119850203
Yrast states and band crossings in the neutron-deficient platinum isotopes 169-173 Pt
The yrast states in the light platinum isotopes Pt169-173 have been investigated in a recoil-decay tagging experiment using the JUROGAM gamma-ray spectrometer in conjunction with the RITU gas-filled recoil separator and the GREAT tagging spectrometer. Gamma-ray transitions have been established for the first time in the odd-N isotopes, Pt-169 and Pt-173, and the yrast sequences in Pt-170 and Pt-172 have been extended. We discuss the possibility that the weakly deformed yrast structures of Pt-170, Pt-172, and Pt-173 are crossed by a deformed intruder configuration at spin similar to 8h.
115613705
Identification of the Kpi=8- rotational band in 138Gd
117103201
alpha decay of Re159 and proton emission from Ta155
121158687
High-K four-quasiparticle states in Gd-138
States above the known K(pi) = 8(-) 6 mu s isomer in (138)Gd have been populated with the (106)Cd((36)Ar,2p2n) reaction at a beam energy of 180 MeV at the University of Jyvaskyla, Finland. The recoil-isomer tagging technique was utilized to correlate delayed gamma-ray decays, detected in the GREAT focal plane spectrometer, with prompt decays measured in the JUROGAM II spectrometer at the target position. The lifetime of the K(pi) = 8(-) isomeric state has been remeasured as 6.2(2) mu s. Two high-lying strongly coupled bands have been established with K(pi) >= 12(-). Potential-energy surface calculations, in conjunction with g factor measurements, reveal that they are built upon four-quasiparticle structures comprising two-quasineutron plus two-quasiproton configurations. The short half-life or lack of hindrance for the decays from these four-quasiparticle band-head states is reasoned to be a consequence of increased triaxial deformation and mixing due to the high density of states relative to the lower two-quasiparticle 6-mu s isomeric state.
1861803
Gamma-ray spectroscopy at the limits: first observation of rotational bands in 255Lr.
The rotational band structure of 255Lr has been investigated using advanced in-beam gamma-ray spectroscopic techniques. To date, 255Lr is the heaviest nucleus to be studied in this manner. One rotational band has been unambiguously observed and strong evidence for a second rotational structure was found. The structures are tentatively assigned to be based on the 1/2-[521] and 7/2-[514] Nilsson states, consistent with assignments from recently obtained alpha decay data. The experimental rotational band dynamic moment of inertia is used to test self-consistent mean-field calculations using the Skyrme SLy4 interaction and a density-dependent pairing force.
120743809
Spectroscopy of Ho-144 using recoil-isomer tagging
Excited states in the proton-unbound odd-odd nucleus {sup 144}Ho have been populated using the {sup 92}Mo({sup 54}Fe,pn){sup 144}Ho reaction and studied using the recoil-isomer-tagging technique. The alignment properties and signature splitting of the rotational band above the I{sup p}i=(8{sup +}){sup 144m}Ho isomer have been analyzed and the isomer confirmed to have a pih{sub 11/2} x nuh{sub 11/2} two-quasiparticle configuration. The configuration-constrained blocking method has been used to calculate the shapes of the ground and isomeric states, which are both predicted to have triaxial nuclear shapes with |gamma|approx =24 deg.
122659887
The STAR Time Projection Chamber
The STAR Time Projection Chamber was successfully operated during the first RHIC run in 2000. Most of the STAR contributions reported in these proceedings are based on the analysis of data from the TPC. In this article, we show that the performance achieved by the TPC, in terms of track reconstruction, position resolution, and particle identification are well suited for measuring precise and reliable physics observables.
1190941
Higher moments of net proton multiplicity distributions at RHIC.
We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.
123035920
The ALICE trigger system performance for p-p and Pb-Pb collisions
The ALICE trigger system installed in the experimental cavern processes information from triggering detectors at 3 hardware levels, and is used in p-p and Pb-Pb collisions. Many automatic functions have been developed to facilitate work in the control room. The hardware is permanently monitored, and around 1200 counters, with considerable built-in redundancy, are read at regular intervals (at least once per minute). This provides relevant physics information and also verifies the consistency of the hardware operation. In order to compensate for seasonal drift, the CORDE module has been installed, which allows the LHC clock to be delayed in steps of 10 ps. This paper describes the current status of the ALICE trigger system after experience with p-p and Pb-Pb runs, the new firmware developments and the appropriate software for this electronics.
110002735
The integration of the ALICE trigger system with sub-detectors
Abstract The ALICE Trigger electronics (TRG) has been installed in the experimental cavern and tested with each of the detectors, both individually (‘standalone’ mode) and in ‘global’ runs, i.e. those involving other detectors. Global runs were performed with cosmic ray triggers, and also during the LHC startup period in September 2008. In this paper the status of the trigger system will be reviewed, in particular describing recent extensions to the system.
123238985
Testing models of hadron production with strange hadrons in the intermediate pT region using the STAR detector
We report on the transverse momentum dependence of strangeness production measured with the STAR detector. Identified particle spectra are used to provide a test of models of hadron production in the intermediate transverse momentum region, 2 < pT < 6 GeV/c. Further insight into hadron production is obtained from the nuclear modification factor, Rcp, in Au+Au collisions, which shows that there is a different pT dependence of hadron suppression in central collisions for baryons and mesons, consistent with quark coalescence. Evidence for a similar baryon–meson difference is also found in d+Au collisions.