8,303 research outputs found

    Dynamics and Decay of Heavy-Light Hadrons

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    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 0+0^+ and 1+1^+ states. Roughly 200 strong decay amplitudes of DD and DsD_s states up to 3.3 GeV are presented. Applications include determining flavour content in η\eta mesons and the mixing angle in PP and DD wave states and probes of putative molecular states. We advocate searching for radially excited DsD_s^* 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

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    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

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    We studied properties of the strange axial mesons in the relativized quark model. We calculated the K1K_1 decay constant in the quark model and showed how it can be used to extract the K1(3P1)K1(1P1)K_1 (^3P_1) - K_1 (^1P_1) mixing angle (θK\theta_K) from the weak decay τK1ντ\tau \to K_1 \nu_\tau. The ratio BR(τντK1(1270))/BR(τντK1(1400))BR(\tau \to \nu_\tau K_1 (1270))/BR(\tau\to \nu_\tau K_1(1400)) 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 30oθK50o-30^o \lesssim \theta_K \lesssim 50^o 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 3P11P1^3P_1 - ^1P_1 mixing angle of θK45o\theta_K \simeq 45^o. 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

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    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

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    The discovery potential and diagnostic abilities of proposed future colliders for new heavy neutral (ZZ') and charged (WW') gauge bosons are summarized. Typical bounds achievable on MZ,WM_{Z',W'} at the TEVATRON, DI-TEVATRON, LHC, 500 GeV NLC, and 1 TeV NLC are \sim1~TeV, \sim2~TeV, \sim4~TeV, 1--3~TeV, and 2--6~TeV, respectively. For MZM_{Z'} \sim1 TeV the LHC will have the capability to determine the magnitude of normalized ZZ' quark and lepton couplings to around 1020%10-20\%, 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

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    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

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    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

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    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 1/m1m21/m_1m_2 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 DsD_s system, where the newly discovered state at 2.32 GeV provides the third measured level, and to the DD system. The mixing of the two JP=1+J^P=1^+ 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

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    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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