Quantum thermodynamics at critical points during melting and solidification processes

We systematically explore and show the existence of finite-temperature continuous quantum phase transition (CTQPT) at a critical point, namely, during solidification or melting such that the first-order thermal phase transition is a special case within CTQPT. Infact, CTQPT is related to chemical reaction where quantum fluctuation (due to wavefunction transformation) is caused by thermal energy and it can occur maximally for temperatures much higher than zero Kelvin. To extract the quantity related to CTQPT, we use the ionization energy theory and the energy-level spacing renormalization group method to derive the energy-level spacing entropy, renormalized Bose-Einstein distribution and the time-dependent specific heat capacity. This work unambiguously shows that the quantum phase transition applies for any finite temperatures.Comment: To be published in Indian Journal of Physics (Kolkata

Modification of magicity towards the dripline and its impact on electron-capture rates for stellar core-collapse

The importance of microphysical inputs from laboratory nuclear experiments and theoretical nuclear structure calculations in the understanding of the core collapse dynamics, and the subsequent supernova explosion, is largely recognized in the recent literature. In this work, we analyze the impact of the masses of very neutron rich nuclei on the matter composition during collapse, and the corresponding electron capture rate. To this aim, we introduce an empirical modification of the popular Duflo-Zuker mass model to account for possible shell quenching far from stability, and study the effect of the quenching on the average electron capture rate. We show that the preeminence of the $N=50$ and $N=82$ closed shells in the collapse dynamics is considerably decreased if the shell gaps are reduced in the region of $^{78}$Ni and beyond. As a consequence, local modifications of the overall electron capture rate up to 30\% can be expected, with integrated values strongly dependent on the stiffness of magicity quenching and progenitor mass and potential important consequences on the entropy generation, the neutrino emissivity, and the mass of the core at bounce. Our work underlines the importance of new experimental measurements in this region of the nuclear chart, the most crucial information being the nuclear mass and the Gamow-Teller strength. Reliable microscopic calculations of the associated elementary rate, in a wide range of temperatures and electron densities, optimized on these new empirical information, will be additionally needed to get quantitative predictions of the collapse dynamics.Comment: 12 pages, 10 figure

Solving QCD evolution equations in rapidity space with Markovian Monte Carlo

This work covers methodology of solving QCD evolution equation of the parton distribution using Markovian Monte Carlo (MMC) algorithms in a class of models ranging from DGLAP to CCFM. One of the purposes of the above MMCs is to test the other more sophisticated Monte Carlo programs, the so-called Constrained Monte Carlo (CMC) programs, which will be used as a building block in the parton shower MC. This is why the mapping of the evolution variables (eikonal variable and evolution time) into four-momenta is also defined and tested. The evolution time is identified with the rapidity variable of the emitted parton. The presented MMCs are tested independently, with ~0.1% precision, against the non-MC program APCheb especially devised for this purpose.Comment: version compatible with with the erratum in Acta Physica Polonic

Price setting behaviour in the Netherlands: results of a survey

This paper presents the results of a survey among Dutch firms on price setting behaviour in the Netherlands. It aims to identify how sticky prices are, which prices are sticky and why they are sticky. It is part of the Eurosystem Inflation Persistence Network (IPN). The most distinctive feature of the Dutch survey is its broad coverage of the business community (seven sectors and seven size classes). Our primary finding is that price setting behaviour depends critically on both a firm’s size and the competitive environment it faces. Small firms in particular adopt more rigid pricing policies, and the weaker the competition a firm faces, the stickier a company’s price will be. Furthermore, we find that wholesale and retail prices are more flexible than those for business-to-business services. The survey suggests that explicit and informal contracting are the most important sources of price stickiness. Menu costs and psychological pricing – two prominent explanations of price stickiness in the literature – are of minor importance. Finally, there is clear evidence of asymmetries in shocks driving price increases and decreases. JEL Classification: E30, D40nominal rigidity, price setting, survey data

Nanoscale-targeted patch-clamp recordings of functional presynaptic ion channels

Important modulatory roles have been attributed to presynaptic NMDA receptors (NMDARs) located on cerebellar interneuron terminals. Evidence supporting a presynaptic location includes an increase in the frequency of mini events following the application of NMDA and gold particle-labelled NMDA receptor antibody localisation. However, more recent work, using calcium indicators, casts doubt on the idea of presynaptic NMDARs because basket cell varicosities did not show the expected calcium rise following either the local iontophoresis of L-aspartate or the two-photon uncaging of glutamate. (In theory such calcium imaging is sensitive enough to detect the calcium rise from even a single activated receptor.) It has therefore been suggested that the effects of NMDA are mediated via the activation of somatodendritic channels, which subsequently cause a subthreshold depolarization of the axon. Here we report results from a vibrodissociated preparation of cerebellar Purkinje cells, in which the interneuron cell bodies are no longer connected but many of their terminal varicosities remain attached and functional. This preparation can retain both inhibitory and excitatory inputs. We find that the application of NMDA increases the frequency of both types of synaptic event. The characteristics of these events suggest they can originate from interneuron, parallel fiber and even climbing fiber terminals. Interestingly, retrograde signalling seems to activate only the inhibitory terminals. Finally, antibody staining of these cells shows NMDAR-like immunoreactivity co-localised with synaptic markers. Since the Purkinje cells show no evidence of postsynaptic NMDAR-mediated currents, we conclude that functional NMDA receptors are located on presynaptic terminals

Some aspects of the phase diagram of nuclear matter relevant to compact stars

Dense matter as it can be found in core-collapse supernovae and neutron stars is expected to exhibit different phase transitions which impact the matter composition and the equation of state, with important consequences on the dynamics of core-collapse supernova explosion and on the structure of neutron stars. In this paper we will address the specific phenomenology of two of such transitions, namely the crust-core solid-liquid transition at sub-saturation density, and the possible strange transition at super-saturation density in the presence of hyperonic degrees of freedom. Concerning the neutron star crust-core phase transition at zero and finite temperature, it will be shown that, as a consequence of the presence of long-range Coulomb interactions, a clusterized phase is expected which is not accessible in the grand-canonical ensemble. A specific quasi-particle model will be introduced and some quantitative results relevant for the supernova dynamics will be shown. The opening of hyperonic degrees of freedom at higher densities corresponding to the neutron stars core also modifies the equation of state. The general characteristics and order of phase transitions in this regime will be analyzed in the framework of a self-consistent mean-field approach.Comment: arXiv admin note: substantial text overlap with arXiv:1206.4924, arXiv:1301.695

Thermodynamics of baryonic matter with strangeness within non-relativistic energy density functional model

We study the thermodynamical properties of compressed baryonic matter with strangeness within non-relativistic energy density functional models with a particular emphasis on possible phase transitions found earlier for a simple $n,p,e,\Lambda$-mixture. The aim of the paper is twofold: I) examining the phase structure of the complete system, including the full baryonic octet and II) testing the sensitivity of the results to the model parameters. We find that, associated to the onset of the different hyperonic families, up to three separate strangeness-driven phase transitions may occur. Consequently, a large fraction of the baryonic density domain is covered by phase coexistence with potential relevance for (proto)-neutron star evolution. It is shown that the presence of a phase transition is compatible both with the observational constraint on the maximal neutron star mass, and with the present experimental information on hypernuclei. In particular we show that two solar mass neutron stars are compatible with important hyperon content. Still, the parameter space is too large to give a definitive conclusion of the possible occurrence of a strangeness driven phase transition, and further constraints from multiple-hyperon nuclei and/or hyperon diffusion data are needed.Comment: 11 pages, 7 figure