25 research outputs found
Theoretical description of the decays
We calculate the invariant and helicity amplitudes for the transitions
where the
are -type ground and excited states with
quantum numbers . The calculations are
performed in the framework of a covariant confined quark model previously
developed by us. We find that the values of the helicity amplitudes for the
and the are
suppressed compared with those for the ground state
and the excited state . This analysis is
important for the identification of the hidden charm pentaquark states
and which were discovered in the decay chain
because the cascade decay chain
involves the same
final state.Comment: 15 pages, 4 figures. Minor corrections don
Extended Rein-Sehgal model for tau lepton production
The polarization density matrix formalism is employed to include the final
lepton mass and spin into the popular model by Rein and Sehgal for single pion
neutrinoproduction. We investigate the effect of the lepton mass on the
differential cross sections. The lepton polarization evaluated within the
extended RS model is compared against that follows from the single resonance
production model based upon the Rarita-Schwinger formalism with
phenomenological transition form factors.Comment: Contribution to the 3rd International Workshop on Neutrino-Nucleus
Interactions in the Few-GeV Region, 17-21 March, Gran Sasso (Italy
Polarization of Tau Leptons Produced in Quasielastic Neutrino--Nucleon Scattering
A numerical analysis of the polarization vector of tau leptons produced
through quasielastic neutrino and antineutrino interactions with free nucleons
is given with two models for vector electromagnetic form factors of proton and
neutron. The impact of G parity violating axial and vector second-class
currents is investigated by applying a simple heuristic model for the induced
scalar and tensor form factors.Comment: Thesis of a talk given at the 8th Scientific Conference (SCYSS-04),
Dubna, Russia, 2 - 6 Feb 2004. 11 pages, 6 figures; added references, figures
and discussion; conclusions unchange
Lepton Polarization in Neutrino-Nucleon Interactions
We derive generic formulas for the polarization density matrix of leptons
produced in neutrino and antineutrino collisions and briefly consider some
important particular cases. Next we employ the general formalism in order to
include the final lepton mass and spin into the popular model by Rein and
Sehgal for single pion neutrinoproduction.Comment: Talk given at 10th International Workshop on High-Energy Spin Physics
(SPIN 03), Dubna, Russia, 16-20 Sep 2003. 12 pages; extended version, typos
remove
Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p + p interactions at the CERN Super Proton Synchrotron
Results on two-particle ΔηΔϕ correlations in inelastic p + p interactions at 20, 31, 40, 80, and 158 GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the Epos and UrQMD models.ISSN:1434-6044ISSN:1434-605