Fun with higher-loop Feynman diagrams

We review recent progress that we have achieved in evaluating the class of fully massive vacuum integrals at five loops. After discussing topics that arise in classification, evaluation and algorithmic codification of this specific set of Feynman integrals, we present some selected new results for their expansions around 4 - 2ε dimensions

On top quark mass effects to gg → ZH at NLO

We compute next-to-leading order QCD corrections to the process gg → ZH. In the effective-theory approach we confirm the results in the literature. We consider top quark mass corrections via an asymptotic expansion and show that there is a good convergence below the top quark threshold which describes approximately a quarter of the total cross section. Our corrections are implemented in the publicly available C++ program ggzh

Fully massive vacuum integrals at 5 loops

Luthe T. Fully massive vacuum integrals at 5 loops. Bielefeld: Universität Bielefeld; 2015.Massive vacuum integrals with a single mass scale are a class of Feynman integrals that appear in many precision calculations within the Standard Model of particle physics and have been calculated to the 4-loop level. In this thesis I start pushing this limit to 5 loops by considering the subclass of fully massive vacuum integrals, which can be used to determine the β-function of Quantum Chromodynamics (QCD). To this end I employ a method devised by Laporta for the evaluation of multi-loop Feynman integrals based on difference equations and factorial series. Significant improvements to this method are introduced to account for the great increase in complexity when going from 4 to 5 loops. An implementation of the improved approach in C ++ is then used to obtain high-precision numerical results for the integrals needed for the 5-loop correction to the QCD β-function

Towards the five-loop Beta function for a general gauge group.

We present analytical results for the N4 f and N3 f terms of the five-loop Beta function, for a general gauge group. While the former term agrees with results available from large-Nf studies, the latter is new and extends the value known for SU(3) from an independent calculation

Cardiac troponin I elevation in acute pulmonary embolism is associated with right ventricular dysfunction

AbstractOBJECTIVESThe purpose of this study was to evaluate the prevalence and diagnostic utility of cardiac troponin I to identify patients with right ventricular (RV) dysfunction in pulmonary embolism.BACKGROUNDRight ventricular overload resulting from elevated pulmonary resistance is a common finding in major pulmonary embolism. However, biochemical markers to assess the degree of RV dysfunction have not been evaluated so far.METHODSIn this prospective, double-blind study we included 36 study patients diagnosed as having acute pulmonary embolism.RESULTSAmong the whole study population, 14 patients (39%) had positive troponin I tests. Ten of 16 patients (62.5%) with RV dilatation had increased serum troponin I levels, while only 4 of 14 patients (28.6%) with elevated troponin I values had a normal RV diameter as assessed by echocardiography, indicating that positive troponin I tests were significantly associated with RV dilatation (p = 0.009). Patients with positive troponin I tests had significantly more segmental defects in ventilation/perfusion lung scans than patients with normal serum troponin I (p = 0.0002).CONCLUSIONSOur data demonstrate that more than one-third of patients clinically diagnosed as having pulmonary embolism presented with elevated serum troponin I concentrations. Troponin I tests helped to identify patients with RV dilatation who had significantly more segmental defects in lung scans. Thus, troponin I assays are useful to detect minor myocardial damage in pulmonary embolism

Mountain Resilience:A Systematic Literature Review and Paths to the Future

Mountains are home to a considerable share of the human population. Around a billion people live in mountainous areas, which harbor rich natural and sociocultural diversity. Today, many people living in mountainous areas worldwide face fundamental changes to their cultural and economic living conditions. At the same time, mountain communities have defied harsh environments in the past by adapting to changing natural conditions and showing remarkable levels of resilience. In this review paper, we provide a comprehensive overview of English-language scientific literature on resilience-related topics in mountain areas based on a systematic review of the Scopust literature database. We propose a structured starting point for science–practice interactions and concrete action-based activities to support livelihoods and strengthen resilience in mountain areas. We suggest that existing knowledge gaps can be addressed by relying on local knowledge and cocreating solutions with communities. In this way, we can build innovative capacity and actively buffer against the impact of crises while supporting deliberate transformation toward sustainability and regeneration to further enhance resilience.ISSN:0276-4741ISSN:1994-715

Influencia de los procesos mesoescalares en el impacto regional de las emisiones a la atmósfera y sus implicaciones desde el punto de vista de la gestión de la calidad del aire

We discuss the recent calculation of the five-loop Beta function and the full set of the renormalization constants of QCD up to the linear term in the gauge parameter$ξ = 1 − ξ_L$