61 research outputs found
Photofragment angular momentum distributions in the molecular frame. II. Single state dissociation, multiple state interference, and nonaxial recoil in photodissociation of polyatomic molecules
Stark shift and parity non-conservation for near-degenerate states of xenon
We identify a pair of near-degenerate states of opposite parity in atomic Xe,
the 5p^5 10s \,\, ^2[3/2]_2^o at cm and 5p^5 6f
\,\, ^2[5/2]_2 at cm, for which parity- and
time-odd effects are expected to be enhanced by the small energy separation. We
present theoretical calculations which indicate narrow widths for both states
and we report a calculated value for the weak matrix element, arising from
configuration mixing, of Hz for Xe. In addition, we measured
the Stark effect of the and
() states. The Stark-shift of the states
is observed to be negative, revealing the presence of nearby states at
higher energies, which have not been observed before. The Stark-shift
measurements imply an upper limit on the weak matrix element of Hz
for the near-degenerate states (10s \,\, ^2[3/2]_2^o and 6f \,\,
^2[5/2]_2), which is in agreement with the presented calculations.Comment: 11 pages, 6 figure
Measurements of Cl-atom photofragment angular momentum distributions in the photodissociation of Cl-2 and ICl
Polarized Proton Beams from Laser-induced Plasmas
We report on the concept of an innovative source to produce polarized
proton/deuteron beams of a kinetic energy up to several GeV from a laser-driven
plasma accelerator. Spin effects have been implemented into the PIC simulation
code VLPL to make theoretical predictions about the behavior of proton spins in
laser-induced plasmas. Simulations of spin-polarized targets show that the
polarization is conserved during the acceleration process. For the experimental
realization, a polarized HCl gas-jet target is under construction using the
fundamental wavelength of a Nd:YAG laser system to align the HCl bonds and
simultaneously circular polarized light of the fifth harmonic to
photo-dissociate, yielding nuclear polarized H atoms. Subsequently, their
degree of polarization is measured with a Lamb-shift polarimeter. The final
experiments, aiming at the first observation of a polarized particle beam from
laser-generated plasmas, will be carried out at the 10 PW laser system SULF at
SIOM/Shanghai.Comment: 7 pages, 7 figure
Enhanced nuclear spin dependent parity violation effects using the 199HgH molecule
Electron interactions with the nuclear-spin-dependent (NSD) parity
non-conserving (PNC) anapole moment are strongly enhanced within heteronuclear
diatomic molecules. A novel, low-energy optical rotation experiment is being
proposed with the aim of observing NSD PNC interactions in HgH. Based on the
relativistic coupled cluster method we present a complete calculation of the
circular polarization parameter for the optical
transition of HgH, where is a dimensionless constant determined by the
nuclear anapole moment. This provides an improvement in sensitivity to NSD PNC
by 2 -- 3 orders of magnitude over the leading atomic Xe, Hg, Tl, Pb and Bi
optical rotation experiments, and shows that the proposed measurement will be
sensitive enough to extract the Hg anapole moment and shed light on the
underlying theory of hadronic parity violation
Oriented chlorine atoms as a probe of the nonadiabatic photodissociation dynamics of molecular chlorine
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