Leptogenesis, Z' bosons, and the reheating temperature of the Universe

We study the impact for leptogenesis of new U(1) gauge bosons coupled to the heavy Majorana neutrinos. They can significantly enhance the efficiency of thermal scenarios in the weak washout regime as long as the Z' masses are not much larger than the reheating temperature ($M_{Z'}<10 T_{rh}$), with the highest efficiencies obtained for Z' bosons considerably heavier than the heavy neutrinos ($M_{Z'} > 100 M_1$). We show how the allowed region of the parameter space is modified in the presence of a Z' and we also obtain the minimum reheating temperature that is required for these models to be successful.Comment: 14 pages, 6 figures; One figure added, discussion on the reheating temperature extende

Competitive nucleation in metastable systems

Metastability is observed when a physical system is close to a first order phase transition. In this paper the metastable behavior of a two state reversible probabilistic cellular automaton with self-interaction is discussed. Depending on the self-interaction, competing metastable states arise and a behavior very similar to that of the three state Blume-Capel spin model is found

Basic Ideas to Approach Metastability in Probabilistic Cellular Automata

Cellular Automata are discrete--time dynamical systems on a spatially extended discrete space which provide paradigmatic examples of nonlinear phenomena. Their stochastic generalizations, i.e., Probabilistic Cellular Automata, are discrete time Markov chains on lattice with finite single--cell states whose distinguishing feature is the \textit{parallel} character of the updating rule. We review some of the results obtained about the metastable behavior of Probabilistic Cellular Automata and we try to point out difficulties and peculiarities with respect to standard Statistical Mechanics Lattice models.Comment: arXiv admin note: text overlap with arXiv:1307.823

A comparison between different cycle decompositions for Metropolis dynamics

In the last decades the problem of metastability has been attacked on rigorous grounds via many different approaches and techniques which are briefly reviewed in this paper. It is then useful to understand connections between different point of views. In view of this we consider irreducible, aperiodic and reversible Markov chains with exponentially small transition probabilities in the framework of Metropolis dynamics. We compare two different cycle decompositions and prove their equivalence

Analisis Semantik Sinonim Tomodachi, Yuujin, dan Nakama dalam Kalimat Bahasa Jepang

This research was about a synonym of tomodachi, yuujin, and nakama in Japanese.Tomodachi, yuujin, and nakama have similar meaning in Japanese, that is „friend‟, but the USAgeis different in sentence, depend on the context and situation of sentence. The purpose of thisresearch wants to know of the meaning and similar meaning of tomodachi, yuujin, and nakama.The collecting data from some Japanese dictionary, Japan movie, and Japanese books relatedwith this research

Simulation of the channelling of ions from MeV C60 in crystalline solids

Simulations were performed describing the motion and breakup of energetic C60 ions interacting with crystalline targets. A hybrid algorithm was used that employs a binary collision model for the scattering of the carbon ions by the atoms of the solid, and molecular dynamics for the Coulomb interactions of the 60 carbon ions with one another. For the case of yttrium iron garnet (YIG), directions such as [1 1 0], [1 0 0], [0 1 0] and [0 0 1] demonstrate channelling for a large fraction of the C ions. For directions such as [1 1 1], [2 1 1] and [7 5 3] the trajectories show no more channelling than for random directions. The effects of tilt, shielding and wake-field interactions were investigated for YIG and α-quartz

Simulation of the interaction of high-energy C60 cluster ions with amorphous targets

Detailed simulations of the interaction of energetic C-60 beams with amorphous targets are presented here. The spatial evolution of the cluster components is calculated accounting for multiple scattering and Coulomb explosion by means of Monte Carlo and molecular dynamics, respectively. The charge states of the individual cluster components (atoms, atomic ions, fragment cluster ions) as a function of penetration depth are also calculated in tandem with the above calculations by means of the Monte Carlo method. The relative importance of scattering versus Coulomb repulsion is studied as a function of the C-60 cluster energy. The effect of the neighboring cluster constituents on the average charge state of the cluster atoms is calculated as a function of the depth of penetration for a C-60 cluster of 40 MeV. The calculation accounts for the increase in ionization energy of the atom due to the other constituents. Relative track radii are calculated as a function of penetration depth and good agreement with the experimental results is obtained for the interaction of a 30 MeV carbon cluster with silicon. Track splitting observed well into the target as measured by Dunlop in yttrium iron garnet is obtained in the simulations described here for the case of amorphous carbon, provided the Coulomb repulsion is screened by the four valence electrons. Collective energy deposition enhancement is calculated for the 720 MeV cluster. Here the cluster constituents are nearly fully ionized, thereby minimizing the ambiguity related to the value of the ionic charge in the calculation

Study on TIME Efficiency of Tuna (Thunnus SP) Catches Landing Toward Mooring TIME of the Long Liner at Fishing Port of Bungus, West Sumatera Province

A series survey activity was conducted on April-Mei 2013 at the fishing port Bungus,Padang city West Sumatera province. Purpose of this study is to know efficiency level of longliner fishing catches, which has been landed in fishing port and its factor influenced. The resultshow that the efficiency level of fishing catches landing time was 56.98-72.73%, with uploadingefficiency time was 64,65% in average. There is seven free variable influence on the timeefficiency of fishing landing, with the value r=0,836 and R2=83,6%. So the diversity ofindependent variable gives the contribution to the diversity assess of time efficiency as 83,6%