92,263 research outputs found
Non-Gaussian statistics, maxwellian derivation and stellar polytropes
In this letter we discuss the Non-gaussian statistics considering two
aspects. In the first, we show that the Maxwell's first derivation of the
stationary distribution function for a dilute gas can be extended in the
context of Kaniadakis statistics. The second one, by investigating the stellar
system, we study the Kaniadakis analytical relation between the entropic
parameter and stellar polytrope index . We compare also the
Kaniadakis relation with proposed in the Tsallis
framework.Comment: 10 pages, 1 figur
The Phillips - Barger model for the elastic cross section and the Odderon
Inspired by the recent TOTEM data for the elastic proton -- proton ()
scattering at 8 and 13 TeV, we update previous studies of the
differential cross sections using the Phillips -- Barger (PB) model, which
parametrizes the amplitude in terms of a small number of free parameters. We
demonstrate that this model is able to describe the recent data on a
statistically acceptable way. Additionally, we perform separate fits of the
data for each center - of - mass energy and propose a parametrization for
the energy dependence of the parameters present in the PB model. As a
consequence, we are able to present the PB predictions for the elastic proton -
proton cross section at GeV and TeV, which are compared
with the existing antiproton -- proton () data. We show that the PB
predictions, constrained by the data, are not able to describe the
data. In particular, the PB model predicts a dip in the differential
cross section that is not present in the data. Such result suggests
the contribution of the Odderon exchange at high energies.Comment: 6 pages, 4 tables, 2 figures, results updated, matches published
versio
On the rotation of ONC stars in the Tsallis formalism context
The theoretical distribution function of the projected rotational velocity is
derived in the context of the Tsallis formalism. The distribution is used to
estimate the average for a stellar sample from the Orion Nebula Cloud
(ONC), producing an excellent result when compared with observational data. In
addition, the value of the parameter q obtained from the distribution of
observed rotations reinforces the idea that there is a relation between this
parameter and the age of the cluster.Comment: 6 pages, 2 figure
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