Thermal Abundances of Heavy Particles
نویسنده
چکیده
Matsumoto and Yoshimura [hep-ph/9910393] have argued that there are loop corrections to the number density of heavy particles (in thermal equilibrium with a gas of light particles) that are not Boltzmann suppressed by a factor of e at temperatures T well below the mass M of the heavy particle. We argue that this conclusion follows from an inappropriate definition of the number density of the heavy particles. We study the case where the heavy particles carry a conserved U(1) charge, and the light particles do not. The fluctuations of the net charge in a given volume then provide a measure of the total number of heavy particles in that same volume. We show that these charge fluctuations are Boltzmann suppressed (to all orders in perturbation theory). Therefore, we argue, the number density of heavy particles must also be Boltzmann suppressed. Typeset using REVTEX E–mail: [email protected]
منابع مشابه
Thermal hadron production in high energy collisions
It is shown that hadron abundances in high energy ee, pp and pp̄ collisions, calculated by assuming that particles originate in hadron gas fireballs at thermal and partial chemical equilibrium, are in very good agreement with the data. The freeze-out temperature of the hadron gas fireballs turns out to be nearly constant over a large center of mass energy range and not dependent on the initial c...
متن کاملBioremediation of thermal power plant effluents with chitosan and chitosan nano particels
Water pollution caused by thermal power plant effluent discharges has become a worrisome phenomenon due to its impact on environmental health and safety. Many treatment processes that have been used to remove heavy metals from wastewater are suffered from high cost. Chitosan is a low cost adsorbent which is biodegradable and biocompatible polymer obtained from shrimp biowaste. In the present st...
متن کاملNon-thermal desorption from interstellar dust grains via exothermic surface reactions
Context. xxx Aims. The gas-phase abundance of methanol in dark quiescent cores in the interstellar medium cannot be explained by gas-phase chemistry. In fact, the only possible synthesis of this species appears to be production on the surfaces of dust grains followed by desorption into the gas. Yet, evaporation is inefficient for heavy molecules such as methanol at the typical temperature of 10...
متن کاملThe first second of the Universe
The history of the Universe after its first second is now tested by high quality observations of light element abundances and temperature anisotropies of the cosmic microwave background. The epoch of the first second itself has not been tested directly yet; however, it is constrained by experiments at particle and heavy ion accelerators. Here I attempt to describe the epoch between the electrow...
متن کاملStrange Hadron Resonances: Freeze-Out Probes in Heavy-Ion Collisions
Hyperon resonances are becoming an extremely useful tool allowing the study of the properties of hadronic fireballs made in heavy ion collisions. Their yield, compared to stable particles with the same quark composition, depends on hadronization conditions. The resonance’s short lifetime makes them ideal probes of the fireball chemical freeze-out mechanisms. An analysis of resonance abundance i...
متن کامل