Nuclear spin-lattice relaxation rate in the D+iD superconducting state: implications for CoO superconductor

We calculated the nuclear spin-lattice relaxation rate $1/T_1$ for the D+iD superconducting state with impurities. We found that small amount of unitary impurities quickly produces the residual density of states inside the gap. As a result, the T-linear behavior in 1/T$_1$ is observed at low temperatures. Our results show that the D+iD pairing symmetry of the superconducting state of Na$_{0.35}$CoO$_{2} \cdot y$H$_2$ O is compatible with recent $^{59}$Co 1/T$_1$ experiments of several groups.Comment: 5 pages, 4 figures, minor change

Theoretical study of electronic Raman scattering of Borocarbide superconductors

The electronic Raman scattering of Borocarbide superconductors is studied based on the weak coupling theory with $s+g$-wave gap symmetry. The low energy behaviors and the relative peak positions can be naturally understood, while the explanation of the detailed shape of the $B_{1g}$ peak seems to require a strong inelastic interaction not present in the weak coupling theory.Comment: Revtex 4 file, 9 pages and 5 figure

Different Types of Corona Discharges Associated With High-Altitude Positive Narrow Bipolar Events Nearby Cloud Top

Single- and multi-pulse blue corona discharges are frequently observed in thunderstorm clouds. Although we know they often correlate with Narrow Bipolar Events (NBEs) in Very Low Frequency/Low Frequency radio signals, their physics is not well understood. Here, we report a detailed analysis of different types of blue corona discharges observed by the Atmosphere-Space Interactions Monitor during an overpass of a thundercloud cell nearby Malaysia. Both single- and multi-pulse blue corona discharges were associated with positive NBEs at the top of the cloud, reaching about 18 km altitude. We find that the primary pulses of multi-pulse discharges have weaker current moments than the single-pulse discharges, suggesting that the multi-pulse discharges either have shorter vertical channels or have weaker currents than the single-pulse discharges. The subsequent pulse trains of the multi-pulse discharges delayed some milliseconds are likely from horizontally oriented electrical discharges, but some NBEs, correlated with both single-and multi-pulse discharges, include small-amplitude oscillations within a few microseconds inside their waveforms, which are unresolved in the optical observation and yet to be understood. Furthermore, by jointly analyzing the optical and radio observations, we estimate the photon free mean path at the cloud top to be ∼6 m. © 2023. The Authors.This work was supported by the European Research Council (ERC) under the European Union H2020 programme/ERC Grant agreement 681257. It also received funding from the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant agreement SAINT 722337. Additionally, this work was supported by the Spanish Ministry of Science and Innovation, MINECO, under project PID2019-109269RB-C43 and FEDER program. D.L. would like to acknowledge the Independent Research Fund Denmark (Danmarks Frie Forskningsfond) under Grant agreement 1026-00420B. D.L., A.L., F.J.G.V. and F.J.P.I. would like to acknowledge financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). G.L. is supported by the Chinese Meridian Project, and the International Partnership Program of Chinese Academy of Sciences (No.183311KYSB20200003). ASIM is a mission of the European Space Agency (ESA) and is funded by ESA and by national grants of Denmark, Norway and Spain. The ASIM Science Data Centre is supported by ESA PRODEX contracts C 4000115884 (DTU) and 4000123438 (Bergen).Peer reviewe

Edge reconstruction in the fractional quantum Hall regime

The interplay of electron-electron interaction and confining potential can lead to the reconstruction of fractional quantum Hall edges. We have performed exact diagonalization studies on microscopic models of fractional quantum Hall liquids, in finite size systems with disk geometry, and found numerical evidence of edge reconstruction under rather general conditions. In the present work we have taken into account effects like layer thickness and Landau level mixing, which are found to be of quantitative importance in edge physics. Due to edge reconstruction, additional nonchiral edge modes arise for both incompressible and compressible states. These additional modes couple to electromagnetic fields and thus can be detected in microwave conductivity measurements. They are also expected to affect the exponent of electron Green's function, which has been measured in tunneling experiments. We have studied in this work the electric dipole spectral function that is directly related to the microwave conductivity measurement. Our results are consistent with the enhanced microwave conductivity observed in experiments performed on samples with an array of antidots at low temperatures, and its suppression at higher temperatures. We also discuss the effects of the edge reconstruction on the single electron spectral function at the edge.Comment: 19 pages, 12 figure

Partial Wave Analysis of J/ψ→γ(K+K−π+π−)J/\psi \to \gamma (K^+K^-\pi^+\pi^-)

BES data on $J/\psi \to \gamma (K^+K^-\pi^+\pi^-)$ are presented. The $K^*\bar K^*$ contribution peaks strongly near threshold. It is fitted with a broad $0^{-+}$ resonance with mass $M = 1800 \pm 100$ MeV, width $\Gamma = 500 \pm 200$ MeV. A broad $2^{++}$ resonance peaking at 2020 MeV is also required with width $\sim 500$ MeV. There is further evidence for a $2^{-+}$ component peaking at 2.55 GeV. The non-$K^*\bar K^*$ contribution is close to phase space; it peaks at 2.6 GeV and is very different from $K^{*}\bar{K^{*}}$.Comment: 15 pages, 6 figures, 1 table, Submitted to PL

Measurements of the Mass and Full-Width of the ηc\eta_c Meson

In a sample of 58 million $J/\psi$ events collected with the BES II detector, the process J/$\psi\to\gamma\eta_c$ is observed in five different decay channels: $\gamma K^+K^-\pi^+\pi^-$, $\gamma\pi^+\pi^-\pi^+\pi^-$, $\gamma K^\pm K^0_S \pi^\mp$ (with $K^0_S\to\pi^+\pi^-$), $\gamma \phi\phi$ (with $\phi\to K^+K^-$) and $\gamma p\bar{p}$. From a combined fit of all five channels, we determine the mass and full-width of $\eta_c$ to be $m_{\eta_c}=2977.5\pm1.0 ({stat.})\pm1.2 ({syst.})$ MeV/$c^2$ and $\Gamma_{\eta_c} = 17.0\pm3.7 ({stat.})\pm7.4 ({syst.})$ MeV/$c^2$.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.

A Measurement of Psi(2S) Resonance Parameters

Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been measured in the vicinity of the Psi(2S) resonance using the BESII detector operated at the BEPC. The Psi(2S) total width; partial widths to hadrons, pi+pi- J/Psi, muons; and corresponding branching fractions have been determined to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)= (2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)= (97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%, respectively.Comment: 8 pages, 6 figure

Corpus callosum injury after neurosurgical intervention for posthemorrhagic ventricular dilatation and association with neurodevelopmental outcome at 2 years

OBJECTIVE Direct injury to the corpus callosum (CC) due to neurosurgical interventions in infants with posthemorrhagic ventricular dilatation (PHVD) has not been reported in the literature. The authors observed a subset of infants who had suffered penetrating CC injury after neurosurgical interventions for PHVD and hypothesized that this pattern of injury may result in suboptimal CC maturation and neurodevelopmental impairment.METHODS In this multicenter, retrospective, observational study, 100 preterm and 17 full-term infants with PHVD were included and compared with 23 preterm controls. Both neonatal and postneonatal brain MRI scans were assessed for injury, and measurements were performed on postneonatal MRI scans at 2 years' corrected age. Neurodevelopmental outcome was assessed at 2 years' corrected age.RESULTS A total of 269 brain MRI scans of 140 infants were included. Of infants with PHVD, 48 (41%) had penetrating CC injury following neurosurgical interventions. The median (IQR) CC midsagittal surface area was smaller in infants with CC injury when compared with infants with PHVD who had intact CC and controls (190 mm(2) [149-262 mm(2)] vs 268 mm(2) [206-318 mm(2)] vs 289 mm(2) [246-320 mm(2)], respectively; p < 0.001). In the univariate analysis, the area of the CC was associated with cognitive Z score (coefficient 0.009 [95% CI 0.005-0.012], p < 0.001) and motor Z score (coefficient 0.009 [95% CI 0.006-0.012], p < 0.001). In the multivariable model, CC injury was not independently associated with cognitive and motor Z score after adjusting for gestational age and presence of periventricular hemorrhagic infarction (coefficient 0.04 [95% CI -0.36 to 0.46] and -0.37 [95% CI -0.83 to 0.09], p = 0.7 and 0.1, respectively).CONCLUSIONS CC injury was not uncommon following neurosurgical interventions for PHVD in both preterm and full-term infants. At the age of 2 years, the CC midsagittal surface area was smaller in infants with injury, but CC injury was not independently associated with cognitive and motor outcomes at 2 years' corrected age.Developmen