2,398 research outputs found
Consistency Conditions for AdS/CFT Embeddings
The group embeddings used in orbifolding the AdS/CFT correspondence to arrive
at quiver gauge field theories are studied for both supersymmetric and
non-supersymmetric cases. For an orbifold the
conditions for embeddings of the finite group in the
isotropy of are stated in the form of consistency rules, both for Abelian
and Non-Abelian .Comment: 10 pages LaTe
Editorial: In use, in situ: extending field research methods
A case for evaluating in use and in-situ
Many authors have argued the need for a broader understanding of context and the situatedness of activity when approaching the evaluation of systems. However, prevailing practice often still tends towards attempting to understand the use of designed artefacts by focusing on a core set of tasks that are thought to define the system. A consequence of such focus is that other tasks are considered peripheral and outside the scope of design and evaluation activities. To illustrate the point, consider the experience, familiar to many of us, of being involved in an evaluation activity where participants provide unstructured qualitative feedback. Irrespective of whether the activity is carried out in a laboratory, in a high fidelity simulation or in a naturalistic setting, participants will frequently volunteer unsolicited feedback about tasks and goals that were not originally within the ambit of the design activity. This unprompted feedback, we suggest, is a cue for the evaluators to pay attention to the relationship between the tool and the practice in which it will be used. In other words a cue to consider the situations in which artefact will be used, the tasks and activities that may be affected by the new system, and so on. These are empirical questions that cannot be answered a priori by the development team, whether the evaluation is taking place in âartificialâ or ânaturalâ setting
Comment On ``Grand Unification and Supersymmetric Threshold"
Barbieri and Hall have argued that threshold effects at the scale of
grand-unification wipe out predictions on the SUSY scale, M_S. Using triviality
arguments we give upper bounds on ultraheavy particles, while proton stability
gives lower bounds on the mass of the higgs color-triplet. We find no useful
lower bound on the supermultiplet, but if the strong coupling constant
is as large as recent experiments suggest, unification in the minimal SUSY
SU(5) model requires that the masses be and that the
color octet and weak triplet be split in mass by a factor of 100.Comment: 6 pages (revised
High-power test results of a 3 GHz single-cell cavity
Compact, reliable and little consuming accelerators are required for the
treatment of tumours with ions. TERA proposes the "cyclinac", composed of a
high-frequency, fast-cycling linac which boosts the energy of the particles
previously accelerated in a cyclotron. The dimensions of the linac can be
reduced if high gradients are used. TERA initiated a high-gradient test program
to understand the operational limit of such structures. The program foresees
the design, prototyping and high-power test of several high-gradient structures
operating at 3 and 5.7 GHz. The high-power tests of the 3 GHz single-cell
cavity were completed in Winter 2012. The maximum BDR threshold measured for
Emax of 170 MV/m and RF pulses of 2.5 \mu s was 3 x 10-6 bpp/m
Phenomenological Analysis of and Elastic Scattering Data in the Impact Parameter Space
We use an almost model-independent analytical parameterization for and
elastic scattering data to analyze the eikonal, profile, and
inelastic overlap functions in the impact parameter space. Error propagation in
the fit parameters allows estimations of uncertainty regions, improving the
geometrical description of the hadron-hadron interaction. Several predictions
are shown and, in particular, the prediction for inelastic overlap
function at TeV shows the saturation of the Froissart-Martin
bound at LHC energies.Comment: 15 pages, 16 figure
Neutrino masses and flavor symmetries
The problem of neutrino masses and mixing angles is analysed in a class of
supersymmetric grand unified models, with SO(10) gauge symmetry and global U(2)
flavour symmetry. Adopting the seesaw mechanism for the generation of the
neutrino masses, one obtains a mass matrix for the left-handed neutrinos which
is directly related to the parameters of the charged sector, while the unknown
parameters of the right-handed Majorana mass matrix are inglobed in a single
factor.Comment: 17 pages, 1 eps figure, uses graphicx.sty, LaTeX 2e, to be published
on "Il Nuovo Cimento
On Upper Limits for Gravitational Radiation
A procedure with a Bayesan approach for calculating upper limits to
gravitational wave bursts from coincidence experiments with multiple detectors
is described.Comment: 10 pages, 2 figures, latex files using cernlik.cls (included). This
paper and related work are also available at
http://grwav3.roma1.infn.it/pia/papersweb.html Version number 2: text
unchanged. Modified two references, adding the hep number
What do experimental data "say" about growth of hadronic total cross-section?
We reanalyse and high energy data of the elastic scattering
above GeV on the total cross-section and on the
forward -ratio for various models of Pomeron, utilizing two methods. The
first one is based on analytic amplitudes, the other one relies on assumptions
for and on dispersion relation for . We argue that it is
not possible, from fitting only existing data for forward scattering, to select
a definite asymptotic growth with the energy of . We find
equivalent fits to the data together with a logarithmic Pomeron giving a
behavior , and with
a supercritical Pomeron giving a behavior ,
.Comment: LaTeX, 18 pages, 5 eps figures included, to be published in Il Nuovo
Ciment
3D-in-2D Displays for ATC.
This paper reports on the efforts and accomplishments
of the 3D-in-2D Displays for ATC project at the end of Year 1.
We describe the invention of 10 novel 3D/2D visualisations that
were mostly implemented in the Augmented Reality ARToolkit.
These prototype implementations of visualisation and interaction
elements can be viewed on the accompanying video. We have
identified six candidate design concepts which we will further
research and develop. These designs correspond with the early
feasibility studies stage of maturity as defined by the NASA
Technology Readiness Level framework. We developed the
Combination Display Framework from a review of the literature,
and used it for analysing display designs in terms of display
technique used and how they are combined. The insights we
gained from this framework then guided our inventions and the
human-centered innovation process we use to iteratively invent.
Our designs are based on an understanding of user work
practices. We also developed a simple ATC simulator that we
used for rapid experimentation and evaluation of design ideas.
We expect that if this project continues, the effort in Year 2 and 3
will be focus on maturing the concepts and employment in a
operational laboratory settings
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