Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

The elliptic, $v_2$, triangular, $v_3$, and quadrangular, $v_4$, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range $|\eta|<0.8$ at different collision centralities and as a function of transverse momentum, $p_{\rm T}$, out to $p_{\rm T}=20$ GeV/$c$. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for $p_{\rm T}>8$ GeV/$c$. The small $p_{\rm T}$ dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to $p_{\rm T}=8$ GeV/$c$. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least $p_{\rm T}=8$ GeV/$c$ indicating that the particle type dependence persists out to high $p_{\rm T}$.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Resonant cavity enhanced photodetectors for the mid-wave infrared

We present III-Sb resonant cavity-enhanced (RCE) photodetectors suitable for gas detection in the mid-wave infrared. AlAsSb/GaSb DBRs and absorbers of bulk InAsSb or a type-II InAsSb-InAs SLS were grown on GaSb, allowing for operation at 3.72 μm or 4.52 μm, with linewidth Δλ 20x reduction in noise compared with a conventional nBn detector with full thickness absorber. At 3.72 μm, performance above the BLIP limit imposed on broadband photodetectors was found by calculating for the specific detectivity

Resonant cavity enhanced photodiodes on GaSb for the mid-wave infrared

We report the design, growth, processing, and characterization of resonant cavity enhanced photodiodes for the midwave infrared at ∼3.72 μm on GaSb. Using AlAsSb/GaSb mirrors, AlAsSb barrier and spacer layers and a thin 96 nm InAsSb absorber, we observed dark current and detectivity behavior superior to common InAsSb nBn detectors in the literature, with peak specific detectivity values of 8 × 10 10 and 1 × 10 10 cm Hz 1 / 2 W - 1 measured at 250 K and 300 K, respectively. In the same temperature range, the linewidth of the detector response was 60% where the enhancement due to the resonant cavity was ∼20x. We estimate that the devices can operate close to, or slightly above, the background-limited infrared performance limit imposed on broadband detectors for a 300 K scene

Mid-wavelength infrared resonant cavity enhanced photodiodes for infrared spectroscopic sensing of chemicals and other narrow-band optical signals

Inserting an infrared detector architecture into an optical cavity between two high-reflectivity mirrors allows incident light to reflect and pass through the detector multiple times, thereby enhancing absorption within the active region. This allows for a 40-100x thinner optical absorbing region compared to conventional infrared detector structures which reduces the detector dark current and noise and enhances SNR. We report the design, growth, fabrication and characterization of resonant cavity enhanced MWIR photodiodes on GaSb substrates. Devices on GaSb use AlAsSb/GaSb mirrors, AlAsSb spacer layers, and a narrow 96 nm InAsSb absorber. Dark current and detectivity behavior better than equivalent broadband nBn detectors in the literature have been observed. 34nm linewidth detector response is observed. Resonant cavity-enhanced photodiodes with resonant wavelengths of 3.6μm and 3.72μm are demonstrated with dark currents equal to or lower than Rule 07 over the operating temperature range of the device. D∗ in excess of 1×10 10 cm Hz 1/2W -1 at 300K and 8×10 10 cm Hz 1/2W -1 at 250K have been achieved. Amethyst Research has produced packaged resonant-cavity detectors. The 3.6 μm resonant-cavity enhanced photodiode was packaged within an Amethyst Research designed pre-amplifier package with an integrated TEC for detector cooling