J.C. Peng , G.T. Garvey , T.C. Awes, M.E. Beddo, M.L. Brooks , C.N. Brown, J.D. Bush, T.A. Carey , T.H. Chang, W.E. Cooper, C.A. Gagliardi, D.F. Geesaman, E.A. Hawker, X.C. He, L.D. Isenhower, S.B. Kaufman, D.M. Kaplan, P.N. Kirk, D.D. Koetke, G. Kyle, D.M. Lee , W.M. Lee, M.J. Leitch , N. Makins, P.L. McGaughey , J.M. Moss , B.A. Mueller, P.M. Nord, B.K. Park , V. Papavassiliou, G. Petitt, P.E. Reimer , M.E. Sadler, J. Selden, P.W. Stankus, W.E. Sondheim , T.N. Thompson , R.S. Towell, R.E. Tribble , M.A. Vasiliev, Y.C. Wang, Z.F. Wang, J.C. Webb, J.L. Willis, D.K. Wise, G.R. Young

A polarized proton beam extracted from SATURNE II and the Saclay polarized proton target were used to determine the spin correlation parameter Aoosk and the rescattering observablesK os″ so; Dos″ok, Nos″sn, andN onsk at 1.80 and 2.10 GeV. The beam polarization was oriented perpendicular to the beam direction in the horizontal scattering plane and the target polarization was directed either along the vertical axis or longitudinally. Left-right and up-down asymmetries in the second scattering were measured. A check for the beam optimization with the beam and target polarizations oriented vertically provided other observables, of which results forD onon andK onno at 1.80, 1.85, 2.04, and 2.10 GeV are listed here. The new data at 2.10 GeV suggest a smooth energy dependence of spin triplet scattering amplitudes at fixed angles in the vicinity of this energy.

An introduction to the STAR detector and a brief overview of the physics goals of the experiment are presented.

Details concerning the design, fabrication and performance of the STAR Barrel Electromagnetic Calorimeter are presented.

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at sqrt(s_NN)=130 GeV using the STAR TPC at RHIC. The elliptic flow signal, v_2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

¯ 2u ) and *(d ¯ 2u ¯ )dx are evaluated for 0.015,x,0.35. These results are compared with parametrizations of various parton distribution functions, models and experimental results from NA51, NMC and HERMES.

Measurements at 19 beam kinetic energies between 1795 and 2235 MeV are reported fur the pp elastic scattering spin correlation parameter A(00nn)=A(NN)=C-NN. The c.m. angular range is typically 60-100 degrees. The measurements were performed at Saturne II with a vertically polarized beam and target (transverse to the beam direction and scattering plane), a magnetic spectrometer and a recoil detector, both instrumented with multi-wire proportional chambers, and beam polarimeters. These results are compared to previous data from Saturne II and elsewhere.

Method and results of the beam polarization measurements are presented. The measurements were carried out at the proton polarized beam of Saturne-II accelerator as well as at the JINR (Dubna) synchrophasotron vector polarized deuteron beam. The analysis of the elastic (quasi-elastic) pp-scattering polarization is used as a method of the polarization measurements. The energy range of the measurement is 1.0≤ T p ≤2.8 GeV for polarized proton and 1.66≤ T d ≤7.3 GeV for polarized deuteron beams.

High quality analyzing powers for the {Pi}{sup -}p{yields}{yields}{Pi}{sup 0}n reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing {Pi}N single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the {Delta}(1232) resonance. They will also be helpful for constraining the evaluation of the pion-nucleon {sigma} term from the scattering amplitudes.

Measurements at 18 beam kinetic energies between 1975 and 2795 MeV and at 795 MeV are reported for the pp elastic-scattering single spin parameter A(ooon)=A(oono)=A(N)=P. The c.m. angular range is typically 60-100 degrees. These results are compared to previous data from Saturne II and other accelerators. A search for energy-dependent structure at fixed c.m. angles is performed, but no rapid changes are observed. [S0556-2813(99)03710-3].

.   The pp elastic scattering analyzing power was measured in small energy steps in the vicinity of the accelerator depolarizing resonance at 2.202 GeV. A vertically polarized proton beam was extracted from SATURNE II at energies above the resonance and passed through different copper degraders. The beam was focused on the beam line polarimeter CH target. Its halo was removed by four powerful magnets. Measurements at degraded energies were complemented by data obtained with the directly extracted polarized beam outside the resonance region. Analyzing power results at fixed laboratory angles are compared with existing data in the region under discussion, with polynomial fits from 1.6 to 3.5 GeV, and with phase shift analysis predictions.

A polarized proton beam from SATURNE II, the Saclay polarized targets with \(^6\)Li compounds, and an unpolarized \(\mathrm{CH}_2\) target were used to measure spin-dependent observables for protons scattered on bound nucleons. The beam and target polarizations were oriented vertically. The analyzing power \(A_{\mathrm{oono}}\) and the depolarization \(D_{\mathrm{nono}}\) were determined at seven energies between 1.1 and 2.4 GeV. The spin correlation parameter \(A_{\mathrm{oonn}}\) was measured at only 1.1 and 1.6 GeV. Measurements with the \(\mathrm{CH}_2\) target at 1.1 GeV provided \(A_{\mathrm{oono}}\) data for scattering of polarized protons on neutrons in carbon. The quasi-elastic observables are compared with previous elastic scattering measurements and at 1.1 GeV with predictions of phase shift analyses.

High quality analyzing powers for the ${\ensuremath{\pi}}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}n$ reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing $\ensuremath{\pi}N$ single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the $\ensuremath{\Delta}(1232)$ resonance. They will also be helpful for constraining the evaluation of the pion-nucleon $\ensuremath{\sigma}$ term from the scattering amplitudes.

The pp elastic scattering analyzing power was measured in small energy steps in the vicinity of the accelerator depolarizing resonance \(\gamma G= 6 \) at 2.202 GeV. A vertically polarized proton beam was extracted from SATURNE II at energies above the resonance and passed through different copper degraders. The beam was focused on the beam line polarimeter CH\(_2\) target. Its halo was removed by four powerful magnets. Measurements at degraded energies were complemented by data obtained with the directly extracted polarized beam outside the resonance region. Analyzing power results at fixed laboratory angles are compared with existing data in the region under discussion, with polynomial fits from 1.6 to 3.5 GeV, and with phase shift analysis predictions.

A polarized proton beam extracted from SATURNE II, the Saclay polarized target with \(^6\)Li compounds, and a \(\mathrm{CH}_2\) target were used to measure elastic and quasi-elastic pp spin-dependent observables in the angular region \(60^{\circ} < \theta_{\mathrm{CM}} < 105^{\circ}\). The beam and/or target polarizations were oriented vertically. Accurate pp data for the analyzing power \(A_{\mathrm{oono}}\), spin-correlation parameter \(A_{\mathrm{oonn}}\), and the polarization transfer \(K_{\mathrm{onno}}\) were measured at 1.1 GeV. The observables \(A_{\mathrm{oono}}\) and \(K_{\mathrm{onno}}\) were determined at six other energies between 1.6 and 2.4 GeV. At 1.6 GeV, \(A_{\mathrm{oonn}}\) was also obtained. The individual contributions from H, \(^6\)Li, and \(^6\)LiD were deduced. The \(\mathrm{CH}_2\) target provided \(A_{\mathrm{oono}}(\mathrm{pp})\) results on free hydrogen and on protons in carbon. The elastic and quasi-elastic observables are compared with existing data and with phase-shift analysis predictions.

Experimental results are presented for the pp elastic-scattering single spin observable A(oono)=A(ooon)=A(N) =P, or the analyzing power, at 19 beam kinetic energies between 1795 and 2235 MeV. The typical c.m. angular range is 60-100 degrees. The measurements were performed at Saturne II with a vertically polarized beam and target (transverse to the beam direction and scattering plane), a magnetic spectrometer and a recoil detector, both instrumented with multiwire proportional chambers, and beam polarimeters. [S0556-2813(99)03610-9].

High quality analyzing powers for the ${\ensuremath{\pi}}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}n$ reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing $\ensuremath{\pi}N$ single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the $\ensuremath{\Delta}(1232)$ resonance. They will also be helpful for constraining the evaluation of the pion-nucleon $\ensuremath{\sigma}$ term from the scattering amplitudes.