A Study of the S=1/2 Alternating Chain using Multiprecision Methods

In this paper we present results for the ground state and low-lying excitations of the $S=1/2$ alternating Heisenberg antiferromagnetic chain. Our more conventional techniques include perturbation theory about the dimer limit and numerical diagonalization of systems of up to 28 spins. A novel application of multiple precision numerical diagonalization allows us to determine analytical perturbation series to high order; the results found using this approach include ninth-order perturbation series for the ground state energy and one magnon gap, which were previously known only to third order. We also give the fifth-order dispersion relation and third-order exclusive neutron scattering structure factor for one-magnon modes and numerical and analytical binding energies of S=0 and S=1 two-magnon bound states.Comment: 16 pages, 9 figures. for submission to Phys.Rev.B. PICT files of figs available at http://csep2.phy.ornl.gov/theory_group/people/barnes/barnes.htm

A certified plasmid reference material for the standardisation of BCR-ABL1 mRNA quantification by real-time quantitative PCR

Serial quantification of BCR–ABL1 mRNA is an important therapeutic indicator in chronic myeloid leukaemia, but there is a substantial variation in results reported by diff

Amygdala reactivity to emotional faces at high and low intensity in generalized social phobia: A 4T functional MRI study

Contains fulltext : 55412.pdf (publisher's version ) (Closed access)Using functional magnetic resonance imaging, we measured amygdala reactivity to faces varying on emotional intensity in subjects with generalized social phobia (GSP) and matched healthy controls, and observed greater bilateral activation to high (vs. low) intensity expressions in the phobic group, suggesting that more arousing social–emotional cues contribute to limbic hyperactivity in GSP

Limbic reactivity to partner reputation and rejection in social phobia: fMRl of the trust game

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