practices undertaken to widen the audience for higher education knowledge, increase engagement with higher education materials and improve participation in formal access higher education courses and programmes. It presents a framework for understanding the role of open educational resources and open and distance learning in widening participation based on their availability, accessibility, and acceptability. The paper concludes that open educational resources are beginning to influence educational opportunities in Europe, but that new policies and practices are required at all levels in the higher education system to address issues of openness and open educational resources in higher education study and the role that they can play in increasing and widening engagement and participation. There needs to be better collaboration between the various stakeholders if OER are not to be seen as a way of simply widening the audience for higher education knowledge rather than widening participation in formal studies
Vacuum Alignment in Technicolor Theories-I. The Technifermion Sector
We have carried out numerical studies of vacuum alignment in technicolor
models of electroweak and flavor symmetry breaking. The goal is to understand
alignment's implications for strong and weak CP nonconservation in quark
interactions. In this first part, we restrict our attention to the
technifermion sector of simple models. We find several interesting phenomena,
including (1) the possibility that all observable phases in the technifermions'
unitary vacuum-alignment matrix are integer multiples of \pi/N' where N' \le N,
the number of technifermion doublets, and (2) the possibility of exceptionally
light pseudoGoldstone technipions.Comment: 19 pages, Latex with one postscript figur
The ultimate tactics of self-referential systems
Mathematics is usually regarded as a kind of language. The essential behavior
of physical phenomena can be expressed by mathematical laws, providing
descriptions and predictions. In the present essay I argue that, although
mathematics can be seen, in a first approach, as a language, it goes beyond
this concept. I conjecture that mathematics presents two extreme features,
denoted here by {\sl irreducibility} and {\sl insaturation}, representing
delimiters for self-referentiality. These features are then related to physical
laws by realizing that nature is a self-referential system obeying bounds
similar to those respected by mathematics. Self-referential systems can only be
autonomous entities by a kind of metabolism that provides and sustains such an
autonomy. A rational mind, able of consciousness, is a manifestation of the
self-referentiality of the Universe. Hence mathematics is here proposed to go
beyond language by actually representing the most fundamental existence
condition for self-referentiality. This idea is synthesized in the form of a
principle, namely, that {\sl mathematics is the ultimate tactics of
self-referential systems to mimic themselves}. That is, well beyond an
effective language to express the physical world, mathematics uncovers a deep
manifestation of the autonomous nature of the Universe, wherein the human brain
is but an instance.Comment: 9 pages. This essay received the 4th. Prize in the 2015 FQXi essay
contest: "Trick or Truth: the Mysterious Connection Between Physics and
Mathematics
Lower Paleozoic Rocks around Today´s Arctic Ocean: Two Ancestral Continents and Associated Plates; Alaskan Rotation Unnecessary and Unlikely
Technicolor Signatures at the High Energy Muon Collider
I discuss high mass signatures of technicolor that would be observable at a very high energy muon collider. Most intriguing is the spectrum of spin-one technihadrons, rho_T, omega_T and A_{1T}, which may extend to 100 TeV and beyond in a walking technicolor theory
Pseudo-Goldstone Boson Effects in Top-Antitop Productions at High Energy Hadron Colliders and Testing Technicolor Models
We study the top quark pair production process p+p(anti-p)-->top+antitop in
various kinds of technicolor (TC) models at the Fermilab Tevatron Run II and
the CERN LHC. The s-channel neutral pseudo-Goldstone bosons (PGB's) contribute
dominately to the production amplitudes from its coupling to the gluons through
the triangle loops of techniquarks and the top quark. Cross sections in
different TC models with s-channel PGB contributions are calculated. It is
shown that the PGB effects can be experimentally tested and different TC models
under consideration can be distinguished at the LHC. Therefore, the
p+p-->top+antitop process at the LHC provides feasible tests of the TC models.Comment: 10 pages in RevTex and 4 PS-files for the figures. Paramemter range
is changed, and some references are added. Version for publication in Phys.
Rev.
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