Roper resonances and quasi-normal modes of Skyrmions

Radial vibrations of charge one hedgehog Skyrmions in the full Skyrme model are analysed. We investigate how the properties of the lowest resonance modes (quasi normal modes) - their frequencies and widths - depend on the form of the potential (value of the pion mass as well as the addition of further potentials) and on the inclusion of the sextic term. Then we consider the inverse problem, where certain values for the frequencies and widths are imposed, and the field theoretic Skyrme model potential giving rise to them is reconstructed. This latter method allows to reproduce the physical Roper resonances, as well as further physical properties of nucleons, with high precision.Comment: LaTex, 24 pages, 18 figure

Radial vibrations of BPS skyrmions

We study radial vibrations of spherically symmetric skyrmions in the BPS Skyrme model. Concretely, we numerically solve the linearised field equations for small fluctuations in a skyrmion background, both for linearly stable oscillations and for (unstable) resonances. This is complemented by numerical solutions of the full nonlinear system, which confirm all the results of the linear analysis. In all cases, the resulting fundamental excitation provides a rather accurate value for the Roper resonance, supporting the hypothesis that the BPS Skyrme model already gives a reasonable approximate description of this resonance. Further, for many potentials additional higher resonances appear, again in agreement with known experimental results.Comment: Latex, 41 pages, 22 pdf figures; v2: minor change

Comparison of Wind Speed, Soil Moisture, and Cloud Cover to Relative Humidity to Verify Dew Formation

Satellites such as SMOS are important tools used in many different scientific fields. These satellite readings can have errors due to any number of reasons. Dew can cause a scattering or absorption effect from the microwave emissions which in turn causes errors in satellite data being relayed to scientists and a correction is needed in order to get accurate information. Dew formation can be estimated using relative humidity, but a clear understanding of conditions needed to form dew is desired. Light wind speeds are hypothesized to be needed to induce dew formation in order to have horizontal moisture advection without turbulent mixing. Clear skies overnight are hypothesized to be needed in order to have radiative cooling and high soil moisture is hypothesized to induce dew rise. In this study we will focus on wind speed, cloud cover, and soil moisture over Hardin County, Iowa, and how they can relate to dew formation. Here it was shown that wind speed and cloud cover is not a conclusive way to predict dew formation and soil moisture is the best variable to indicate dew. Therefore, dew rise is the most likely cause of dew formation

Skyrme models and nuclear matter equation of state

We investigate the role of pressure in a class of generalised Skyrme models. We introduce pressure as the trace of the spatial part of the energy-momentum tensor and show that it obeys the usual thermodynamical relation. Then, we compute analytically the mean-field equation of state in the high and medium pressure regimes by applying topological bounds on compact domains. The equation of state is further investigated numerically for the charge one skyrmions. We identify which term in a generalised Skyrme model is responsible for which part in the equation of state. Further, we compare our findings with the corresponding results in the Walecka model

Electromagnetic transition strengths for light nuclei in the Skyrme model

We calculate reduced $B(E2)$ electromagnetic transition strengths for light nuclei of mass numbers $B=8,12,16,20,24$ and $32$ within the Skyrme model. We find that the predicted transition strengths are of the correct order of magnitude and the computed intrinsic quadrupole moments match the experimentally observed effective nuclear shapes. For the Hoyle state we predict a large $B(E2)\!\uparrow$ value of $0.0521\, \rm{e}^2\rm{b}^2$. For Oxygen-16, we can obtain a quantitative understanding of the ground state rotational band and the rotational excitations of the second spin-0 state, $0_2^+$.This work was partly undertaken on the COSMOS Shared Memory system at DAMTP, University of Cambridge operated on behalf of the STFC DiRAC HPC Facility. This equipment is funded by BIS National E-infrastructure capital grant no. ST/J005673/1 and STFC grants no. ST/J001341/1, ST/H008586/1, ST/K00333X/1. M.H. has been partially funded by the UK Science and Technology Facilities Council under grant no. ST/J000434/1. M.H. thanks Andrzej Wereszczynski and the Jagiellonian University, Krakow for hospitality. P.H.C.L. thanks Ling-Yan Hung and Fudan University in Shanghai for hospitality. P.H.C.L. acknowledges support as an International Research Fellow of the Japan Society for the Promotion of Science (JSPS).This is the author accepted manuscript. The final version is available from the American Physical Society via http://dx.doi.org/10.1103/PhysRevC.93.03430

Radial vibrations of BPS skyrmions

We study radial vibrations of spherically symmetric Skyrmions in the Bogomol’nyi-Prasad-Sommerfield Skyrme model. Concretely, we numerically solve the linearized field equations for small fluctuations in a Skyrmion background, both for linearly stable oscillations and for (unstable) resonances. This is complemented by numerical solutions of the full nonlinear system, which confirm all the results of the linear analysis. In all cases, the resulting fundamental excitation provides a rather accurate value for the Roper resonance, supporting the hypothesis that the Bogomol’nyi-Prasad-Sommerfield Skyrme model already gives a reasonable approximate description of this resonance. Furthermore, for many potentials additional higher resonances appear, again in agreement with known experimental results

A Prototype ROI Builder for the Second Level Trigger of ATLAS Implemented in FPGAs

The design and implementation of a Region of Interest (ROI) Builder connecting the ATLAS Level 1 Trigger to the Level 2 Trigger Supervisor is described. A highly parallel design implemented in high large, high-speed FPGA's is described and results of tests are presented

ATLAS TDAQ RoI Builder and the Level 2 Supervisor system

The ATLAS High Level Trigger (HLT) uses information from the hardware based Level 1 Trigger system to guide the retrieval of information from the readout system. The Level 1 Trigger elements (jet, electromagnetic, muon candidate, etc.) determine Regions of Interest (RoIs) that seed further trigger decisions. This paper describes the device - the RoI Builder (RoIB) - that collects these data from the Level 1 Trigger and the Level 2 Supervisors (L2SV) Farm that makes these data available to the HLT. The status of the system design and the results of the tests and integration into ATLAS TDAQ system are presented