16,534 research outputs found
On the polarization properties of the charmed baryon Lambda^+_c in the Lambda^+_c -> p + K^- + pi^+ + pi^0 decay
The polarization properties of the charmed Lambda^+_c baryon are investigated
in weak non-leptonic four-body Lambda^+_c -> p + K^- + pi^+ + pi^0 decay. The
probability of this decay and the angular distribution of the probability are
calculated in the effective quark model with chiral U(3)XU(3) symmetry
incorporating Heavy Quark Effective theory (HQET) and the extended
Nambu-Jona-Lasinio model with a linear realization of chiral U(3)XU(3)
symmetry. The theoretical value of the probability of the decay Lambda^+_c -> p
+ K^- + pi^+ + pi^0 relative to the probability of the decay Lambda^+_c -> p +
K^- + pi^+ does not contain free parameters and fits well experimental data.
The application of the obtained results to the analysis of the polarization of
the Lambda^+_c produced in the processes of photo and hadroproduction is
discussed.Comment: 10 pages, no figures, Late
K -> pi pi and a light scalar meson
We explore the Delta-I= 1/2 rule and epsilon'/epsilon in K -> pi pi
transitions using a Dyson-Schwinger equation model. Exploiting the feature that
QCD penguin operators direct K^0_S transitions through 0^{++} intermediate
states, we find an explanation of the enhancement of I=0 K -> pi pi transitions
in the contribution of a light sigma-meson. This mechanism also affects
epsilon'/epsilon.Comment: 7 pages, REVTE
On UHECR energy estimation algorithms based on the measurement of electromagnetic component parameters in EAS
Model calculations are performed of extensive air shower (EAS) component
energies using a variety of hadronic interaction parameters. A conversion
factor from electromagnetic component energy to the energy of ultra-high energy
cosmic rays (UHECRs) and its model and primary mass dependence is studied. It
is shown that model dependence of the factor minimizes under the necessary
condition of the same maximum position and muon content of simulated showers.Comment: contracted version is accepted for publication in Doklady Physic
Relating Superembeddings and Non-linear Realisations
We discuss the relation between the superembedding method for deriving
worldvolume actions for D-branes and the method of Partially Broken Global
Supersymmetry based upon linear and non-linear realisations of SUSY. We give
the explicit relation for the cases of space filling branes in 3 and 4
dimensions and show that the standard F-constraint of the superembedding method
is the source of the required covariant non-linear constraints for the PBGS
method.Comment: 19 pages. Improved spelling, references adde
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