Many challenges face the pharmacist in a combat zone hospital. The 13th Evacuation Hospital, Wisconsin Army National Guard was deployed in support of Operation Desert Storm. Its mission before and ...during the ground campaign identified key areas where pharmacy involvement assisted in the provision of care. Special skills and subject areas were determined. This article reviews the authors' experiences and offers suggestions to aid pharmacy personnel in preparation for future deployment.
Inclusive e$^+$e$^-$ production has been studied with HADES in $\pi^-$ + p,
$\pi^-$ + C and $\pi^- + \mathrm{CH}_2$ reactions, using the GSI pion beam at
$\sqrt{s_{\pi p}}$ = 1.49 GeV. Invariant mass ...and transverse momentum
distributions have been measured and reveal contributions from Dalitz decays of
$\pi^0$, $\eta$ mesons and baryon resonances. The transverse momentum
distributions are very sensitive to the underlying kinematics of the various
processes. The baryon contribution exhibits a deviation up to a factor seven
from the QED reference expected for the dielectron decay of a hypothetical
point-like baryon with the production cross section constrained from the
inverse $\gamma$ n$\rightarrow \pi^-$ p reaction. The enhancement is attributed
to a strong four-momentum squared dependence of the time-like electromagnetic
transition form factors as suggested by Vector Meson Dominance (VMD). Two
versions of the VMD, that differ in the photon-baryon coupling, have been
applied in simulations and compared to data. VMD1 (or two-component VMD)
assumes a coupling via the $\rho$ meson and a direct coupling of the photon,
while in VMD2 (or strict VMD) the coupling is only mediated via the $\rho$
meson. The VMD2 model, frequently used in transport calculations for dilepton
decays, is found to overestimate the measured dielectron yields, while a good
description of the data can be obtained with the VMD1 model assuming no phase
difference between the two amplitudes. Similar descriptions have also been
obtained using a time-like baryon transition form factor model where the pion
cloud plays the major role.
Hadron production (\(\pi^\pm\), proton, \(\Lambda\), \(K_S^0\), \(K^\pm\)) in \(\pi^- + \mathrm{C}\) and \(\pi^- + \mathrm{W}\) collisions is investigated at an incident pion beam momentum of ...\(1.7~\mathrm{GeV}/c\). This comprehensive set of data measured with HADES at SIS18/GSI significantly extends the existing world data on hadron production in pion induced reactions and provides a new reference for models that are commonly used for the interpretation of heavy-ion collisions. The measured inclusive differential production cross-sections are compared with state-of-the-art transport model (GiBUU, SMASH) calculations. The (semi-) exclusive channel \(\pi^- + A \rightarrow \Lambda + K_S^0 +X\), in which the kinematics of the strange hadrons are correlated, is also investigated and compared to a model calculation. Agreement and remaining tensions between data and the current version of the considered transport models are discussed.
The global polarization of {\Lambda} hyperons along the total orbital angular momentum of a relativistic heavy-ion collision is presented based on the high statistics data samples collected in Au+Au ...collisions at \sqrt{s_{NN}} = 2.4 GeV and Ag+Ag at 2.55 GeV with the High-Acceptance Di-Electron Spectrometer (HADES) at GSI, Darmstadt. This is the first measurement below the strangeness production threshold in nucleon-nucleon collisions. Results are reported as a function of the collision centrality as well as a function of the hyperon transverse momentum (p_T) and rapidity (y_{CM}) for the range of centrality 0--40%. We observe a strong centrality dependence of the polarization with an increasing signal towards peripheral collisions. For mid-central (20--40%) collisions the polarization magnitudes are <P_{\Lambda}>(%) = 6.8 \pm 1.3 (stat.) \pm 2.1 (syst.) for Au+Au and <P_{\Lambda}>(%) = 6.2 \pm 0.4 (stat.) \pm 0.6 (syst.) for Ag+Ag, which are the largest values observed so far. This observation thus provides a continuation of the increasing trend previously observed by STAR and contrasts expectations from recent theoretical calculations predicting a maximum in the region of collision energies about 3 GeV. The observed polarization is of a similar magnitude as predicted by 3D fluid dynamics and the UrQMD plus thermal vorticity model and significantly above results from the AMPT model.
Eur.Phys.J.A 59 (2023) 4, 80 High precision measurements of flow coefficients $v_{n}$ ($n = 1 - 4$) for
protons, deuterons and tritons relative to the first-order spectator plane have
been performed ...in Au+Au collisions at $\sqrt{s_{NN}} = 2.4$ GeV with the
High-Acceptance Di-Electron Spectrometer (HADES) at the SIS18/GSI. Flow
coefficients are studied as a function of transverse momentum $p_{t}$ and
rapidity $y_{cm}$ over a large region of phase space and for several classes of
collision centrality. A clear mass hierarchy is found for the slope of $v_{1}$,
$d v_{1}/d y^{\prime}|_{y^{\prime} = 0}$ where $y^{\prime}$ is the scaled
rapidity, and for $v_{2}$ at mid-rapidity. Scaling with the number of nucleons
is observed for the $p_{t}$ dependence of $v_{2}$ and $v_{4}$ at mid-rapidity,
which is indicative for nuclear coalescence as the main process responsible for
light nuclei formation. $v_{2}$ is found to scale with the initial eccentricity
$\langle \epsilon_{2} \rangle$, while $v_{4}$ scales with $\langle \epsilon_{2}
\rangle^{2}$ and $\langle \epsilon_{4} \rangle$. The multi-differential
high-precision data on $v_{1}$, $v_{2}$, $v_{3}$, and $v_{4}$ provides
important constraints on the equation-of-state of compressed baryonic matter.
In nuclear collisions the incident protons generate a Coulomb field which acts on produced charged particles. The impact of these interactions on charged pion transverse-mass and rapidity spectra, as ...well as on pion-pion momentum correlations is investigated in Au+Au collisions at \(\sqrt{s_{NN}}\) = 2.4 GeV. We show that the low-mt part of the data (\(m_t < 0.2\) GeV/c\(^2\)) can be well described with a Coulomb-modified Boltzmann distribution that also takes changes of the Coulomb field during the expansion of the fireball into account. The observed centrality dependence of the fitted mean Coulomb potential deviates strongly from a \(A_{part}^{2/3}\) scaling, indicating that, next to the fireball, the non-interacting charged spectators have to be taken into account. For the most central collisions, the Coulomb modifications of the HBT source radii are found to be consistent with the potential extracted from the single-pion transverse-mass distributions. This finding suggests that the region of homogeneity obtained from two-pion correlations coincides with the region in which the pions freeze-out. Using the inferred mean-square radius of the charge distribution at freeze-out, we have deduced a baryon density, in fair agreement with values obtained from statistical hadronization model fits to the particle yields.
First information on the timelike electromagnetic structure of baryons in the second resonance region has been obtained from measurements of invariant mass and angular distributions in the quasi-free ...reaction \(\pi^- p \to nee\) at \(\sqrt{s_{\pi^- p}}\) = 1.49 GeV with the High Acceptance Di-Electron Spectrometer (HADES) detector at GSI using the pion beam impinging on a CH\(_2\) target. We find a total cross section \(\sigma (\pi^- p \to nee) = 2.97 \pm 0.07^{data} \pm 0.21^{acc} \pm 0.31^{\rm{Z}_{\rm{eff}}} \mu\)b. Combined with the Partial Wave Analysis of the concurrently measured two-pion channel, these data sets provide a crucial test of Vector Meson Dominance (VMD) inspired models. The commonly used "strict VMD" approach strongly overestimates the \(e^+e^-\) yield. Instead, approaches based on a VMD amplitude vanishing at small \(e^+e^-\) invariant masses supplemented coherently by a direct photon amplitude provide a better agreement. A good description of the data is also obtained using a calculation of electromagnetic timelike baryon transition form factors in a covariant spectator-quark model, demonstrating the dominance of meson cloud effects. The angular distributions of \(e^+e^-\) pairs demonstrate the contributions of virtual photons with longitudinal polarization, in contrast to real photons. The virtual photon angular dependence supports the dominance of J=3/2, I=1/2 contributions observed in both the \(\gamma^{\star} n\) and the \(\pi \pi n\) channels.
For precise start time determination a Beam Fragmentation T\(_0\) Counter (BFTC) is under development for the Time-of-Flight Wall of the Compressed Baryonic Matter Spectrometer (CBM) at the Facility ...for Antiproton and Ion Research (FAIR) at Darmstadt/Germany. This detector will be located around the beam pipe, covering the front area of the Projectile Spectator Detector. The fluxes at this region are expected to exceed 10\(^5\)cm\(^{-2}\)s\(^{-1}\). Resistive plate chambers (RPC) with ceramic composite electrodes could be use because of their high rate capabilities and radiation hardness of material. Efficiency \(\ge\) 97\%, time resolution \(\le\) 90 ps and rate capability \(\ge\) 10\(^5\)cm\(^{-2}\)s\(^{-1}\) were confirmed during many tests with high beam fluxes of relativistic electrons. We confirm the stability of these characteristics with low resistive Si\(_3\)N\(_4\)/SiC floating electrodes for a prototype of eight small RPCs, where each of them contains six gas gaps. The active RPC size amounts 20\(\times\)20 mm\(^2\) produced on basis of Al\(_3\)O\(_2\) and Si\(_3\)N\(_4\)/SiC ceramics. Recent test results obtained with relativistic electrons at the linear accelerator ELBE of the Helmholtz-Zentrum Dresden-Rossendorf with new PADI-10 Front-end electronic will be presented.
A feasibility study has been performed in order to investigate the performance of the HADES detector to measure the electromagnetic decays of the hyperon resonances \(\Sigma(1385)^0\), ...\(\Lambda(1405)\) and \(\Lambda{\Lambda}(1520)\) as well as the production of double strange baryon systems \(\Xi^-\) and \(\Lambda\Lambda\) in p+p reactions at a beam kinetic energy of 4.5 GeV. The existing HADES detector will be upgraded by a new Forward Detector, which extends the detector acceptance into a range of polar angles that plays a crucial role for these investigations. The analysis of each channel is preceded by a consideration of the production cross-sections. Afterwards the expected signal count rates using a target consisting of either liquid hydrogen or polyethylene are summarized.
In this letter we report the first multi-differential measurement of correlated pion-proton pairs from 2 billion Au+Au collisions at \sqrt{s_{NN}} = 2.42 GeV collected with HADES. In this energy ...regime the population of \Delta(1232) resonances plays an important role in the way energy is distributed between intrinsic excitation energy and kinetic energy of the hadrons in the fireball. The triple differential d3N/dM{\pi}pdpTdy distributions of correlated {\pi}p pairs have been determined by subtracting the {\pi}p combinatorial background using an iterative method. The invariant-mass distributions in the \Delta(1232) mass region show strong deviations from a Breit-Wigner function with vacuum width and mass. The yield of correlated pion-proton pairs exhibits a complex isospin, rapidity and transverse-momentum dependence. In the invariant mass range 1.1 < Minv (GeV/c2) < 1.4, the yield is found to be similar for {\pi}+p and {\pi}-p pairs, and to follow a power law ^{\alpha}, where is the mean number of participating nucleons. The exponent {\alpha} depends strongly on the pair transverse momentum (pT) while its pT-integrated and charge-averaged value is {\alpha} = 1.5 \pm 0.08stat \pm 0.2sys.
