Search for the Chiral Magnetic Effect in Au+Au collisions at sNN=27\sqrt{s_{_{\rm{NN}}}}=27 GeV with the STAR forward Event Plane Detectors

A decisive experimental test of the Chiral Magnetic Effect (CME) is considered one of the major scientific goals at the Relativistic Heavy-Ion Collider (RHIC) towards understanding the nontrivial topological fluctuations of the Quantum Chromodynamics vacuum. In heavy-ion collisions, the CME is expected to result in a charge separation phenomenon across the reaction plane, whose strength could be strongly energy dependent. The previous CME searches have been focused on top RHIC energy collisions. In this Letter, we present a low energy search for the CME in Au+Au collisions at $\sqrt{s_{_{\rm{NN}}}}=27$ GeV. We measure elliptic flow scaled charge-dependent correlators relative to the event planes that are defined at both mid-rapidity $|\eta|<1.0$ and at forward rapidity $2.1 < |\eta|<5.1$. We compare the results based on the directed flow plane ($\Psi_1$) at forward rapidity and the elliptic flow plane ($\Psi_2$) at both central and forward rapidity. The CME scenario is expected to result in a larger correlation relative to $\Psi_1$ than to $\Psi_2$, while a flow driven background scenario would lead to a consistent result for both event planes[1,2]. In 10-50\% centrality, results using three different event planes are found to be consistent within experimental uncertainties, suggesting a flow driven background scenario dominating the measurement. We obtain an upper limit on the deviation from a flow driven background scenario at the 95\% confidence level. This work opens up a possible road map towards future CME search with the high statistics data from the RHIC Beam Energy Scan Phase-II.Comment: main: 8 pages, 5 figures; supplementary material: 2 pages, 1 figur

A simulation based design framework for large scale infrastructure systems design

This paper discusses an enhanced use of Modeling and Simulation (M&S) in the design cycle of large scale infrastructure systems. After a short review of the use of M&S in the current systems design process, we identify some issues in multi-actor design environment. A Simulation Based Design (SBD) framework is proposed to tackle these issues using a multi-methodological approach. The framework is specified with formal description, and the tree-like structuring and refinement of design alternatives are explained. A case of applying the framework to container terminal design is presented and the evaluation is reported.Multi Actor SystemsTechnology, Policy and Managemen

A systems theoretical perspective on data-driven modeling and simulation

HarvestSystem Engineerin

Towards automated model calibration and validation in rail transit simulation

System Engineerin

A DEVS library for rail operations simulation

NEOSystem Engineerin

Towards automated model calibration and validation in rail transit simulation

The benefit of modeling and simulation in rail transit operations has been demonstrated in various studies. However, the complex dynamics involved and the ever-changing environment in which rail systems evolve expose the limits of classical simulation. Changing environmental conditions and second order dynamics challenge the validity of the models and seriously reduce model (re-)usability. This paper discusses the potential benefits and requirements of dynamic data-driven simulation in rail systems. The emphasis is placed on automated model reconfiguration, calibration, and validation through the use of data analysis methods. The rationale and requirements are discussed and a process model for data driven calibration and validation is proposed.Multi Actor SystemsTechnology, Policy and Managemen

Exploring multi-level model dynamics: Performance and accuracy (WIP)

Multi Actor SystemsTechnology, Policy and Managemen

The Architecture and Components of LIBROS: Strengths, Limitations, and Plans

System Engineerin

From data to simulation models : component-based model generation with a data-driven approach

Harvest, NEOSystem Engineerin