Microscopic model approaches to fragmentation of nuclei and phase transitions in nuclear matter

The properties of excited nuclear matter and the quest for a phase transition which is expected to exist in this system are the subject of intensive investigations. High energy nuclear collisions between finite nuclei which lead to matter fragmentation are used to investigate these properties. The present report covers effective work done on the subject over the two last decades. The analysis of experimental data is confronted with two major problems, the setting up of thermodynamic equilibrium in a time-dependent fragmentation process and the finite size of nuclei. The present status concerning the first point is presented. Simple classical models of disordered systems are derived starting with the generic bond percolation approach. These lattice and cellular equilibrium models, like percolation approaches, describe successfully experimental fragment multiplicity distributions. They also show the properties of systems which undergo a thermodynamic phase transition. Physical observables which are devised to show the existence and to fix the order of critical behaviour are presented. Applications to the models are shown. Thermodynamic properties of finite systems undergoing critical behaviour are advantageously described in the framework of the microcanonical ensemble. Applications to the designed models and to experimental data are presented and analysed. Perspectives of further developments of the field are suggested.Comment: 150 pages including 28 figures. To be published in Phys. Rep. Corrected discussion in section 3.2.3 and new Fig.5. New caption of Fig.2

Antitumour activity of EPA-enriched phospholipids liposomes against S180 ascitic tumour-bearing mice

The health benefits of eicosapentaenoic acid (EPA)-enriched phospholipids (PL) have witnessed a recent upsurge. In the present study, PL from starfish Asterias amurensis (SFP) and sea cucumber Cucumaria frondosa (SCP) were extracted and the liposomes were prepared. Both SFP and SCP liposomes showed antitumour effects in vitro and exhibited high transport and uptake effects in small intestinal epithelial cell models. The results also demonstrated that dietary SFP and SCP liposomes prolonged the life span and ameliorated oxidative stress status of S180 ascitic tumour-bearing mice. Results also showed that dietary SFP and SCP liposomes up-regulated the expression of Bax and down-regulated Bcl-2 level in tumour cells, then induced release of cytochrome c from mitochondria to cytosol, thus the activation of caspase 9 and caspase 3. Taken together, these findings suggest that SFP and SCP liposomes exert antitumour effects mainly via activation of mitochondrial apoptotic pathways in tumour-bearing mice. (C) 2015 Elsevier Ltd. All rights reserved

Measurement of the I = 1/2 Kπ S-wave amplitude from Dalitz plot analyses of η[subscript c] → K[bar over K]π in two-photon interactions

We study the processes γγ → K[0 over S]K[superscript ±]π[superscript ∓] and γγ → K[superscript +]K[superscript -]π[superscript 0] using a data sample of 519  fb[superscript -1] recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy e[superscript +]e[superscript -] collider at center-of-mass energies at and near the Υ(nS) (n = 2, 3, 4) resonances. We observe η[subscript c] decays to both final states and perform Dalitz plot analyses using a model-independent partial wave analysis technique. This allows a model-independent measurement of the mass-dependence of the I = 1/2 Kπ S-wave amplitude and phase. A comparison between the present measurement and those from previous experiments indicates similar behavior for the phase up to a mass of 1.5  GeV/c[superscript 2]. In contrast, the amplitudes show very marked differences. The data require the presence of a new a[subscript 0](1950) resonance with parameters m = 1931 ± 14 ± 22  MeV/c[superscript 2] and Γ = 271 ± 22 ± 29  MeV.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Measurement of the D* (2010)(+) -D+ Mass Difference

We measure the mass difference, $\Delta m_+$, between the $D^{*}(2010)^+$ and the $D^+$ using the decay chain $D^{*}(2010)^+\to D^+ \pi^0$ with $D^+\to K^-\pi^+\pi^+$. The data were recorded with the BABAR detector at center-of-mass energies at and near the $\Upsilon(4S)$ resonance, and correspond to an integrated luminosity of approximately 468 ${\rm fb}^{-1}$. We measure $\Delta m_+ = \left(140\,601.0 \pm 6.8[{\rm stat}] \pm 12.9[{\rm syst}]\right)$ keV. We combine this result with a previous BABAR measurement of $\Delta m_0\equiv m(D^{*}(2010)^+) - m (D^0)$ to obtain $\Delta m_D = m(D^+) - m(D^0) = \left(4\,824.9 \pm 6.8[{\rm stat}] \pm 12.9[{\rm syst}]\right)$ keV. These results are compatible with and approximately five times more precise than the Particle Data Group averages.Comment: 7 pages, 3 figures, submitted to Physical Review Letter