Low scale type II seesaw: Present constraints and prospects for displaced vertex searches

The type II seesaw mechanism is an attractive way to generate the observed light neutrino masses. It postulates a SU(2)$_\mathrm{L}$-triplet scalar field, which develops an induced vacuum expectation value after electroweak symmetry breaking, giving masses to the neutrinos via its couplings to the lepton SU(2)$_\mathrm{L}$-doublets. When the components of the triplet field have masses around the electroweak scale, the model features a rich phenomenology. We discuss the current allowed parameter space of the minimal low scale type II seesaw model, taking into account all relevant constraints, including charged lepton flavour violation as well as collider searches. We point out that the symmetry protected low scale type II seesaw scenario, where an approximate "lepton number"-like symmetry suppresses the Yukawa couplings of the triplet to the lepton doublets, is still largely untested by the current LHC results. In part of this parameter space the triplet components can be long-lived, potentially leading to a characteristic displaced vertex signature where the doubly-charged component decays into same-sign charged leptons. By performing a detailed analysis at the reconstructed level we find that already at the current run of the LHC a discovery would be possible for the considered parameter point, via dedicated searches for displaced vertex signatures. The discovery prospects are further improved at the HL-LHC and the FCC-hh/SppC.Comment: 21 pages, 10 figures, 1 tabl

Sustainable Architecture for Future High Density Cities: An Applied Design Approach

This paper presents a series of speculative, research-driven architectural design proposals addressing sustainability in the high-density urban contexts of Shanghai and Hong Kong. The projects each address specific urban problems arising from the site contexts while also developing and utilising innovative ideas generated from architectural and technological considerations. Design results include speculative mid-rise buildings that employ innovative sustainable design approaches ranging from the social to the material dimension. While findings confirm the general notion that an integrated architectural approach must address social, ecological and economic issues to ensure sustainability and viability, this paper further informs researchers as well as practitioners in the creative disciplines with regards to the short- and long-term priorities we have established amongst these issues through the discussed investigation

Explaining excesses in four-leptons at the LHC with a double peak from a CP violating Two Higgs Doublet Model

Extended scalar sectors with additional degrees of freedom appear in many scenarios beyond the Standard Model. Heavy scalar resonances that interact with the neutral current could be discovered via broad resonances in the tails of the four-lepton invariant mass spectrum, where the Standard Model background is small and well understood. In this article we consider a recent ATLAS measurement of four-lepton final states, where the data is in excess over the background for invariant masses above 500 GeV. We discuss the possibility that this excess could be interpreted as a “double peak” from the two extra heavy neutral scalars of a CP violating Two Higgs Doublet Model, both coupling to the Z boson. We apply an iterative fitting procedure to find viable model parameters that can match the excess, resulting in a benchmark point where the observed four-lepton invariant mass spectrum can be explained by two scalar particles H2 and H3, with masses of 544 GeV and 629 GeV, respectively, being admixtures of the CP eigenstates. Our explanation predicts additional production processes for tt¯, W+W−, 4b and γγ, some of which have cross sections close to the current experimental limits. Our results further imply that the electric dipole moment of the electron should be close to the present bounds

Kann künstliche Schwerkraft Bettruhe bedingten Muskelschwund an der Wade verringern?

Einleitung: Ein Aufenthalt in Schwerelosigkeit hat vielfältige Auswirkungen auf den menschlichen Körper. Um die eintretenden Effekte von Schwerelosigkeit beobachten zu können, wurde Zentrifugation genutzt, um Muskelschwund an der Wade aufgrund von Bettruhe zu untersuchen. Methoden: In der Studie wurden 24 gesunde Probanden und Probandinnen für 60 Tage in zwei Untersuchungsblöcken auf -6° zum Kopf hin geneigte Betten gelegt. Es erfolgte eine Aufteilung in drei verschiedene Gruppen. Die Probanden der Interventionsgruppe rotierten 30 Minuten ohne Unterbrechung auf einer Kurzarm-Zentrifuge mit 1 g. Die Testpersonen der Intervallgruppe wurden sechsmal fünf Minuten der Rotation ausgesetzt, die Pausen dazwischen betrugen ebenfalls fünf Minuten. Die Kontrollgruppe erfuhr keine Zentrifugation. Untersucht wurde die Änderung des Muskelvolumens anhand von MRT Bildern. Ergebnisse: 20 von 24 Probanden haben die Studie beendet. Dabei wurde bei dem M. gastrocenmius medialis (p = 0,005) und dem M. soleus (p = 0,000) eine Wirksamkeit der Intervention durch die Kurzarm-Zentrifuge festgestellt, wohingegen bei dem M. gastrocnemius lateralis (p=0,433) keine signifikante Änderung sichtbar wurde. Schlussfolgerung: Diese Arbeit hat die Auswirkungen von künstlicher Schwerkraft auf Bettruhe bedingten Muskelschwund an der Wade untersucht. Dabei konnte nur bei zwei von drei Muskeln signifikante Veränderungen des Volumens festgestellt werden

Underachievement oder: Schlaue Köpfe mit schlechten Noten:Lern- und Leistungsschwierigkeiten bei besonders begabten Kindern: Entwicklung und Evaluation von Interventionsmaßnahmen zur Verbesserung der Handlungskompetenz ; eine empirische Analyse auf der Basis von Einzelfallstudien

Begabungen können nicht immer in entsprechende Leistungen umgesetzt werden. Besondere Auswirkungen haben diese Minderleistungen häufig im schulischen Kontext bei besonders begabten SuS mit Lern- und Leistungsschwierigkeiten, den sog. Underachievern. In dieser Arbeit wird einerseits das Ziel verfolgt, eine gegenstandsbezogene Theorie zum Konstrukt Underachievement zu präzisieren und andererseits ein wirksames Training zur Intervention bei Underachievement zu entwickeln und zu überprüfen. Als Forschungsansatz wurde die Grounded Theory auf Fallstudien angewendet. Wesentliche Ergebnisse sind einerseits ein Modell, das die Einflussfaktoren auf drei Ebenen darstellt und andererseits der Nachweis der Effektivität des entwickelten Trainings, in dem u.a. ein Handlungssteuerungsmodell und ein lösungsorientierter Beratungsansatz miteinander kombiniert wurden. Das Training zeigte die größten Effekte hinsichtlich Willensstärke, Selbstmotivierung, Selbstberuhigung und Zielerreichung bei den Probanden

Fundamental bounds on qubit reset

Qubit reset is a key task in the operation of quantum devices which, for many quantum hardware platforms, presently limits device clock speed. While it is known that coupling the qubit to an ancilla on demand allows for the fastest qubit reset, the limits on reset accuracy and speed due to the choice of ancilla have not yet been identified-despite the great flexibility in device design for most quantum hardware platforms. Here, we derive bounds on qubit reset in terms of maximum fidelity and minimum time, assuming control over the qubit and no control over the ancilla. For two-level ancillas, we find a provably time-optimal protocol which consists of purity exchange between qubit and ancilla brought into resonance. The globally minimal time can only be realized for specific choices of coupling and control which we identify. When increasing the size of the ancilla Hilbert space, the maximally achievable fidelity increases, whereas the reset time remains constant. Our results translate into device design principles for realizing, in a given quantum architecture, the fastest and most accurate protocol for qubit reset

Plant diversity effects on plant longevity and their relationships to population stability in experimental grasslands

Identifying to what degree inherent characteristics of plant species and their variation in response to their environment regulate the temporal stability of plant populations is important to understand patterns of species coexistence and the stability of ecosystems. Longevity is a key characteristic of plant life history and an important component of demographic storage, but age is usually unknown for herbaceous species. In a 12-year-old biodiversity experiment (Jena Experiment) comprising 80 grassland communities with six levels of plant species richness (1, 2, 4, 8, 16 and 60 species) and four levels of functional groups richness (1, 2, 3 and 4 functional groups), we studied populations of 38 dicotyledonous forb species (N = 1,683 plant individuals). The sampled individuals represented three plant functional groups (legumes, small herbs and tall herbs) and two different growth forms (species with long-lived primary roots and clonal species with rhizomes/stolons). We assessed the age of plant individuals by means of growth ring analysis and related the age of plant populations to their temporal stability in terms of peak biomass production. On average, plant species richness did not affect the mean age of the populations or the maximum age of individuals found in a population. Age of herbs with taproots increased and age of herbs with clonal growth decreased with increasing species richness, cancelling out each other when growth forms were analysed together. Mean population age was lowest for small herbs and highest for tall herbs, while legumes had an intermediate population age. Herbs with a taproot were on average older than herbs with a rhizome. Across all species-richness levels, populations with older individuals were more stable in terms of biomass production over time. Synthesis. Our study shows for the first time across multiple species that the longevity of forbs is affected by the diversity of the surrounding plant community, and that plant longevity as an important component of demographic storage increases the temporal stability of populations of grassland forb species