Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new user$eta$ and $omega$ mesons as new degrees of freedom in the intranuclear cascade model INCL
54
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The intranuclear cascade model INCL (Li`ege Intranuclear Cascade) is now able to simulate spallation reactions induced by projectiles with energies up to roughly 15 GeV. This was made possible thanks to the implementation of multipion emission in the NN, $Delta$N and $pi$N interactions. The results obtained with reactions on nuclei induced by nucleons or pions gave confidence in the model. A next step will be the addition of the strange particles, $Lambda$, $Sigma$ and Kaons, in order to not only refine the high-energy modeling, but also to extend the capabilities of INCL, as studying hypernucleus physics. Between those t
rate research
Read More
The production of pseudo scalar, Eeta, Eta-prime, and vector, Omega, Rho, Phi, mesons in NN collisions at threshold-near energies is analyzed within a covariant effective meson-nucleon theory. It is shown that a good description of cross sections and angular distributions, for vector meson production, can be accomplished by considering meson and nucleon currents only, while for pseudo scalar production an inclusion of nucleon resonances is needed. The di-electron production from subsequent Dalitz decay of the produced mesons, $etato gamma gamma^* togamma e^+e^-$ and $omegato pigamma^*to pi e^+e^-$ is also considered and numerical results are presented for intermediate energies and kinematics of possible experiments with HADES, CLAS and KEK-PS. We argue that the transition form factor $omegato gamma^*pi$ as well as $etato gamma^*gamma$ can be defined in a fairly model independent way and the feasibility of an experimental access to transition form factors is discussed.
We report the measurement of differential cross sections for $omega$ and $eta$ photoproduction from protons at backward angles ($-1.0<cosTheta_{C.M}^{X}<-0.8$) using linearly polarized photons at $E_{gamma}=$$1.5-3.0$ GeV. Differential cross sections for $omega$ mesons are larger than the predicted $u$-channel contribution in the energy range $2.0leqsqrt{s}leq2.4$ GeV. The differential cross sections for $omega$ and $eta$ mesons become closer to the predicted $u$-channel contribution at $sqrt{s}>2.4$ GeV. A bump structure in the $sqrt{s}$ dependence of the differential cross sections for $eta$ mesons was observed at $sqrt{s}sim$2.35 GeV.
The first measurement of the p n -> d omega total cross section has been achieved at mean excess energies of Q = 28 and 57 MeV by using a deuterium cluster-jet target. The momentum of the fast deuteron was measured in the ANKE spectrometer at COSY-Juelich and that of the slow spectator proton p(sp) from the p d -> p(sp) d omega reaction in a silicon telescope placed close to the target. The cross sections lie above those measured for p p -> p p omega but seem to be below theoretical predictions.
The total cross section for omega production in the pp -> pp omega reaction has been measured at five c.m. excess energies from 3.8 to 30 MeV. The energy dependence is easily understood in terms of a strong proton-proton final state interaction combined with a smearing over the width of the state. The ratio of near-threshold phi and omega production is consistent with the predictions of a one-pion-exchange model and the degree of violation of the OZI rule is similar to that found in the pi-p -> n omega/phi reactions.
Excited states in the neutron-rich uc{70}{Fe} nucleus were populated in a one-proton removal reaction from uc{71}{Co} projectiles at 87~MeV/nucleon. A new transition was observed with the $gamma$-ray tracking array GRETINA and shown to feed the previously assigned $4^+_1$ state. In comparison to reaction theory calculations with shell-model spectroscopic factors, it is argued that the new $gamma$ ray possibly originates from the $6^+_1$ state. It is further shown that the Doppler-reconstructed $gamma$-ray spectra are sensitive to the very different lifetimes of the $2^+$ and $4^+$ states, enabling their approximate measurement. The emerging structure of uc{70}{Fe} is discussed in comparison to LNPS-new large-scale shell-model calculations.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
