38 research outputs found
Thermal Pions at Finite Isospin Chemical Potential
The density corrections, in terms of the isospin chemical potential ,
to the mass of the pions are studied in the framework of the SU(2) low energy
effective chiral lagrangian. The pion decay constant is
also analized. As a function of temperature for , the mass remains
quite stable, starting to grow for very high values of , confirming previous
results. However, there are interesting corrections to the mass when both
effects (temperature and chemical potential) are simultaneously present. At
zero temperature the should condensate when . This is not longer valid anymore at finite . The mass of the
acquires also a non trivial dependence on due to the finite
temperature.Comment: 13 pages, 5 figure
The Equation of State for Dense QCD and Quark Stars
We calculate the equation of state for degenerate quark matter to leading
order in hard-dense-loop (HDL) perturbation theory. We solve the
Tolman-Oppenheimer-Volkov equations to obtain the mass-radius relation for
dense quark stars. Both the perturbative QCD and the HDL equations of state
have a large variation with respect to the renormalization scale for quark
chemical potential below 1 GeV which leads to large theoretical uncertainties
in the quark star mass-radius relation.Comment: 7 pages, 3 figure
Effect of naloxone on intake of cornstarch, sucrose and polycose diets in restricted and non-restricted rats
We studied the effect of the opioid receptor antagonist naloxone on intake of three isocaloric diets containing cornstarch, sucrose, or Polycose as the predominant carbohydrate in ad libitum-fed and food-restricted rats. A large body of evidence suggests that opioids affect palatability (reward)-rater than hunger (energy deficit)-driven food intake. We expected food intake to be driven by both energy needs and palatability in ad libitum-fed rats, whereas in food-restricted rats we expected intake to be driven by energy needs with a relatively small palatability component in the preferred sucrose and Polycose diet groups. In the ad libitum-fed rats, naloxone significantly reduced nocturnal intake of all three diets at doses of 0.3, 1.0, and 3.0 mg/kg. In contrast, naloxone failed to alter intake of the cornstarch diet in chronically food-restricted rats. However, naloxone decreased intake of the sucrose diet in food-restricted rats at doses of 0.3, 1.0, and 3.0 mg/kg and decreased intake of the Polycose diet at the 3 mg/kg dose. These data lend further support to the notion that opioids are involved in some other component of feeding than that induced by energy needs. </jats:p