117490380
In-beam gamma-ray and alpha-decay spectroscopy of 170Ir
Excited states in the highly neutron deficient odd-odd nucleus Ir-170 have been investigated. The experiment was performed using the Sn-112(Ni-60, pn)Ir-170 reaction and employing the recoil-decay ...
115613705
Identification of the Kpi=8- rotational band in 138Gd
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.
117103201
alpha decay of Re159 and proton emission from Ta155
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.
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.
119253430
Beam-energy and system-size dependence of dynamical net charge fluctuations
We present measurements of net charge fluctuations in Au+Au collisions at s(NN)=19.6, 62.4, 130, and 200 GeV, Cu+Cu collisions at s(NN)=62.4 and 200 GeV, and p+p collisions at s=200 GeV using the dynamical net charge fluctuations measure nu(+-,dyn). We observe that the dynamical fluctuations are nonzero at all energies and exhibit a modest dependence on beam energy. A weak system size dependence is also observed. We examine the collision centrality dependence of the net charge fluctuations and find that dynamical net charge fluctuations violate 1/N(ch) scaling but display approximate 1/N(part) scaling. We also study the azimuthal and rapidity dependence of the net charge correlation strength and observe strong dependence on the azimuthal angular range and pseudorapidity widths integrated to measure the correlation.
122129144
Recent developments on the STARS detector system at RHIC
Abstract A progress report is given for the various components of the STAR detector system. We report on the recent developments in the detector proto-typing and construction, with an emphasis on the main TPC, recent TPC cosmic ray testing and shipping to Brookhaven National Laboratory
8230888
Measurement of the cross section for electromagnetic dissociation with neutron emission in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV.
The first measurement of neutron emission in electromagnetic dissociation of ^{208}Pb nuclei at the LHC is presented. The measurement is performed using the neutron zero degree calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at sqrt[s(NN)]=2.76 TeV with neutron emission are σ(singleEMD)=187.4 ± 0.2(stat)(-11.2)(+13.2) (syst) b and σ(mutualEMD) = 5.7 ± 0.1(stat) ± 0.4(syst) b, respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.
119780031
Charged-particle multiplicity measurement in proton–proton collisions at $\sqrt{s}=7$ TeV with ALICE at LHC
The pseudorapidity density and multiplicity distribution of charged particles produced in proton–proton collisions at the LHC, at a centre-of-mass energy $\sqrt{s}=7$ TeV, were measured in the central pseudorapidity region |η|<1. Comparisons are made with previous measurements at $\sqrt{s}=0.9$ TeV and 2.36 TeV. At $\sqrt{s}=7$ TeV, for events with at least one charged particle in |η|<1, we obtain $\mathrm{d}N_{\mathrm{ch}}/\mathrm{d}\eta=6.01\pm0.01(\mathrm {stat.})^{+0.20}_{-0.12}(\mathrm{syst.})$. This corresponds to an increase of $57.6\%\pm0.4\%(\mathrm{stat.})^{+3.6}_{-1.8}\%(\mathrm{syst.})$ relative to collisions at 0.9 TeV, significantly higher than calculations from commonly used models. The multiplicity distribution at 7 TeV is described fairly well by the negative binomial distribution.
119643427
Star detector overview
An introduction to the STAR detector and a brief overview of the physics goals of the experiment are presented.