8 research outputs found
A possibility for precise Weinberg angle measurement in centrosymmetric crystals with axis
We demonstrate that parity nonconserving interaction due to the nuclear weak
charge Q_W leads to nonlinear magnetoelectric effect in centrosymmetric
paramagnetic crystals. It is shown that the effect exists only in crystals with
special symmetry axis k. Kinematically, the correlation (correction to energy)
has the form H_PNC ~ Q_W (E,[B,k])(B,k), where B and E are the external
magnetic and electric fields. This gives rise to magnetic induction M_PNC ~ Q_W
{k(B,[k,E]) + [k,E](B,k)}. To be specific we consider rare-earth trifluorides
and, in particular, dysprosium trifluoride which looks the most suitable for
experiment. We estimate the optimal temperature for the experiment to be of a
few kelvin. For the magnetic field B = 1 T and the electric field E = 10 kV/cm,
the expected magnetic induction is 4 \pi M_PNC = 0.5 * 10^-11 G, six orders of
magnitude larger than the best sensitivity currently under discussion.
Dysprosium has several stable isotopes, and so, comparison of the effects for
different isotopes provides possibility for precise measurement of the Weinberg
angle.Comment: 7 pages, 1 figure, 2 tables; version 2 - added discussion of neutron
distribution uncertaint
A suggested search for 207Pb nuclear Schiff moment in PbTiO3 ferroelectric
We suggest two types of experiments, NMR and macroscopic magnetometry, with
solid PbTiO3 to search for the nuclear Schiff moment of 207Pb. Both kinds of
experiments promise substantial improvement over the presently achieved
sensitivities. Statistical considerations show that the improvement of the
current sensitivity can be up to 10 orders of magnitude for the magnetometry
experiment and up to 6 orders of magnitude for the NMR experiment. Such
significant enhancement is due to the strong internal electric field of the
ferroelectric, as well as due to the possibility to cool the nuclear-spin
subsystem in the compound down to nanokelvin temperatures.Comment: 4 pages; revised sensitivity estimate for NMR experimen
Enhancement of the electron electric dipole moment in gadolinium garnets
Effects caused by the electron electric dipole moment (EDM) in gadolinium
garnets are considered. Experimental studies of these effects could improve
current upper limit on the electron EDM by several orders of magnitude. We
suggest a consistent theoretical model and perform calculations of observable
effects in gadolinium gallium garnet and gadolinium iron garnet. Our
calculation accounts for both direct and exchange diagrams.Comment: 9 page
First-principles design and subsequent synthesis of a material to search for the permanent electric dipole moment of the electron
We describe the first-principles design and subsequent synthesis of a new
material with the specific functionalities required for a solid-state-based
search for the permanent electric dipole moment of the electron. We show
computationally that perovskite-structure europium barium titanate should
exhibit the required large and pressure-dependent ferroelectric polarization,
local magnetic moments, and absence of magnetic ordering even at liquid helium
temperature. Subsequent synthesis and characterization of
EuBaTiO ceramics confirm the predicted desirable
properties.Comment: Nature Materials, in pres
Flavour Physics of Leptons and Dipole Moments.
This chapter of the report of the ``Flavour in the era of the LHC'' Workshop
discusses the theoretical, phenomenological and experimental issues related to
flavour phenomena in the charged lepton sector and in flavour-conserving
CP-violating processes. We review the current experimental limits and the main
theoretical models for the flavour structure of fundamental particles. We
analyze the phenomenological consequences of the available data, setting
constraints on explicit models beyond the Standard Model, presenting benchmarks
for the discovery potential of forthcoming measurements both at the LHC and at
low energy, and exploring options for possible future experiments.Comment: Report of Working Group 3 of the CERN Workshop ``Flavour in the era
of the LHC'', Geneva, Switzerland, November 2005 -- March 200