Nuclear matter and neutron matter for improved quark mass density- dependent model with ρ\rho mesons

A new improved quark mass density-dependent model including u, d quarks, $\sigma$ mesons, $\omega$ mesons and $\rho$ mesons is presented. Employing this model, the properties of nuclear matter, neutron matter and neutron star are studied. We find that it can describe above properties successfully. The results given by the new improved quark mass density- dependent model and by the quark meson coupling model are compared.Comment: 18 pages, 7 figure

Free Quarks and Antiquarks versus Hadronic Matter

Meson-meson reactions A(q_1 \bar{q}_1) + B(q_2 \bar{q}_2) to q_1 + \bar{q}_1 + q_2 + \bar{q}_2 in high-temperature hadronic matter are found to produce an appreciable amount of quarks and antiquarks freely moving in hadronic matter and to establish a new mechanism for deconfinement of quarks and antiquarks in hadronic matter.Comment: 9 pages, 3 figure

The Friedmann equation in modified entropy-area relation from entropy force

According to the formal holographic principle, a modification to the assumption of holographic principle in Verlinder's investigation of entropy force is obtained. A more precise relation between entropy and area in the holographic system is proposed. With the entropy corrections to the area-relation, we derivate Newton's laws and Einstein equation with a static spherically symmetric holographic screen. Furthermore we derived the correction terms to the modified Friedmann equation of the FRW universe starting from the holographic principle and the Debye model.Comment: Mod. Phys. Lett. A26, 489-500 (2011

Improved quark mass density- dependent model with quark and non-linear scalar field coupling

The improved quark mass density- dependent model which includes the coupling between the quarks and a non-linear scalar field is presented. Numerical analysis of solutions of the model is performed over a wide range of parameters. The wave functions of ground state and the lowest one-particle excited states with even and odd parity are given. The root-mean squared radius, the magnetic moment and the ratio between the axial-vector and the vector beta-decay coupling constants of the nucleon are calculated. We found that the present model is successful to describe the properties of nucleon.Comment: 7pages, 6 figure

Unwrapping the Deadweight Loss of Gift Giving

anonymous referees of this journal and seminar participants at Ben-Gurion University, Universite Louis-Pasteur and the 1998 ESA meetings in Mannheim for comments. Unwrapping the Deadweight Loss of Gift Giving Two previous surveys used to measure the welfare implications of Christmas gift giving in the U.S. have reached opposite conclusions. Waldfogel (1993) nds a 10-33 % welfare reduction associated with Christmas giving. Curiously, Solnick and Hemenway's (1996) (henceforth S&H) replication of Waldfogel's survey turns up just the opposite result: a 214 % welfare gain. We design a series of controlled laboratory experiments to determine why thetwopapers arrive at opposite conclusions. We do not produce our own estimate of the deadweight lossofgift giving; rather, our aim is to understand how, and which among, the di erences in methodology between the two studies account for their divergent ndings. Waldfogel (1993) surveyed 58 students enrolled in an intermediate microeconomics class about speci c gifts they had received for Christmas. In addition to eliciting details about the gifts received, the recipient's background, and her relationship to the gift giver, Waldfogel asked recipients to estimate the amount paid by the giver for each gift received. Finally, recipients were asked to place avalue on each gift they received. Respondents were instructed to estimate the value of a gift as the...amountofcashsuch that you are indi erent between the gift and the cash, not counting the sentimental value of the gift. (Waldfogel, 1993, p.1331) Waldfogel measures the welfare yield of a gift as the di erence between the re-1 cipient's valuation and her cost estimate of the gift. Based on 278 gifts reported, Waldfogel nds that gifts have anaverage yield of 87.1%, indicating that gifts lose about 13 % of their value in the exchange from giver to receiver. When cash gifts are excluded, the average yield falls further to 83.9%. 1 S&H were intrigued enough byWaldfogel's results to replicate his study. Contrar

Quark deconfinement phase transition for improved quark mass density-dependent model

By using the finite temperature quantum field theory, we calculate the finite temperature effective potential and extend the improved quark mass density-dependent model to finite temperature. It is shown that this model can not only describe the saturation properties of nuclear matter, but also explain the quark deconfinement phase transition successfully. The critical temperature is given and the effect of $\omega$- meson is addressed.Comment: 18 pages, 7 figure

Quark mass density- and temperature- dependent model for strange quark matter

It is found that the radius of a stable strangelet decreases as the temperature increases in a quark mass density-dependent model. To overcome this difficulty, we extend this model to a quark mass density- and temperature- dependent model in which the vacuum energy density at zero baryon density limit B depends on temperature. An ansatz is introduced and the regions for the best choice of the parameters are studied.Comment: 5 pages, 4 figure