19,600 research outputs found
Dynamical symmetry of isobaric analog 0+ states in medium mass nuclei
An algebraic sp(4) shell model is introduced to achieve a deeper
understanding and interpretation of the properties of pairing-governed 0+
states in medium mass atomic nuclei. The theory, which embodies the simplicity
of a dynamical symmetry approach to nuclear structure, is shown to reproduce
the excitation spectra and fine structure effects driven by proton-neutron
interactions and isovector pairing correlations across a broad range of nuclei.Comment: 7 pages, 5 figure
Composite Scalars at LEP: Constraining Technicolor Theories
LEPI and LEPII data can be used to constrain technicolor models with light,
neutral pseudo-Nambu-Goldstone bosons, Pa. We use published limits on branching
ratios and cross sections for final states with photons, large missing energy,
jet pairs, and b bbar pairs to constrain the anomalous Pa Z0 Z0, Pa Z0 photon,
and Pa photon photon couplings. From these results, we derive bounds on the
size of the technicolor gauge group and the number of technifermion doublets in
models such as Low-scale Technicolor.Comment: 27 pages (including title page), 15 figures, 6 tables. version 2: In
addressing PRD referee comments, we have significantly expanded our
manuscript, to include detailed discussion of limits from LEP II data, as
well as expanding the number or specific models to which we apply our
results. As a result, we have changed the title from "Z0 decays to composite
scalars: constraining technicolor theories
Tannakian approach to linear differential algebraic groups
Tannaka's Theorem states that a linear algebraic group G is determined by the
category of finite dimensional G-modules and the forgetful functor. We extend
this result to linear differential algebraic groups by introducing a category
corresponding to their representations and show how this category determines
such a group.Comment: 31 pages; corrected misprint
Orders and dimensions for sl(2) or sl(3) module categories and Boundary Conformal Field Theories on a torus
After giving a short description, in terms of action of categories, of some
of the structures associated with sl(2) and sl(3) boundary conformal field
theories on a torus, we provide tables of dimensions describing the semisimple
and co-semisimple blocks of the corresponding weak bialgebras (quantum
groupoids), tables of quantum dimensions and orders, and tables describing
induction - restriction. For reasons of size, the sl(3) tables of induction are
only given for theories with self-fusion (existence of a monoidal structure).Comment: 25 pages, 5 tables, 9 figures. Version 2: updated references. Typos
corrected. Several proofs added. Examples of ADE and generalized ADE
trigonometric identities have been removed to shorten the pape
Interferometric Observations of V838 Monocerotis
We have used long-baseline near-IR interferometry to resolve the peculiar
eruptive variable V838 Mon and to provide the first direct measurement of its
angular size. Assuming a uniform disk model for the emission we derive an
apparent angular diameter at the time of observations (November-December 2004)
of milli-arcseconds. For a nominal distance of kpc,
this implies a linear radius of . However, the data are
somewhat better fit by elliptical disk or binary component models, and we
suggest that the emission may be strongly affected by ejecta from the outburst.Comment: 12 pages, 1 two-part encapsulated postscript figure. Accepted by
ApJL. Added a table of observation
Long-term feeding issue and its impact on the daily life of congenital diaphragmatic hernia survivors: results of the first patient-led survey
BACKGROUND: CDH UK is a registered charity governed by a volunteer committee and providing informal support to patients, families and healthcare workers affected directly or indirectly with congenital diaphragmatic hernia (CDH) internationally. This is the first patient-led survey undertaken by CDH UK aiming for highlighting the feeding problems and their impact on the daily life of CDH survivors. METHODS: Answers from CDH survivors were collected through an online questionnaire (SurveyMonkey®) undertaken by CDH UK. The questionnaire contained questions about their feeding problems and support they were receiving for it. MAIN RESULTS: Overall, 151 patients answered some parts of the survey and 102 patients completed the questionnaire. Overall, 116 (76.8%) responders reported suffering from any type of feeding issue. Gastric acid reflux (GER) and growth retardation were the commonest symptoms experienced by 97 (91.5%) and 72 (62.2%) responders, respectively. Only 18 (17.0%) responders have received any written information on feeding or details of patient/parent support. Eighty (75.5%) responders are satisfied with the level of support they are receiving, but 78 (76.4%) answered that the whole experience associated with the disease has been very or extremely stressful. CONCLUSIONS: CDH survivors frequently have various issues with feeding, which may not be adequately supported or discussed clinically. It is desirable to assist the patients to reliable resources of long-term support, including multidisciplinary team (MDT) approach
Probing the subshell closure: factor of the Mg(2) state
The first-excited state ~factor of Mg has been measured relative to
the factor of the Mg() state using the high-velocity
transient-field technique, giving . This new measurement is in
strong disagreement with the currently adopted value, but in agreement with the
-shell model using the USDB interaction. The newly measured factor,
along with and systematics, signal the closure of the subshell at . The possibility that precise -factor
measurements may indicate the onset of neutron admixtures in first-excited
state even-even magnesium isotopes below Mg is discussed and the
importance of precise excited-state -factor measurements on ~shell
nuclei with to test shell-model wavefunctions is noted.Comment: 8 pages, 5 figure
The Collider Phenomenology of Technihadrons in the Technicolor Straw Man Model
We discuss the phenomenology of the lightest SU(3)_C singlet and non-singlet
technihadrons in the Straw Man Model of low-scale technicolor (TCSM). The
technihadrons are assumed to be those arising in topcolor--assisted technicolor
models in which topcolor is broken by technifermion condensates. We improve
upon the description of the color--singlet sector presented in our earlier
paper introducing the TCSM (hep-ph/9903369). These improvements are most
important for subprocess energies well below the masses of the technirho and
techniomega, and, therefore, apply especially to e+e- colliders such as LEP and
a low--energy linear collider. In the color--octet sector, we consider mixing
of the gluon, the coloron V_8 from topcolor breaking, and four isosinglet
color--octet technirho mesons. We assume, as expected in walking technicolor,
that these technirhos decay into qbar-q, gg, and g-technipion final states, but
not into technipion pairs. All the TCSM production and decay processes
discussed here are included in the event generator Pythia. We present several
simulations appropriate for the Tevatron Collider, and suggest benchmark model
lines for further experimental investigation.Comment: 42 pages, 7 figure
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