Probing Exotic Charged Higgs Decays in the Type-II 2HDM through Top Rich Signal at a Future 100 TeV pp Collider

The exotic decay modes of non-Standard Model Higgs bosons are efficient in probing the hierarchical Two Higgs Doublet Models (2HDM). In particular, the decay mode $H^\pm\to HW^\pm$ serves as a powerful channel in searching for charged Higgses. In this paper, we analyzed the reach for $H^\pm\to HW^\pm \to t\bar{t}W$ at a 100 TeV $pp$ collider, and showed that it extends the reach of the previously studied $\tau\tau W$ final states once above the top threshold. Top tagging technique is used, in combination with the boosted decision tree classifier. Almost the entire hierarchical Type-II 2HDM parameter space can be probed via the combination of all channels at low $\tan\beta$ region.Comment: 17 page

Light Scalars at FASER

FASER, the ForwArd Search ExpeRiment, is a currently operating experiment at the Large Hadron Collider (LHC) that can detect light long-lived particles produced in the forward region of the LHC interacting point. In this paper, we study the prospect of detecting light CP-even and CP-odd scalars at FASER and FASER 2. Considering a model-independent framework describing the most general interactions between a CP-even or CP-odd scalar and SM particles using the notation of coupling modifiers in the effective Lagrangian, we develop the general formalism for the scalar production and decay. We then analyze the FASER and FASER 2 reaches of light scalars in the large $\tan\beta$ region of the Type-I two Higgs double model as a case study, in which light scalars with relatively long lifetime could be accommodated. In the two benchmark scenarios we considered, the light (pseudo)scalar decay length varies in $(10^{-8}, 10^5)$ meters. Both FASER and FASER 2 can probe a large part of the parameter space in the large $\tan\beta$ region up to $10^5$, extending beyond the constraints of the other existing experiments.Comment: 37 pages, 6 figure

Size-scaling effects for microparticles and cells manipulated by optoelectronic tweezers

In this work, we investigated the use of optoelectronic tweezers (OET) to manipulate objects that are larger than those commonly positioned with standard optical tweezers. We studied the forces that could be produced on differently sized polystyrene microbeads and MCF-7 breast cancer cells with light-induced dielectrophoresis (DEP). It was found that the DEP force imposed on the bead/cell did not increase linearly with the volume of the bead/cell, primarily because of the non-uniform distribution of the electric field above the OET bottom plate. Although this size-scaling work focuses on microparticles and cells, we propose that the physical mechanism elucidated in this research will be insightful for other micro-objects, biological samples, and micro-actuators undergoing OET manipulation

METHODS FOR ASSESSING STRENGTH OF HEAT EXCHANGERS WITH LIQUID METAL CARRIERS

Приведен аналитический обзор научной литературы по методам оценки прочности теплообменников с жидкометаллическими теплоносителями в результате жидкометаллического охрупчивания, водородного охрупчивания и коррозии. Выявлены ключевые проблемы в данной области, а также предложены направления будущих исследований для преодоления этих проблем. Обсуждаются новые подходы, применение которых позволит усовершенствовать методы оценки прочности и повысить надежность теплообменников с жидкометаллическими теплоносителями. В качестве ключевых направлений будущих исследований предлагаются усовершенствованные методы неразрушающего контроля, компьютерное моделирование для исследования коррозии, а также использование цифровых двойников и искусственного интеллекта.An analytical review of scientific literature on methods for assessing strength of heat exchangers with liquid metal coolants because of liquid metal embrittlement, hydrogen embrittlement and corrosion is presented. Key challenges in field are identified, and directions for future research to overcome these challenges are suggested. New approaches are discussed, use of which will improve methods for assessing strength and increase reliability of heat exchangers with liquid metal coolants. Improved non-destructive testing techniques, computer modeling for corrosion research, and the use of digital twins and artificial intelligence are suggested as key areas for future research

Manufacturing with light – micro-assembly of opto-electronic microstructures

Optical micromanipulation allows the movement and patterning of discrete micro-particles within a liquid environment. However, for manufacturing applications it is desirable to remove the liquid, leaving the patterned particles in place. In this work, we have demonstrated the use of optoelectronic tweezers (OET) to manipulate and accurately assemble Sn62Pb36Ag2 solder microspheres into tailored patterns. A technique based on freeze-drying technology was then developed that allows the assembled patterns to be well preserved and fixed in place after the liquid medium in the OET device is removed. After removing the liquid from the OET device and subsequently heating the assembled pattern and melting the solder microspheres, electrical connections between the microspheres were formed, creating a permanent conductive bridge between two isolated metal electrodes. Although this method is demonstrated with 40 µm diameter solder beads arranged with OET, it could be applied to a great range of discrete components from nanowires to optoelectronic devices, thus overcoming one of the basic hurdles in using optical micromanipulation techniques in a manufacturing micro-assembly setting

Reconfigurable multi-component micromachines driven by optoelectronic tweezers

There is great interest in the development of micromotors which can convert energy to motion in sub-millimeter dimensions. Micromachines take the micromotor concept a step further, comprising complex systems in which multiple components work in concert to effectively realize complex mechanical tasks. Here we introduce light-driven micromotors and micromachines that rely on optoelectronic tweezers (OET). Using a circular micro-gear as a unit component, we demonstrate a range of new functionalities, including a touchless micro-feed-roller that allows the programming of precise three-dimensional particle trajectories, multi-component micro-gear trains that serve as torque- or velocity-amplifiers, and micro-rack-and-pinion systems that serve as microfluidic valves. These sophisticated systems suggest great potential for complex micromachines in the future, for application in microrobotics, micromanipulation, microfluidics, and beyond

Beyond the Standard Model Higgses at Future Colliders

Motivated by several long-standing puzzles confronting the Standard Model (SM) in particle physics, many Beyond Standard Models (BSM) with extended Higgs sectors were proposed. The Two-Higgs-Doublet Model (2HDM) is a prototype model with two doublets in the Higgs sector. Other than the SM-like Higgs h, the low energy spectrum of 2HDM contains four BSM Higgs states, the neutral CP-even Higgs H, the neutral CP-odd Higgs A and a pair of charged Higgs H±. Along with the four incarnations, namely type-I, type-II, type-L and type-F, it provides rich phenomenologies for exploration. In this thesis, we explore four types of 2HDMs at several future colliders as well as the opportunities to distinguish them. Two general methods are employed: the direct search at a future 100 TeV pp collider and a multi-TeV muon collider and the indirect search at several proposed Higgs factories and Z-factories. With direct search, we study the exotic charged Higgs decay H± -> HW± in a hierarchical Type-II 2HDM at a 100 TeV pp collider and find that almost the entire space can be probed after combining with other exotic Higgs decay modes. In addition, due to the clean environment at a muon collider, it allows the probe of heavy BSM Higgses at an unprecedentedly high scale and offers remarkable chances for discrimination among the four types. With an indirect search, BSM Higgses are explored by accurately studying their corrections to the SM Higgs and Z-pole precision observables. For illustration, we study the impact on Type-I 2HDM and find the parameter space can be tightly constrained. The discovery potential and the extent to which the four types of 2HDMs could be distinguishable are also examined. We find that most of the currently allowed parameter regions permit a 5σ discovery at future Higgs factories and the four types of 2HDMs can be largely distinguishable once a 5σ discovery is made