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Title: Theoretical studies of the 6s{sup 2}S{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2}{yields}5d{sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} parity-nonconserving transition amplitude in Ba{sup +} and associated properties

Abstract

It is widely believed that the standard model of particle physics is just an intermediate step in understanding the properties of the elementary physics in nature and the interactions between them. Over the past twenty years, studies of the parity nonconservation in atomic systems based on nonaccelerator methods have made remarkable progress. An experiment to measure parity nonconservation in singly ionized barium has been proposed as an independent test of the standard model. We have employed the relativistic coupled-cluster theory to calculate the parity nonconserving 6s{sup 2}S{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2}{yields}5d{sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} transition amplitude and associated properties. We have also shown contributions from various intermediate states which play a significant role in the determination of this transition amplitude.

Authors:
; ; ;  [1];  [2];  [2]
  1. Max Planck Institute for the Physics of Complex Systems, D-01187 Dresden (Germany)
  2. (India)
Publication Date:
OSTI Identifier:
20982304
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.75.032507; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; BARIUM IONS; CATIONS; CORRECTIONS; ELECTRONIC STRUCTURE; INTERMEDIATE STATE; PARTICLES; RELATIVISTIC RANGE; STANDARD MODEL; TRANSITION AMPLITUDES; WEAK INTERACTIONS

Citation Formats

Sahoo, B. K., Das, B. P., Chaudhuri, R. K., Mukherjee, D., Non-Accelerator Particle Physics Group, Indian Institute of Astrophysics, Bangalore-34, and Department of Physical Chemistry, Indian Association for Cultivation of Science, Kolkata-700 032. Theoretical studies of the 6s{sup 2}S{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2}{yields}5d{sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} parity-nonconserving transition amplitude in Ba{sup +} and associated properties. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.032507.
Sahoo, B. K., Das, B. P., Chaudhuri, R. K., Mukherjee, D., Non-Accelerator Particle Physics Group, Indian Institute of Astrophysics, Bangalore-34, & Department of Physical Chemistry, Indian Association for Cultivation of Science, Kolkata-700 032. Theoretical studies of the 6s{sup 2}S{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2}{yields}5d{sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} parity-nonconserving transition amplitude in Ba{sup +} and associated properties. United States. doi:10.1103/PHYSREVA.75.032507.
Sahoo, B. K., Das, B. P., Chaudhuri, R. K., Mukherjee, D., Non-Accelerator Particle Physics Group, Indian Institute of Astrophysics, Bangalore-34, and Department of Physical Chemistry, Indian Association for Cultivation of Science, Kolkata-700 032. Thu . "Theoretical studies of the 6s{sup 2}S{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2}{yields}5d{sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} parity-nonconserving transition amplitude in Ba{sup +} and associated properties". United States. doi:10.1103/PHYSREVA.75.032507.
@article{osti_20982304,
title = {Theoretical studies of the 6s{sup 2}S{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2}{yields}5d{sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} parity-nonconserving transition amplitude in Ba{sup +} and associated properties},
author = {Sahoo, B. K. and Das, B. P. and Chaudhuri, R. K. and Mukherjee, D. and Non-Accelerator Particle Physics Group, Indian Institute of Astrophysics, Bangalore-34 and Department of Physical Chemistry, Indian Association for Cultivation of Science, Kolkata-700 032},
abstractNote = {It is widely believed that the standard model of particle physics is just an intermediate step in understanding the properties of the elementary physics in nature and the interactions between them. Over the past twenty years, studies of the parity nonconservation in atomic systems based on nonaccelerator methods have made remarkable progress. An experiment to measure parity nonconservation in singly ionized barium has been proposed as an independent test of the standard model. We have employed the relativistic coupled-cluster theory to calculate the parity nonconserving 6s{sup 2}S{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2}{yields}5d{sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} transition amplitude and associated properties. We have also shown contributions from various intermediate states which play a significant role in the determination of this transition amplitude.},
doi = {10.1103/PHYSREVA.75.032507},
journal = {Physical Review. A},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • The two metastable levels 5d {sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} and 5d {sup 2}D{sub 5} at {sub {approx}}{sub sol{approx}} at {sub 2} in Ba II both show extremely long lifetimes of the order of several tens of seconds each. This has been found both by experiments and by theoretical predictions. The small transition probabilities associated with these two levels make them interesting and challenging for theoreticians as well as for experimentalists. Several calculations and measurements of these two lifetimes have been made previously but discrepancies between the results are present. This article presents values ofmore » {tau}=89.4{+-}15.6 s for the {sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} level and {tau}=32.0{+-}4.6 s for the {sup 2}D{sub 5} at {sub {approx}}{sub sol{approx}} at {sub 2} level measured in a beam-laser experiment performed at the ion storage ring CRYRING. These values are supported by our new calculations resulting in {tau}=82.0 s for the {sup 2}D{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2} level and {tau}=31.6 s for the {sup 2}D{sub 5} at {sub {approx}}{sub sol{approx}} at {sub 2} level.« less
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  • Resonance enhanced multiphoton ionization of the X{sub 1} {sup 2}{pi}{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2} state of lead monofluoride ({sup 208}Pb{sup 19}F) via the B {sup 2}{sigma}{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2} state is demonstrated. The ionization potential is observed to be 7.54(1) eV. Limits on the lifetime of the B state are found to be consistent with that reported by Chen et al. The transition dipole moment for the X{sub 1}{yields}B transition is found to be 0.005(1) a.u. Limits on the ionization cross section of the B state are found.
  • Experimental cross sections are reported for the Fe{sup 13+} coronal green line transition 3s{sup 2}3p {sup 2}P{sub 1} at {sub {approx}}{sub sol{approx}} at {sub 2}{sup o}-3s{sup 2}3p {sup 2}P{sub 3} at {sub {approx}}{sub sol{approx}} at {sub 2}{sup o} at {lambda}5303 A ring (2.338 eV). The center-of-mass interaction energies are in the range 1.7 eV (below threshold) through threshold, to 6.6 eV (2.9xthreshold). Data are compared with results of a 135-level Breit-Pauli R-matrix theory. Present experiment detects a strong maximum in the excitation cross section of magnitude 15x10{sup -16} cm{sup 2} at 2.6 eV. Smaller structures are observed between 3 eVmore » and 6.6 eV, with a maximum cross section never exceeding about 1.2x10{sup -16} cm{sup 2}. All features are due to enhancement of the direct excitation via a multitude of narrow, closely-spaced resonances calculated by the theory, the effects of which are convoluted by the 125 meV energy resolution of the present experiment. Iron is present in practically every astrophysical object, as well as being an impurity in fusion plasmas. Present results are the highest charge state in any ion for which an absolute excitation cross section has been measured.« less
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