Event-by-Event Fluctuations of Particle Ratios in Heavy-Ion Collisions

We study event-by-event dynamical fluctuations of various particle ratios at different energies. We assume that particle production in final state is due to chemical equilibrium processes. We compare results from resonance gas model with available experimental data. At SPS energies, the model can very well reproduce the experimentally measured fluctuations. We make predictions for dynamical fluctuations of strangeness and non-strangeness particle ratios. We found that the energy-dependence is non-monotonic. Furthermore, we found that fluctuations strongly depend on particle ratios.Comment: 6 pages, 2 figure, 1 tabl

Finite temperature quantum correlations in SU(2)cSU(2)_c quark states and quantum spin models

The entanglement at finite temperatures are analyzed by using thermal models for colored quarks making up the hadron physical states. We have found that these quantum correlations entirely vanish at $T_c\geq m_q/\ln(1.5)$. For temperatures larger than $T_c$ the correlations are classical. Also we worked out the entanglement for the transverse Ising spin chain. In dependence on both temperature $T$ and transverse field $\lambda$ we can identify a certain region, where the quantum effects are likely to dominate the system. We suggest the mutual information as a quantitative measure for the correlations in ground state.Comment: 15 pages, 10 eps-figure

The influence of strange quarks on QCD phase diagram and chemical freeze-out: Results from the hadron resonance gas model

We confront the lattice results on QCD phase diagram for two and three flavors with the hadron resonance gas model. Taking into account the truncations in the Taylor-expansion of energy density $\epsilon$ done on the lattice at finite chemical potential $\mu$, we find that the hadron resonance gas model under the condition of constant $\epsilon$ describes very well the lattice phase diagram. We also calculate the chemical freeze-out curve according to the entropy density $s$. The $s$-values are taken from lattice QCD simulations with two and three flavors. We find that this condition is excellent in reproducing the experimentally estimated parameters of the chemical freeze-out.Comment: 5 pages, 3 figures and 1 table Talk given at VIIIth international conference on ''Strangeness in Quark Matter'' (SQM 2004), Cape Town, South Africa, Sep. 15-20 200

Matter-Antimatter Asymmetry in the Large Hadron Collider

The matter-antimatter asymmetry is one of the greatest challenges in the modern physics. The universe including this paper and even the reader him(her)self seems to be built up of ordinary matter only. Theoretically, the well-known Sakharov's conditions remain the solid framework explaining the circumstances that matter became dominant against the antimatter while the universe cools down and/or expands. On the other hand, the standard model for elementary particles apparently prevents at least two conditions out of them. In this work, we introduce a systematic study of the antiparticle-to-particle ratios measured in various $NN$ and $AA$ collisions over the last three decades. It is obvious that the available experimental facilities turn to be able to perform nuclear collisions, in which the matter-antimatter asymmetry raises from $\sim 0$ at AGS to $\sim 100$ at LHC. Assuming that the final state of hadronization in the nuclear collisions takes place along the freezeout line, which is defined by a constant entropy density, various antiparticle-to-particle ratios are studied in framework of the hadron resonance gas (HRG) model. Implementing modified phase space and distribution function in the grand-canonical ensemble and taking into account the experimental acceptance, the ratios of antiparticle-to-particle over the whole range of center-of-mass-energies are very well reproduced by the HRG model. Furthermore, the antiproton-to-proton ratios measured by ALICE in $pp$ collisions is also very well described by the HRG model. It is likely to conclude that the LHC heavy-ion program will produce the same particle ratios as the $pp$ program implying the dynamics and evolution of the system would not depend on the initial conditions. The ratios of bosons and baryons get very close to unity indicating that the matter-antimatter asymmetry nearly vanishes at LHC.Comment: 9 pages, 5 eps-figures, revtex4-styl

The Effects of Quantum Entropy on the Bag Constant

The effects of quantum entropy on the bag constant are studied at low temperatures and small chemical potentials. The inclusion of the quantum entropy of the quarks in the equation of state provides the hadronic bag with an additional heat which causes a decrease in the effective latent heat inside the bag. We have considered two types of baryonic bags, $\Delta$ and $\Omega^-$. In both cases we have found that the bag constant without the quantum entropy almost does not change with the temperature and the quark chemical potential. The contribution from the quantum entropy to the equation of state clearly decreases the value of the bag constant.Comment: 7 pages, 2 figures (two parts each

Conditions driving chemical freeze-out

We propose the entropy density as the thermodynamic condition driving best the chemical freeze-out in heavy-ion collisions. Taking its value from lattice calculations at zero chemical potential, we find that it is excellent in reproducing the experimentally estimated freeze-out parameters. The two characteristic endpoints in the freeze-out diagram are reproduced as well.Comment: 8 pages, 5 eps figure

The QCD phase diagram: A comparison of lattice and hadron resonance gas model calculations

We compare the lattice results on QCD phase diagram for two and three flavors with the hadron resonance gas model (HRGM) calculations. Lines of constant energy density $\epsilon$ have been determined at different baryo-chemical potentials $\mu_B$. For the strangeness chemical potentials $\mu_S$, we use two models. In one model, we explicitly set $\mu_S=0$ for all temperatures and baryo-chemical potentials. This assignment is used in lattice calculations. In the other model, $\mu_S$ is calculated in dependence on $T$ and $\mu_B$ according to the condition of vanishing strangeness. We also derive an analytical expression for the dependence of $T_c$ on $\mu_B/T$ by applying Taylor expansion of $\epsilon$. In both cases, we compare HRGM results on $T_c-\mu_B$ diagram with the lattice calculations. The agreement is excellent, especially when the trigonometric function of $\epsilon$ is truncated up to the same order as done in lattice simulations. For studying the efficiency of the truncated Taylor expansion, we calculate the radius of convergence. For zero- and second-order radii, the agreement with lattice is convincing. Furthermore, we make predictions for QCD phase diagram for non-truncated expressions and physical masses. These predictions are to be confirmed by heavy-ion experiments and future lattice calculations with very small lattice spacing and physical quark masses.Comment: 25 pages, 8 eps figure

The impact of metabolic syndrome on the clinical profile and tumor characteristics of endometrial carcinoma

Background: The objective is to study the influence of different components of metabolic syndrome on clinical behavior and tumor characteristics of endometrial cancer cases and to evaluate if metformin usage affects the stage and grade of endometrial cancer.Methods: 60 women attending the gynecological oncology clinic at El Shatby Maternity University Hospital, after being diagnosed as endometrial carcinoma, were recruited in the study. Serum samples were collected to detect insulin level and lipid profile, and then allocated into two groups according to metabolic syndrome existence. After the recommended surgery, and the routine histopathological diagnosis followed by histopathological chemilumeniscence technique to detect staining intensity, percentage of estrogen receptors ER, and score out of 8 according to Allred score.Results: Endometrial cancer EC patients with metabolic syndrome had a significantly higher age, higher FIGO stages, and higher grade compared to EC without metabolic syndrome (p˂0.05). There was no statically significant difference between both groups in estrogen receptors scoring. HDL was an important factor affecting grade of EC patients, as when HDL decreased by one mg/dl, the grade increased by 0.033% (P=0.030, OR=0.899, OR adjusted=0.826), Insulin level was found to be an important factor affecting stage as when insulin level increased by one Uiu/ml, the stage increased by1.091% (p=<0.001, OR=1.064, OR adjusted=1.091).Conclusions: Hyperinsulinemia was the most important factor affecting aggressiveness of the tumor as regards stage and risk group classification. Metformin failed to show a protective effect against endometrial cancer progression