1,838 research outputs found
Lifetime of Kaonium
The kaon--antikaon system is studied in both the atomic and the strongly
interacting sector. We discuss the influence of the structures of the
and the mesons on the lifetime of kaonium. The strong
interactions are generated by vector meson exchange within the framework of the
standard invariant effective Lagrangian. In the atomic
sector, the energy levels and decay widths of kaonium are determined by an
eigenvalue equation of the Kudryavtsev--Popov type, with the strong interaction
effects entering through the complex scattering length for scattering
and annihilation. The presence of two scalar mesons, and ,
leads to a ground state energy for the kaonium atom that is shifted above the
point Coulomb value by a few hundred eV. The effect on the lifetime for the
kaonium decay into two pions is much more dramatic. This lifetime is reduced by
two orders of magnitude from sec for annihilation in a
pure Coulomb field down to sec when the strong
interactions are included. The analysis of the two photon decay width of the
suggests a generalization of the molecular picture which reduces the
lifetime of kaonium still further to .Comment: 33 pages, 12 figures;3 new figures and new comment concerning the a
A multifarious understanding of eschatology in Ephesians: A possible solution to a vexing issue
Although an almost forgotten debate, the issue of eschatology in Ephesians remains unresolved and possibly insoluble. However, presuppositions inevitably determine the final outcome of investigations. This latter datum is characterized, indicating the outcome of the investigations of both those who would endorse and those who would deny the premises of the Early Catholicism Hypothesis. By postulating that differences from so-called authentic Pauline letters in Ephesians are merely as a result of addressing a different contingent situation, as well as by accepting that the composite eschatological profile in Ephesians is merely an adaptation of Pauline eschatology to that specific contingent situation, it is argued that it is possible to retain futuristic eschatological dimensions in Ephesians
Umbilical Hernia Incarceration: A Complication of Medical Therapy of Ascites
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73352/1/j.1572-0241.1983.tb01875.x.pd
Shape-memory polymers as flexible resonator substrates for continuously tunable organic DFB lasers
We introduce shape-memory polymers (SMP) as substrate material for active optical devices. As an exemplary application we build a tunable organic semiconductor distributed feedback (DFB) laser. Hence, we transfer a second order Bragg grating with a period of 400 nm into SMP foils by hot embossing. The composite organic gain medium Alq3:DCM evaporated on the SMP substrate serves as laser active material. Mechanical stretching of the substrate increases the grating period temporarily and triggering the shape-memory effect afterwards reduces the period on demand. In this way, we can adjust the grating period to achieve a broad continuously tuning of the laser emission wavelength by 30 nm
Defects of the Broad Ligament of the Uterus
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74780/1/j.1572-0241.1986.tb01505.x.pd
KKbar molecules with momentum-dependent interactions
It is shown that the momentum-dependent kaon-antikaon interactions generated
via vector meson exchange from the standard SU_V(3) x SU_A(3) interaction
Lagrangian lead to a non-local potential in coordinate space that can be
incorporated without approximation into a non-relativistic version of the
Bethe-Salpeter wave equation containing a radial-dependent effective kaon mass
appearing in a fully symmetrized kinetic energy operator, in addition to a
local potential. Estimates of the mass and decay widths of f_0(980) and
a_0(980), considered as KKbar molecules of isospin 0 and 1, as well as for
K^+K^- atomic bound states (kaonium) are presented, and compared with previous
studies of a similar nature. It is argued that without a better knowledge of
hadronic form factors it is not possible to distinguish between the molecular
versus elementary particle models for the structure of the light scalar mesons.Comment: 14 pages, 2 tables, 5 figures. Added subsection on s-channel
exchange, additional remarks on the possible effect of gluon exchange, and 1
additional figur
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