1,457 research outputs found

    Residual interaction effects on deeply bound pionic states in Sn and Pb isotopes

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    We have studied the residual interaction effects theoretically on the deeply bound pionic states in Pb and Sn isotopes. We need to evaluate the residual interaction effects carefully in order to deduce the nuclear medium effects for pion properties, which are believed to provide valuable information on nuclear chiral dynamics. The s- and p-wave πN\pi-N interactions are used for the pion-nucleon residual interactions. We show that the complex energy shifts are around [(10-20)+i(2-7)]keV for 1s states in Sn, which should be taken into account in the analyses of the high precision data of deeply bound pionic 1s1s states in Sn isotopes.Comment: REVTEX4, 6 pages, 5 tables, Submitted to Phys. Rev. C, Some explanations are added in Version

    The Pseudogap in La(2-x)Sr(x)CuO(4): A Raman Viewpoint

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    We report the results of Raman scattering experiments on single crystals of La(2-x)Sr(x)CuO(4) [La214] as a function of temperature and doping. In underdoped compounds low-energy B1g spectral weight is depleted in association with the opening of a pseudogap on regions of the Fermi surface located near (pi, 0) and (0, pi). The magnitude of the depletion increases with decreasing doping, and in the most underdoped samples, with decreasing temperature. The spectral weight that is lost at low-energies (omega < 800 cm-1) is transferred to the higher energy region normally occupied by multi-magnon scattering. From the normal state B2g spectra we have determined the scattering rate Gamma(omega, T) of qausiparticles located near the diagonal directions in k-space, (pi/2, pi/2) regions. In underdoped compounds, Gamma(omega, T) is suppressed at low temperatures for energies less than Eg(x) ~ 800 cm-1. The observed doping dependence of the two-magnon scattering and the scattering rate suppression thus suggest that the pseudogap is characterized by an energy scale Eg ~ J, where J is the antiferromagnetic super-exchange energy. Comparison with the results from other techniques provides a consistent picture of the pseudogap in La214.Comment: 6 pages, 5 figures, minor revisions include correct form of the B2g Raman response function and new figures of the recalculated B2g scattering rate. Presented at the APS March99 Meeting, accepted for publication in the Canadian Journal of Physic

    Performance measurements of mixed data acquisition and LAN traffic on a credit-based flow-controlled ATM network

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    Nuclear Quadrupole Effects in Deeply Bound Pionic Atoms

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    We have studied nuclear quadrupole deformation effects in deeply bound pionic atoms theoretically. We have evaluated the level shifts and widths of the hyperfine components using the first order perturbation theory and compared them with the effects of neutron skin. We conclude that the nuclear quadrupole deformation effects for deeply bound 1s1s and 2p2p states are very difficult to observe and that the effects could be observed for 3d3d states. We also conclude that the deformation effects are sensitive to the parameters of the pion-nucleus optical potential.Comment: Latex 11pages, Figures available on reques

    Interlayer magnetoresistance due to chiral soliton lattice formation in hexagonal chiral magnet CrNb3S6

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    We investigate the interlayer magnetoresistance (MR) along the chiral crystallographic axis in the hexagonal chiral magnet CrNb3S 6. In a region below the incommensurate-commensurate phase transition between the chiral soliton lattice and the forced ferromagnetic state, a negative MR is obtained in a wide range of temperature, while a small positive MR is found very close to the Curie temperature. Normalized data of the negative MR almost falls into a single curve and is well fitted by a theoretical equation of the soliton density, meaning that the origin of the MR is ascribed to the magnetic scattering of conduction electrons by a nonlinear, periodic, and countable array of magnetic soliton kinks. © 2013 American Physical Society

    Nano-Hall sensors with granular Co-C

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    We analyzed the performance of Hall sensors with different Co-C ratios, deposited directly in nano-structured form, using Co2(CO)8Co_2(CO)_8 gas molecules, by focused electron or ion beam induced deposition. Due to the enhanced inter-grain scattering in these granular wires, the Extraordinary Hall Effect can be increased by two orders of magnitude with respect to pure Co, up to a current sensitivity of 1Ω/T1 \Omega/T. We show that the best magnetic field resolution at room temperature is obtained for Co ratios between 60% and 70% and is better than 1μT/Hz1/21 \mu T/Hz^{1/2}. For an active area of the sensor of 200×200nm2200 \times 200 nm^2, the room temperature magnetic flux resolution is ϕmin=2×105ϕ0\phi_{min} = 2\times10^{-5}\phi_0, in the thermal noise frequency range, i.e. above 100 kHz.Comment: 5 pages, 4 figure
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