4,581 research outputs found
Nuclear matter and neutron matter for improved quark mass density- dependent model with mesons
A new improved quark mass density-dependent model including u, d quarks,
mesons, mesons and 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 - 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
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