Magnetic moment of hyperons in nuclear matter by using quark-meson coupling models

We calculate the magnetic moments of hyperons in dense nuclear matter by using relativistic quark models. Hyperons are treated as MIT bags, and the interactions are considered to be mediated by the exchange of scalar and vector mesons which are approximated as mean fields. Model dependence is investigated by using the quark-meson coupling model and the modified quark-meson coupling model; in the former the bag constant is independent of density and in the latter it depends on density. Both models give us the magnitudes of the magnetic moments increasing with density for most octet baryons. But there is a considerable model dependence in the values of the magnetic moments in dense medium. The magnetic moments at the nuclear saturation density calculated by the quark meson coupling model are only a few percents larger than those in free space, but the magnetic moments from the modified quark meson coupling model increase more than 10% for most hyperons. The correlations between the bag radius of hyperons and the magnetic moments of hyperons in dense matter are discussed.Comment: substantial changes in the text, submitted to PL

Generating Log-normal Mock Catalog of Galaxies in Redshift Space

We present a public code to generate a mock galaxy catalog in redshift space assuming a log-normal probability density function (PDF) of galaxy and matter density fields. We draw galaxies by Poisson-sampling the log-normal field, and calculate the velocity field from the linearised continuity equation of matter fields, assuming zero vorticity. This procedure yields a PDF of the pairwise velocity fields that is qualitatively similar to that of N-body simulations. We check fidelity of the catalog, showing that the measured two-point correlation function and power spectrum in real space agree with the input precisely. We find that a linear bias relation in the power spectrum does not guarantee a linear bias relation in the density contrasts, leading to a cross-correlation coefficient of matter and galaxies deviating from unity on small scales. We also find that linearising the Jacobian of the real-to-redshift space mapping provides a poor model for the two-point statistics in redshift space. That is, non-linear redshift-space distortion is dominated by non-linearity in the Jacobian. The power spectrum in redshift space shows a damping on small scales that is qualitatively similar to that of the well-known Fingers-of-God (FoG) effect due to random velocities, except that the log-normal mock does not include random velocities. This damping is a consequence of non-linearity in the Jacobian, and thus attributing the damping of the power spectrum solely to FoG, as commonly done in the literature, is misleading.Comment: 38 pages, 16 figures, code publicly available as "lognormal_galaxies" at http://wwwmpa.mpa-garching.mpg.de/~komatsu/codes.html Matches published version : added figures and explanatory comment

Einfluß der Oberfläche auf die atmosphärische Zirkulation des Mars: Studien mit einem allgemeinen Zirkulationsmodell

Unlike on Earth where 3/4 of the surface is covered by oceans, the Martian surface has a topography with greater magnitudes of mountains and valleys. This and other differences indicate that the Martian atmosphere should be very sensitive to the forcing from below. The major mechanism which provides vertical coupling are atmospheric waves generated in the lower atmosphere near the surface. They transport momentum, energy, and heat away from the lower atmosphere. Propagating upward the disturbances grow in amplitude, and ultimately break or dissipate. They release energy and momentum to the zonal mean circulation, and affect the global transport in the atmosphere of Mars. The main task of this work is to study these physical phenomena in the atmosphere near the surface with an emphasis on the mechanisms of wave generation. Effects of large scale longitudinal disturbances on the general circulation, especially in the upper and middle atmosphere, are explored. Results of numerical experiments with a General Circulation Model of the Martian Atmosphere show the sensitivity of the zonal mean circulation to the surface properties. Planetary waves of different scales are generated over the topography as well as by the inhomogeneous reaction of the surface and the lower atmospheric layers to the solar heating. Solar tides are excited as well. These large scale disturbances propagate upward and horizontally according to the selective transmission properties of the atmosphere, and redistribute momentum and energy. Breaking waves provide a torque to the mean zonal wind and maintain the global meridional transport. The results of the numerical simulations showing the sensitivity of the polar night jet to the topography, the inhomogeneous thermal inertia and the surface albedo, are presented here. To validate the simulations, the results are compared with observations from the Thermal Emission Spectrometer onboard the Mars Global Surveyor.Der Mars verfügt im Vergleich zur Erde, bei der 3/4 der Oberfläche mit Ozeanen bedeckt ist über eine wesentlich rauere Oberfläche mit höheren Bergen und tieferen Schluchten sowie eine flachere planetare Grenzschicht. Der Einfluss der Oberfläche auf die Atmosphäre sollte deshalb auf Mars wesentlich stärker ausgeprägt sein als auf der Erde. Die wichtigste vertikale Kopplung geschieht dabei durch oberflächennah erzeugte atmosphärische Wellen. Sie transportieren mechanische Energie, Impuls und Wärme. Mit zunehmender Höhe wachsen die Amplituden der Wellen, bis sie schließlich brechen und dabei Energie und Impuls an den zonalen Grundstrom abgeben und somit den globalen Transport beeinflussen. In dieser Arbeit werden verschiedene physikalische Mechanismen der oberflächennahen Wellenerzeugung erforscht. Numerische Experimente mit dem am MPS entwickelten allgemeinen Zirkulationsmodell der Marsatmosphäre MAOAM zeigen die Abhängigkeit der mittleren zonalen Zirkulation von der Beschaffenheit der Oberfläche. Planetare Wellen unterschiedlicher Skalenlänge werden sowohl durch Strömung über die Orographie als auch durch inhomogene Reaktionen von Oberfläche und unteren Atmosphärenschichten auf die Sonneneinstrahlung erzeugt. Der Tagesgang der Absorption solarer Energie durch die Atmosphäre und insbesondere der Oberfläche regt thermische Gezeiten an. Die horizontale und vertikale Ausbreitung dieser großskaligen Störungen werden durch die selektiven Transmissionseigenschaften der Atmosphäre bestimmt und dementsprechend Wellenimpuls- und Energie verteilt. Schwerpunkt der vorliegenden Arbeit ist die Untersuchung der Einflüsse von Orographie sowie von Inhomogenitäten der thermischen Trägheit und Albedo der Marsoberfläche auf den polaren Nacht-Jet mit Hilfe numerischer Simulationen. Die Ergebnisse werden mit Beobachtungen des Thermal Emission Spectrometer auf Mars Global Surveyor (MGS-TES) verglichen

study with a general circulation model

Unlike on Earth where 3/4 of the surface is covered by oceans, the Martian surface has rougher topography with greater magnitudes of mountains and valleys. The Martian atmosphere is less dense compared to the terrestrial one. The planetary boundary layer is significantly shallower on Mars than on Earth. These differences indicate that the Martian atmosphere should be very sensitive to the forcing from below. The major mechanism which provides vertical coupling are atmospheric waves generated in the lower atmosphere near the surface. These waves transport the momentum, energy, and heat away from places of their generation in the lower atmosphere. Propagating upward the wave disturbances grow in amplitude, and ultimately break or dissipate. They release the wave energy and momentum to the zonal mean circulation, and thus affect the global transport in the atmosphere of Mars. The main task of this work is to study various physical phenomena which take place in the atmosphere near the surface with an emphasis on the mechanisms of wave generation ...thesi

Discovery reach for wino and higgsino dark matter with a disappearing track signature at a 100 TeV pppp collider

Within the theory of supersymmetry, the lightest neutralino is a dark matter candidate and is often assumed to be the lightest supersymmetric particle (LSP) as well. If the neutral wino or higgsino is dark matter, the upper limit of the LSP mass is determined by the observed relic density of dark matter. If the LSP is a nearly-pure neutral state of the wino or higgsino, the lightest chargino state is expected to have a significant lifetime due to a tiny mass difference between the LSP and the chargino. This article presents discovery potential of the 100 TeV future circular hadron collider (FCC) for the wino and higgsino dark matter using a disappearing-track signature. The search strategy to extend the discovery reach to the thermal limits of wino/higgsino dark matter is discussed with detailed studies on the background rate and the reference design of the FCC-hadron detector under possible running scenarios of the FCC-hadron machine. A proposal of modifying the detector layout and several ideas to improve the sensitivity further are also discussed.Comment: 10 pages, 7 figures, 4 table

EVALUATION OF SPEED CHANGE IN 100 M SPRINT RUNNING

The purpose of this study was to propose a method to evaluate speed in 100m running with modified exponential equations. The speed changes in 100m sprint race of ninetysix sprinters (62 men and 34 women) were measured with a LAVEG system. The 100m race was divided into the acceleration and deceleration phases based on the maximum speed, and speed were estimated. 1) The exponential equations proposed in this study well estimated the speed change pattern of the 100m on the different record groups. The average errors between the official time and the time estimated were 0.024±0.040s in men and 0.04±0.039 in women. 2) The maximum speed was the most important factor for both men and women sprinters to achieve best performance the race. 3) The men world class sprinters accelerated quickly (large k), but reached the maximum speed later than the other sprinters, which resulted in shorter deceleration phase and smaller decreases in speed after reaching the maximum speed

Hadron Masses in Medium and Neutron Star Properties

We investigate the properties of the neutron star with relativistic mean field models. We incorporate in the quantum hadrodynamics and in the quark-meson coupling models a possible reduction of meson masses in nuclear matter. The equation of state for neutron star matter is obtained and is employed in Oppenheimer-Volkov equation to extract the maximum mass of the stable neutron star. We find that the equation of state, the composition and the properties of the neutron stars are sensitive to the values of the meson masses in medium.Comment: 18 pages, 5 figures and 2 tables. To be published in EPJ

The prevalence of and factors related to calcium pyrophosphate dihydrate crystal deposition in the knee joint

SummaryObjectivesThe purpose of this study was to reveal the accurate prevalence and related factors to the presence of calcium pyrophosphate dihydrate (CPPD) crystal deposition in cadaveric knee joints.DesignControlled laboratory study.MethodsSix hundred and eight knees from 304 cadavers (332 male knees and 276 female knees, formalin fixed, Japanese anatomical specimens) were included in this study. The average age of the cadavers was 78.3 ± 10.7 years. Knees were macroscopically evaluated for the existence of CPPD, and the depth of cartilage degeneration of the femoro-tibial joint following the Outerbridge's classification. CPPD crystal was confirmed under Fourier transform infrared spectroscopy (FTIR) analysis using light microscopy. Statistical analysis was performed to reveal the correlation between the occurrence of CPPD deposition in the knee joint and gender, age, and the depth of cartilage degeneration of the femoro-tibial joint.ResultsThe prevalence of grossly visible CPPD crystal was 13% (79 knees). In all of these knees, CPPD crystal was confirmed under FTIR analysis. Statistical analysis showed significant correlation between the occurrence of CPPD deposition and gender (P < 0.001), and depth of cartilage degeneration in the femoro-tibial joint (P < 0.001). In the cartilage degeneration positive knees (Over grade 3 in Outerbridge's classification), average age of CPPD deposition knee was significantly higher than CPPD negative knees.ConclusionsIn this study, the prevalence of CPPD deposition disease was evaluated in a relatively large sample size of cadaveric knees. The prevalence of CPPD deposition disease was 13%, and was significantly correlated with the subject's age, gender, and severity of cartilage degeneration in the femoro-tibial joint

Conductivity landscape of highly oriented pyrolytic graphite surface containing ribbons and edges

We present an extensive study on electrical spectroscopy of graphene ribbons and edges of highly oriented pyrolytic graphite (HOPG) using atomic force microscope (AFM). We have addressed in the present study two main issues, (1) How does the electrical property of the graphite (graphene) sheet change when the graphite layer is displaced by shear forces? and (2) How does the electrical property of the graphite sheet change across a step edge? While addressing these two issues we observed, (1) variation of conductance among the graphite ribbons on the surface of HOPG. The top layer always exhibits more conductance than the lower layers, (2) two different monolayer ribbons on the same sheet of graphite shows different conductance, (3) certain ribbon/sheet edges show sharp rise in current, (4) certain ribbons/sheets on the same edge shows both presence and absense of the sharp rise in the current, (5) some lower layers at the interface near a step edge shows a strange dip in the current/conductance (depletion of charge). We discuss possible reasons for such rich conducting landscape on the surface of graphite.Comment: 13 pages, 9 figures. For better quality figures please contact autho