2,939 research outputs found
Photoproduction of the Hypertriton
In the framework of the impulse approximation we study the photoproduction of
the hypertriton H by using realistic He wave functions
obtained as solutions of Faddeev equations with the Reid soft-core potential
for different H wave functions. We obtain relatively small cross
sections of the order of 1 nb. We also find that the influence of Fermi motion
is important, while the effect of different off-shell assumptions on the cross
section is not too significant.Comment: 6 pages in Latex. Talk given at the 15th International Conference on
Few-Body Problems in Physics, Groningen, Netherlands, 22-26 July 1997. To be
published in Nucl. Phys.
Gerasimov-Drell-Hearn Sum Rule and the Discrepancy between the New CLAS and SAPHIR Data
Contribution of the K^+\Lambda channel to the Gerasimov-Drell-Hearn (GDH) sum
rule has been calculated by using the models that fit the recent SAPHIR or CLAS
differential cross section data. It is shown that the two data sets yield quite
different contributions. Contribution of this channel to the forward spin
polarizability of the proton has been also calculated. It is also shown that
the inclusion of the recent CLAS C_x and C_z data in the fitting data base does
not significantly change the result of the present calculation. Results of the
fit, however, reveal the role of the S_{11}(1650), P_{11}(1710), P_{13}(1720),
and P_{13}(1900) resonances for the description of the C_x and C_z data. A
brief discussion on the importance of these resonances is given. Measurements
of the polarized total cross section \sigma_{TT'} by the CLAS, LEPS, and MAMI
collaborations are expected to verify this finding.Comment: 15 pages, 8 figure
Kaon photoproduction on the nucleon: overview of some applications
Some applications of the elementary kaon photoproduction process are
discussed: the investigation of missing resonances in the p(gamma,K+)Lambda
channel, the role of the P_{13}(1720) state in the p(gamma,K0)Sigma+ channel,
and the calculation of the Gerasimov-Drell-Hearn sum rule. For the latter, we
present an extension of our previous study to higher energies.Comment: 3 pages, contribution to FB2000 (Taiwan) March 2000, to be published
in Nucl. Phys.
Kaon photoproduction on the nucleon: Contributions of kaon-hyperon final states to the magnetic moment of the nucleon
By using the Gerasimov-Drell-Hearn (GDH) sum rule and an isobaric model of
kaon photoproduction, we calculate contributions of kaon-hyperon final states
to the magnetic moment of the proton and the neutron. We find that the
contributions are small. The approximation of sigma_{TT'} by sigma_{T} clearly
overestimates the value of the GDH integral. We find a smaller upper bound for
the contributions of kaon-hyperon final states to the proton's anomalous
magnetic moment in kaon photoproduction, and a positive contribution for the
square of the neutron's magnetic moment.Comment: 6 pages, revtex, 1 postscript figure, to appear in Phys. Rev.
Strange Particle Production Via The Weak Interaction
The differential cross sections for the neutrino-induced weak charged current
production of strange particles in the threshold energy region are presented.
The general representation of the weak hadronic current is newly developed in
terms of eighteen unknown invariant amplitudes to parametrize the hadron
vertex. The Born term approximation is used for the numerical calculations in
the framework of the Cabibbo theory and SU(3) symmetry. For unpolarized octet
baryons four processes are investigated, whereas in the case of polarized
baryons only one process is chosen to study the sensitivity of the differential
cross section to the various polarizations of the initial state nucleon and the
final state hyperon.Comment: This paper was originally submitted to Physical Review C and
published on 30 August, 201
Quantum Chinos Game: winning strategies through quantum fluctuations
We apply several quantization schemes to simple versions of the Chinos game.
Classically, for two players with one coin each, there is a symmetric stable
strategy that allows each player to win half of the times on average. A partial
quantization of the game (semiclassical) allows us to find a winning strategy
for the second player, but it is unstable w.r.t. the classical strategy.
However, in a fully quantum version of the game we find a winning strategy for
the first player that is optimal: the symmetric classical situation is broken
at the quantum level.Comment: REVTEX4.b4 file, 3 table
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