Violation of lepton flavour universality in composite Higgs models

We investigate whether the $2.6\sigma$ deviation from lepton flavour universality in $B^+\to K^+\ell^+\ell^-$ decays recently observed at the LHCb experiment can be explained in minimal composite Higgs models. We show that a visible departure from universality is indeed possible if left-handed muons have a sizable degree of compositeness. Constraints from $Z$-pole observables are avoided by a custodial protection of the muon coupling. The deficit in the invisible $Z$ width at LEP is explained in the same region of parameters.Comment: 5 pages, 2 figures. v4: discussion of invisible Z width adde

Direct and indirect signals of natural composite Higgs models

We present a comprehensive numerical analysis of a four-dimensional model with the Higgs as a composite pseudo-Nambu-Goldstone boson that features a calculable Higgs potential and protective custodial and flavour symmetries to reduce electroweak fine-tuning. We employ a novel numerical technique that allows us for the first time to study constraints from radiative electroweak symmetry breaking, Higgs physics, electroweak precision tests, flavour physics, and direct LHC bounds on fermion and vector boson resonances in a single framework. We consider four different flavour symmetries in the composite sector, one of which we show to not be viable anymore in view of strong precision constraints. In the other cases, all constraints can be passed with a sub-percent electroweak fine-tuning. The models can explain the excesses recently observed in $WW$, $WZ$, $Wh$ and $\ell^+\ell^-$ resonance searches by ATLAS and CMS and the anomalies in angular observables and branching ratios of rare semi-leptonic $B$ decays observed by LHCb. Solving the $B$ physics anomalies predicts the presence of a dijet or $t\bar t$ resonance around 1 TeV just below the sensitivity of LHC run 1. We discuss the prospects to probe the models at run 2 of the LHC. As a side product, we identify several gaps in the searches for vector-like quarks at hadron colliders, that could be closed by reanalyzing existing LHC data.Comment: 74 pages, 21 figures. v2: references added, discussion in 3.2.6 extende

Electroweak symmetry breaking and collider signatures in the next-to-minimal composite Higgs model

We conduct a detailed numerical analysis of the composite pseudo-Nambu-Goldstone Higgs model based on the next-to-minimal coset $\text{SO}(6)/\text{SO}(5)\cong\text{SU}(4)/\text{Sp}(4)$, featuring an additional SM singlet scalar in the spectrum, which we allow to mix with the Higgs boson. We identify regions in parameter space compatible with all current experimental constraints, including radiative electroweak symmetry breaking, flavour physics, and direct searches at colliders. We find the additional scalar, with a mass predicted to be below a TeV, to be virtually unconstrained by current LHC data, but potentially in reach of run 2 searches. Promising indirect searches include rare semi-leptonic $B$ decays, CP violation in $B_s$ mixing, and the electric dipole moment of the neutron.Comment: 32 pages + appendices, 9 figures. v2: minor clarifications, matches the JHEP versio

Status of the B→K∗μ+μ−B\to K^*\mu^+\mu^- anomaly after Moriond 2017

Motivated by recent results by the ATLAS and CMS collaborations on the angular distribution of the $B \to K^* \mu^+\mu^-$ decay, we perform a state-of-the-art analysis of rare $B$ meson decays based on the $b \to s \mu \mu$ transition. Using standard estimates of hadronic uncertainties, we confirm the presence of a sizable discrepancy between data and SM predictions. We do not find evidence for a $q^2$ or helicity dependence of the discrepancy. The data can be consistently described by new physics in the form of a four-fermion contact interaction $(\bar s \gamma_\alpha P_L b)(\bar \mu \gamma^\alpha \mu)$. Assuming that the new physics affects decays with muons but not with electrons, we make predictions for a variety of theoretically clean observables sensitive to violation of lepton flavour universality.Comment: 20 pages, 8 figures, 3 tables. v3: numerics updated using v2 of arXiv:1606.04731. Conclusions unchanged. Matches published version. Example script available at https://github.com/DavidMStraub/paper-bkstarmumu-ans

TISSUE RESPONSE TO IMPACT LOADING IN SPORTS

The response of biological tissue to impact like mechanical loading in sports is of vital interest in sports biomechanics, athletic training research and especially the development of an injury reduction model. Bone and articular cartilage react differently to mechanical loading in the long term. A strong association to the loading patterns for the response of bone but not for that of cartilage has been be identified. For the short term experimental results provide evidence on two different articular cartilage responses related to loading regimes (high frequent impact vs. low frequent impact). From the reported results the risk of overuse through impact loading was derived as a function of sports related impact loading patterns and subject specific prerequisites

THE CHOICE OF TRAINING FOOlWEAR HAS AN EFFECT ON CHANGES :IN MORPHOLOGY AND FUNCTION OF FOOT AND SHANK MUSCLES

The use of minimal footwear leads to higher muscle activity of the M. flexor hallucis longus and to a higher range of motion in the metatarsophalangeal joints (MPJ). This could lead to training effects of in-and extrinsic foot structures as muscles and tendons. The purpose of the study was to determine whether muscle strength or the anatomical cross sectional area of foot and shank muscles are affected by the use of minimal footwear. In a longitudinal prospective intervention study the effect of the use of a minimal shoe was evaluated. Therefore isometric MPJ f1exion strength, inversion strength and plantar f1exion strength were determined. The effect on the anatomical cross sectional areas (ACSA) of selected foot and shank muscles were measured using MRI. ACSA as well as muscular performance increased significantly using the minimal shoe in comparison to conventional footwear. This should lead to performance enhancement and injury prevention

Year-round population dynamics of Limacina spp. early stages in a high-Arctic fjord (Adventfjorden, Svalbard)

The thecosome pteropods Limacina helicina and L. retroversa are important contributors to the zooplankton community in high-latitude environments but little is known about their distribution and life cycle under polar conditions. We collected the early life stages (< 1 mm) of the thecosome population in 2012 and 2013 at a bi-weekly to monthly resolution in fjord highly influenced by Arctic waters as well as Atlantic inflows (Adventfjorden, Svalbard, 78°N), together with environmental parameters. L. retroversa only occurred episodically, in association with the inflow of Atlantic water, with low numbers and random size distributions. This suggests that this boreal species does not fulfill its life cycle in Adventfjorden. In contrast, young specimens of L. helicina were present during the entire study. Veligers hatched in late summer/autumn and measured 0.14 mm on average. They grew with rates of 0.0006 mm day− 1 over the 10–11 months of development. Only thereafter, growth accelerated by one order of magnitude and maximal rates were reached in autumn (0.0077 mm day− 1). Our results indicate that L. helicina reaches a size of 1 mm after approximately 1.5 years in Adventfjorden. We therefore suggest that L. helicina overwinters the first year as a small juvenile and that it needs at least 2 years to reach an adult size of 5 mm in Adventfjorden. This reveals an complex and delicate aspect of the life-cycle of L. helicina and further research is needed to determine if it makes the population especially vulnerable towards climate changes

Thermodynamic Model of a Solar Receiver for Superheating of Sulfur Trioxide and Steam at Pilot Plant Scale

Within the European research project SOL2HY2, key components for a solar hybrid sulfur cycle are being developed and demonstrated at pilot scale in a real environment. Regarding the thermal portion, a plant for solar sulfuric acid decomposition is set up and initially operated at the research platform of the DLR Solar Tower in Jülich, Germany. One major component is the directly irradiated volumetric receiver, superheating steam and SO3 coming from a tube-type evaporator to above 1000 °C. At the design flow rate of sulfuric acid (50%-wt.) of 1 l/min, a nominal solar power of 57 kW is required at the receiver. With a flat ceramic absorber made from SiC and a flat quartz glass window, the design is based on lab scale reactors successfully demonstrated at the solar furnace of the German Aerospace Centre (DLR) in Cologne, Germany. A flexible lumped thermodynamic tool representing the receiver, compiled to assess different configurations, is presented in detail. An additional raytracing model has been established to provide the irradiation boundaries and support the design of a conical secondary concentrator with an aperture diameter of 0.6 m. A comparison with first experimental data (up to 65% nominal power), obtained during initial operation, indicates the models to be viable tools for design and operational forecast of such systems. With a provisional method to account for the efficiency of the secondary concentrator, measured fluid outlet temperatures (up to 1000 °C) are predicted with deviations of ±60 °C. Respective absorber front temperatures (up to 1200 °C) are under-predicted by 100-200 °C, with lower deviations at higher mass flows. The measured window temperature (up to 700 °C) mainly depends on the absorber front temperature level, which is well predicted by the model

Survey on brachytherapy training among radiation oncology residents in the German-speaking regions of Europe.

PURPOSE This survey aimed to determine the perception of brachytherapy training among residents in the DACH region, consisting of Austria, Germany and Switzerland. MATERIAL & METHODS An online questionnaire containing 22 questions related to trainee demographics (n = 5) and to brachytherapy training (n = 17) was sent in two iterations in 11/2019 and 02/2020. The following topics were evaluated: institutional support, barriers to training, extent of training, site-specific training (prostate, gynaecology, breast, gastrointestinal and skin), preferences for further training and outlook on overall development of brachytherapy. The responses were mostly based on a Likert scale of 1 to 5, thereby reflecting strength of opinion. Descriptive statistics were used to describe frequencies. RESULTS Among the 108 respondents, approximately 69% of residents considered the ability to perform brachytherapy independently to be important or somewhat important. However, only 31% of respondents reported to have a dedicated brachytherapy training during residency. The major limitation to achieve independence in performing brachytherapy was seen in a low case load in Austria, in the lack of training in Switzerland and in both of them in Germany. CONCLUSION The interest in brachytherapy training among residents in German-speaking countries was generally high, but there is a perceived lack of sufficient case volumes and partially also in formal training opportunities. Fellowships at departments with a high case load as part of a formalised curriculum and dedicated hands-on workshops at national or international conferences might help to overcome these issues

Isolated Grauer's gorilla populations differ in diet and gut microbiome

The animal gut microbiome has been implicated in a number of key biological processes, ranging from digestion to behavior, and has also been suggested to facilitate local adaptation. Yet studies in wild animals rarely compare multiple populations that differ ecologically, which is the level at which local adaptation may occur. Further, few studies simultaneously characterize diet and gut microbiome from the same sample, despite their likely interdependence. Here, we investigate the interplay between diet and gut microbiome in three geographically isolated populations of the critically endangered Grauer's gorilla, which we show to be genetically differentiated. We find population- and social group-specific dietary and gut microbial profiles and co-variation between diet and gut microbiome, despite the presence of core microbial taxa. There was no detectable effect of age, and only marginal effects of sex and genetic relatedness on the microbiome. Diet differed considerably across populations, with the high-altitude population consuming a lower diversity of plants compared to low-altitude populations, consistent with plant availability constraining diet. The observed pattern of covariation between diet and gut microbiome is likely a result of long-term social and environmental factors. Our study suggests that the gut microbiome is sufficiently plastic to support flexible food selection and hence contribute to local adaptation