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Title: Approximations for crossing two nearby spin resonances

Publication Date:
Sponsoring Org.:
OSTI Identifier:
Grant/Contract Number:
AC02-98CH10886; AC02-05CH11231
Resource Type:
Journal Article: Published Article
Journal Name:
Physical Review Special Topics - Accelerators and Beams
Additional Journal Information:
Journal Volume: 18; Journal Issue: 1; Related Information: CHORUS Timestamp: 2017-06-22 23:15:50; Journal ID: ISSN 1098-4402
American Physical Society
Country of Publication:
United States

Citation Formats

Ranjbar, V. H. Approximations for crossing two nearby spin resonances. United States: N. p., 2015. Web. doi:10.1103/PhysRevSTAB.18.014001.
Ranjbar, V. H. Approximations for crossing two nearby spin resonances. United States. doi:10.1103/PhysRevSTAB.18.014001.
Ranjbar, V. H. 2015. "Approximations for crossing two nearby spin resonances". United States. doi:10.1103/PhysRevSTAB.18.014001.
title = {Approximations for crossing two nearby spin resonances},
author = {Ranjbar, V. H.},
abstractNote = {},
doi = {10.1103/PhysRevSTAB.18.014001},
journal = {Physical Review Special Topics - Accelerators and Beams},
number = 1,
volume = 18,
place = {United States},
year = 2015,
month = 1

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevSTAB.18.014001

Citation Metrics:
Cited by: 2works
Citation information provided by
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  • Solutions to the T-BMT spin equation have to date been confined to the single resonance crossing. However, in reality most cases of interest concern the overlapping of several resonances. To date there has been several serious studies of this problem; however, a good analytical solution or even approximation has eluded the community. We show that the T-BMT equation can be transformed into a Hill’s like equation. In this representation it can be shown that, while the single resonance crossing represents the solution to the Parabolic Cylinder equation, the overlapping case becomes a parametric type of resonance. We present possible approximationsmore » for both the non-accelerating case and accelerating case.« less
  • The problem of crossing-symmetry violation in calculations of Regge cuts in absorption-model approximations is discussed for reactions in which spin effects are important. It is shown that for reactions that have any type of exact internal symmetry, rules can be derived theoretically for calculating two-reggeon cuts with no difficulties with crossing symmetry when specific intermediate states are taken into account.
  • The first observation of level-crossing resonances in ortho-para conversion is presented. A sharp increase in the conversion rate of gaseous {sup 13}CH{sub 3}F is observed when an applied electricfield produces crossing of molecular ortho and para levels. The experimental results are described well by the spin conversion theory based on intramolecular ortho-para state mixing. The results provide direct identification of the levels being mixed and the interaction responsible. The observed spectrum may be considered as an example of Doppler-free spectroscopy. {copyright} {ital 1996 The American Physical Society.}
  • The nearby isolated neutron stars (INSs) are a group of seven relatively slowly rotating neutron stars that show thermal X-ray spectra, most with broad absorption features. They are interesting both because they may allow one to determine fundamental neutron-star properties by modeling their spectra, and because they appear to be a large fraction of the overall neutron-star population. Here, we describe a series of XMM -Newton observations of the nearby INS RX J0806.4-4123, taken as part of larger program of timing studies. From these, we limit the spin-down rate to nu-dot=(-4.3+-2.3)x10{sub -16}Hz s{sup -1}. This constrains the dipole magnetic fieldmore » to be <3.7 x 10{sup 13} G at 2sigma, significantly less than the field of approx10{sup 14} G implied by simple models for the X-ray absorption found at 0.45 keV. We confirm that the spectrum is thermal and stable (to within a few percent), but find that the 0.45 keV absorption feature is broader and more complex than previously thought. Considering the population of INSs, we find that magnetic field decay from an initial field of approx<3 x 10{sup 14} G accounts most naturally for their timing and spectral properties, both qualitatively and in the context of the models for field decay of Pons and collaborators.« less