855 research outputs found

    Dark polariton-solitons in semiconductor microcavities

    Full text link
    We report the existence, symmetry breaking and other instabilities of dark polariton-solitons in semiconductor microcavities operating in the strong coupling regime. These half-light half-matter solitons are potential candidates for applications in all-optical signal processing. Their excitation time and required pump powers are a few orders of magnitude less than those of their weakly coupled light-only counterparts.Comment: submitted to PR

    New Signals of Quark-Gluon-Hadron Mixed Phase Formation

    Full text link
    Here we present several remarkable irregularities at chemical freeze-out which are found using an advanced version of the hadron resonance gas model. The most prominent of them are the sharp peak of the trace anomaly existing at chemical freeze-out at the center of mass energy 4.9 GeV and two sets of highly correlated quasi-plateaus in the collision energy dependence of the entropy per baryon, total pion number per baryon, and thermal pion number per baryon which we found at the center of mass energies 3.8-4.9 GeV and 7.6-10 GeV. The low energy set of quasi-plateaus was predicted a long time ago. On the basis of the generalized shock-adiabat model we demonstrate that the low energy correlated quasi-plateaus give evidence for the anomalous thermodynamic properties inside the quark-gluon-hadron mixed phase. It is also shown that the trace anomaly sharp peak at chemical freeze-out corresponds to the trace anomaly peak at the boundary between the mixed phase and quark gluon plasma. We argue that the high energy correlated quasi-plateaus may correspond to a second phase transition and discuss its possible origin and location. Besides we suggest two new observables which may serve as clear signals of these phase transformations.Comment: 14 pages, 4 figures, new signals of QGP formation are suggeste

    Hadron Resonance Gas Model with Induced Surface Tension

    Full text link
    Here we present a physically transparent generalization of the multicomponent Van der Waals equation of state in the grand canonical ensemble. For the one-component case the third and fourth virial coefficients are calculated analytically. It is shown that an adjustment of a single model parameter allows us to reproduce the third and fourth virial coefficients of the gas of hard spheres with small deviations from their exact values. A thorough comparison of the compressibility factor and speed of sound of the developed model with the one and two component Carnahan-Starling equation of state is made. It is shown that the model with the induced surface tension is able to reproduce the results of the Carnahan-Starling equation of state up to the packing fractions 0.2-0.22 at which the usual Van der Waals equation of state is inapplicable. At higher packing fractions the developed equation of state is softer than the gas of hard spheres and, hence, it breaks causality in the domain where the hadronic description is expected to be inapplicable. Using this equation of state we develop an entirely new hadron resonance gas model and apply it to a description of the hadron yield ratios measured at AGS, SPS, RHIC and ALICE energies of nuclear collisions. The achieved quality of the fit per degree of freedom is about 1.08. We confirm that the strangeness enhancement factor has a peak at low AGS energies, while at and above the highest SPS energy of collisions the chemical equilibrium of strangeness is observed. We argue that the chemical equilibrium of strangeness, i.e. γs1\gamma_s \simeq 1, observed above the center of mass collision energy 4.3 GeV may be related to the hadronization of quark gluon bags which have the Hagedorn mass spectrum, and, hence, it may be a new signal for the onset of deconfinement

    PROSPECTS FOR THE USE OF VALUE-ORIENTED MANAGEMENT IN TOURISM ENTERPRISES

    Get PDF
    Актуальні проблеми та перспективи розвитку харчових виробництв, готельно-ресторанного та туристичного бізнесу : мтеріали Міжнародної науково-практичної конференції, присвяченої 45-річчю від дня заснування факультету ХТГРТБ, (м. Полтава, 20-21 листопада 2019 р.). - Полтава : ПУЕТ, 2019. - 126 с

    Procedure for Event Characterization in Pb-Pb Collisions at 40A GeV in the NA49 Experiment at the CERN SPS

    Get PDF
    The time evolution of the strongly interacting matter created in a heavy-ion collision depends on the initial geometry and the collision centrality. This makes important the experimental determination of the collision geometry. In this paper a procedure for event classification and estimation of the geometrical parameters in inelastic Pb-Pb collisions at the beam energy of 4

    Hard-core Radius of Nucleons within the Induced Surface Tension Approach

    Full text link
    In this work we discuss a novel approach to model the hadronic and nuclear matter equations of state using the induced surface tension concept. Since the obtained equations of state, classical and quantum, are among the most successful ones in describing the properties of low density phases of strongly interacting matter, they set strong restrictions on the possible value of the hard-core radius of nucleons. Therefore, we perform a detailed analysis of its value which follows from hadronic and nuclear matter properties and find the most trustworthy range of its values: the hard-core radius of nucleons is 0.30--0.36 fm. A comparison with the phenomenology of neutron stars implies that the hard-core radius of nucleons has to be temperature and density dependent.Comment: 12 pages, 4 figures, references added, typos correcte

    Patterns and localized structures in bistable semiconductor resonators

    Full text link
    We report experiments on spatial switching dynamics and steady state structures of passive nonlinear semiconductor resonators of large Fresnel number. Extended patterns and switching front dynamics are observed and investigated. Evidence of localization of structures is given.Comment: 5 pages with 9 figure

    Testicular diffuse large B-cell lymphoma. Clinical lecture and case report

    Get PDF
    Lymphoma is a heterogeneous group of lymphocyte malignancies that may involve lymphatic tissue, bone marrow, or extranodal sites. The lecture provides a  brief overview of the current state of the problem of diagnosis and treatment of primary testicular lymphoma. Primary testicular lymphoma (PTL) is a rare lymphoid malignancy. Though it is rare, PTL is the most common type of testicular tumor in men over 60 years of age. The most common histological type is diffuse large B-cell lymphoma. To date, there are no well-documented etiological or risk factors for PTL. In contrast to other common testicular neoplasms, there was no statistically significant association of PTL with cryptorchidism, trauma, chronic orchitis, or infertility. Ultrasound is generally the first-line imaging method used to characterize testicular lesions. PTL manifests itself in the form of a hypoechoic formation, which can take the form of either a single large formation or multiple small formations that occupy most of the testicular parenchyma or completely replace it. Systemic treatment, including orchiectomy, chemotherapy, radiation therapy, and intrathecal prophylaxis, is necessary for all patients with PTL. In addition to achieving complete remission, the goal of PTL treatment is to prevent recurrences in the contralateral testis and central nervous system. The presented information is supplemented by our own observation and images. Personal medical data is published with the written consent of the patient. In our case, the patient’s age was 38 years, which does not fall into the specified age group for primary testicular lymphoma. In our opinion, the publication of this clinical case and analysis of scientific literature on this topic are relevant

    Second virial coefficients of light nuclear clusters and their chemical freeze-out in nuclear collisions

    Full text link
    Here we develop a new strategy to analyze the chemical freeze-out of light (anti)nuclei produced in high energy collisions of heavy atomic nuclei within an advanced version of the hadron resonance gas model. It is based on two different, but complementary approaches to model the hard-core repulsion between the light nuclei and hadrons. The first approach is based on an approximate treatment of the equivalent hard-core radius of a roomy nuclear cluster and pions, while the second approach is rigorously derived here using a self-consistent treatment of classical excluded volumes of light (anti)nuclei and hadrons. By construction, in a hadronic medium dominated by pions, both approaches should give the same results. Employing this strategy to the analysis of hadronic and light (anti)nuclei multiplicities measured by ALICE at sNN=2.76\sqrt{s_{NN}} =2.76 TeV and by STAR at sNN=200\sqrt{s_{NN}} =200 GeV, we got rid of the existing ambiguity in the description of light (anti)nuclei data and determined the chemical freeze-out parameters of nuclei with high accuracy and confidence. At ALICE energy the nuclei are frozen prior to the hadrons at the temperature T=175.13.9+2.3T = 175.1^{+2.3}_{-3.9} MeV, while at STAR energy there is a single freeze-out of hadrons and nuclei at the temperature T=167.2±3.9T = 167.2 \pm 3.9 MeV. We argue that the found chemical freeze-out volumes of nuclei can be considered as the volumes of quark-gluon bags that produce the nuclei at the moment of hadronization.Comment: 15 pages, 4 figures, 3 table
    corecore