We generate a new complete equation of state (EOS) of nuclear matter for a wide range of temperatures, densities, and proton fractions ready for use in astrophysical simulations of supernovae and neutron star mergers. Our previous two papers tabulated the EOS at over 180,000 grid points in the temperature range $T$ = 0 to 80 MeV, the density range $n_B$ = 10$^{-8}$ to 1.6 fm$^{-3}$, and the proton fraction range $Y_P$ = 0 to 0.56. In this paper we combine these data points using a suitable interpolation scheme to generate a single equation of state table on a finer grid. This table is thermodynamically consistent and conserves entropy during adiabatic compression tests. We present various thermodynamic quantities and the composition of matter in the new EOS, along with several comparisons with existing EOS tables. Our equation of state table is available for download.

We study the equation of state (EOS) of nuclear matter at subnuclear density in a virial expansion for a nonideal gas. The gas consists of neutrons, protons, alpha particles, and 8980 species of nuclei with $A\ensuremath{\geqslant}12$ and masses from the finite-range droplet model. At very low density, the virial expansion reduces to nuclear statistical equilibrium. At higher density, the virial results match smoothly to the relativistic mean field results discussed in our previous paper. We tabulate the resulting EOS at over 73 000 grid points in the temperature range $T=0.158$ to 15.8 MeV, the density range ${n}_{B}={10}^{\ensuremath{-}8}$ to 0.1 fm${}^{\ensuremath{-}3}$, and the proton fraction range ${Y}_{P}=0.05$ to 0.56. In the future we plan to match these low-density results to our earlier high-density mean field results, and generate a full EOS table for use in supernova and neutron star merger simulations. This virial EOS is exact in the low-density limit.

We calculate the equation of state (EoS) of dense matter, using a relativistic mean field (RMF) model with a density dependent coupling that is a slightly modified form of the original NL3 interaction. For nonuniform nuclear matter we approximate the unit lattice as a spherical Wigner-Seitz cell, wherein the meson mean fields and nucleon Dirac wave functions are solved fully self-consistently. We also calculate uniform nuclear matter for a wide range of temperatures, densities, and proton fractions, and match them to non-uniform matter as the density decreases. The calculations took over 6,000 CPU days in Indiana University's supercomputer clusters. We tabulate the resulting EoS at over 107,000 grid points in the proton fraction range $Y_P$ = 0 to 0.56. For the temperature range $T$ = 0.16 to 15.8 MeV we cover the density range $n_B$ = 10$^{-4}$ to 1.6 fm$^{-3}$; and for the higher temperature range $T$ = 15.8 to 80 MeV we cover the larger density range $n_B$ = 10$^{-8}$ to 1.6 fm$^{-3}$. In the future we plan to study low density, low temperature (T$<$15.8 MeV), nuclear matter using a Virial expansion, and we will match the low density and high density results to generate a complete EoS table for use in astrophysical simulations of supernova and neutron star mergers.

We describe the design and operation of a detector system for measuring all-photon decays of mesons photoproduced in a tagged photon beam with energies between 4.3 and 5.4 GeV and a flux of 5 x 10(7) tagged photons per second. Photons from meson decays were detected with a lead-glass calorimeter with an energy resolution of 11% at I GeV. Various veto and trigger components were also present. Final states with as many as six photons were successfully detected and reconstructed. (c) 2006 Elsevier B.V. All rights reserved.

We describe a method for calibration of a lead-glass calorimeter that does not require a beam of known energy. The technique was used to calibrate the radphi lead-glass calorimeter at Jefferson Lab. The technique described can be applied to any segmented electromagnetic calorimeter capable of detecting all-photon decays of mesons, for example, π0→2γ, η→2γ or ω→π0γ. We also demonstrate how the measured 2γ mass width of the π0 and η mesons can be unfolded to extract the single-shower energy and position resolution functions of the calorimeter.

A partial wave analysis (PWA) of the ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ systems produced in the reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}(3\ensuremath{\pi}{)}^{\ensuremath{-}}p$ at $18\text{ }\text{ }\mathrm{GeV}/c$ was carried out using an isobar model assumption. This analysis is based on 3.0 M ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ events and 2.6 M ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ events and shows production of the ${a}_{1}(1260)$, ${a}_{2}(1320)$, ${\ensuremath{\pi}}_{2}(1670)$, and ${a}_{4}(2040)$ resonances. Results of detailed studies of the stability of partial wave fits are presented. An earlier analysis of 250 K ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ events from the same experiment showed possible evidence for a ${J}^{PC}={1}^{\ensuremath{-}+}$ exotic meson with a mass of $\ensuremath{\sim}1.6\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ decaying into $\ensuremath{\rho}\ensuremath{\pi}$. In this analysis of a higher statistics sample of the $(3\ensuremath{\pi}{)}^{\ensuremath{-}}$ system in two charged modes we find no evidence of an exotic meson.

A partial wave analysis (PWA) of the $\pi^- \pi^- \pi^+$ and $\pi^- \pi^0 \pi^0$ systems produced in the reaction $\pi^- p \to (3\pi)^-p$ at 18 GeV/$c$ was carried out using an \emph{isobar} model assumption. This analysis is based on 3.0M $\pi^- \pi^0 \pi^0$ events and 2.6M $\pi^- \pi^-\pi^+$ events and shows production of the $a_1(1260)$, $a_2(1320)$, $\pi_2(1670)$ and $a_4(2040)$ resonances. Results of detailed studies of the stability of partial wave fits are presented. An earlier analysis of 250K $\pi^- \pi^- \pi^+$ events from the same experiment showed possible evidence for a $J^{PC}=1^{-+}$ exotic meson with a mass of $\sim$1.6 GeV/$c^2$ decaying into $\rho \pi$. In this analysis of a higher statistics sample of the $(3\pi)^-$ system in two charged modes we find no evidence of an exotic meson.

The time and amplitude characteristics of a scintillation counter were investigated on an accelerator beam with a momentum of 5 GeV/ c at the Institute for High Energy Physics. The scintillator, with a length of 2 m and a cross section of 2.5 × 2.5 cm 2 , was viewed from its end faces by ΦЭУ-115M photomultiplier tubes (PMTs). The dependences of the signal amplitude and the time resolution of a PMT on the position of a particle track along the scintillator were described by quadratic exponentials. When a constant fraction discriminator was used to form the PMT signal, the time resolutions at the center and at the periphery of the counter were 150 and 80 ps, respectively. Better results were obtained with a standard leading-edge discriminator after correcting the dependence of its response time on the signal amplitude.

A partial wave analysis of the ππ system produced in the charge exchange reaction: πp → ππn at an incident momentum of 18.3 GeV/c is presented as a function of ππ invariant mass, mπ0π0 , and momentum transfer squared, |t|, from the incident π − to the outgoing ππ system. For small values of |t|, the S-wave intensity shows a broad enhancement at low mπ0π0 with a sharp dip in the vicinity of the f0 (980). A dip is also observed in the vicinity of the f0 (1500). There is rapid variation of the S to D0 relative phase difference in these mass regions. For large values of |t|, the f0 (980) appears as a bump. The f2 (1270),

Timing properties of two types of scintillation counters have been studied in 5GeV/c hadron beam of the IHEP (Protvino) accelerator. The counters are prototypes of hodoscope elements that will be used in experiments for particle identification and fast timing of events. Scintillator cross-sections are 1.25×6.0 and 2.5×2.5cm2 and their length is 2m. The dependence of the time resolution on the particle coordinate along the counters and on the beam intensity is presented.

Phototubes associated with a Cherenkov counter, with a wall of scintillation counters for time-of-flight measurements and with a wall of lead glass blocks of an electro-magnetic calorimeter will operate in the fringe field of a superconducting solenoid in the GlueX experiment. The solenoid will be operated with a central magnetic field of ≈2.5T. The maximum fringe field in the vicinity of the phototubes will be approximately 150G. Various techniques for magnetic shielding of phototubes were studied using a 1-m diameter Helmholtz coil arrangement operated with a maximum central field of 200G. Results are presented.

Several recent experiments have reported evidence for a narrow baryon resonance with positive strangeness $({\ensuremath{\Theta}}^{+})$ at a mass of $1.54\mathrm{GeV}{/c}^{2}.$ Baryons with $S=+1$ cannot be conventional qqq states and the reports have thus generated much theoretical speculation about the nature of possible $S=+1$ baryons, including a 5-quark, or pentaquark, interpretation. We show that narrow enhancements in the ${K}^{+}n$ effective mass spectrum can be generated as kinematic reflections resulting from the decay of mesons, such as the ${f}_{2}(1275),$ the ${a}_{2}(1320)$ and the ${\ensuremath{\rho}}_{3}(1690).$

We discuss a coupled channel analysis of the ηπ and η'π systems produced in π - p interactions at 18 GeV/c. We show that known QQ resonances, together with residual soft meson-meson rescattering, saturate the spectra including the exotic J P C = 1 - + channel. The possibility of a narrow exotic resonance at a mass near 1.6 GeV/c 2 cannot, however, be ruled out.

A partial wave analysis (PWA) of the etapi(0) system (where eta-->gammagamma) produced in the charge exchange reaction pi(-)p-->etapi(0)n at an incident momentum of 18 GeV/c is presented as a function of the etapi(0) invariant mass m(etapi)0 and momentum transfer squared t(pi--->etapi), from the incident pi(-) to the outgoing etapi(0) system. S, P, and D waves were included in the PWA. The a(0)(0980) and a(2)(1320) states are clearly observed in the overall etapi(0) effective mass distribution as well as in the amplitudes associated with S wave and D waves, respectively, after partial wave decomposition. The observed distributions in moments (averages of spherical harmonics) were compared to the results from the PWA and the two are consistent. The distribution in t(pi--->etapi) for individual D waves associated with natural and unnatural parity exchange in the t channel are consistent with Regge phenomenology. Of particular interest in this study is the P wave since this leads to an exotic J(PC)=1(-+) for the etapi system. A P wave is present in the data; however, attempts to describe the mass dependence of the amplitude and phase motion with respect to the D wave as a Breit-Wigner resonance are problematic. This has implications regarding the existence of a reported exotic J(PC)=1(-+) meson decaying into etapi(0) with a mass near 1.4 GeV/c(2).

We discuss a coupled channel analysis of the etapi and eta'pi systems produced in pi(-)p interactions at 18 GeV/c. We show that known Q(-)Q resonances, together with residual soft meson-meson rescattering, saturate the spectra including the exotic J(PC)=1(-+) channel. The possibility of a narrow exotic resonance at a mass near 1.6 GeV/c(2) cannot, however, be ruled out.

Based on 1.35 x 10(6) polarized Xi(-) events, we measure the parameter phi(Xi) to be -1.61 degrees +/-2.66 degrees +/-0.37 degrees for the Xi(-)-->Lambda pi(-) decay. New results for the parameters beta(Xi) and gamma(Xi) are also presented. Assuming that the CP-violating phase difference is negligible, we deduce the strong phase difference between the P-wave and S-wave amplitudes of the Lambda pi final state to be 3.17 degrees +/-5.28 degrees +/-0.73 degrees, reducing the uncertainty in estimating the level of CP violation in Xi-hyperon decay.