Exploiting the WH/ZH symmetry in the search for New Physics

We suggest to isolate the loop-induced gluon-initiated component ($gg\to ZH$) for associated $ZH$ production by using the similarity of the Drell-Yan-like component for $ZH$ production to the $WH$ process. We argue that the cross-section ratio of the latter two processes can be predicted with high theoretical accuracy. Comparing it to the experimental $ZH/WH$ cross-section ratio should allow to probe for New Physics in the $gg\to ZH$ component at the HL-LHC. We consider typical BSM scenarios in order to exemplify the effect they would have on the proposed observable.Comment: 22 pages, 10 figures. v2: Minor changes; matches published versio

The light CP-even MSSM Higgs mass resummed to fourth logarithmic order

We present the calculation of the light neutral CP-even Higgs mass in the MSSM for a heavy SUSY spectrum by resumming enhanced terms through fourth logarithmic order (N$^3$LL), keeping terms of leading order in the top Yukawa coupling $\alpha_t$, and NNLO in the strong coupling $\alpha_s$. To this goal, the three-loop matching coefficient for the quartic Higgs coupling of the SM to the MSSM is derived to order $\alpha_t^2\alpha_s^2$ by comparing the perturbative EFT to the fixed-order expression for the Higgs mass. The new matching coefficient is made available through an updated version of the program Himalaya. Numerical effects of the higher-order resummation are studied using specific examples, and sources of theoretical uncertainty on this result are discussed.Comment: 26 pages, 3 figures, matches version published in EPJ

Improved red color with cholesteric liquid crystals in Bragg reflection mode

The helical pitch of the cholesteric liquid crystal (CLC) can be adjusted to reflect the colors red, green, and blue. Additive mixing of these colors in displays results in multicolor images and it is easy to use pure primary blue and green colors, but the red color is in general very unsaturated. We show by simulations that this poor red color performance is due to reflection sidebands on the smaller wavelength side of the normal red Bragg reflection band. We discuss five approaches to improve the red color performance, namely, two types of spectral filtering (dyes or filters), a very low birefringence CLC, a gradient in the birefringence of the CLC, and the use of a bluish reflector. The two methods of spectral filtering are also experimentally tested. © 2002 Society of Photo-Optical Instrumentation Engineers

Transcriptome profiling of ontogeny in the acridid grasshopper Chorthippus biguttulus

Acridid grasshoppers (Orthoptera:Acrididae) are widely used model organisms for developmental, evolutionary, and neurobiological research. Although there has been recent influx of orthopteran transcriptomic resources, many use pooled ontogenetic stages obscuring information about changes in gene expression during development. Here we developed a de novo transcriptome spanning 7 stages in the life cycle of the acridid grasshopper Chorthippus biguttulus. Samples from different stages encompassing embryonic development through adults were used for transcriptomic profiling, revealing patterns of differential gene expression that highlight processes in the different life stages. These patterns were validated with semi-quantitative RT-PCR. Embryonic development showed a strongly differentiated expression pattern compared to all of the other stages and genes upregulated in this stage were involved in signaling, cellular differentiation, and organ development. Our study is one of the first to examine gene expression during post-embryonic development in a hemimetabolous insect and we found that only the fourth and fifth instars had clusters of genes upregulated during these stages. These genes are involved in various processes ranging from synthesis of biogenic amines to chitin binding. These observations indicate that post-embryonic ontogeny is not a continuous process and that some instars are differentiated. Finally, genes upregulated in the imago were generally involved in aging and immunity. Our study highlights the importance of looking at ontogeny as a whole and indicates promising directions for future research in orthopteran development

Cold adaptation drives population genomic divergence in the ecological specialist, Drosophila montana

Funding: UK Natural Environment Research Council (Grant Number(s): NE/L501852/1, NE/P000592/1); Academy of Finland (GrantNumber(s): 267244, 268214, 322980), Ella ja Georg Ehrnroothin Säätiö.Detecting signatures of ecological adaptation in comparative genomics is challenging, but analysing population samples with characterised geographic distributions, such as clinal variation, can help identify genes showing covariation with important ecological variation. Here, we analysed patterns of geographic variation in the cold-adapted species Drosophila montana across phenotypes, genotypes and environmental conditions and tested for signatures of cold adaptation in population genomic divergence. We first derived the climatic variables associated with the geographic distribution of 24 populations across two continents to trace the scale of environmental variation experienced by the species, and measured variation in the cold tolerance of the flies of six populations from different geographic contexts. We then performed pooled whole genome sequencing of these six populations, and used Bayesian methods to identify SNPs where genetic differentiation is associated with both climatic variables and the population phenotypic measurements, while controlling for effects of demography and population structure. The top candidate SNPs were enriched on the X and fourth chromosomes, and they also lay near genes implicated in other studies of cold tolerance and population divergence in this species and its close relatives. We conclude that ecological adaptation has contributed to the divergence of D. montana populations throughout the genome and in particular on the X and fourth chromosomes, which also showed highest interpopulation FST. This study demonstrates that ecological selection can drive genomic divergence at different scales, from candidate genes to chromosome-wide effects.Publisher PDFPeer reviewe

Higgs-mass predictions in the MSSM and beyond

Predictions for the Higgs masses are a distinctive feature of supersymmetric extensions of the Standard Model, where they play a crucial role in constraining the parameter space. The discovery of a Higgs boson and the remarkably precise measurement of its mass at the LHC have spurred new efforts aimed at improving the accuracy of the theoretical predictions for the Higgs masses in supersymmetric models. The "Precision SUSY Higgs Mass Calculation Initiative" (KUTS) was launched in 2014 to provide a forum for discussions between the different groups involved in these efforts. This report aims to present a comprehensive overview of the current status of Higgs-mass calculations in supersymmetric models, to document the many advances that were achieved in recent years and were discussed during the KUTS meetings, and to outline the prospects for future improvements in these calculations

Inter- and intra-specific genomic divergence in Drosophila montana shows evidence for cold adaptation

The genomes of species that are ecological specialists will likely contain signatures of genomic adaptation to their niche. However, distinguishing genes related to ecological specialism from other sources of selection and more random changes is a challenge. Here we describe the genome of Drosophila montana, which is the most extremely cold-adapted Drosophila species. We use branch tests to identify genes showing accelerated divergence in contrasts between cold- and warm adapted species and identify about 250 genes that show differences, possibly driven by a lower synonymous substitution rate in cold-adapted species. We look for evidence of accelerated divergence between D. montana and D. virilis, a previously sequenced relative, and do not find strong evidence for divergent selection on coding sequence variation. Divergent genes are involved in a variety of functions, including cuticular and olfactory processes. We also re-sequenced three populations of D. montana from its ecological and geographic range. Outlier loci were more likely to be found on the X chromosome and there was a greater than expected overlap between population outliers and those genes implicated in cold adaptation between Drosophila species, implying some continuity of selective process at these different evolutionary scales

Reconstructing rational functions with FireFly

We present the open-source C++ library FireFly for the reconstruction of multivariate rational functions over finite fields. We discuss the involved algorithms and their implementation. As an application, we use FireFly in the context of integration-by-parts reductions and compare runtime and memory consumption to a fully algebraic approach with the program Kira