There is a problem that semiconductor probe pin has a short lifespan. In order to solve this problem, Ti having excellent conductivity was doped to tetrahedral amorphous carbon (ta-C) having ...excellent hardness and abrasion resistance. This experiment was planned through the Taguchi robust design to determine the effect of the control factor of the ta-C:Ti coating film. The effect and contribution of control factors such as Unbalanced Magnetron Sputter(UBM) discharge current, arc discharge current, temperature, and bias voltage on ta-C:Ti characteristics were analyzed from the perspective of electrical and mechanical characteristics. The UBM discharge current was set to 4, 6, and 8 A. The main control factor of thickness and resistance is the UBM discharge current, and the thickness increased and the resistance decreased as the current increased. The decrease in resistance is due to the increase in the Ti content of the ta-C:Ti coating film. The arc discharge current was set to 60, 80, and 100 A. The main control factor of hardness and wear is the arc discharge current, and as the current rises, the hardness increases and the wear area decreases. This is due to the increased ta-C content of the ta-C:Ti coating film. Since resistance and wear are important for Probe Pin, the optimal level is set from the perspective of resistance and wear and a confirmation experiment is conducted.
This research presents tetrahedral amorphous (ta-C) coating on the artificial tooth for improving the durability and functionality (esthtics, foreign body of tooth) by filtered cathodic vacuum arc ...(FCVA). A differentiated coating method is required for a ta-C coating on polymer owing to the low melting point of the polymer, inter-facial adhesion, low friction, and non-conductivity. Herein, ta-C coating is applied below 50℃, and the potential difference of the carbon plasma drawn to the substrate was controlled by applying a positive duct bias voltage without using a substrate bias voltage. Consequently, the ta-C coating with a thickness of 70nm using the duct bias condition of 20V with the highest plasma intensity satisfies the esthetics of the artificial tooth and had a 5B level of inter-facial adhesion. In addition, the composite hardness of ta-C/polymer is 380 MPa, and correlations with esthetics, sp3 bonding, and mechanical properties. The friction coefficient (CoF) of the ta-C coating in a water-lubricated environment is 0.07, showing a six-fold reduction in CoF compared with that of a polymer.
The recent measurement of muon anomalous magnetic dipole moment (muon $g-2$)
suggests that there might exist new physics that dominantly interacts with
muons. The observed gamma-ray excess from ...Fermi-LAT indicates that dark matter
annihilates into a specific charged fermions. We propose a successful model
simultaneously to explain the Fermi-LAT GeV gamma-ray excess and sizable muon
$g-2$ with a modular $A_4$ symmetry. Due to nature of this symmetry, our DM
only interacts with pairs of muon and we explain sizable muon $g-2$ without
suffering from constraints of any lepton flavor violations. We numerically show
our allowed spaces on each measurements of Fermi-LAT, relic density of DM and
muon $g-2$, randomly scanning our input parameters.
Recently CDF II Collaboration reported that they measured W boson mass precisely. The measurement is deviated from the Standard Model (SM) Prediction at 7\(\sigma\). Also, the recent FNAL measurement ...of the muon magnetic moment shows a \(4.2\sigma\) deviation. To resolve the W boson as well as the muon \((g-2)\) anomalies, we explore the type-X two Higgs doublet model (2HDM). We analyze the \((m_A, \tan\beta)\) parameter space of the type-X 2HDM consistent with the muon \((g-2)\), lepton universality test and recent \(W\) boson mass measurments from the CDF II collaboration. We find that the measurement of the \(h\to AA\) branching ratio gives a strong lower mass bound on \(m_H\).
The Belle II collaboration recently announced that they observed the $B^+
\!\to K^+\nu\bar{\nu}$ decay process for the first time. This dineutrino mode
of $B^+ \!\to K^+\nu\bar{\nu}$ has been ...theoretically identified as a very
clean channel. However, their result encounters a $2.7{}^{}\sigma$ deviation
from the Standard Model (SM) calculation. On the other hand, last year,
Fermilab released new data on muon $g-2$ away from the SM expectation with
$5{}^{}\sigma$. In this letter, we study the simplest UV-complete
$\text{U}(1)_{\textsf{L}_\mu - \textsf{L}_\tau}^{}$-charged complex scalar Dark
Matter (DM) model. Thanks to the existence of light dark Higgs boson and light
dark photon, we can explain the observed relic density of DM and resolve the
results reported by both Belle II and Fermilab experiments simultaneously. As a
byproduct, the Hubble tension is alleviated by taking $\Delta N_\textsf{eff}^{}
\simeq 0.3$ induced by the light dark photon.
In this work, we revisit pseudo Nambu Goldstone boson (pNGB) DM model where global \(U(1)\) dark symmetry is spontaneously broken as well as explicitly with broken by with linear symmetry breaking, ...focusing on the dark matter mass range in \(500 {\rm GeV} \lesssim m_{\rm DM} \lesssim O(10)\) TeV. This model is interesting not only in its own in the context of pNGB DM, but also in the context of cosmological collider signatures from heavy particle mass regime without Boltzmann suppressions, \(H \lesssim m_{\rm heavy} \lesssim 60 H\), through the chemical potential type interaction. After imposing perturbative unitarity, perturbativity, correct thermal relic density and constraints from colliders and (in)direct detection experiments, we find that pNGB DM mass is allowed up to \(\sim 1 (10)\) TeV for the dark Higgs mass \(m_{H_2} = 1 (100)\) TeV for the Higgs-dark Higgs mixing \(\sin \theta = 0.1\). We also consider the case where global \(U(1)\) dark symmetry is not spontaneously broken, where DM is no longer pNGB. In this case, DM and dark Higgs masses are nearly degenerate in the range of a few TeV \(\lesssim m_{{\rm DM}, H_2} \lesssim \sim 70\) TeV. Low mass region for pNGB DM and \(H_2\) could be directly probed in colliders or indirect DM detections, whereas the heavy mass regime could be probed through the non-Gaussianity at the level of \(f_{\rm NL} \sim O(0.01-10)\) if \(H\) is as low as \(O(1-10)\) TeV.
Schwann cells are glial cells that are responsible for the synthesis and maintenance of the myelin sheath in the peripheral nerve system. Under pathological conditions, such as physical nerve injury ...and inflammatory neuropathies, Schwann cells undergo a substantial phenotype transformation that is not related to their intended function. For example, Schwann cells dedifferentiate into immature states and thereby cease to express myelin genes after nerve injury.
We consider the possibility that the weakly interacting massive particles produced from the evaporation of primordial black hole can explain both the relic density of dark matter and the baryon ...asymmetry of the Universe, through their annihilation which violate B and CP-symmetry. We find that the primordial black hole with mass less than \(10^7 {\rm g}\) is a good candidate as an source of TeV dark matter with the total annihilation cross section \(\left\langle\sigma_a \upsilon\right\rangle \lesssim 10^{-7} \ {\rm GeV}^{-2}\) and the B-violating scattering cross section \(\left\langle\sigma_B \upsilon\right\rangle \lesssim 2\times 10^{-9} \ {\rm GeV^{-2}}\). This large annihilation cross section of dark matter in this model would make it available to search them in the indirect search for dark matter such as gamma-ray or neutrino observations.
We consider the axion-mediated scattering processes between dark matter (DM) and nucleon. The substantial contributions are made via the CP-odd gluonic current. Since the QCD axion is too feebly ...coupled to the visible particles, non-QCD axions are necessary to accomplish the relevant sensitivity from the current DM experiments. In the case of multi-component DM models, the inelastic scattering processes also make sizable contributions to the direct detection. The supersymmetry (SUSY) and clockwork (CW) mechanism provide a realistic model for the QCD axion and the axion-mediated DM scattering processes. In the SUSY CW axion model, the lightest axino is the DM particle and the axions mediate the elastic and inelastic scattering processes between the DM axino and nucleon. We show that the current and future XENONnT can produce relevant constraints for some parameter space of the model.
The recent measurement of muon anomalous magnetic dipole moment (muon \(g-2\)) suggests that there might exist new physics that dominantly interacts with muons. The observed gamma-ray excess from ...Fermi-LAT indicates that dark matter annihilates into a specific charged fermions. We propose a successful model simultaneously to explain the Fermi-LAT GeV gamma-ray excess and sizable muon \(g-2\) with a modular \(A_4\) symmetry. Due to nature of this symmetry, our DM only interacts with pairs of muon and we explain sizable muon \(g-2\) without suffering from constraints of any lepton flavor violations. We numerically show our allowed spaces on each measurements of Fermi-LAT, relic density of DM and muon \(g-2\), randomly scanning our input parameters.
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