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Particle physics today faces the challenge of explaining the mystery of dark matter, the origin of matter over anti-matter in the Universe, the origin of the neutrino masses, the apparent fine-tuning of the electro-weak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves new physics at mass scales comparable to familiar matter, below the GeV-scale, or even radically below, down to sub-eV scales, and with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and indeed, existing data provide numerous hints for such possibility. A vibrant experimental program to discover such physics is under way, guided by a systematic theoretical approach firmly grounded on the underlying principles of the Standard Model. This document represents the report of the FIPs 2022 workshop, held at CERN between the 17 and 21 October 2022 and aims to give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs. [ABSTRACT FROM AUTHOR]

We study a simplified model of lepton-flavoured complex scalar dark matter coupling to right-handed leptons and the Higgs boson. The model is set up in the Dark Minimal Flavour Violation framework. In contrast to previous studies of similar models we consider the most general case and do not a priori constrain the hierarchy of dark matter masses and couplings in any way aside from the chosen parameter ranges. In the first part of the analysis we discuss the impact of Higgs portal interactions and the generalised mass hierarchy on the model's phenomenology. We find that they render new physics masses around the electroweak scale viable, thus qualifying this model to address the (g − 2)μ puzzle. After reviewing the current situation of the latter, we perform two combined analyses — one in which (g − 2)μ allows for significant new physics effects and one in which it does not. We find that while the latter scenario allows for a larger range of new physics scales, both scenarios are equally viable. [ABSTRACT FROM AUTHOR]

The well-known school question-joke about weighing of a kilogram of iron and a kilogram of cotton wool is considered. The correct answer takes into account the influence of Archimedean force, the the Earth's magnetic field, the gravity and the centrifugal force caused by Earth rotation. Rated assessments of these factors under some external conditions are given. On the example of this task are illustrated the possible problems of evaluating real knowledge of the student, based on the results of closed type examination tests. [ABSTRACT FROM AUTHOR]

This paper represents an effort to provide robust constraints on the galaxy–halo connection and simultaneously test the Planck ΛCDM cosmology using a fully numerical model of small-scale galaxy clustering. We explore two extensions to the standard Halo Occupation Distribution model: assembly bias, whereby halo occupation depends on both halo mass and the larger environment, and velocity bias, whereby galaxy velocities do not perfectly trace the velocity of the dark matter within the halo. Moreover, we incorporate halo mass corrections to account for the impact of baryonic physics on the halo population. We identify an optimal set of clustering measurements to constrain this "decorated" HOD model for both low- and high-luminosity galaxies in SDSS DR7. We find that, for low-luminosity galaxies, a model with both assembly bias and velocity bias provides the best fit to the clustering measurements, with no tension remaining in the fit. In this model, we find evidence for both central and satellite galaxy assembly bias at the 99% and 95% confidence levels, respectively. In addition, we find evidence for satellite galaxy velocity bias at the 99.9% confidence level. For high-luminosity galaxies, we find no evidence for either assembly bias or velocity bias, but our model exhibits significant tension with SDSS measurements. We find that all of these conclusions still stand when we include the effects of baryonic physics on the halo mass function, suggesting that the tension we find for high-luminosity galaxies may be due to a problem with our assumed cosmological model. [ABSTRACT FROM AUTHOR]

In this paper, for given mass m > 0 , we focus on the existence and nonexistence of constrained minimizers of the energy functional I (u) := a 2 ∫ R 3 | ∇ u | 2 d x + b 4 (∫ R 3 | ∇ u | 2 d x) 2 − ∫ R 3 F (u) d x on S m := { u ∈ H 1 (R 3) : ‖ u ‖ 2 2 = m } , where a , b > 0 and F satisfies the almost optimal mass subcritical growth assumptions. We also establish the relationship between the normalized ground state solutions and the ground state to the action functional I (u) − λ 2 ‖ u ‖ 2 2 . Our results extend, nontrivially, the ones in Shibata (Manuscripta Math. 143 (2014) 221–237) and Jeanjean and Lu (Calc. Var. 61 (2022) 214) to the Kirchhoff type equations, and generalize and sharply improve the ones in Ye (Math. Methods. Appl. Sci. 38 (2015) 2603–2679) and Chen et al. (Appl. Math. Optim. 84 (2021) 773–806). [ABSTRACT FROM AUTHOR]

In scale-invariant models of fundamental physics all mass scales are generated via spontaneous symmetry breaking. In this work, we study inflation in scale-invariant quadratic gravity, in which the Planck mass is generated classically by a scalar field, which evolves from an unstable fixed point to a stable one thus breaking scale-invariance. We investigate the dynamics by means of dynamical system standard techniques. By computing the spectral indices and comparing them with data, we put some constraints on the three dimensionless parameters of the theory. We show that certain regions of the parameter space will be within the range of future CMB missions like CMB-S4, LiteBIRD and STPol. The second half of the paper is dedicated to the analysis of inflationary first-order tensor perturbations and the calculation of the power spectrum of the gravitational waves. We comment on our results and compare them with the ones of mixed Starobinsky-Higgs inflation. [ABSTRACT FROM AUTHOR]

One of the key mysteries of star formation is the origin of the stellar initial mass function (IMF). The IMF is observed to be nearly universal in the Milky Way and its satellites, and significant variations are only inferred in extreme environments, such as the cores of massive elliptical galaxies and the Central Molecular Zone. In this work, we present simulations from the STARFORGE project that are the first cloud-scale radiation-magnetohydrodynamic simulations that follow individual stars and include all relevant physical processes. The simulations include detailed gas thermodynamics, as well as stellar feedback in the form of protostellar jets, stellar radiation, winds, and supernovae. In this work, we focus on how stellar radiation, winds, and supernovae impact star-forming clouds. Radiative feedback plays a major role in quenching star formation and disrupting the cloud; however, the IMF peak is predominantly set by protostellar jet physics. We find that the effect of stellar winds is minor, and supernovae 'occur too late' to affect the IMF or quench star formation. We also investigate the effects of initial conditions on the IMF. We find that the IMF is insensitive to the initial turbulence, cloud mass, and cloud surface density, even though these parameters significantly shape the star formation history of the cloud, including the final star formation efficiency. Meanwhile, the characteristic stellar mass depends weakly on metallicity and the interstellar radiation field, which essentially set the average gas temperature. Finally, while turbulent driving and the level of magnetization strongly influence the star formation history, they only influence the high-mass slope of the IMF. [ABSTRACT FROM AUTHOR]

The Higgs boson with mass mh = 126 GeV was discovered at the Large Hadron Collider in 2012. Its mass corresponds both to the Standard Model of elementary-particles physics and to the mass of the most lightweight Higgs boson in the minimal supersymmetric standard model (MSSM). In this paper, we consider MSSM that does not preserve the CP-invariance and contains a large amount of parameters to be varied. Using the experimental value of the Higgs boson mass, we obtain restrictions on the parameters of the model, determine phenomenological scenarios, and analyze possible areas of the space of parameters. [ABSTRACT FROM AUTHOR]

Problems of difference equations with jump (discontinuity) conditions have an important role for many branches of sciences. They can be used to model a wide range of real-world applications such as heating, massing in physics, bursting rhythm models in medicine, optimal control models in economics, and so on. In this paper, we consider some spectral and scattering properties of matrix difference equations with jump conditions and hyperbolic eigenparameter. Using the asymptotic behavior of Jost function, we find eigenvalues, spectral singularities, resolvent operator, and spectrum of this problem. Also, we investigate scattering matrix and get some properties of scattering matrix. Finally, we present an example about the scattering matrix and the existence of eigenvalues in special cases. [ABSTRACT FROM AUTHOR]

We examined the sensitivity of GRACE Follow‐On (GRACE‐FO) laser ranging interferometer (LRI) measurements to sub‐monthly time‐variable gravity (TVG) signals caused by transient, high‐frequency mass changes in the Earth system. GRACE‐FO LRI provides complementary inter‐satellite ranging measurements with higher precision over a wider range of frequencies than the baseline K‐band microwave ranging system. The common approach for studying mass variation relies on the inverted TVG or mascon solutions over a period of, for example, one month or 10 days which are adversely affected by temporal aliasing and/or smoothing. In this article, we present the alternative along‐orbit analysis methodology in terms of line‐of‐sight gravity difference (LGD) to fully exploit the higher precision LRI measurements for examination of sub‐monthly mass changes. The discrepancy between "instantaneous" LGD LRI observations and monthly‐mean LGD (from Level‐2 data) at satellite altitude indicates the sub‐monthly gravitational variability not captured by monthly‐mean solutions. In conjunction with the satellite ocean altimetry observations, high‐frequency non‐tidal atmosphere and ocean models, and hydrology models, we show that the LGD LRI observations detect the high‐frequency oceanic mass variability in the Argentine Basin and the Gulf of Carpentaria, and sub‐monthly variations in surface (river) water in the Amazon Basin. We demonstrate the benefits gained from repeat ground track analysis of GRACE‐FO LRI data in the case of the Amazon surface water flow. The along‐orbit analysis methodology based on LGD LRI time series presented here is especially suitable for quantifying temporal and spatial evolution of extreme, rapidly changing mass variations. Plain Language Summary: The GRACE Follow‐On (GRACE‐FO) mission, launched on 22 May 2018, is extending the legacy of GRACE by measuring time‐variable gravity field of the Earth. Temporal variation in Earth gravity field is caused by mass change on and near the Earth surface due to various processes in hydrosphere, cryosphere, solid Earth, and ocean. In addition to the Ka‐band ranging system, the GRACE‐FO satellites are also equipped with a laser ranging interferometer (LRI) which measures the inter‐satellite distance change with higher precision. When GRACE‐FO satellites fly over a mass change anomaly, the LRI measurements capture the corresponding gravitational changes at ∼500 km altitude. We directly examine the LRI gravitational measurements and show that they clearly detect the rapid mass variability associated with the high‐frequency (a) oceanic gyre in the Argentine Basin, (b) oceanic mass changes in the Gulf of Carpentaria, and (c) river water variation in the Amazon Basin. Such processes show large mass variability within a month and, thus, they cannot be adequately studied using the standard monthly‐mean data products from GRACE‐FO mission. Therefore, the presented along‐orbit analysis approach broadens the scope of geophysical applications that can be addressed by GRACE‐FO satellites data. Key Points: We present the line‐of‐sight gravity difference (LGD) gravimetric data product from GRACE Follow‐On (GRACE‐FO) inter‐satellite laser ranging measurementsLGD observations from laser ranging measurements clearly detect rapid (sub‐monthly) mass change signals in the Earth systemAlong‐orbit analysis of inter‐satellite ranging data can broaden the scope of geophysical applications from GRACE‐FO [ABSTRACT FROM AUTHOR]

In this paper, we study the Soret effect in ternary fluid mixtures of isotopic argon like atoms. Soret coefficients have been computed using non-equilibrium molecular dynamics and a theoretical approach based on our extended Prigogine model (with mass effect) and generalized to mixtures with any number of components. As is well known for binary mixture studies, the heaviest component always accumulates on the cold side whereas the lightest species accumulate on the hot side. An interesting behavior is observed for the species with the intermediate mass: it can accumulate on both sides, depending on composition and mass ratios. A simple picture can be given to understand this change of sign: the intermediate mass species can be seen as evolving in an equivalent fluid whose species mass varies with composition. An excellent prediction of all simulated data has been obtained using our model including the change of sign of the Soret coefficient for species with intermediate mass. [ABSTRACT FROM AUTHOR]

In fire resistance tests, stone wool's organic matter undergoes exothermic oxidative reactions sustained by external heat, causing mass transfer in the structure. The previous modelling attempts, lacking the mass transfer physics, fall short in predicting the temperature of high density and high organic content samples. To fill this gap in the fire engineering modelling capability, we include mass transfer in our calculation, and validate the model using experimental fire resistance data. As an alternative, we use a heat conduction -based model lacking the gas transfer but with reaction kinetics coupled to the stone wool's organic mass %. The results show that the thermal effects of the oxidative degradation can be predicted by introducing the simplified diffusion processes. The oxygen transfer and exothermic reactions depend upon the amount of organic content, and the uncertainty of temperature predictions is ± 20 % . In average, temperatures and critical times are more accurately predicted by the heat conduction model, while, the peak temperature prediction uncertainty is low ( ± 10 % ) with the multiphysics model. The uncertainty compensation method reduces the difference between the two model predictions. Nevertheless, further validation study is needed to generalize the uncertainty compensation metrics. Finally, we demonstrate how a gas flow barrier on the cold side (sandwich) can effectively reduce the peak temperature of the high organic content-stone wools. [ABSTRACT FROM AUTHOR]

• Experimental tests on hybrid rockets using paraffin wax. • Effect of the grain length on the motor performance. • Effect of the grain length on the fuel regression rate. • Effect of the grain length on the combustion stability. An experimental campaign was carried out on a hybrid rocket engine, using gaseous oxygen and paraffin wax-based fuel, to investigate the effect of fuel grain length on motor performance and internal ballistics. The results of the current work offer the reader a comprehensive overview of the pros and cons of reducing the fuel grain length and the difficulties in optimizing combustion efficiency. Steady-state numerical analyses were also performed to support the experimental findings. The motivation for the current work originates from a previous explorative test campaign performed with a 220 mm fuel grain length where only fuel-rich conditions were experienced. A trade-off analysis was carried out by introducing two additional configurations with grain lengths of 130 mm and 70 mm, since the grain length directly affects the mixture ratio and engine performance. Propellant mixing, combustion instability, entrainment, and regression rate are the main topics discussed in the paper. The results show that the reduction of the grain length increases the mixture ratio close to the optimum value, but mixing and combustion instability issues are promoted. No significant effects of the grain length on the regression rate have been found, leading to a discussion on the physics of the mass transfer mechanism of paraffin wax. [ABSTRACT FROM AUTHOR]

Optimal control strategies may efficiently manage and operate assets in contemporary oil and gas fields, lowering costs and maximizing yield. However, during this process, we encounter a traditional modeling challenge: obtaining an appropriate system representation. Concerning this task, the current research introduces a new hybrid model for simulating multi-phase mass flow in an offshore oil and gas production field. We investigate a concept based on Physics-Informed Neural Networks (PINN) to characterize the mass flow dynamics in a production wellbore. PINN models have been demonstrated as a feasible alternative for training neural networks using a small number of training data samples and estimating the parameters of physics equations that guide the underlying dynamics. The concept might provide alternatives to modeling and balancing the task of learning from physics and data in oil-gas systems. This research analyzes the performance of neural networks inspired by physics in a synthetic database constructed from the physics laws of mass conservation and conservation of momentum. After solidifying the principles, the study assessed the power of model assimilation in a real-world oilfield situation. [ABSTRACT FROM AUTHOR]

Wearable exoskeletal devices can enhance locomotor performance, but their mass results in a metabolic penalty. Previous studies have quantified the metabolic cost of running with added mass on the feet, but less is known about the effects of adding mass to the thigh and shank segments. To quantify the metabolic cost of running with additional leg mass. 15 participants (7 F, 8 M) completed treadmill running trials (3 m/s) normally and with lead mass (300–1350 g) attached to either the thigh, shank, or foot, bilaterally. We measured metabolic power using expired gas analysis. Per 1000 g of added mass per leg, gross metabolic power increased by approximately 16% (foot) and 11% (shank) for females which was slightly greater than the 11% and 8% increases for males, respectively. For thigh loading, metabolic power increased by just 4% per 1000 g in both sexes. Adding mass more distally on the leg increases the metabolic cost of running to a greater extent. For the same absolute added mass on the foot or shank, metabolic power increases more in females. • Adding mass to distal segments (foot or shank) has higher effect then proximal (thigh) on metabolic. • Females had higher increase in metabolic power compared to males for mass added at foot or shank. • Currant metabolic power predictive equations are adjusted to include, foot and shank loading. • A demonstration of these adjustments is preformed using the equations by Epstein et al. (1987) • The findings provide insights for considering the effect of the mass of wearable assistive devices. [ABSTRACT FROM AUTHOR]

Nearly a decade of collisions and a decade of analysis yield the fundamental particle's mass with the highest precision to date. [ABSTRACT FROM AUTHOR]

The physics of variable mass systems is not as widely known as it should be; the required modifications to Newton's laws and to the Euler–Lagrange equation are here outlined with a simple example of a chain lifted by a balloon. The confusion surrounding this subject is clarified, and a useful technique for avoiding the pitfalls of variable mass analysis is presented. [ABSTRACT FROM AUTHOR]

We use photometry and proper motions from Gaia DR2 to determine the blue straggler star (BSS) populations of 16 old (1–10 Gyr), nearby (d < 3500 pc) open clusters. We find that the fractional number of BSS compared to red giant branch stars increases with age, starting near zero at 1 Gyr and flattening to ∼0.35 by 4 Gyr. Fitting stellar evolutionary tracks to these BSSs, we find that their mass distribution peaks at a few tenths of a solar mass above the main-sequence turnoff. BSSs more than 0.5 M⊙ above the turnoff make up only ∼25% of the sample, and BSSs more than 1.0 M⊙ above the turnoff are rare. We compare this to Compact Object Synthesis and Monte Carlo Investigation Code population synthesis models of BSSs formed via mass transfer. We find that standard population synthesis assumptions dramatically under-produce the number of BSS in old open clusters. We also find that these models overproduce high-mass BSSs relative to lower-mass BSSs. The expected number of BSSs formed through dynamics do not fully account for this discrepancy. We conclude that in order to explain the observed BSS populations from Roche lobe overflow, mass transfer from giant donors must be more stable than assumed in canonical mass-transfer prescriptions, and including nonconservative mass transfer is important in producing realistic BSS masses. Even with these modifications, it is difficult to achieve the large number of BSSs observed in the oldest open clusters. We discuss some additional physics that may explain the large number of observed blue stragglers among old stellar populations. [ABSTRACT FROM AUTHOR]

Many elementary students have a well-known misconception that when the shape of an object changes, its weight also changes. To overcome this misconception, students need to rethink critically on their sensory judgments about shape and weight. In this viewpoint, examples of the visual illusions were introduced to let students be interested in their restriction of visual recognition. In this study, we hypothesized that discussions on the visual illusion are effective for elementary students to understand the volume and weight of objects correctly. Pre- and post-class tests showed that the students in the class who experienced the visual illusions and discussed them made significant improvements in overcoming misconception about the weight of the object [ABSTRACT FROM AUTHOR]

The binary mutual neutralization (MN) of a series of 17 cations ( O2+, NO+, NO2+, CO+, CO2+, Cl+, Cl2+, SO2+, CF3+, C2F5+, NH3+, H3+, D3+, H2O+, H3O+, ArH+, ArD+) with 3 halide anions (Cl-, Br-, I-) has been investigated in a flowing afterglow-Langmuir probe apparatus using the variable electron and neutral density attachment mass spectrometry technique. The MN rate constants of atom-atom reactions are dominated by the chemical nature of the system (i.e., the specific locations of curve crossings). As the number of atoms in the system increases, the MN rate constants become dominated instead by the physical nature of the system (e.g., the relative velocity of the reactants). For systems involving 4 or more atoms, the 300 K MN rate constants are well described by 2.7 × 10-7 μ-0.5, where the reduced mass is in Da and the resulting rate constants in cm³ s-1. An upper limit to the MN rate constants appears well described by the complex potential model described by Hickman assuming a cross-section to neutralization of 11 000 Ų at 300 K, equivalent to 3.5 × 10-7 μ-0.5. [ABSTRACT FROM AUTHOR]

The heteroepitaxial growth of ScN films was investigated on various substrates by hydride vapor phase epitaxy (HVPE). Single crystalline mirror-like ScN(100) and ScN(110) layers were successfully deposited on r- and m-plane sapphire substrates, respectively. Homogeneous stoichiometric films (N/Sc ratio 1.01±0.10) up to 40 μm in thickness were deposited. Their mosaicity drastically improved with increasing the film thickness. The band gap was determined by optical methods to be 2.06 eV. Impurity concentrations including H, C, O, Si, and Cl were investigated through energy dispersive X-ray spectrometry and secondary ion mass spectrometry. As a result, it was found that the presence of impurities was efficiently suppressed in comparison with that of HVPE-grown ScN films reported in the past, which was possible thanks to the home-designed corrosion-free HVPE reactor. Room-temperature Hall measurements indicated that the residual free electron concentrations ranged between 1018-1020 cm-3, which was markedly lower than the reported values. The carrier mobility increased monotonically with the decreasing in carrier concentration, achieving the largest value ever reported, 284 cm2V-1 s-1 at n=3.7 × 1018 cm-3. [ABSTRACT FROM AUTHOR]

It was shown recently that the Force Feedback Microscope (FFM) can avoid the jump-to-contact in Atomic force Microscopy even when the cantilevers used are very soft, thus increasing force resolution. In this letter, we explore theoretical aspects of the associated real time control of the tip position. We take into account lever parameters such as the lever characteristics in its environment, spring constant, mass, dissipation coefficient, and the operating conditions such as controller gains and interaction force. We show how the controller parameters are determined so that the FFM functions at its best and estimate the bandwidth of the system under these conditions. [ABSTRACT FROM AUTHOR]

The formation of monocarbon cluster ions has been investigated by electron ionization mass spectrometry of cold helium nanodroplets doped with nitrogen/methane mixtures. Ion yields for two groups of clusters, CHmN2+ or CHmN4+, were determined for mixtures with different molecular ratios of CH4. The possible geometrical structures of these clusters were analyzed using electronic structure computations. Little correlation between the ion yields and the associated binding energies has been observed indicating that in most cases kinetic control ismore important than thermodynamic control for forming the clusters. [ABSTRACT FROM AUTHOR]

The special mass shift coefficient and field parameter factor of four multiples, 3s4P → 3p4P°, 3s4P → 3p4D°, 3s 2D → 5p 2D°, and 3s 2P → 3p 2P°, of 14N and 15N were studied using the multi-configuration Dirac-Hartree-Fock method and the relativistic configuration interaction approach. The normal mass shifts, special mass shifts, field shifts, and isotope shifts of N(I) were derived from the theoretical calculated normal mass shift parameter, special mass shift parameter and field parameter factor, and compared with the reported experimental measurements and theoretical results. [ABSTRACT FROM AUTHOR]

It remains a major challenge to derive a theory of cloud-scale (⁠|$\lesssim100$|  pc) star formation and feedback, describing how galaxies convert gas into stars as a function of the galactic environment. Progress has been hampered by a lack of robust empirical constraints on the giant molecular cloud (GMC) lifecycle. We address this problem by systematically applying a new statistical method for measuring the evolutionary timeline of the GMC lifecycle, star formation, and feedback to a sample of nine nearby disc galaxies, observed as part of the PHANGS-ALMA survey. We measure the spatially resolved (∼100 pc) CO-to-H α flux ratio and find a universal de-correlation between molecular gas and young stars on GMC scales, allowing us to quantify the underlying evolutionary timeline. GMC lifetimes are short, typically |$10\!-\!30\,{\rm Myr}$|⁠ , and exhibit environmental variation, between and within galaxies. At kpc-scale molecular gas surface densities |$\Sigma _{\rm H_2}\ge 8\,\rm {M_\odot}\,{{\rm pc}}^{-2}$|⁠ , the GMC lifetime correlates with time-scales for galactic dynamical processes, whereas at |$\Sigma _{\rm H_2}\le 8\,\rm {M_\odot}\,{{\rm pc}}^{-2}$| GMCs decouple from galactic dynamics and live for an internal dynamical time-scale. After a long inert phase without massive star formation traced by H α (75–90 per cent of the cloud lifetime), GMCs disperse within just |$1\!-\!5\,{\rm Myr}$| once massive stars emerge. The dispersal is most likely due to early stellar feedback, causing GMCs to achieve integrated star formation efficiencies of 4–10 per cent. These results show that galactic star formation is governed by cloud-scale, environmentally dependent, dynamical processes driving rapid evolutionary cycling. GMCs and H  ii regions are the fundamental units undergoing these lifecycles, with mean separations of |$100\!-\!300\,{{\rm pc}}$| in star-forming discs. Future work should characterize the multiscale physics and mass flows driving these lifecycles. [ABSTRACT FROM AUTHOR]

Rivers are dynamical systems that are thought to evolve towards a steady-state configuration. Then, geomorphic parameters, such as channel width and slope, are constant over time. In the mathematical description of the system, the steady state corresponds to a fixed point in the dynamic equations in which all time derivatives are equal to zero. In alluvial rivers, steady state is characterized by grade. This can be expressed as a so-called order principle: an alluvial river evolves to achieve a state in which sediment transport is constant along the river channel and is equal to transport capacity everywhere. In bedrock rivers, steady state is thought to be achieved with a balance between channel incision and uplift. The corresponding order principle is the following: a bedrock river evolves to achieve a vertical bedrock incision rate that is equal to the uplift rate or base-level lowering rate. In the present work, considerations of process physics and of the mass balance of a bedrock channel are used to argue that bedrock rivers evolve to achieve both grade and a balance between channel incision and uplift. As such, bedrock channels are governed by two order principles. As a consequence, the recognition of a steady state with respect to one of them does not necessarily imply an overall steady state. For further discussion of the bedrock channel evolution towards a steady state, expressions for adjustment timescales are sought. For this, a mechanistic model for lateral erosion of bedrock channels is developed, which allows one to obtain analytical solutions for the adjustment timescales for the morphological variables of channel width, channel bed slope, and alluvial bed cover. The adjustment timescale to achieve steady cover is of the order of minutes to days, while the adjustment timescales for width and slope are of the order of thousands of years. Thus, cover is adjusted quickly in response to a change in boundary conditions to achieve a graded state. The resulting change in vertical and lateral incision rates triggers a slow adjustment of width and slope, which in turn affects bed cover. As a result of these feedbacks, it can be expected that a bedrock channel is close to a graded state most of the time, even when it is transiently adjusting its bedrock channel morphology. [ABSTRACT FROM AUTHOR]

Ultralight-axion (ULA) dark matter is one of the possible solutions to resolve small-scale problems, especially the core–cusp problem. This is because ULA dark matter can create a central soliton core in all dark matter haloes stemmed from the quantum pressure against gravity below the de Broglie wavelength, which becomes manifest on astrophysical scales with axion mass range ∼10−22 eV. In this work, we apply our non-spherical dynamical models to the kinematic data of eight classical dwarf spheroidals (dSphs) to obtain more reliable and realistic limits on ULA particle mass. This is motivated by the reasons that the light distributions of the dSphs is not spherical, nor are the shapes of dark matter haloes predicted by ULA dark matter simulations. Compared with the previous studies on ULA dark matter assuming spherical mass models, our result is less stringent than those constraints due to the uncertainties on non-sphericity. On the other hand, remarkably, we find that the dSphs would prefer to have a flattened dark matter halo rather than a spherical one; especially, Draco favours a strongly elongated dark matter halo caused naively by the assumption of a soliton-core profile. Moreover, our consequent non-spherical core profiles are much more flattened than numerical predictions based on ULA dark matter, even though there are still uncertainties on the estimation of dark matter halo structure. To alleviate this discrepancy, further understanding of baryonic and/or ULA dark matter physics on small mass scales might be needed. [ABSTRACT FROM AUTHOR]

The Circular Electron Positron Collider and the International Linear Collider are two electron-positron Higgs factories. They are designed to operate at a center-of-mass energy of 240 and 250 GeV and accumulate 5.6 and 2 a b - 1 of integrated luminosity. This paper estimates their performance on the H → τ + τ - benchmark measurement. Using the full simulation analysis, the CEPC is expected to measure the signal strength to a relative accuracy of 0.8%. Extrapolating to the ILC setup, we conclude the ILC can reach a relative accuracy of 1.1% or 1.2%, corresponding to two benchmark beam polarization setups. The physics requirement on the mass resolution of the Higgs boson with hadronic decay final states is also discussed, showing that the CEPC baseline design and reconstruction fulfill the accuracy requirement of the H → τ + τ - signal strength. [ABSTRACT FROM AUTHOR]

Large-scale galactic winds driven by stellar feedback are one phenomenon that influences the dynamical and chemical evolution of a galaxy, redistributing material throughout the circumgalatic medium. Non-thermal feedback from galactic cosmic rays (CRs) – high-energy charged particles accelerated in supernovae and young stars – can impact the efficiency of wind driving. The streaming instability limits the speed at which they can escape. However, in the presence of turbulence, the streaming instability is subject to suppression that depends on the magnetization of turbulence given by its Alfvén Mach number. While previous simulations that relied on a simplified model of CR transport have shown that super-Alfvénic streaming of CRs enhances galactic winds, in this paper we take into account a realistic model of streaming suppression. We perform three-dimensional magnetohydrodynamic simulations of a section of a galactic disc and find that turbulent damping dependent on local magnetization of turbulent interstellar medium (ISM) leads to more spatially extended gas and CR distributions compared to the earlier streaming calculations, and that scale heights of these distributions increase for stronger turbulence. Our results indicate that the star formation rate increases with the level of turbulence in the ISM. We also find that the instantaneous wind mass loading is sensitive to local streaming physics with the mass loading dropping significantly as the strength of turbulence increases. [ABSTRACT FROM AUTHOR]

We use a recently proposed metric, termed the point-to-set correlation functions, to probe the molecular weight dependence of the relevant static length scales in glass-forming oligomeric chain liquids of 4, 5, 8, and 10 repeat units. In agreement with the results for simple, monatomic fluids, we find that static length scales of the oligomers increase monotonically when the temperature is lowered towards the glass transition temperature of the fluid. More interestingly, the static length scale increases with increasing chain length. Within the bounds of error in our simulations, the static length scale appears to scale as the radius of gyration of the oligomer, but with a prefactor, which is much larger than unity and which grows with the temperature. The preceding behavior contrasts with the length scales extracted from the radial distribution function of the oligomer system, which is practically independent of the chain length. [ABSTRACT FROM AUTHOR]

M3O4 (M = Sc, Y, and La) were produced in a pulsed laser-vaporization molecular beam source and studied by mass-analyzed threshold ionization (MATI) spectroscopy and electronic structure calculations. Adiabatic ionization energies (AIEs) of the neutral clusters and vibrational frequencies of the cations were measured accurately for the first time from the MATI spectra. Five possible structural isomers of M3O4 were considered in the calculations and spectral analysis. A cage-like structure in C3v point group was identified as the most stable one. The structure is formed by fusing three M2O2 fragments together, each sharing two O-M bonds with others. The ground electronic state of the neutral clusters is 2A1 with the unpaired electron being largely a metal-based s character. Ionization of the 2A1 state yields a 1A1 ion state in a similar geometry to the neutral cluster. The AIEs of the clusters are 4.4556 (6), 4.0586(6), and 3.4750(6) eV for M = Sc, Y, and La, respectively. The observed vibrational modes of the cations include metal-oxygen stretching, metal triangle breathing, and oxygen-metal-oxygen rocking in the frequency range of 200-800 cm-1. [ABSTRACT FROM AUTHOR]

Many important processes at the microscale require far-from-equilibrium conditions to occur, as in the functioning of mesoscopic bioreactors, nanoscopic rotors, and nanoscale mass conveyors. Achieving such conditions, however, is typically based on energy inputs that strongly affect the thermal properties of the environment and the controllability of the system itself. Here, we present a general class of far-from-equilibrium processes that suppress the net thermal exchange with the environment by maintaining the Maxwell-Boltzmann velocity distribution intact. This new phenomenon, referred to as ghost equilibrium, results from the statistical cancellation of superheated and subcooled nonequilibrated degrees of freedom that are autonomously generated through a microscale energy sorting process. We provide general conditions to observe this phenomenon and study its implications for manipulating energy at the microscale. The results are applied explicitly to two mechanistically different cases, an ensemble of rotational dipoles and a gas of trapped particles, which encompass a great variety of common situations involving both rotational and translational degrees of freedom. [ABSTRACT FROM AUTHOR]

We have grown single-crystalline samples of Zn-substituted type-VIII clathrate Ba8Ga16Sn30 with n-type carriers by Sn-flux method. The actual compositions of the single crystals were found to be described as Ba8Ga15.8-2yZnySn30.2+y (y = 0 ∼ 0.54), where the charge balance is well maintained. As y goes from 0 to 0.42, the resistivity at 300 K decreases from 5.3 to 3.0 mΩ cm gradually, but the effective mass is essentially constant at 1.2 ∼ 1.5m0, indicating intact band structure near the conduction band minima upon Zn substitution for Ga. At elevated temperatures, the ambipolar effect on the thermal conductivity becomes less pronounced upon Zn doping, and the dimensionless figure of merit ZT for y = 0.07 and 0.42 remains at rather high values compared with the nondoped sample. [ABSTRACT FROM AUTHOR]

This paper is concerned with the equivalent extensional and flexural rigidities of a single layer graphene sheet by treating it as a plane lattice structure made of tightly packed carbon atoms into an array of honeycomb-shaped cells. Each carbon atom is modeled as a node with concentrated atomic mass and prescribed six degrees of freedom. The covalent bond between adjacent carbon atoms provides axial, bending, and torsional stiffness. Using the Poisson's ratio of 0.16 and thickness of 3.4 Å, the equivalent Young's moduli are found to be approximately 0.112 TPa for bending and in the range of 1.03-1.04 TPa for in-plane modes. Subsequently, the graphene structure is simulated by a classical plate with prescribed geometric and mechanical properties. The in-plane and out-of-plane free vibration analyses of the rectangular plate provide the natural frequencies and associated mode shapes. Results are compared with eigen analyses of the lattice structure model for different sizes of graphene. Examples are considered to show close agreement in the results from these two methods. Mode shapes reveal that the lattice structure model shows symmetry about the horizontal and vertical axes and also about the diagonals. [ABSTRACT FROM AUTHOR]

The infrared spectrum of mass-selected Na+-D2 complexes is recorded in the D-D stretch vibration region (2915-2972 cm-1) by detecting Na+ photofragments resulting from photo-excitation of the complexes. Analysis of the rotationally resolved spectrum confirms a T-shaped equilibrium geometry for the complex and a vibrationally averaged intermolecular bond length of 2.461 Å. The D-D stretch band centre occurs at 2944.04 cm-1, representing a -49.6 cm-1 shift from the Q1(0) transition of the free D2 molecule. Variational rovibrational energy level calculations are performed for Na+-D2 utilising an ab initio potential energy surface developed previously for investigating the Na+-H2 complex [B. L. J. Poad et al., J. Chem. Phys. 129, 184306 (2008)]. The theoretical approach predicts a dissociation energy for Na+-D2 of 923 cm-1 with respect to the Na++ D2 limit, reproduces the experimental rotational constants to within 1-2%, and gives a simulated spectrum closely matching the experimental infrared spectrum. [ABSTRACT FROM AUTHOR]

A mixture of isobutyric acid + water has an upper consolute point at 38.8 mass % isobutyric acid and temperature near 26 °C. Nickel (II) oxide dissolves in this mixture by reacting with the acid to produce water and nickel isobutyrate. The solubility of nickel (II) oxide in isobutyric acid + water has been measured as a function of temperature at compositions, 25, 38.8, and 60 mass % isobutyric acid. For values of the temperature, T, which were at least 2 K in excess of the liquid-liquid phase transition temperature, the measured values of the solubility, s, lie on a straight line when plotted in van't Hoff form with ln s versus 1/T. The slope, (∂ln s/∂(1/T)), of the line is negative indicating that the dissolution reaction is endothermic. When the temperature was within 2 K of the phase transition temperature, however, (∂ln s/∂(1/T)) diverged toward negative infinity. The principle of critical point universality predicts that when excess solid nickel (II) oxide is in dissolution equilibrium with liquid isobutyric acid + water, (∂ln s/∂(1/T)) should diverge upon approaching the consolute point along the critical isopleth at 38.8 mass % isobutyric acid. As determined by the sign of the enthalpy of solution, the sign of this divergence is expected to be negative. Not only do our experiments confirm these predictions, but they also show that identical behavior can be observed at both 25 and 60 mass % isobustyric acid, compositions which lie substantially to either side of the critical composition. [ABSTRACT FROM AUTHOR]

Re-examination of dynamical ionic polarizabilities in water solutions leads to the formulation of a solution function r(c), which combines the indices of refraction and mass densities of solutions. We show that this function should be independent of ionic concentration if the composite polarizabilities of hydrated solute clusters are constant. Using existing experimental data for a number of aqueous salt and organic solutions, we find that the r(c) function is either constant or varies linearly with concentration, in most cases with negligible slope. We use this function to compare ionic polarizabilities of crystals and aqueous solutions and to highlight how solute polarizabilities at infinite dilution scale with the electronic valence shell of cations and anions. The proposed r(c) function can be used generally to verify the consistency of experimental measurements and of simulation results, and it provides a test of assumptions in current theories of ionic polarizabilities. [ABSTRACT FROM AUTHOR]