arXiv subjects
Publications and source records attributed to Inga Kuznetsova.
The properties of the quark and hadron Universe are explored. Kinetic theory considerations are presented proving that hadron abundances after phase transformation from quarks to hadrons remain intact till abundances of hadrons become irrelevant. The hadronization process and the evolution of hadron yields is described in detail.
We study the initial properties and positron annihilation within a small electron-positron plasma drop formed by intense laser pulse. Such QED cascade initiated plasma is, in general, far below the chemical (particle yield) equilibrium. We find that the available electrons and positrons equilibrate kinetically, yet despite relatively high particle density, the electron-positron annihilation is very slow, suggesting a rather long lifespan of the plasma drop.
We study kinetic master equations for chemical reactions involving the formation and the natural decay of unstable particles in a thermal bath. We consider the decay channel of one into two particles, and the inverse process, fusion of two thermal particles into one. We present the master equations the evolution of the density of the unstable particles in the early Universe. We obtain the thermal invariant reaction rate using as an input the free space (vacuum) decay time and show the medium quantum effects on $π+π\leftrightarrow ρ$ reaction relaxation time. As another laboratory example we describe the $K+K \leftrightarrow ϕ$ process in thermal hadronic gas in heavy-ion collisions. A particularly interesting application of our formalism is the $π^{0}\leftrightarrow γ+γ$ process in the early Universe. We also explore the physics of $π^{\pm}$ and $μ^{\pm}$ freeze-out in the Universe.
The equilibrium size and temperature limits of thermally and chemically equilibrated $e^+e^-γ$ plasma drops are investigated at a given energy content. For a plasma to be equilibrated it must be opaque to electron and photon interactions. The opaqueness condition is determined by comparing plasma size with the mean free electron and photon paths. We calculate those paths using thermal Lorentz-invariant reaction rates for pair production and electron(positron) and photon scattering. The range of the corresponding plasma temperature and size is evaluated numerically. Considering the energy and size we find that the opaque and equilibrated plasma drop may be experimentally attainable.
We study particle production and its density evolution and equilibration in hot dense medium. One type of hot dense medium, which we study, is hadronic gas produced at quark gluon plasma hadronization in heavy ions collisions in SPS, RHIC and LHC experiments. We study hadron production at non-equilibrium quark gluon plasma hadronization and their evolution in thermal hadronic gas phase. We use non-equilibrium hadronization as the initial condition in the study of hadronic kinetic phase. During this time period some hadronic resonances can be produced in lighter hadrons fusion. Production of resonances is dominant over decay if there is non-equilibrium excess of decay products. Within this model we explain apparently contradictory experimental results reported in RHIC experiments: Sigma(1385) yield is enhanced while Lambda(1520) yield is suppressed compared to the statistical hadronization model expectation obtained without kinetic phase. We also predict Delta(1232) enhancement. The second type of plasma medium we consider is the relativistic electron positron photon plasma drop. This plasma is expected to be produced in decay of supercritical field created in ultrashort laser pulse. We study at what conditions this plasma drop is opaque for photons and therefore may reach thermal and chemical equilibrium. Further we consider muon and pion production in this plasma also as a diagnostic tool. Finally all these theoretical developments can be applied to begin a study of particles evolution in early universe in temperatures domain from QGP hadronization (160 MeV) to nucleosynthesis (0.1 MeV). The first results on pion equilibration are presented here.
We investigate the yield of $Λ(1520)$ resonance in heavy ion collisions within the framework of a kinetic master equation without the assumption of chemical equilibrium. We show that reactions such as $Λ(1520)+π\leftrightarrow Σ^*$ can favor $Σ^*$ production, thereby decreasing the $Λ(1520)$ yield. Within the same approach we thus find a yield enhancement for $Σ(1385)$ and a yield suppression for $Λ(1520)$.
We study production and equilibration of pions and muons in relativistic electron-positron-photon plasma at a temperature $T\ll m_μ, m_π$. We argue that the observation of pions and muons can be a diagnostic tool in the study of the initial properties of such a plasma formed by means of strong laser fields. Conversely, properties of muons and pions in thermal environment become accessible to precise experimental study.
Yields of Delta(1230), Sigma(1385) resonances produced in heavy ion collisions are studied within the framework of a kinetic master equation. The time evolution is driven by the process Delta(1230) \leftrightarrow N π, Sigma(1385) \leftrightarrow Λπ. We obtain resonance yield both below and above chemical equilibrium, depending on initial hadronization condition and separation of kinetic and chemical freeze-out.
The yields of heavy flavored hadrons emitted from strangeness-rich QGP are evaluated within chemical non-equilibrium statistical hadronization model, conserving strangeness, charm, and entropy yields at hadronization.
We explore entropy and strangeness as signature of QGP for top AGS energy and the energy scan at SPS. We find that the hadronization dynamics changes between 20 and 30 $A$ GeV projectile energy. The high energy results are consistent with QGP.
We study b, c quark hadronization from QGP. We obtain the yields of charm and bottom flavored hadrons within the statistical hadronization model. The important novel feature of this study is that we take into account the high strangeness and entropy content of QGP, conserving strangeness and entropy yields at hadronization.
The yields of charmed hadrons emitted by strangeness rich QGP are evaluated within chemical non-equilibrium statistical hadronization model, conserving strangeness, charm, and entropy yields at hadronization.