Fluctuations and Correlations of Conserved Charges in QCD at Finite Temperature with Effective Models

We study fluctuations of conserved charges including baryon number, electric charge, and strangeness as well as the correlations among these conserved charges in the 2+1 flavor Polyakov--Nambu--Jona-Lasinio model at finite temperature. The calculated results are compared with those obtained from recent lattice calculations performed with an improved staggered fermion action at two values of the lattice cutoff with almost physical up and down quark masses and a physical value for the strange quark mass. We find that our calculated results are well consistent with those obtained in lattice calculations except for some quantitative differences for fluctuations related with strange quarks. Our calculations indicate that there is a pronounced cusp in the ratio of the quartic to quadratic fluctuations of baryon number, i.e. $\chi_{4}^{B}/\chi_{2}^{B}$, at the critical temperature during the phase transition, which confirms that $\chi_{4}^{B}/\chi_{2}^{B}$ is a useful probe of the deconfinement and chiral phase transition.Comment: 24 pages, 11 figures; final version published in Phys. Rev.

Filament L1482 in the California molecular cloud

Aims. The process of gravitational fragmentation in the L1482 molecular filament of the California molecular cloud is studied by combining several complementary observations and physical estimates. We investigate the kinematic and dynamical states of this molecular filament and physical properties of several dozens of dense molecular clumps embedded therein. Methods. We present and compare molecular line emission observations of the J=2--1 and J=3--2 transitions of 12CO in this molecular complex, using the KOSMA 3-meter telescope. These observations are complemented with archival data observations and analyses of the 13CO J=1--0 emission obtained at the Purple Mountain Observatory 13.7-meter radio telescope at Delingha Station in QingHai Province of west China, as well as infrared emission maps from the Herschel Space Telescope online archive, obtained with the SPIRE and PACS cameras. Comparison of these complementary datasets allow for a comprehensive multi-wavelength analysis of the L1482 molecular filament. Results. We have identified 23 clumps along the molecular filament L1482 in the California molecular cloud. All these molecular clumps show supersonic non-thermal gas motions. While surprisingly similar in mass and size to the much better known Orion molecular cloud, the formation rate of high-mass stars appears to be suppressed in the California molecular cloud relative to that in the Orion molecular cloud based on the mass-radius threshold derived from the static Bonnor Ebert sphere. Our analysis suggests that these molecular filaments are thermally supercritical and molecular clumps may form by gravitational fragmentation along the filament. Instead of being static, these molecular clumps are most likely in processes of dynamic evolution.Comment: 10 pages, 9 figures, 2 tables, accepted to Astronomy and Astrophysic

A Value-Based Framework for Internet-Enabled CRM Services

The global competition for enterprises has been the significant issue for recent years. However, the customer needs are difficult to satisfy due to specialized characteristic of existing customers. A good CRM strategy may assist firms to earn advanced profits, increase customer perceived value, and acquire new customers. This research aims to provide a holistic framework based on two dimensions. The first dimension is the level of customer needs which is related to customer perceived value. The second value is the process of CRM; for instance, attracting, interacting, and retaining customers. This paper intends to: (1) identify the level of needs based on perceived value, (2) recognize the possible step of CRM processes, and (3) recommend an appropriate CRM e-service to a customer

Superradiant Transition to a Fermionic Quasicrystal in a Cavity

Recently, the steady state superradiance in degenerate Fermi gases has been realized in a cavity, following the previous discovery of the Dicke transition in Bose gases. The most prominent signature of fermionic Dicke transition is its density dependence, which is manifested as the Fermi surface nesting effect and the Pauli blocking effect. We study the superradiant transition in one-dimensional Fermi gases in a cavity with the presence of an incommensurate dipolar lattice. We find a first-order Dicke transition induced by indirect resonance effect, which is a resonance between two atomic levels by the level repulsion from a third level, and causes extra gap opening. By formulating a phenomenological theory, we find that the critical pumping strength for this first-order Dicke transition shows a linear V-shape kink near a particular indirect resonance modified filling $\nu_{\rm IRM}$. The presence and the unique density dependence of this transition manifest the fermionic nature and verify the mechanism of the quasicrystal superradiant transition.Comment: 5+8 pages, 3+6 figure

Aqua­[6-carboxyl­ato-N′-(pyridin-2-yl­methyl­idene)pyridine-2-carbohydrazidato]copper(II) trihydrate

In the title compound, [Cu(C13H8N4O3)(H2O)]·3H2O, the complex molecule, except for the aqua ligand, is essentially planar [r.m.s. deviation = 0.034 (2) Å]. The coordination polyhedron of the Cu2+ cation is a square-pyramid, with the aqua ligand at the apex. The compound exhibits a three-dimensional structure, which is is stabilized by O—H⋯O and O—-H⋯N hydrogen bonds and π–π inter­actions [centroid–centroid distance = 2.987 (3) Å]