Refine
Year of publication
Document Type
- Article (49)
- Part of Periodical (9)
- Book (2)
- Preprint (1)
Language
- English (61)
Has Fulltext
- yes (61)
Is part of the Bibliography
- no (61)
Keywords
- Antlion (1)
- Biology (1)
- Dejunaleon (1)
- Di-hadron correlations (1)
- Interference fragmentation function (1)
- La biología (1)
- New World (1)
- Paranthaclisis floridensis (Neuroptera: Myrmeleontidae) (1)
- Stenorrhachus, Chile (1)
- Transversity (1)
The tribe Acanthaclisini Navas contains 14 described genera which we recognize as valid. We have reared larvae of 8 of these (Acanthaclisis Rambur, Centroclisis Navas, Fadrina Navas, Paranthaclisis Banks, Phanoclisis Banks, Synclisis Navas, Syngenes Kolbe, and Vella Navas). In addition, we have studied preserved larvae from Australia which probably represent the genus Heoclisis Navas. This represents the majority of the taxa, lacking only the small genera Avia Navas, Cosina Navas, Madrasta Navas, Mestressa Navas, and Stiphroneuria Gerstaecker. Studies of these larvae have revealed structural differences, especially of the mandible, which we have employed to provide identification of these genera by means of descriptions, keys, and illustrations. Also, since no modern key exists, we are providing a key to the genera based on adults which will provide some further insight on the generic relationships. Observations on the tribal differences of Myrmeleontidae based on larvae are made with a preliminary key to the known tribes.
Mansell (1983) described two new species and genera of Crocinae from Peru and Bolivia bringing the total number of South American species of this subfamily to five species. However, all five species occur well south of the equator. Recently the authors discovered a sixth species in northern Venezuela greatly extending the northern range of the family in South America. This new species belongs to the genus Moranida Mansell. Both adults and larvae were found and are described here with a key to the species of Crocinae of South America. We also found and reared Moranida peruviensis Mansell from Lambayeque, Peru, and provide this new record. This paper represents contribution No. 645 of the Bureau of Entomology.
A taxonomic study of the new world genus Dimarella has led to the recognition of 17 species, 9 of which are newly described. Three subgenera are recognized, one of which is described as new. Larvae are described for 11 species and biological data are given. Keys to adults and larvae are provided as well as photographs of larvae and taxonomic drawings. Distribution is summarized in maps.
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.
Two-pion correlation functions in Au+Au collisions at sqrt[sNN] = 130 GeV have been measured by the STAR (solenoidal tracker at RHIC) detector. The source size extracted by fitting the correlations grows with event multiplicity and decreases with transverse momentum. Anomalously large sizes or emission durations, which have been suggested as signals of quark-gluon plasma formation and rehadronization, are not observed. The Hanbury Brown-Twiss parameters display a weak energy dependence over a broad range in sqrt[sNN].
The first measurements of light antinucleus production in Au+Au collisions at the Relativistic Heavy-Ion Collider are reported. The observed production rates for d-bar and 3He-bar are much larger than in lower energy nucleus-nucleus collisions. A coalescence model analysis of the yields indicates that there is little or no increase in the antinucleon freeze-out volume compared to collisions at CERN SPS energy. These analyses also indicate that the 3He-bar freeze-out volume is smaller than the d-bar freeze-out volume.
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[sNN] = 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.
The minimum-bias multiplicity distribution and the transverse momentum and pseudorapidity distributions for central collisions have been measured for negative hadrons ( h-) in Au+Au interactions at sqrt[sNN] = 130 GeV. The multiplicity density at midrapidity for the 5% most central interactions is dNh-/d eta | eta = 0 = 280±1(stat)±20(syst), an increase per participant of 38% relative to pp-bar collisions at the same energy. The mean transverse momentum is 0.508±0.012 GeV/c and is larger than in central Pb+Pb collisions at lower energies. The scaling of the h- yield per participant is a strong function of pperp. The pseudorapidity distribution is almost constant within | eta |<1.
We report the first measurement of inclusive antiproton production at midrapidity in Au+Au collisions at sqrt[sNN] = 130 GeV by the STAR experiment at RHIC. The antiproton transverse mass distributions in the measured transverse momentum range of 0.25<pperp<0.95 GeV/c are found to fall less steeply for more central collisions. The extrapolated antiproton rapidity density is found to scale approximately with the negative hadron multiplicity density.
Elliptic flow holds much promise for studying the early-time thermalization attained in ultrarelativistic nuclear collisions. Flow measurements also provide a means of distinguishing between hydrodynamic models and calculations which approach the low density (dilute gas) limit. Among the effects that can complicate the interpretation of elliptic flow measurements are azimuthal correlations that are unrelated to the reaction plane (nonflow correlations). Using data for Au + Au collisions at sqrt[sNN]=130 GeV from the STAR time projection chamber, it is found that four-particle correlation analyses can reliably separate flow and nonflow correlation signals. The latter account for on average about 15% of the observed second-harmonic azimuthal correlation, with the largest relative contribution for the most peripheral and the most central collisions. The results are also corrected for the effect of flow variations within centrality bins. This effect is negligible for all but the most central bin, where the correction to the elliptic flow is about a factor of 2. A simple new method for two-particle flow analysis based on scalar products is described. An analysis based on the distribution of the magnitude of the flow vector is also described.