Related papers: Viscosity in a Lepton-Photon Universe
The inflationary expansion of our early-time universe is considered in terms of the van der Waals equation, as equation of state for the cosmic fluid, where a bulk viscosity contribution is assumed to be present. The corresponding…
A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV/$c^2$ decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV, collected by the LHCb…
A search is performed for massive long-lived particles (LLP) decaying semileptonically into a muon and two quarks. Two kinds of LLP production processes were considered. In the first, a Higgs-like boson with mass from 30 to 200 GeV is…
We present a measurement of the density of GeV muons in near-vertical air showers using three years of data recorded by the IceTop array at the South Pole. Depending on the shower size, the muon densities have been measured at lateral…
We investigate in detail the leptogenesis by the decay of coherent right-handed sneutrino $\widetilde{N}$ having dominated the energy density of the early universe, which was originally proposed by HM and TY. Once the $\widetilde{N}$…
We investigate the temperature dependence of the shear and bulk viscosities and their ratios to the entropy density via a continuum QCD approach. We calculate the pion mass and decay constant in the framework of Dyson-Schwinger equations of…
We analyse the effects of thermal quasiparticles in leptogenesis using hard-thermal-loop-resummed propagators in the imaginary time formalism of thermal field theory. We perform our analysis in a leptogenesis toy model with three…
For the first time, a reliable estimation for the equations of state (EoS), bulk viscosity, and relaxation time, at temperatures ranging from a few MeV up to TeV or energy density up to $10^{16}~$GeV/fm$^3$. This genuine study covers both…
We study the impact that a heavy generation of vector-like leptons can have on the value of the electric dipole moment of the electron, and the rates for the flavor violating processes mu --> e gamma and mu --> 3e. The smallness of the…
The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A…
Bursts of weakly interacting particles such as neutrinos or even more weakly interacting particles such as wimps and gravitons from the very early universe would offer a much deeper ``look back time'' to early epochs than is possible with…
The IceCube detector allows for the first time a measurement of atmospheric muon and neutrino energy spectra from tens of GeV up to the PeV range. The lepton flux in the highest energy region depends on both the primary cosmic ray…
Strongly-coupled theories at the TeV can naturally drive a long period of supercooling in the early universe. Trapped into the deconfined phase, the universe could inflate and cool down till the temperature reaches the QCD strong scale. We…
We study the bulk viscosity of dense matter, taking into account non-linear effects which arise in the large amplitude "supra-thermal" region where the deviation $\mu_\Delta$ of the chemical potentials from chemical equilibrium fulfills…
We calculate the transport coefficient of hadronic matter in the presence of temperature and magnetic field using the linear sigma model. In the relaxation time approximation, we estimate the shear viscosity over entropy density $\eta/s$.…
After a brief discussion of baryon and lepton number nonconservation, we review the status of thermal leptogenesis with GUT scale neutrino masses, as well as low scale alternatives with keV neutrinos as dark matter and heavy neutrino masses…
Within a supersymmetric (SUSY) type-I seesaw framework with flavor-blind universal boundary conditions, we study the consequences of requiring that the observed baryon asymmetry of the Universe be explained by either thermal or non-thermal…
The evolution of a vacuum component of the Universe is investigated in the quantum as well as the classical regimes. Probably our Universe has arisen as a vacuum fluctuation and very probably that it has had a high symmetry for Planckian…
The physics of the intracluster medium, in particular the values for the thermal conductivity and the viscosity are largely unknown and subject to an ongoing debate. Here, we study the effect of viscosity on the thermal state of the…
The quarks are regarded as quasiparticles, which acquire an effective mass generated by the interaction with the other quarks of the dense system. The bulk viscosity is re-expressed in the case of interacting strange quark matter. We find…