Soft-core hyperon-nucleon potentials

A new Nijmegen soft-core OBE potential model is presented for the low-energy YN interactions. Besides the results for the fit to the scattering data, which largely defines the model, we also present some applications to hypernuclear systems using the G-matrix method. An important innovation with respect to the original soft-core potential is the assignment of the cut-off masses for the baryon-baryon-meson (BBM) vertices in accordance with broken SU(3)$_F$, which serves to connect the NN and the YN channels. As a novel feature, we allow for medium strong breaking of the coupling constants, using the $^3P_0$ model with a Gell-Mann--Okubo hypercharge breaking for the BBM coupling. We present six hyperon-nucleon potentials which describe the available YN cross section data equally well, but which exhibit some differences on a more detailed level. The differences are constructed such that the models encompass a range of scattering lengths in the $\Sigma N$ and $\Lambda N$ channels. For the scalar-meson mixing angle we obtained values $\theta_S=37$ to 40 degrees, which points to almost ideal mixing angles for the scalar $q\bar{q}$ states. The G-matrix results indicate that the remarkably different spin-spin terms of the six potentials appear specifically in the energy spectra of $\Lambda$ hypernuclei.Comment: 37 pages, 4 figure

Quark-Model Baryon-Baryon Interaction and its Applications to Hypernuclei

The quark-model baryon-baryon interaction fss2, proposed by the Kyoto-Niigata group, is a unified model for the complete baryon octet (B_8=N, Lambda, Sigma and Xi), which is formulated in a framework of the (3q)-(3q) resonating-group method (RGM) using the spin-flavor SU_6 quark-model wave functions and effective meson-exchange potentials at the quark level. Model parameters are determined to reproduce properties of the nucleon-nucleon system and the low-energy cross section data for the hyperon-nucleon scattering. Due to the several improvements including the introduction of vector-meson exchange potentials, fss2 has achieved very accurate description of the NN and YN interactions, comparable to various one-boson exchange potentials. We review the essential features of fss2 and our previous model FSS, and their predictions to few-body systems in confrontation with the available experimental data. Some characteristic features of the B_8 B_8 interactions with the higher strangeness, S=-2, -3, -4, predicted by fss2 are discussed. These quark-model interactions are now applied to realistic calculations of few-body systems in a new three-cluster Faddeev formalism which uses two-cluster RGM kernels. As for the few-body systems, we discuss the three-nucleon bound states, the Lambda NN-Sigma NN system for the hypertriton, the alpha alpha Lambda system for 9Be Lambda, and the Lambda Lambda alpha system for 6He Lambda Lambda.Comment: 20 pages, 12 figures, 18th Nishinomiya Yukawa Memorial Symposium on Strangeness in Nuclear Matter, 4 - 5 December 2003, Nishinomiya, Japan. (to be published in Prog. Theor. Phys. Suppl.

Building comfort control using MPC: Development of a Coupled EnergyPlus-MATLAB Simulation Framework for Model Predictive Control of Integrated Electrical and Thermal Residential Renewable Energy System

The urge of modernizing the building stock in the European Union comes from one clear evidence: it is the largest energy consuming sector, accounting for up to one-third of the total final energy consumption. The vast majority of houses and offices in EU countries were built before 1990 and did not undergo any renovation, meaning they show poor thermal insulation capability, and no smart technique is implemented for the control and reduction of both the electricity and heating demands. This results in significantly high emissions. Almost 40% of EU carbon dioxide emissions indeed come from the building sector [1] , indirectly in the construction process and directly during operation. The set of contaminants also include greenhouse gases such as hydrofluorocarbons, fine particles (PM2.5/PM10) and toxic dusts recognized as one of the main causes of cancer onset [2]. This is precisely related to the fuel mix each country employs to cover the sector needs: 38.2% of the OECD countries residential demand is covered by natural gas and a phasing-out 10% by oil [3]. Technologically advanced solutions such as hydrogen Fuel Cells, integrated with other renewable sources, can represent a clean solution to push down emissions but also energy consumptions by digitalizing the system and implementing control strategies to optimally match demand and generation. This study aims at developing a coupled EnergyPlus-MATLAB Simulation Framework of an integrated electrical and thermal residential renewable energy system with a Model Predictive Controller (MPC) to size and control the operation of a fuel cell stack. A recently renovated single-family house in the province of Turin (IT) is the case-study modelled in EnergyPlus. The simulation requires the building geometry and thermophysical properties and the weather conditions as inputs, and by designing appropriately the controller, a schedule for the heating demand and the resulting evolution of the indoor temperature is obtained.IncomingObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminan

Correlations and flavors in jets in ALICE

We report on the measurement of hadron composition in charged jets in pp at $\sqrt{s}=7$ TeV and show the first data on particle type dependent jet fragmentation at the LHC. Further, we present $(\Lambda+\bar{\Lambda})/2$K$^{0}_{\mathrm{S}}$ ratios measured in charged jets in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 2.76$ TeV and in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV. While the ratio of the inclusive $p_{\mathrm{T}}$ spectra of $\Lambda$ and K$^{0}_{\mathrm{S}}$ exhibits centrality dependent enhancement both in Pb-Pb and p-Pb system, the $(\Lambda+\bar{\Lambda})/2$K$^{0}_{\mathrm{S}}$ ratio measured in charged jets reveals that jet fragmentation does not contribute to the observed baryon anomaly. Finally, we discuss the measurement of semi-inclusive $p_{\mathrm{T}}$ spectra of charged jets that recoil from a high-$p_{\mathrm{T}}$ hadron trigger in Pb-Pb and pp collisions at $\sqrt{s_{\mathrm{NN}}} = 2.76$ TeV and $\sqrt{s} = 7$ TeV, respectively. The jet yield uncorrelated with the trigger hadron is removed at the event-ensemble level without introducing a bias on the jet population which is therefore infrared and collinear safe. The recoil jet yield in central Pb-Pb is found to be suppressed w.r.t. that from pp PYTHIA reference. On the other hand, there is no sign of intra-jet broadening even for anti-$k_{\mathrm{T}}$ jets with a resolution parameter as large as $R=0.5$.Comment: Proceedings of Strangeness in Quark Matter conference, 6 July - 11 July 2015, Dubna, Russi

A simultaneous two-dimensionally constraint disaggregate trip generation, distribution and mode choice model - Theory and application for a Swiss national model

The Swiss federal government has asked the IVT, ETH Zürich in collaboration with the TU Dresden and Emch+Berger, Zürich to estimate origin-destination matrices by mode and purpose for the year 2000. The zoning system employing about 3’000 zones of very uneven size required a solution algorithm which is fast, but also able to model generation, distribution and mode choice simultaneously, while addressing the different data availability for traffic within, destined for and passing through the country. The EVA algorithm developed by Lohse (1997) was adapted for this purpose. The key proper-ties of the algorithm are its disaggregate description of demand, its use of appropriate logit-type models for the demand distribution, while maintaining the known marginal distributions of the matrices generated. This last point is of particular importance in a large scale planning applica-tion such as the one at hand. The algorithm calculates trip production and attractions by zone using activity pairs. The 17 ac-tivity pairs distinguished are the combinations of two activities, such as home-work or work-leisure. The relevant daily rates are derived for each of the 17 activity pairs from the 2000 Swiss National Travel Survey (Bundesamt für Statistik and Bundesamt für Raumentwicklung, 2001). The zonal attractivity is defined separately for each trip purpose. In addition to the common variables, such as employment or population, detailed descriptions of education places, shop-ping or leisure facilities, overnight accommodations, shopping centres etc. are employed (see Tschopp, Keller and Axhausen, 2003 for the data). The combined destination and mode choice models estimated for the different traveller types and activity pairs are based on the Swiss National Travel survey (RP data), but incorporates re-sults from a prior SP study on mode and route choice (Vrtic and Axhausen, 2004). The different zone sizes and the different levels of data available required the formulation of new additional models for the transit traffic passing through Switzerland and the traffic originat-ing outside, respectively leaving the country The matching network models for public transport and road traffic were implemented using VISUM 9.0 of PTV AG, Karlsruhe. The timetable based assignment considers all scheduled train services plus the relevant interurban bus services, in particular in rural areas. The paper has three main parts: the first main part derives and describes for the first time the EVA algorithm in English, including the solution method used. The second part summarizes the results of choice model estimation using the generalised cost elasticities of demand by purpose and traveller type. The third part assesses the quality of the results. These assessments are based on two independently derived matrices, which are available for rail-travel from on board - counts and for commuters from the 2000 national census. In addition, we compare the assign-ment results with the available cross section counts. The conclusions discuss computing times, accuracy and issues for further research.

Type-driven automated program transformations and cost modelling for optimising streaming programs on FPGAs

In this paper we present a novel approach to program optimisation based on compiler-based type-driven program transformations and a fast and accurate cost/performance model for the target architecture. We target streaming programs for the problem domain of scientific computing, such as numerical weather prediction. We present our theoretical framework for type-driven program transformation, our target high-level language and intermediate representation languages and the cost model and demonstrate the effectiveness of our approach by comparison with a commercial toolchain

Gamma-Ray Spectroscopy of Λ16^{16}_\LambdaO and Λ15^{15}_\LambdaN Hypernuclei via the 16^{16}O(K−,π−)(K^-, \pi^-) reaction

he bound-state level structures of the $^{16}_{\Lambda}$O and $^{15}_{\Lambda}$N hypernuclei were studied by $\gamma$-ray spectroscopy using a germanium detector array (Hyperball) via the $^{16}$O ($K^-, \pi^- \gamma$) reaction. A level scheme for $^{16}_{\Lambda}$O was determined from the observation of three $\gamma$-ray transitions from the doublet of states ($2^-$,$1^-$) at $\sim 6.7$ MeV to the ground-state doublet ($1^-$,$0^-$). The $^{15}_{\Lambda}$N hypernuclei were produced via proton emission from unbound states in $^{16}_{\Lambda}$O . Three $\gamma$ -rays were observed and the lifetime of the $1/2^+;1$ state in $^{15}_{\Lambda}$N was measured by the Doppler shift attenuation method. By comparing the experimental results with shell-model calculations, the spin-dependence of the $\Lambda N$ interaction is discussed. In particular, the measured $^{16}_{\Lambda}$O ground-state doublet spacing of 26.4 $\pm$ 1.6 $\pm$ 0.5 keV determines a small but nonzero strength of the $\Lambda N$ tensor interaction.Comment: 22 pages, 17 figure

Fake Run-Time Selection of Template Arguments in C++

C++ does not support run-time resolution of template type arguments. To circumvent this restriction, we can instantiate a template for all possible combinations of type arguments at compile time and then select the proper instance at run time by evaluation of some provided conditions. However, for templates with multiple type parameters such a solution may easily result in a branching code bloat. We present a template metaprogramming algorithm called for_id that allows the user to select the proper template instance at run time with theoretical minimum sustained complexity of the branching code.Comment: Objects, Models, Components, Patterns (50th International Conference, TOOLS 2012

Collective dynamics of colloids at fluid interfaces

The evolution of an initially prepared distribution of micron sized colloidal particles, trapped at a fluid interface and under the action of their mutual capillary attraction, is analyzed by using Brownian dynamics simulations. At a separation \lambda\ given by the capillary length of typically 1 mm, the distance dependence of this attraction exhibits a crossover from a logarithmic decay, formally analogous to two-dimensional gravity, to an exponential decay. We discuss in detail the adaption of a particle-mesh algorithm, as used in cosmological simulations to study structure formation due to gravitational collapse, to the present colloidal problem. These simulations confirm the predictions, as far as available, of a mean-field theory developed previously for this problem. The evolution is monitored by quantitative characteristics which are particularly sensitive to the formation of highly inhomogeneous structures. Upon increasing \lambda\ the dynamics show a smooth transition from the spinodal decomposition expected for a simple fluid with short-ranged attraction to the self-gravitational collapse scenario.Comment: 13 pages, 12 figures, revised, matches version accepted for publication in the European Physical Journal