Chiral Spin Liquid Ground State in YBaCo3FeO7

A chiral spin liquid state is discovered in the highly frustrated, noncentrosymmetric swedenborgite compound YBaCo3FeO7, a layered kagome system of hexagonal symmetry, by advanced polarized neutron scattering from a single domain crystalline sample. The observed diffuse magnetic neutron scattering has an antisymmetric property that relates to its specific chirality, which consists of three cycloidal waves perpendicular to the c axis, forming an entity of cylindrical symmetry. Chirality and symmetry agree with relevant antisymmetric exchanges arising from broken spatial parity. Applying a Fourier analysis to the chiral interference pattern, with distinction between kagome sites and the connecting trigonal interlayer sites of threefold symmetry, the chiral spin correlation function is determined. Characteristic chiral waves originate from the trigonal sites and extend over several periods in the kagome planes. The chiral spin liquid is remarkably stable at low temperatures despite strong antiferromagnetic spin exchange. The observation raises a challenge, since the commonly accepted ground states in condensed matter either have crystalline long-range order or form a quantum liquid. We show that, within the classical theory of magnetic order, a disordered ground state may arise from chirality. The present scenario, with antisymmetric exchange acting as a frustrating gauge background that stabilizes local spin lumps, is similar to the avoided phase transition in coupled gauge and matter fields for subnuclear particles

A Search for the Electric Dipole Moment of the Tau-Lepton

Using the ARGUS detector at the e+e- storage ring DORIS II, we have searched for the real and imaginary part of the electric dipole formfactor d_tau of the tau lepton in the production of tau pairs at q^2=100 GeV^2. This is the first direct measurement of this CP violating formfactor. We applied the method of optimised observables which takes into account all available information on the observed tau decay products. No evidence for CP violation was found, and we derive the following results: Re(d_tau)=(1.6+-.9)*10^(-16) ecm and Im(d_tau)=(-0.2+-0.8)*10^(-16) ecm, where statistical and systematic errors have been combined.Comment: 8 pages, 5 figures (10 subfigures

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Study of inclusive semileptonic B meson decays

Using the ARGUS detector at the $e^+e^−$ storage ring DORIS-II, we have measured the inclusive semileptonic decays of B-mesons into electrons and muons. The data originate from 220.5 events/pb on the $ϒ(4S)$ resonance. We find BR $(B→e^+v_eX = (10.3 ± 0.6 ± 0.2)$ and BR $(B→μ^+v_μX) = (10.0 ± 0.6 ± 0.2)$ using the model of Altarelli et al. for extrapolating over all lepton momenta, and BR $(B→e^+v_eX) = (9.9±0.6)$ using the model of Grinstein et al. For semileptonic decays into baryons, we obtain an upper limit of BR$(B→pe^+vX)<0.16$

Reconstruction of the decay B&quot;-#-&gt;#D_1&quot;o(2414)#pi#&quot;-

We present the results of a partial reconstruction of the decay channel B&quot;-#-&gt;#D_J&quot;(&quot;*&quot;)&quot;0#pi#&quot;- performed using the ARGUS detector operating at the e&quot;+e&quot;- storage-ring DORIS II. In the context of this paper, D_J&quot;(&quot;*&quot;)&quot;0 is an L=1 excited charm meson decaying to D&quot;*&quot;+#pi#&quot;-. The measured product of branching ratios is Br(B&quot;-#-&gt;#D_1&quot;0(2414)#pi#&quot;-).Br((D_1&quot;0#-&gt;#D&quot;*&quot;+#pi#&quot;-)=(0.17#+-#0.05#+-#0.04)% where the first error is statistical and the second systematic. No evidence for the decay B&quot;-#-&gt;#D_2&quot;*&quot;0(2459)#pi#&quot;- is observed. We calculate the upper limit Br(B&quot;-#-&gt;#D_2&quot;*&quot;0(2459)#pi#&quot;-).Br(D_2&quot;*&quot;0#-&gt;#D&quot;*&quot;+#pi#&quot;-)&lt;0.07% at the 90% confidence level. (orig.)SIGLEAvailable from TIB Hannover: RA 2999(94-069) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Mortality from esophagectomy for esophageal cancer across low, middle, and high-income countries: An international cohort study.

BACKGROUND No evidence currently exists characterising global outcomes following major cancer surgery, including esophageal cancer. Therefore, this study aimed to characterise impact of high income countries (HIC) versus low and middle income countries (LMIC) on the outcomes following esophagectomy for esophageal cancer. METHOD This international multi-center prospective study across 137 hospitals in 41 countries included patients who underwent an esophagectomy for esophageal cancer, with 90-day follow-up. The main explanatory variable was country income, defined according to the World Bank Data classification. The primary outcome was 90-day postoperative mortality, and secondary outcomes were composite leaks (anastomotic leak or conduit necrosis) and major complications (Clavien-Dindo Grade III - V). Multivariable generalized estimating equation models were used to produce adjusted odds ratios (ORs) and 95% confidence intervals (CI). RESULTS Between April 2018 to December 2018, 2247 patients were included. Patients from HIC were more significantly older, with higher ASA grade, and more advanced tumors. Patients from LMIC had almost three-fold increase in 90-day mortality, compared to HIC (9.4% vs 3.7%, p < 0.001). On adjusted analysis, LMIC were independently associated with higher 90-day mortality (OR: 2.31, CI: 1.17-4.55, p = 0.015). However, LMIC were not independently associated with higher rates of anastomotic leaks (OR: 1.06, CI: 0.57-1.99, p = 0.9) or major complications (OR: 0.85, CI: 0.54-1.32, p = 0.5), compared to HIC. CONCLUSION Resections in LMIC were independently associated with higher 90-day postoperative mortality, likely reflecting a failure to rescue of these patients following esophagectomy, despite similar composite anastomotic leaks and major complication rates to HIC. These findings warrant further research, to identify potential issues and solutions to improve global outcomes following esophagectomy for cancer