(2808) Proposal to Reject the Name Acalypha supera (Euphorbiaceae)

(2808) Acalypha supera Forssk.; Fl. Aegypt.-Arab.: 162. 1 Oct 1775[Angiosp.: Euphorb.]; nom. utique rej. prop.Typus: non designatus

(2807) Proposal to Conserve the Name Acalypha wilkesiana against A. tricolor (Euphorbiaceae)

(2807) Acalypha wilkesiana Müll. Arg. in Candolle; Prodr. 15(2):817. Aug (sero) 1866 [Angiosp.: Euphorb.]; nom. cons. prop.Typus: Fiji; [Viti Levu]; Rewa; “Unit. Stat. explor. exped.under Capt. Wilkes” (G-DC barcodes G00324021 &G00324022; isotypi: GH barcode GH00045512; K barcodeK000959008; US Nos. 1944717 & 1944718 [barcodes00096423 & 00096424]). (=) Acalypha tricolor Veitch ex Mast. in Gard. Chron. 1866:483. 26 Mai 1866; nom rej. prop.Neotypus (hic designatus): “Hort. Veitch; New Hebrides[Vanuatu]”; Jul 1844 (K barcode K001235482)

Chemical Freeze-out of Strange Particles and Possible Root of Strangeness Suppression

Two approaches to treat the chemical freeze-out of strange particles in hadron resonance gas model are analyzed. The first one employs their non-equillibration via the usual \gamma_s factor and such a model describes the hadron multiplicities measured in nucleus-nucleus collisions at AGS, SPS and RHIC energies with \chi^2/dof = 1.15. Surprisingly, at low energies we find not the strangeness suppression, but its enhancement. Also we suggest an alternative approach to treat the strange particle freeze-out separately, but with the full chemical equilibration. This approach is based on the conservation laws which allow us to connect the freeze-outs of strange and non-strange hadrons. Within the suggested approach the same set of hadron multiplicities can be described better than within the conventional approach with \chi^2/dof = 1.06. Remarkably, the fully equilibrated approach describes the strange hyperons and antihyperons much better than the conventional one.Comment: 6 pages, 5 figure

New Signals of Quark-Gluon-Hadron Mixed Phase Formation

Here we present several remarkable irregularities at chemical freeze-out which are found using an advanced version of the hadron resonance gas model. The most prominent of them are the sharp peak of the trace anomaly existing at chemical freeze-out at the center of mass energy 4.9 GeV and two sets of highly correlated quasi-plateaus in the collision energy dependence of the entropy per baryon, total pion number per baryon, and thermal pion number per baryon which we found at the center of mass energies 3.8-4.9 GeV and 7.6-10 GeV. The low energy set of quasi-plateaus was predicted a long time ago. On the basis of the generalized shock-adiabat model we demonstrate that the low energy correlated quasi-plateaus give evidence for the anomalous thermodynamic properties inside the quark-gluon-hadron mixed phase. It is also shown that the trace anomaly sharp peak at chemical freeze-out corresponds to the trace anomaly peak at the boundary between the mixed phase and quark gluon plasma. We argue that the high energy correlated quasi-plateaus may correspond to a second phase transition and discuss its possible origin and location. Besides we suggest two new observables which may serve as clear signals of these phase transformations.Comment: 14 pages, 4 figures, new signals of QGP formation are suggeste

Hadron Resonance Gas Model with Induced Surface Tension

Here we present a physically transparent generalization of the multicomponent Van der Waals equation of state in the grand canonical ensemble. For the one-component case the third and fourth virial coefficients are calculated analytically. It is shown that an adjustment of a single model parameter allows us to reproduce the third and fourth virial coefficients of the gas of hard spheres with small deviations from their exact values. A thorough comparison of the compressibility factor and speed of sound of the developed model with the one and two component Carnahan-Starling equation of state is made. It is shown that the model with the induced surface tension is able to reproduce the results of the Carnahan-Starling equation of state up to the packing fractions 0.2-0.22 at which the usual Van der Waals equation of state is inapplicable. At higher packing fractions the developed equation of state is softer than the gas of hard spheres and, hence, it breaks causality in the domain where the hadronic description is expected to be inapplicable. Using this equation of state we develop an entirely new hadron resonance gas model and apply it to a description of the hadron yield ratios measured at AGS, SPS, RHIC and ALICE energies of nuclear collisions. The achieved quality of the fit per degree of freedom is about 1.08. We confirm that the strangeness enhancement factor has a peak at low AGS energies, while at and above the highest SPS energy of collisions the chemical equilibrium of strangeness is observed. We argue that the chemical equilibrium of strangeness, i.e. $\gamma_s \simeq 1$, observed above the center of mass collision energy 4.3 GeV may be related to the hadronization of quark gluon bags which have the Hagedorn mass spectrum, and, hence, it may be a new signal for the onset of deconfinement