An Assessment of Factors That Affect the Performance of Air Force O-3 (Captain) Logisticians Working in a Joint Operations Environment.

Joint operations will likely continue to become more prevalent in the future due to defense spending cuts and the nature of modem warfare. Currently, Air Force O-3 (Captain) logisticians, working in the joint operations environment, receive little if any initial training. Exploratory research, by the authors, indicated that these members felt uncertain about their jobs and how they related to the organization, which has been described in the literature as role ambiguity. Consequently, this research project was designed to determine if AF O-3 logisticians serving in the joint operations environment experience more role ambiguity than their counterparts serving in the single service AF environment. With this aim in mind, a mail survey was administered to all Air Force Captains in the Supply, Transportation and Logistics Plans career fields. Of the 695 surveys distributed, 380 were returned (resulting in a 55% return rate), including 332 non-joint and 48 joint responses. Data analysis of joint returns revealed that role ambiguity responses exhibited a bimodal distribution, based on previous joint operations exercise experience. Those members with no exercise experience exhibited statistically higher levels of role ambiguity than their single service counterparts, while those with exercise experience exhibited significantly lower levels

Threshold J/ψ−J/\psi- production in nucleon-nucleon collisions

We analyze $J/\psi-$ production in nucleon-nucleon collisions near threshold in the framework of a general model independent formalism, which can be applied to any reaction $N+N\to N+N+V^0$, where $V^0=\omega$, $\phi$, or $J/\psi$. Such reactions show large isotopic effects: a large difference for $pp$- and $pn$-collisions, which is due to the different spin structure of the corresponding matrix elements. The analysis of the spin structure and of the polarization observables is based on symmetry properties of the strong interaction. Using existing experimental data on the different decays of $J/\psi-$meson, we suggest a model for $N+N\to N+N+J/\psi$, based on $t-$channel $\eta+\pi$-exchanges. We predict polarization phenomena for the $n+p\to n+p+J/\psi$-reaction and the ratio of cross sections for $np$ and $pp$-collisions. For the processes $\eta(\pi)+N\to N+J/\psi$ we apply two different approaches: vector meson exchange and local four-particle interaction. In both cases we find larger $J/\psi$-production in $np$-collisions, with respect to $pp$-collisions.Comment: 17 pages, 6 figure

Near-Threshold Production of omega Mesons in the pp -> pp omega Reaction

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.Comment: Report in LaTeX2e. 12 pages with 2 eps figure

S-wave eta'-proton FSI; phenomenological analysis of near-threshold production of pi0, eta, and eta' mesons in proton-proton collisions

We describe a novel technique for comparing total cross sections for the reactions pp --> pp pi(0), pp --> pp eta, and pp --> pp eta' close to threshold. The initial and final state proton-proton interactions are factored out of the total cross section, and the dependence of this reduced cross section on the volume of phase space is discussed. Different models of the proton-proton interaction are compared. We argue that the scattering length of the S-wave eta'-proton interaction is of the order of 0.1 fm.Comment: 10 pages, 5 figure

On the close to threshold meson production in neutron-neutron collisions

A method of measuring the close to threshold meson production in neutron-neutron collisions is described where the momenta of the colliding neutrons can be determined with the accuracy obtainable for the proton-proton reaction. The technique is based on the double quasi-free nn --> nn X^0 reaction, where deuterons are used as a source of neutronsComment: 6 pages, 2 figures, to be published in Phys. Lett.

Energy Dependence of the Near-Threshold Total Cross-Section for the pp --> pp eta' Reaction

Total cross sections for the pp --> pp eta' reaction have been measured in the excess energy range from Q = 1.53 MeV to Q = 23.64 MeV. The experiment has been performed at the internal installation COSY-11 using a stochastically cooled proton beam of the COoler SYnchrotron COSY and a hydrogen cluster target. The determined energy dependence of the total cross section weakens the hypothesis of the S-wave repulsive interaction between the eta' meson and the proton. New data agree well with predictions based on the phase-space distribution modified by the proton-proton final-state-interaction (FSI) only.Comment: 12 pages, 1 table, 4 figure

Experimental results on strangeness production in proton-proton collisions at COSY

The production of K+ and K- mesons in elementary proton-proton collision has been investigated at the Cooler Synchrotron COSY in Juelich. A high quality proton beam with low emittance and small momentum spread permitted to study the creation of these mesons very close to the kinematical threshold. The energy dependence of the total cross section is investigated using internal beam facilities providing a high accuracy particle momentum determination as well as an external non-magnetic detection setup with a large geometrical acceptance. The determination of the four-momentum vectors for all ejectiles of each registered event gives the complete kinematical information allowing to study the interaction of the outgoing particles. Results on the performed studies of the pp --> pp K+ K-, pp --> p Lambda K+ and pp --> p Sigma0 K+ reactions will be presented and their relevance to the interpretation of heavy ion collisions will be discussed.Comment: 8 pages, 6 figures, plenary talk at 6th International Conference On Strange Quarks in Matter: '2001 - A Flavorspace Odyssey' (SQM2001), Frankfurt, Germany, September 25-29, 2001, to be published in J. Phys. G: Nucl. Part. Phy

Dilepton production in heavy ion collisions at intermediate energies

We present a unified description of the vector meson and dilepton production in elementary and in heavy ion reactions. The production of vector mesons ($\rho,\omega$) is described via the excitation of nuclear resonances ($R$). The theoretical framework is an extended vector meson dominance model (eVMD). The treatment of the resonance decays $R\longmapsto NV$ with arbitrary spin is covariant and kinematically complete. The eVMD includes thereby excited vector meson states in the transition form factors. This ensures correct asymptotics and provides a unified description of photonic and mesonic decays. The resonance model is successfully applied to the $\omega$ production in $p+p$ reactions. The same model is applied to the dilepton production in elementary reactions ($p+p, p+d$). Corresponding data are well reproduced. However, when the model is applied to heavy ion reactions in the BEVALAC/SIS energy range the experimental dilepton spectra measured by the DLS Collaboration are significantly underestimated at small invariant masses. As a possible solution of this problem the destruction of quantum interference in a dense medium is discussed. A decoherent emission through vector mesons decays enhances the corresponding dilepton yield in heavy ion reactions. In the vicinity of the $\rho/\omega$-peak the reproduction of the data requires further a substantial collisional broadening of the $\rho$ and in particular of the $\omega$ meson.Comment: 32 pages revtex, 19 figures, to appear in PR

Analysing power A_y in the reaction p(pol) p --> p p eta close to threshold

Measurements of the eta meson production with a polarised proton beam in the reaction p(pol) p --> p p eta have been carried out at an excess energy of Q = 40 MeV. The dependence of the analysing power A_y on the polar angle theta^*_q of the eta meson in the center of mass system (CMS) has been studied. The data indicate the possibility of an influence of p- and d-waves to the close to threshold eta production.Comment: 6 pages, 5 figures, in section 3.1 the formula of vec(p) containing fatal typos was removed, and the values in table were correcte