One-neutron transfer study of Xe 137 and systematics of 13/ 21+ and 13/ 22+ levels in N=83 nuclei

Excited states in Xe137 have been studied by using the near-barrier single-neutron transfer reactions C13(Xe136,C12γ)Xe137 and Be9(Xe136,Be8γ)Xe137 in inverse kinematics. Particle-γ and particle-γγ coincidence measurements have been performed with the Phoswich Wall and Digital Gammasphere detector arrays. Evidence is found for a 13/22+ level (E=3137keV) and for additional high-lying 3/2- and 5/2- states. The results are discussed in the framework of realistic shell-model calculations. These calculations are also extended to the 13/21+ and 13/22+ levels in the N=83 isotonic chain. They indicate that there is a need for a value of the neutron 0i13/2 single-particle energy (ESPE=2366keV) lower than the one proposed in the literature. It is also demonstrated that the population patterns of the j=±1/2 single-particle states in Xe137 are different for the two targets used in these measurements and the implications of this effect are addressed

Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration

Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (p_T), elliptic flow, two-particle correlations, non-statistical fluctuations, and suppression of particle production at high p_T. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted to Nuclear Physics A as a regular article; v3 has minor changes in response to referee comments. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Examination of the low-energy enhancement of the γ -ray strength function of Fe 56

A model-independent technique was used to determine the γ-ray strength function (γSF) of Fe56 down to γ-ray energies less than 1 MeV for the first time with GRETINA using the (p,p′) reaction at 16 MeV. No difference was observed in the energy dependence of the γSF built on 2+ and 4+ final states, supporting the Brink hypothesis. In addition, angular distribution and polarization measurements were performed. The angular distributions are consistent with dipole radiation. The polarization results show a small bias towards magnetic character in the region of the enhancement

Examination of the low-energy enhancement of the γ -ray strength function of Fe 56

A model-independent technique was used to determine the γ-ray strength function (γSF) of Fe56 down to γ-ray energies less than 1 MeV for the first time with GRETINA using the (p,p′) reaction at 16 MeV. No difference was observed in the energy dependence of the γSF built on 2+ and 4+ final states, supporting the Brink hypothesis. In addition, angular distribution and polarization measurements were performed. The angular distributions are consistent with dipole radiation. The polarization results show a small bias towards magnetic character in the region of the enhancement

Saturation of azimuthal anisotropy in Au + Au collisions at sqrt(s_NN) = 62 - 200 GeV

New measurements are presented for charged hadron azimuthal correlations at mid-rapidity in Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV. They are compared to earlier measurements obtained at sqrt(s_NN) = 130 GeV and in Pb+Pb collisions at sqrt(s_NN) = 17.2 GeV. Sizeable anisotropies are observed with centrality and transverse momentum (p_T) dependence characteristic of elliptic flow (v_2). For a broad range of centralities, the observed magnitudes and trends of the differential anisotropy, v_2(p_T), change very little over the collision energy range sqrt(s_NN) = 62-200 GeV, indicating saturation of the excitation function for v_2 at these energies. Such a saturation may be indicative of the dominance of a very soft equation of state for sqrt(s_NN) = 62-200 GeV.Comment: 432 authors, 7 pages text, 4 figures, REVTeX4. To be submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

O{sub 3} and stratospheric H{sub 2}O radiative forcing resulting from a supersonic jet transport emission scenario

The tropospheric radiative forcing has been calculated for ozone and water vapor perturbations caused by a realistic High Speed Civil Transport (HSCT) aircraft emission scenario. Atmospheric profiles of water vapor and ozone were obtained using the LLNL 2-D chemical-radiative-transport model (CRT) of the global troposphere and stratosphere. IR radiative forcing calculations were made with the LLNL correlated k-distribution radiative transfer model. UV-Visible-Near IR radiative forcing calculations were made with the LLNL two stream solar radiation model. For the case of water vapor the IR and Near IR radiative forcing was determined at five different latitudes and then averaged using an appropriate latitudinal average to obtain the global average value. Global average values of radiative forcing were approximately 1.2--2.6 10{sup {minus}3} W/m{sup 2}, depending on the background atmospheric water vapor profile. This result is consistent with prior published values for a similar aircraft scenario and supports the conclusion that the water vapor climate forcing effect is very small. The radiative forcing in the IR and UV-Visible spectral ranges, due to the ozone perturbation, was calculated for the globally averaged atmosphere. Global average values of the radiative forcing were 0.034 W/m{sup 2} for the UV-Visible spectral range and 0.006 W/m{sup 2} for the IR spectral range (0.04 W/m{sup 2} total). This result is also consistent with the range of published values obtained for a similar HSCT scenario. As was the case for water vapor, the ozone forcing is too small to be of major consequence

One-neutron transfer study of Xe 137 and systematics of 13/ 21+ and 13/ 22+ levels in N=83 nuclei

Excited states in Xe137 have been studied by using the near-barrier single-neutron transfer reactions C13(Xe136,C12\uce\ub3)Xe137 and Be9(Xe136,Be8\uce\ub3)Xe137 in inverse kinematics. Particle-\uce\ub3 and particle-\uce\ub3\uce\ub3 coincidence measurements have been performed with the Phoswich Wall and Digital Gammasphere detector arrays. Evidence is found for a 13/22+ level (E=3137keV) and for additional high-lying 3/2- and 5/2- states. The results are discussed in the framework of realistic shell-model calculations. These calculations are also extended to the 13/21+ and 13/22+ levels in the N=83 isotonic chain. They indicate that there is a need for a value of the neutron 0i13/2 single-particle energy (ESPE=2366keV) lower than the one proposed in the literature. It is also demonstrated that the population patterns of the j=\uc2\ub11/2 single-particle states in Xe137 are different for the two targets used in these measurements and the implications of this effect are addressed

Examination of the Low-Energy Enhancement of the gamma-ray Strength Function of 56Fe

A model-independent technique was used to determine the γ -ray strength function ( γ SF ) of 56 Fe down to γ -ray energies less than 1 MeV for the first time with GRETINA using the (p,p′ ) reaction at 16 MeV. No difference was observed in the energy dependence of the γ SF built on 2+ and 4+ final states, supporting the Brink hypothesis. In addition, angular distribution and polarization measurements were performed. The angular distributions are consistent with dipole radiation. The polarization results show a small bias towards magnetic character in the region of the enhancement