98 research outputs found
Hamiltonian structures of fermionic two-dimensional Toda lattice hierarchies
By exhibiting the corresponding Lax pair representations we propose a wide
class of integrable two-dimensional (2D) fermionic Toda lattice (TL)
hierarchies which includes the 2D N=(2|2) and N=(0|2) supersymmetric TL
hierarchies as particular cases. We develop the generalized graded R-matrix
formalism using the generalized graded bracket on the space of graded operators
with involution generalizing the graded commutator in superalgebras, which
allows one to describe these hierarchies in the framework of the Hamiltonian
formalism and construct their first two Hamiltonian structures. The first
Hamiltonian structure is obtained for both bosonic and fermionic Lax operators
while the second Hamiltonian structure is established for bosonic Lax operators
only.Comment: 12 pages, LaTeX, the talks delivered at the International Workshop on
Classical and Quantum Integrable Systems (Dubna, January 24 - 28, 2005) and
International Conference on Theoretical Physics (Moscow, April 11 - 16, 2005
AC/DC Susceptibility of the Heavy-Fermion Superconductor CePt3Si under Pressure
We have investigated the pressure dependence of ac and dc susceptibilities of
the heavy-fermion superconductor CePt3Si (Tc= 0.75 K) that coexists with
antiferromagnetism (TN = 2.2 K). As hydrostatic pressure is increased, Tc first
decreases rapidly, then rather slowly near the critical pressure Pc = 0.6 GPa
and shows a stronger decrease again at higher pressures, where Pc is the
pressure at which TN becomes zero. A transition width and a difference in the
two transition temperatures defined in the form of structures in the
out-of-phase component of ac susceptibilities also become small near Pc,
indicating that a double transition observed in CePt3Si is caused by some
inhomogeneous property in the sample that leads to a spatial variation of local
pressure. A sudden increase in the Meissner fraction above Pc suggests the
influence of antiferromagnetism on superconductivity.Comment: 4 pages with 5 figures. This paper will be published in J. Phys. Soc.
Jp
Latitudinal distribution of the deuterium to hydrogen ratio in the atmospheric water vapor retrieved from IMG/ADEOS data
Reconstruction of smooth and discontinuous components of solutions to linear ill-posed problems
A posteriori calculation of delta O-18 and delta D in atmospheric water vapour from ground-based near-infrared FTIR retrievals of (H2O)-O-16, H2O)-O-18, and (HDO)-O-16
Search for Lepton-Flavor-Violating Decays of B Mesons
We have searched a sample of 9.6 million BB-bar events for the
lepton-flavor-violating decays B --> h e^{+-} mu^{-+}, B^+ --> h^- e^+ e^+, B^+
--> h^- e^+ mu^+, and B^+ --> h^- mu^+ mu^+, where h is pi, K, rho, and
K*(892), a total of sixteen modes. We find no evidence for these decays, and
place 90% confidence level upper limits on their branching fractions that range
from 1.0 to 8.3 X 10^{-6}.Comment: 8 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, PRD R
Non-Centrosymmetric Heavy-Fermion Superconductors
In this chapter we discuss the physical properties of a particular family of
non-centrosymmetric superconductors belonging to the class heavy-fermion
compounds. This group includes the ferromagnet UIr and the antiferromagnets
CeRhSi3, CeIrSi3, CeCoGe3, CeIrGe3 and CePt3Si, of which all but CePt3Si become
superconducting only under pressure. Each of these superconductors has
intriguing and interesting properties. We first analyze CePt3Si, then review
CeRhSi3, CeIrSi3, CeCoGe3 and CeIrGe3, which are very similar to each other in
their magnetic and electrical properties, and finally discuss UIr. For each
material we discuss the crystal structure, magnetic order, occurrence of
superconductivity, phase diagram, characteristic parameters, superconducting
properties and pairing states. We present an overview of the similarities and
differences between all these six compounds at the end.Comment: To appear in "Non-Centrosymmetric Superconductors: Introduction and
Overview", Lecture Notes in Physics 847, edited by E. Bauer and M. Sigrist
(Springer-Verlag, Berlin Heidelberg, 2012) Chap. 2, pp. 35-7
Lepton flavor violation decays in the topcolor-assisted technicolor model and the littlest Higgs model with parity
The new particles predicted by the topcolor-assisted technicolor ()
model and the littlest Higgs model with T-parity (called model) can
induce the lepton flavor violation () couplings at tree level or one loop
level, which might generate large contributions to some processes. Taking
into account the constraints of the experimental data on the relevant free
parameters, we calculate the branching ratios of the decay processes
with = , and
in the context of these two kinds of new physics models. We find
that the model and the model can indeed produce significant
contributions to some of these decay processes.Comment: 24 pages, 7 figure
Study of the process in the c.m. energy range from threshold to 2 GeV with the CMD-3 detector
Using a data sample of 6.8 pb collected with the CMD-3 detector at the
VEPP-2000 collider we select about 2700 events of the process and measure its cross section at 12 energy ponts with about
6\% systematic uncertainty. From the angular distribution of produced nucleons
we obtain the ratio
Measurement of the cross section with the CMD-3 detector at the VEPP-2000 collider
The process has been studied in the
center-of-mass energy range from 1500 to 2000\,MeV using a data sample of 23
pb collected with the CMD-3 detector at the VEPP-2000 collider.
Using about 24000 selected events, the cross
section has been measured with a systematic uncertainty decreasing from 11.7\%
at 1500-1600\,MeV to 6.1\% above 1800\,MeV. A preliminary study of
production dynamics has been performed
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