145,907 research outputs found
Heavy Quarkonium
I review heavy quarkonium physics in view of recent experimental results. In
particular, I discuss new results on spin singlet states, photon and hadronic
transitions, D-states and discovery of yet unexplained narrow X(3872) state.Comment: 15 pages, 16 figures. 2nd version: minor changes in references and
text. Invited talk presented at the 21st International Symposium On Lepton
And Photon Interactions At High Energies (LP03) 11-16 August 2003, Batavia,
Illinoi
Automated weighing by sequential inference in dynamic environments
We demonstrate sequential mass inference of a suspended bag of milk powder
from simulated measurements of the vertical force component at the pivot while
the bag is being filled. We compare the predictions of various sequential
inference methods both with and without a physics model to capture the system
dynamics. We find that non-augmented and augmented-state unscented Kalman
filters (UKFs) in conjunction with a physics model of a pendulum of varying
mass and length provide rapid and accurate predictions of the milk powder mass
as a function of time. The UKFs outperform the other method tested - a particle
filter. Moreover, inference methods which incorporate a physics model
outperform equivalent algorithms which do not.Comment: 5 pages, 7 figures. Copyright IEEE (2015
Bound States in n Dimensions (Especially n = 1 and n = 2)
We stress that in contradiction with what happens in space dimensions , there is no strict bound on the number of bound states with the same
structure as the semi-classical estimate for large coupling constant and give,
in two dimensions, examples of weak potentials with one or infinitely many
bound states. We derive bounds for one and two dimensions which have the
"right" coupling constant behaviour for large coupling.Comment: Talk given by A. Martin at Les Houches, October 2001, to appear in
"Few-Body Problems
Phonon Squeezing in a Superconducting Molecular Transistor
Josephson transport through a single molecule or carbon nanotube is
considered in the presence of a local vibrational mode coupled to the
electronic charge. The ground-state solution is obtained exactly in the limit
of a large superconducting gap, and is extended to the general case by
variational analysis. Coherent charge fluctuations are entangled with
non-classical phonon states. The Josephson current induces squeezing of the
phonon mode, which is controlled by the superconducting phase difference and by
the junction asymmetry. Optical probes of non-classical phonon states are
briefly discussed
The period-luminosity and period-radius relations of Type II and anomalous Cepheids
Method: In an accompanying paper (arXiv: 1705.00886) we determined luminosity
and effective temperature for the 335 T2Cs and ACs in the LMC and SMC
discovered in the OGLE-III survey, by constructing the spectral energy
distribution (SED) and fitting this with model atmospheres and a dust radiative
transfer model (in the case of dust excess). Building on these results we study
the PL and PR relations.
Using existing pulsation models for RR Lyrae and classical Cepheids we derive
the period-luminosity-mass-temperature-metallicity relations, and then estimate
the pulsation mass.
Results: The PL relation for the T2Cs does not appear to depend on
metallicity, and, excluding the dusty RV Tau stars, is (for days). Relations for fundamental and first overtone
LMC ACs are also presented. The PR relation for T2C also shows little or no
dependence on metallicity or period. Our preferred relation combines SMC and
LMC stars and all T2C subclasses, and is .
Relations for fundamental and first overtone LMC ACs are also presented. The
pulsation masses from the RR Lyrae and classical Cepheid pulsation models agree
well for the short period T2Cs, the BL Her subtype, and ACs, and are consistent
with estimates in the literature, i.e. \msol\ and
\msol, respectively. The masses of the W Vir appear
similar to the BL Her. The situation for the pWVir and RV Tau stars is less
clear. For many RV Tau the masses are in conflict with the standard picture of
(single-star) post-AGB evolution, the masses being either too large (
1 \msol) or too small ( 0.4 \msol).Comment: A&A accepte
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