The challenge of monochromatization

The FCC-ee could measure the electron Yukawa coupling in a dedicated run at $$\sim $$ ∼ 125 GeV collision energy, provided that the center-of-mass (CM) energy spread can be reduced by means of monochromatization, e.g., through introducing nonzero horizontal dispersion of opposite sign at the interaction point (IP), for the two colliding beams. If the IP dispersion is nonzero, beamstrahlung blows up the horizontal emittance, and self-consistent IP parameters need to be determined. Two configurations are being studied. The first uses crab cavities to establish effective head-on collisions. The second configuration maintains the standard FCC-ee crossing angle, which, together with the IP dispersion, introduces a correlation between the local collision energy and the longitudinal location inside the detector, thereby allowing for an integrated scan of the Higgs resonance curve. We compare both approaches.

A characterization of alternating links in thickened surfaces

We use an extension of Gordon–Litherland pairing to thickened surfaces to give a topological characterization of alternating links in thickened surfaces. If $\Sigma$ is a closed oriented surface and $F$ is a compact unoriented surface in $\Sigma \times I$ , then the Gordon–Litherland pairing defines a symmetric bilinear pairing on the first homology of $F$ . A compact surface in $\Sigma \times I$ is called definite if its Gordon–Litherland pairing is a definite form. We prove that a link $L$ in a thickened surface is non-split, alternating, and of minimal genus if and only if it bounds two definite surfaces of opposite sign.

Accumulation and diffusion of charges in kinetics of polymer electric breakdown

In this paper, the distribution in electric durability [Formula: see text] of polymers in constant electric field at low temperatures has been measured. The results of continuous experiments and experiments of field discontinuous effect on polymer samples being remained not disruptive after exposure for time equal to mean value [Formula: see text] have been compared. During the interval, we have varied the time interval, temperature [Formula: see text] and electric intensity of opposite sign [Formula: see text] according to which various degree of regeneration of polymer electric strength properties has been observed. By the degree of regeneration, relaxation time [Formula: see text] of the accumulated charges in polymers causing breakdown has been found. It is established that the process of charge diffusion, which accumulation leads to breakdown has a thermofluctuation behavior and the activation energy of given process depends on the counter field intensity magnitude.

The role of plicative structures as forecast criteria in the Alakit-Мarkhinsky field (western Yakutia)

This paper describes the tectonic features of the Alakit-Markha kimberlite field, regional factors of kimberlite magmatism control in this area, structural and tectonic preconditions for kimberlite pipe prospecting. The paper highlights kimberlite pipe formation features and the role of tectonics in this process. The most promising areas are those related to low-amplitude negative structures (e.g. depressions), especially transverse low-amplitude complications of the opposite sign for the main plicative structure: for antiforms (elevations), these are saddle-shaped depressions, and antiform elevations are for synforms (depressions).

Demographic and socio-economic shifts partly explain the Martinican nutrition transition: an analysis of 10-year health and dietary changes (2003–2013) using decomposition models

Objective: The Caribbean has seen a dramatic shift in the obesity and chronic disease prevalence over the past decades, suggesting a nutrition transition. Simultaneously, Martinique has faced a demographic transition marked by significant population ageing. We aimed to differentiate the contribution of changes in health status and dietary intakes due to shifts in demographic and socio-economic characteristics (DSEC) from that due to unobserved factors. Design: Two cross-sectional surveys conducted in 2003 (n 743) and 2013 (n 573) on representative samples were used. Dietary intakes were estimated by 24-h recalls. The contribution of changes in health status and dietary intakes due to shifts in observed DSEC was differentiated from that due to unobserved factors over a 10-year interval, using Oaxaca–Blinder decomposition models. Setting: Martinique, French region in the Caribbean. Participants: Martinican adults (≥16 years). Results: Over the study period, health status deteriorated, partly owing to shifts in DSEC, explaining 62 % of the change in the prevalence of hypertension (+13 percentage points (pp)) and 48 % of waist circumference change (+3 cm). Diet quality decreased (mean adequacy ratio –2pp and mean excess ratio + 2 pp) and energy supplied by ultra-processed food increased (+4 pp). Shifts in DSEC marginally explained some changes in dietary intakes (e.g. increased diet quality), while the changes that remained unexplained were of opposite sign, with decreased diet quality, lower fruits, tubers and fish intakes and higher energy provided by ultra-processed foods. Conclusion: Explained dietary changes were of opposite sign to nutrition transition conceptual framework, probably because unobserved drivers are in play, such as food price trends or supermarkets spread.

Spin/valley pumping of resident electrons in WSe2 and WS2 monolayers

Monolayers of transition metal dichalcogenides are ideal materials to control both spin and valley degrees of freedom either electrically or optically. Nevertheless, optical excitation mostly generates excitons species with inherently short lifetime and spin/valley relaxation time. Here we demonstrate a very efficient spin/valley optical pumping of resident electrons in n-doped WSe2 and WS2 monolayers. We observe that, using a continuous wave laser and appropriate doping and excitation densities, negative trion doublet lines exhibit circular polarization of opposite sign and the photoluminescence intensity of the triplet trion is more than four times larger with circular excitation than with linear excitation. We interpret our results as a consequence of a large dynamic polarization of resident electrons using circular light.

Relationship Between Sea Surface Temperature Anomalies In The Southwestern Atlantic Continental Shelf And Atmospheric Variability On Intraseasonal Timescales

The intraseasonal (IS) variability of the sea surface temperature (SST) in the Southwestern Atlantic Northern Argentinean Continental Shelf (SWACS NACS, 45-33°S - 70-50°W), and its relationship with that in the atmosphere, was studied for the austral warm season. SST satellite data (11-km resolution NOAA CoastWatch Program) and data of different atmospheric variables (Reanalysis1 NCEP/NCAR and ERA-Interim) were used. Data were filtered using a 10-90day filter to isolate the IS variability. A Principal Component analysis was applied then to the filtered SST anomalies (SSTA) and the activity of the leading modes was described through the corresponding temporal series. The first three modes are significant. EOF1 (25.7% of variance) exhibits SSTA of opposite sign to the north/south of 42°S. EOF2 (9.0%) and EOF3 (5.1%) are related with centers of SSTA of opposite sign located off the Uruguayan coast and in the middle shelf. Composites of SSTA and of key atmospheric variables were made considering the days in which the main modes were active. They show that the SSTA described by the three modes are associated with distinctive regional sea level pressure anomalies that, in turn, seem to be related to atmospheric Rossby wave trains extending from the Australia area towards South America. The corresponding atmospheric wave sources vary depending on the mode. These results show, therefore, that the SSTA in the SWACS NACS exhibit significant IS variability that is, in part, locally and remotely influenced by atmospheric anomalies oscillating on similar timescales. These ocean-atmosphere teleconnections could help to improve ocean predictability at those timescales in the future.

Fitting the $$ Zb\overline{b} $$ vertex in the two-Higgs-doublet model and in the three-Higgs-doublet model

We investigate the new contributions to the parameters gL and gR of the $$ Zb\overline{b} $$ Zb b ¯ vertex in a multi-Higgs-doublet model (MHDM). We emphasize that those contributions generally worsen the fit of those parameters to the experimental data. We propose a solution to this problem, wherein gR has the opposite sign from the one predicted by the Standard Model; this solution, though, necessitates light scalars and large Yukawa couplings in the MHDM.

Quasi-Dirac neutrinos in the linear seesaw model

We implement a minimal linear seesaw model (LSM) for addressing the Quasi-Dirac (QD) behaviour of heavy neutrinos, focusing on the mass regime of MN ≲ MW. Here we show that for relatively low neutrino masses, covering the few GeV range, the same-sign to opposite-sign dilepton ratio, Rℓℓ, can be anywhere between 0 and 1, thus signaling a Quasi-Dirac regime. Particular values of Rℓℓ are controlled by the width of the QD neutrino and its mass splitting, the latter being equal to the light-neutrino mass mν in the LSM scenario. The current upper bound on mν1 together with the projected sensitivities of current and future |UN ℓ|2 experimental measurements, set stringent constraints on our low-scale QD mass regime. Some experimental prospects of testing the model by LHC displaced vertex searches are also discussed.

Comparison of Dynamic Responses of Parallel-Placed Adjacent High-Rise Buildings under Wind and Earthquake Excitations

Two parallel-placed adjacent high-rise buildings are often linked to each other through passive control devices for vibration mitigation purposes. The mitigation efficiency of these control devices mainly depends on the characteristics of relative dynamic responses, namely, opposite-sign and same-sign responses of the two buildings. The present research first identifies an opposite-sign response factor to estimate the time ratio of opposite-sign responses. Subsequently, a structure comprising two adjacent high-rise buildings (with different natural frequency ratios) subjected to both wind and earthquake excitations is analyzed. Wind-induced responses are evaluated based on wind loads obtained from wind tunnel tests, while earthquake responses are determined through a suite of 44 natural ground-motion records. The results indicate that opposite-sign factors of the displacement, velocity, and acceleration responses under wind loads, especially at across-wind direction, are larger than those under earthquake excitations, and opposite-sign response factors under wind loads are insensitive to variation of the natural frequency ratio of the two adjacent buildings compared with those under earthquake excitations. The conclusions of this research may be helpful for wind-resistant and antiseismic design of parallel-placed adjacent high-rise buildings.