RPC Gap Production and Performance for CMS RE4 Upgrade

CMS experiment constructed the fourth Resistive Plate Chamber (RPC) trigger station composed of 144 RPCs to enhance the high momentum muon trigger efficiency at both endcap regions. All new CMS endcap RPC gaps are produced in accordance with QA and QC at the Korea Detector Laboratory (KODEL) in Korea. All qualified gaps have been delivered to three assembly sites: CERN in Switzerland, BARC in India, and Ghent University in Belgium for the RPC detector assembly. In this paper, we present the detailed procedures used in the production of RPC gaps adopted for the CMS upgrade.Comment: RPC2014 conference contribution, 7 pages, 8 figure

Implications of the dark axion portal for the muon g-2, B-factories, fixed target neutrino experiments and beam dumps

The dark axion portal is a recently introduced portal between the standard model and the dark sector. It connects both the dark photon and the axion (or axion-like particle) to the photon simultaneously through an anomaly triangle. While the vector portal and the axion portal have been popular venues to search for the dark photon and axion, respectively, the new portal provides new detection channels if they coexist. The dark axion portal is not a result of the simple combination of the two portals, and its value is not determined by the other portal values; it should be tested independently. In this paper, we discuss implications of the new portal for the leptonic g-2, B-factories, fixed target neutrino experiments, and beam dumps. We provide the model-independent constraints on the axion-photon-dark photon coupling and discuss the sensitivities of the recently activated Belle-II experiment, which will play an important role in testing the new portal.Comment: 14 pages, 12 figures. v2 - Additional discussion and references added. v3 - Version accepted for publication by PRD. v4 - Correction to equation following Eq. (15

Large-Scale Highly Aligned Nanowire Printing

Nanowires (NWs) are 1D confined nanostructures; this geometry gives them unique properties that have been exploited in fabrication of high-density and high-tech electronic devices. Current method to produce NWs cannot fabricate large-scale-aligned NW arrays with precise control of length, orientation, location, and number of NWs individually; these inabilities hinder application of NWs in practical electronics. This paper describes e-nanowire printing, a method to print highly aligned NWs on a large scale, and then reviews recent progress in various electronic applications with highly aligned NWs. Finally, future research is suggested to advance nanoelectronics.1110Ysciescopu

Classical Mechanics of Collinear Positron-Hydrogen Scattering

We study the classical dynamics of the collinear positron-hydrogen scattering system below the three-body breakup threshold. Observing the chaotic behavior of scattering time signals, we in- troduce a code system appropriate to a coarse grained description of the dynamics. And, for the purpose of systematic analysis of the phase space structure, a surface of section is introduced being chosen to match the code system. Partition of the surface of section leads us to a surprising conjec- ture that the topological structure of the phase space of the system is invariant under exchange of the dynamical variables of proton with those of positron. It is also found that there is a finite set of forbidden patterns of symbol sequences. And the shortest periodic orbit is found to be stable, around which invariant tori form an island of stability in the chaotic sea. Finally we discuss a possible quantum manifestation of the classical phase space structure relevant to resonances in scattering cross sections.Comment: 14 pages, 9 figure