449 research outputs found
`St\"uckelberg interferometry' with ultracold molecules
We report on the realization of a time-domain `St\"uckelberg interferometer',
which is based on the internal state structure of ultracold Feshbach molecules.
Two subsequent passages through a weak avoided crossing between two different
orbital angular momentum states in combination with a variable hold time lead
to high-contrast population oscillations. This allows for a precise
determination of the energy difference between the two molecular states. We
demonstrate a high degree of control over the interferometer dynamics. The
interferometric scheme provides new possibilities for precision measurements
with ultracold molecules.Comment: 4 pages, 5 figure
Towards the electron EDM search. Theoretical study of PbF
We report ab initio relativistic correlation calculations of potential curves
and spectroscopic constants for four lowest-lying electronic states of the lead
monofluoride. We also calculated parameters of the spin-rotational Hamiltonian
for the ground and the first excited states including P,T-odd and P-odd terms.
In particular, we have obtained hyperfine constants of the Pb nucleus.
For the state MHz, MHz and for
the A MHz, MHz. Our values of
the ground state hyperfine constants are in good agreement with the previous
theoretical studies. We discuss and explain seeming disagreement in the sign of
the constant with the recent experimental data. The effective
electric field on the electron , which is important for the planned
experiment to search for the electric dipole moment of the electron, is found
to be 3.3 * 10^{10} V/cm
Measurement of the electron electric dipole moment using GdIG
A new method for the detection of the electron edm using a solid is
described. The method involves the measurement of a voltage induced across the
solid by the alignment of the samples magnetic dipoles in an applied magnetic
field, H. A first application of the method to GdIG has resulted in a limit on
the electron edm of 5E-24 e-cm, which is a factor of 40 below the limit
obtained from the only previous solid-state edm experiment. The result is
limited by the imperfect discrimination of an unexpectedly large voltage that
is even upon the reversal of the sample magnetization.Comment: 10 pages, 5 figures, v2:references corrected, submitted to PRL,
v3:added labels to figure
All electromagnetic form factors
The electromagnetic form factors of spin-1/2 particles are known, but due to
historical reasons only half of them are found in many textbooks. Given the
importance of the general result, its model independence, its connection to
discrete symmetries and their violations we made an effort to derive and
present the general result based only on the knowledge of Dirac equation. We
discuss the phenomenology connected directly with the form factors, and spin
precession in external fields including time reversal violating terms. We apply
the formalism to spin-flip synchrotron radiation and suggest pedagogical
projects.Comment: Latex, 22 page
Electric Dipole moments of charged leptons and lepton flavor violating interactions in the general two Higgs Doublet model
We calculate the electric dipole moment of electron using the experimental
result of muon electric dipole moment and upper limit of the BR(\mu -->
e\gamma) in the framework of the general two Higgs doublet model. Our
prediction is 10^{-32} e-cm, which lies in the experimental current limits.
Further, we obtain constraints for the Yukawa couplings \bar{\xi}^{D}_{N,\tau
e} and \bar{\xi}^{D}_{N,\tau\mu}. Finally we present an expression which
connects the BR(\tau\to \mu\gamma) and the electric dipole moment of
\tau-lepton and study the relation between these physical quantities.Comment: 8 pages, 4 Figures (required epsf sty
The Constraints on CP Violating Phases in models with a dynamical gluino phase
We have analyzed the electric dipole moment and the Higgs mass constraints on
the supersymmetric model which offers dynamical solutions to the \mu and strong
CP problems. The trilinear coupling phases, and \tan\beta-|\mu| are strongly
correlated, particularly in the low-\tan\beta regime. Certain values of the
phases of the trilinear couplings are forbidden, whereas the CP violating phase
from the chargino sector is imprisoned to lie near a CP conserving point, by
the Higgs mass and electric dipole moment constraints.Comment: 19 pages, 11 eps fig
Top quark electric and chromo electric dipole moments in the general two Higgs Doublet model
We study the electric and chromo electric dipole moment of top quark in the
general two Higgs Doublet model (model III). We analyse the dependency of this
quantity to the new phases coming from the complex Yukawa couplings and masses
of charged and neutral Higgs bosons. We observe that the electric and chromo
elecric dipole moments of top quark are at the order of 10^{-21} e cm and
10^{-20} g_s cm, which are extremely large values compared to ones calculated
in the SM and also two Higgs Doublet model with real Yukawa couplings.Comment: 9 pages,10 figure
Measurement of the electron's electric dipole moment using YbF molecules: methods and data analysis
We recently reported a new measurement of the electron's electric dipole
moment using YbF molecules [Nature 473, 493 (2011)]. Here, we give a more
detailed description of the methods used to make this measurement, along with a
fuller analysis of the data. We show how our methods isolate the electric
dipole moment from imperfections in the experiment that might mimic it. We
describe the systematic errors that we discovered, and the small corrections
that we made to account for these. By making a set of additional measurements
with greatly exaggerated experimental imperfections, we find upper bounds on
possible uncorrected systematic errors which we use to determine the systematic
uncertainty in the measurement. We also calculate the size of some systematic
effects that have been important in previous electric dipole moment
measurements, such as the motional magnetic field effect and the geometric
phase, and show them to be negligibly small in the present experiment. Our
result is consistent with an electric dipole moment of zero, so we provide
upper bounds to its size at various confidence levels. Finally, we review the
prospects for future improvements in the precision of the experiment.Comment: 35 pages, 15 figure
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