30,082 research outputs found

    Thermodynamics of Extended Bodies in Special Relativity

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    Relativistic thermodynamics is generalized to accommodate four dimensional rotation in a flat spacetime. An extended body can be in equilibrium when its each element moves along a Killing flow. There are three types of basic Killing flows in a flat spacetime, each of which corresponds to translational motion, spatial rotation, and constant linear acceleration; spatial rotation and constant linear acceleration are regarded as four dimensional rotation. Translational motion has been mainly investigated in the past literature of relativistic thermodynamics. Thermodynamics of the other two is derived in the present paper.Comment: 8 pages, no figur

    Discriminating Minimal SUGRA and Minimal Gauge Mediation Models at the Early LHC

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    Among various supersymmetric (SUSY) standard models, the gravity mediation model with a neutralino LSP and the gauge mediation model with a very light gravitino are attractive from the cosmological view point. These models have different scales of SUSY breaking and their underlying physics in high energy is quite different. However, if the sparticles' decay into the gravitino is prompt in the latter case, their collider signatures can be similar: multiple jets and missing transverse momentum. In this paper, we study the discrimination between these models in minimal cases at the LHC based on the method using the significance variables in several different modes and show the discrimination is possible at a very early stage after the discovery.Comment: 29 pages, 3 figures, captions improved, typos corrected, appendix added, version published in JHE

    Electron paramagnetic resonance, optical absorption and Raman spectral studies on a pyrite/chalcopyrite mineral

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    Pyrite and chalcopyrite mineral samples from Mangampet barite mine, Kadapa, Andhra Pradesh, India are used in the present study. XRD data indicate that the pyrite mineral has a face centered cubic lattice structure with lattice constant 5.4179 Å. Also it possesses an average particle size of 91.9 nm. An EPR study on the powdered samples confirms the presence of iron in pyrite and iron and Mn(II) in chalcopyrite. The optical absorption spectrum of chalcopyrite indicates presence of copper which is in a distorted octahedral environment. NIR results confirm the presence of water fundamentals and Raman spectrum reveals the presence of water and sulfate ions

    Mechanism of CDW-SDW Transition in One Dimension

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    The phase transition between charge- and spin-density-wave (CDW, SDW) phases is studied in the one-dimensional extended Hubbard model at half-filling. We discuss whether the transition can be described by the Gaussian and the spin-gap transitions under charge-spin separation, or by a direct CDW-SDW transition. We determine these phase boundaries by level crossings of excitation spectra which are identified according to discrete symmetries of wave functions. We conclude that the Gaussian and the spin-gap transitions take place separately from weak- to intermediate-coupling region. This means that the third phase exists between the CDW and the SDW states. Our results are also consistent with those of the strong-coupling perturbative expansion and of the direct evaluation of order parameters.Comment: 5 pages(REVTeX), 5 figures(EPS), 1 table, also available from http://wwwsoc.nacsis.ac.jp/jps/jpsj/1999/p68a/p68a42/p68a42h/p68a42h.htm

    Localization length of a soliton from a non-magnetic impurity in a general double-spin-chain model

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    A localization length of a free-spin soliton from a non-magnetic impurity is deduced in a general double-spin-chain model (J0J1J2J3J_0-J_1-J_2-J_3 model). We have solved a variational problem which employs the nearest-neighbor singlet-dimer basis. The wave function of a soliton is expressed by the Airy function, and the localization length (ξ)(\xi) is found to obey a power law of the dimerization (J2J3)(J_2-J_3) with an exponent -1/3; ξ(J2J3)1/3\xi\sim (J_2-J_3)^{-1/3}. This explains why NaV_2O_5 does not show the antiferromagnetic order, while CuGeO_3 does by impurity doping. When the gap exists by the bond-dimerization, a soliton is localized and no order is expected. Contrary, there is a possibility of the order when the gap is mainly due to frustration.Comment: 4 pages, REVTeX, Figures are in eps-file

    Enhanced Polarized Emission from the One-Parsec-Scale Hotspot of 3C 84 as a Result of the Interaction with Clumpy Ambient Medium

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    We present Very Long Baseline Array polarimetric observations of the innermost jet of 3C\sim84 (NGC\sim1275) at 43\simGHz. A significant polarized emission is detected at the hotspot of the innermost re-started jet, which is located \sim1 pc south from the radio core. While the previous report presented a hotspot at the southern end of the western limb, the hotspot location has been moved to the southern end of the eastern limb. Faraday rotation is detected within an entire bandwidth of the 43-GHz band. The measured rotation measure (RM) is at most (6.3±\pm1.9)×105\times10^{5}\simrad\simm2^{-2} and might be slightly time variable on the timescale of a month by a factor of a few. Our measured RM and the RM previously reported by the CARMA and SMA observations cannot be consistently explained by the spherical accretion flow with a power-law profile. We propose that a clumpy/inhomogeneous ambient medium is responsible for the observed rotation measure. Using equipartition magnetic field, we derive the electron density of 2×1042\times10^{4}\simcm3^{-3}. Such an electron density is consistent with the cloud of narrow line emission region around the central engine. We also discuss the magnetic field configuration from black hole scale to pc scale and the origin of low polarization.Comment: 8 pages, 8 figures, accepted for publication in Ap

    Classical and quantum evolution of non-isentropic hot singular layers in finite-temperature general relativity

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    The spherically symmetric layer of matter is considered within the frameworks of general relativity. We perform generalization of the already known theory for the case of nonconstant surface entropy and finite temperature. We also propose the minisuperspace model to determine the behaviour of temperature field and perform the Wheeler-DeWitt quantization.Comment: final version, published in GRG as a lette
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