Non-extensivity of the QCD pT spectra

We try to establish a connection between the hadronic distributions, in proton-proton collisions at very high transverse momentum $p_{\mathrm{T}}$, obtained via perturbative QCD and the Tsallis non extensive statistics. Our motivation is that while the former is expected to be valid at extremely high momentum, due to asymptotic freedom, the latter has been very successful in describing experimental spectra over a wide range of momentum. Matching the non extensive statistics with the asymptotic $p_{\mathrm{T}}$ behaviour expected from QCD leads to the value of $q=1.25$.Comment: 4 page

Systematic properties of the Tsallis Distribution: Energy Dependence of Parameters in High-Energy p-p Collisions

Changes in the transverse momentum distributions with beam energy are studied using the Tsallis distribution as a parameterization. The dependence of the Tsallis parameters q, T and the volume are determined as a function of beam energy. The Tsallis parameter q shows a weak but clear increase with beam energy with the highest value being approximately 1.15. The Tsallis temperature and volume are consistent with being independent of beam energy within experimental uncertainties.Comment: 8 pages, 4 figure

Transverse momentum distributions of hadrons in the Tsallis-1 and Tsallis-2 statistics

We considered the ultrarelativistic transverse momentum distributions of the Tsallis-1 and Tsallis-2 statistics using two regularization schemes. It was revealed that the cut-off parameter strongly influences the behavior of the transverse momentum distribution in both statistics. We have also found that the ultrarelativistic transverse momentum distribution of the Tsallis-1 statistics is transformed to the momentum distribution of the Tsallis-2 statistics by identifying q → 1/qc

Nuclear Multifragmentation in the Non-extensive Statistics - Canonical Formulation

We apply the canonical quantum statistical model of nuclear multifragmentation generalized in the framework of recently proposed Tsallis non-extensive thermostatistics for the description of nuclear multifragmentation process. The test calculation in the system with A=197 nucleons show strong modification of the 'critical' behaviour associated with the nuclear liquid-gas phase transition for small deviations from the conventional Boltzmann-Gibbs statistical mechanics.Comment: 4 pages, 4 figure

Cu In,Ga Se2 surface treatment with Na and NaF A combined photoelectron spectroscopy and surface photovoltage study in ultra high vacuum

Either metallic Na or NaF were deposited onto Cu In,Ga Se2 surfaces and studied by photoelectron spectroscopy and surface photovoltage spectroscopy without breaking the ultra high vacuum. The deposition of elemental Na at room temperature led to the formation of an intermediate Cu and Ga rich layer at the CIGSe surface, whereas for NaF the composition of the CIGSe surface remained unchanged. A metal like surface induced by an inverted near surface region with a reduced number of defect states was formed after the deposition of Na. Under the chosen experimental conditions, the near surface layer was independent on the amount of Na and stable in time. In contrast, the usage of NaF weakened the inversion and led to an increased band bending compared to the untreated CIGSe sample. The SPV signals decreased with proceeding time after the deposition of NaF

Canonical Strangeness and Distillation Effects in Hadron Production

Strangeness canonical ensemble for Maxwell-Boltzmann statistics is reconsidered for excited nuclear systems with non-vanishing net strangeness. A new recurrence relation method is applied to find the partition function. The method is first generalized to the case of quantum strangeness canonical ensemble. Uncertainties in calculation of the K+/pi+ excitation function are discussed. A new scenario based on the strangeness distillation effect is put forward for a possible explanation of anomalous strangeness production observed at the bombarding energy near 30 AGeV. The peaked maximum in the K+/pi+ ratio is considered as a sign of the critical end-point reached in evolution of the system rather than a latent heat jump emerging from the onset of the first order deconfinement phase transition.Comment: 20 pages, 2 figures; typos corrected, 2 references added, minor corrections in text and figure

Thermodynamic Derivation of the Tsallis and R\'enyi Entropy Formulas and the Temperature of Quark-Gluon Plasma

We derive Tsallis entropy, Sq, from universal thermostat independence and obtain the functional form of the corresponding generalized entropy-probability relation. Our result for finite thermostats interprets thermodynamically the subsystem temperature, T1, and the index q in terms of the temperature, T, entropy, S, and heat capacity, C of the reservoir as T1 = T exp(-S/C) and q = 1 - 1/C. In the infinite C limit, irrespective to the value of S, the Boltzmann-Gibbs approach is fully recovered. We apply this framework for the experimental determination of the original temperature of a finite thermostat, T, from the analysis of hadron spectra produced in high energy collisions, by analyzing frequently considered simple models of the quark-gluon plasma.Comment: 4 pages 1 Figure PRL style, revised presentatio

Prevalence of American Foulbrood and Paenibacillus Larvae Genotypes in Bulgaria

This study aimed to analyse the prevalence of American foulbrood and Paenibacillus larvae genotypes in Bulgaria. For this purpose, data concerning American foulbrood outbreaks were used. Also, available data on the number of destroyed bee families covering a twenty-five-year period (1989 - 2013) was collected from the register of Bulgarian Food Safety Agency. In addition, Paenibacillus larvae genotypes in 15 apiaries were established by rep - PCR with BOXA1R and MBOREP1 primers. Results showed broad incidence of the disease, particularly at the beginning of the analysed period, with a tendency to reduction of affected apiaries and bee families at the end of the period. A statistically significant prevalence of American foulbrood in South Bulgaria compared to the northern regions was observed. Genotyping of Paenibacillus larvae revealed two genotypes: ab and AB, with the preponderance of the more virulent AB in South Bulgaria. The obtained results showed the need for conducting regular mandatory screening of bee colonies for early diagnostics of the disease and the implementation of relevant measures for American foulbrood prevention and control