8,380 research outputs found
Dynamics and Decay of Heavy-Light Hadrons
Recent signals for narrow hadrons containing heavy and light flavours are
compared with quark model predictions for spectroscopy, strong decays, and
radiative transitions. In particular, the production and identification of
excited charmed and cs states are examined with emphasis on elucidating the
nature of and states. Roughly 200 strong decay amplitudes of
and states up to 3.3 GeV are presented. Applications include determining
flavour content in mesons and the mixing angle in and wave
states and probes of putative molecular states. We advocate searching for
radially excited states in B decays.Comment: 19 pages, 7 figures, revtex. A numerical error is corrected. Some
strong decay rates have change
Discovery of Two New Class II Methanol Maser Transitions in G345.01+1.79
We have used the Swedish ESO Submillimetre Telescope (SEST) to search for new
class II methanol maser transitions towards the southern source G345.01+1.79.
Over a period of 5 days we observed 11 known or predicted class II methanol
maser transitions. Emission with the narrow line width and characteristic
velocity of class II methanol masers (in this source) was detected in 8 of
these transitions, two of which have not previously been reported as masers.
The new class II methanol maser transitions are the 13(-3)-12(-4)E transition
at 104.1 GHz and the 5(1)-4(2)E transition at 216.9 GHz. Both of these are from
transition series for which there are no previous known class II methanol maser
transitions. This takes the total number of known class II methanol maser
series to 10, and the total number of transitions (or transition groups) to 18.
The observed 104.1 GHz maser suggests the presence of two or more regions of
masing gas with similar line of sight velocities, but quite different physical
conditions. Although these newly discovered transitions are likely to be
relatively rare, where they are observed combined studies using the Australia
Telescope Compact Array and the Atacama Large Millimeter Array offer the
prospect to be able to undertake multi-transition methanol maser studies with
unprecedented detail.Comment: 8 pages, 3 figures, accepted for publication in ApJ Letter
Properties of the Strange Axial Mesons in the Relativized Quark Model
We studied properties of the strange axial mesons in the relativized quark
model. We calculated the decay constant in the quark model and showed how
it can be used to extract the mixing angle
() from the weak decay . The ratio is the most sensitive
measurement and also the most reliable since the largest of the theoretical
uncertainties factor out. However the current bounds extracted from the
TPC/Two-Gamma collaboration measurements are rather weak: we typically obtain
at 68\% C.L. We also calculated the
strong OZI-allowed decays in the pseudoscalar emission model and the flux-tube
breaking model and extracted a mixing angle of . Our analysis also indicates that the heavy quark limit does not give a
good description of the strange mesons.Comment: Revised version to be published in Phys. Rev. D. Minor changes. Latex
file uses revtex version 3 and epsfig, 4 postcript figures are attached. The
full postcript version with embedded figures is available at
ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocipc9512.ps.
Discovery and Identification of W' Bosons at e+e- Colliders
We report on studies of the sensitivity to extra gauge bosons of the
reactions e^+ e^- -> nu nubar gamma and e gamma -> nu q + X to extract
discovery limits for W' 's. The discovery potential for a W' is, for some
models, comparable to that of the LHC. These processes may be also useful for
determining W' and Z' couplings to fermions which would complement measurements
made at the Large Hadron Collider.Comment: 3 pages, 2 postscript figures, Presented at the DPF2000 Conference,
August 9-12, 2000, The Ohio State University, Columbus, Ohi
Discovery and Identification of Extra Gauge Bosons
The discovery potential and diagnostic abilities of proposed future colliders
for new heavy neutral () and charged () gauge bosons are summarized.
Typical bounds achievable on at the TEVATRON, DI-TEVATRON, LHC, 500
GeV NLC, and 1 TeV NLC are 1~TeV, 2~TeV, 4~TeV, 1--3~TeV, and
2--6~TeV, respectively. For 1 TeV the LHC will have the capability
to determine the magnitude of normalized quark and lepton couplings to
around , while the NLC would allow for determination of the couplings
(including their signs) with a factor of 2 larger error-bars, provided heavy
flavor tagging and longitudinal polarization of the electron beam is available.Comment: 34 pages, Latex file using equations.sty and psfig.sty, 6 postcript
figures (uuencoded) added with figures command. Full postcript version,
complete with embedded figures is available at
ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocip9502.ps . Summary of the
Working Subgroup on Extra Gauge Bosons of the DPF Long-Range Planning Study,
to be published in "Electroweak Symmetry Breaking and Beyond the Standard
Model", eds T. Barklow, S. Dawson, H. Haber, and J. Seigris
The red rain phenomenon of Kerala and its possible extraterrestrial origin
A red rain phenomenon occurred in Kerala, India starting from 25th July 2001,
in which the rainwater appeared coloured in various localized places that are
spread over a few hundred kilometers in Kerala. Maximum cases were reported
during the first 10 days and isolated cases were found to occur for about 2
months. The striking red colouration of the rainwater was found to be due to
the suspension of microscopic red particles having the appearance of biological
cells. These particles have no similarity with usual desert dust. An estimated
minimum quantity of 50,000 kg of red particles has fallen from the sky through
red rain. An analysis of this strange phenomenon further shows that the
conventional atmospheric transport processes like dust storms etc. cannot
explain this phenomenon. The electron microscopic study of the red particles
shows fine cell structure indicating their biological cell like nature. EDAX
analysis shows that the major elements present in these cell like particles are
carbon and oxygen. Strangely, a test for DNA using Ethidium Bromide dye
fluorescence technique indicates absence of DNA in these cells. In the context
of a suspected link between a meteor airburst event and the red rain, the
possibility for the extraterrestrial origin of these particles from cometary
fragments is discussed.Comment: 18 pages, 15 figures, accepted for publication in Astrophysics and
Space Scienc
Development of the health and economic consequences of smoking interactive model
Objective-To describe the health and economic consequences of smoking model, a user friendly, web based tool, designed to estimate the health and economic outcomes associated with smoking and the benefits of smoking cessation. Results-An overview of the development of the model equations and user interface is given, and data from the UK are presented as an example of the model outputs. These results show that a typical smoking cessation strategy costs approximately pound 1200 per life year saved and pound 22 000 per death averted. Conclusions-The model successfully captures the complexity required to model smoking behaviour and associated mortality, morbidity, and health care costs. Furthermore, the interface provides the results in a simple and flexible way so as to be useful to a variety of audiences and to simulate a variety of smoking cessation methods
Spin-Orbit and Tensor Forces in Heavy-quark Light-quark Mesons: Implications of the New Ds state at 2.32 GeV
We consider the spectroscopy of heavy-quark light-quark mesons with a simple
model based on the non-relativistic reduction of vector and scalar exchange
between fermions. Four forces are induced: the spin-orbit forces on the light
and heavy quark spins, the tensor force, and a spin-spin force. If the vector
force is Coulombic, the spin-spin force is a contact interaction, and the
tensor force and spin-orbit force on the heavy quark to order are
directly proportional. As a result, just two independent parameters
characterize these perturbations. The measurement of the masses of three p-wave
states suffices to predict the mass of the fourth. This technique is applied to
the system, where the newly discovered state at 2.32 GeV provides the
third measured level, and to the system. The mixing of the two
p-wave states is reflected in their widths and provides additional constraints.
The resulting picture is at odds with previous expectations and raises new
puzzles.Comment: 6 pages, 1 figur
Unveiling the Maelstrom of the Early Breast Cancer Trajectory
Length and complexity of illness and treatment in early breast cancer mean that the acute phase may extend over months. Employing concepts of ‘trajectory’ and ‘work’ from chronic illness, we explored the temporality of the illness experience for women as it unfolded from diagnosis through acute treatment. We performed multiple, qualitative interviews with 14 women at critical points in their first year post-diagnosis. We differentiated between sub-phases of the acute breast cancer trajectory: becoming a person with breast cancer: a turning point; first steps in treatment: struggling to protect self-concept; being and feeling ill: ‘cure’ as suffering; and conditional ‘recovering’: an uncertain future. Each sub-phase represented the distinctive context in which illness management took place with consequences for the work women and those close to them engaged in, to manage the practical, emotional, relational and existential demands of an illness that intruded every aspect of their lives
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