Universal spectral statistics of Andreev billiards: semiclassical approach

The classification of universality classes of random-matrix theory has recently been extended beyond the Wigner-Dyson ensembles. Several of the novel ensembles can be discussed naturally in the context of superconducting-normal hybrid systems. In this paper, we give a semiclassical interpretation of their spectral form factors for both quantum graphs and Andreev billiards.Comment: final improved version (to be published in Physical Review E), 6 pages, revtex

An Assessment on the Influence of Capital Structure on Performance of the Listed Firms in Tanzania

The research mostly assessed and established the influence of capital structure on the performance of firms listed under the Dar Es Salaam stock exchange (DSE). Specifically, the study aimed to assess the influence of total debt to equity ratio (TDE), total debt to assets ratio (TDA), total equity ratio (TEQ) on the performance of listed firms in Tanzania. Also, the study aimed to determine the control effect of firm size (FS) on the relationship between firm performance and capital structure. The quantitative panel data approach was used. The fixed-effect model for ROA was done to see the influence of TDE on ROA. Results indicated that only TEQ has a significant positive influence on the ROA while TDE and TDA have no significant influence on the ROA. Also, the fixed-effect model for ROCE was carried out to see the relationship between TDE and ROCE. Results showed that TDA and TEQ are insignificant to the ROCE, while TDE is significant to the ROCE. Findings also showed that the presence of the FS on the model of capital structure and ROA, results in TDA, and TEQ having a significant influence on ROA, while TDE becomes insignificant to ROA. Moreover, results indicated that the presence of the FS on the model of capital structure and ROCE results in the only TDE to have a significant influence on ROCE, while TDA and TEQ became insignificant to ROA. The study concluded that TDE has no significant influence on the ROA but TDE has a significant influence on ROCE. Also, the study concluded that TDA has no significant influence on both the ROA and ROCE while TEQ influences ROA positively, and has no significant influence on ROCE. Moreover, the study concluded that the presence of the FS on the model of capital structure and ROA, results in TDA, and TEQ having a significant influence on ROA, while TDE becomes insignificant to ROA. Furthermore, FS resulted in TDE having a significant influence on ROCE, while TDA and TEQ become insignificant to ROCE. The study recommends that companies very carefully must decide on a reasonable capital structure to maintain the performance of the company

Both-Sided TOPCon Solar Cells – Towards a Lean Process Flow for Silicon Bottom Solar Cells

Silicon solar cells with both-side full-area passivating hole and electron contacts are viable candidates for application as bottom cells in tandem architectures. In this contribution, cells with poly-Si based contacts at both sides are investigated as a potential upgrade to the emerging i-TOPCon single junction devices featuring a passivating contact (poly-Si(n)/SiOx) only at the rear side and an alternative to the SHJ technology featuring a-Si based full-area passivating hole and electron contacts. We show that a higher thermal budget is needed to mediate between poly-Si(p)/SiOx hole and poly-Si(n)/SiOx electron contact when the same thermal interfacial SiOx is applied. This is addressed by using a PECVD oxide that is adapted to the needs of the hole and/or the electron contact. We present a proof-of-concept poly-Si(n)/SiOx/c-Si/SiOx/poly-Si(n) device with emphasis on a lean process flow. An all-PECVD process sequence for the hole contact, i.e., plasma oxides+i/p-a-Si deposited at 200°C in the same chamber was applied. With co-annealing of the contacts, no additional hydrogenation, and no edge insulation step, we observe no shunting and obtain efficiencies of up to 20.8% for M2 size cells, so far

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum