4,493 research outputs found

    Central-edge asymmetry as a probe of Higgs-top coupling in ttˉht\bar{t}h production at LHC

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    The Higgs-top coupling plays a central role in the hierarchy problem and the vacuum stability of the Standard Model (SM). We propose a central-edge asymmetry (ACEA_{CE}) to probe the CP violating Higgs-top coupling in dileptonic channel of ttˉh(→bbˉ)t\bar{t}h(\to b\bar{b}) production at the LHC. We demonstrate that the CP-violating Higgs-top coupling can affect the central-edge asymmetry through distorting Δyℓ+ℓ−\Delta y_{\ell^+\ell^-} distribution because of the contribution of new top charge asymmetric term. Since Δyℓ+ℓ−\Delta y_{\ell^+\ell^-} distribution is frame-independent and has a good discrimination even in boosted regime, we use the jet substructure technique to enhance the observability of the dileptonic channel of ttˉht\bar{t}h production. We find that (1) the significance of dileptonic channel of ttˉht\bar{t}h production can reach 5σ5\sigma for CP phase ξ=0,π/4,π/2\xi=0,\pi/4,\pi/2 when the luminosity L=795,993,1276{\cal L}=795,993,1276 fb−1^{-1} at 14 TeV LHC. (2) the central-edge asymmetry ACEA_{CE} show a good discrimination power of CP phase of ttˉht\bar{t}h interaction, which are -40.26\%, -26.60\%, -9.47\% for ξ=0\xi=0, π/4\pi/4, π/2 \pi/2 respectively and are hardly affected by the event selections. Besides, by performing the binned-χ2\chi^2 analysis of Δyℓ+ℓ−\Delta y_{\ell^+\ell^-} distribution, we find that the scalar and pseudo-scalar interactions can be distinguished at 95\% C.L. level at 14 TeV HL-LHC.Comment: minor changes, version accepted by PL

    Brain regions and cell type specific Wnt signalling changes in Parkinson’s disease mouse models

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    Parkinson’s disease (PD) is a late onset neurodegenerative disease characterised by the loss of dopaminergic neurons with motor and cognitive symptoms. Different mutations have been identified as a risk factor or direct cause of the disease. LRRK2 gene mutation is a major cause of sporadic and inherited Parkinson’s disease (PD), but the exact mechanism of how LRRK2 mutation causes PD remains to be revealed. LRRK2 is a huge complex protein with both GTPase and Kinase domains. G2019S is the most common LRRK2 mutation on the kinase domain. There is accumulate evidence showing LRRK2 as a scaffolding protein interacts with canonical and noncanonical Wnt signalling pathways. These pathways play an important role on immune responses, nerves system development as well as neuronal maintenance./ This project aims to study how LRRK2 influence Wnt signalling pathways activities, we used LRRK2 wild type (WT), LRRK2 knock-out (KO) and G2019S knock-in (KI) mouse models in the project. We identified the brain regions with Wnt and NFAT signalling activities by applying biosensor system via lentiviral construct transduction into the brain at P0 and investigated the signalling activation by immunohistochemistry at 6 months old. We discovered LRRK2 KO and G2019S KI alter Wnt signalling activity in several brain regions including the PD important striatum. mRNA and protein expression level analysis in selected brain regions showed a region specific dysregulation of Wnt signalling cascade components, the dysregulation was differed between male and female mice./ We discovered Wnt and NFAT signalling activity might be higher in glial cells than neurons in primary culture experiment, which lead us to put our focus on astrocytes. LRRK2 KO and G2019S mutation caused changes in Wnt and NFAT signalling activities in astrocytes under basal and stimulated conditions. These differences were reflected in mRNA expression levels of signalling mediators./ Taken together, these data suggest astrocytes might hold a key insight towards a better understanding of the correlation between Wnt signalling dysregulation and PD progression

    A Visualization System for Hexahedral Mesh Quality Study

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    In this paper, we introduce a new 3D hex mesh visual analysis system that emphasizes poor-quality areas with an aggregated glyph, highlights overlapping elements, and provides detailed boundary error inspection in three forms. By supporting multi-level analysis through multiple views, our system effectively evaluates various mesh models and compares the performance of mesh generation and optimization algorithms for hexahedral meshes.Comment: Accepted by IEEE VIS 2023 Short Papers and will be published on IEEE Xplore. Paper contains 4 pages, and 1 reference page. Supplemental includes 4 page

    Dynamic 3D shape measurement based on the phase-shifting moir\'e algorithm

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    In order to increase the efficiency of phase retrieval,Wang proposed a high-speed moire phase retrieval method.But it is used only to measure the tiny object. In view of the limitation of Wang method,we proposed a dynamic three-dimensional (3D) measurement based on the phase-shifting moire algorithm.First, four sinusoidal fringe patterns with a pi/2 phase-shift are projected on the reference plane and acquired four deformed fringe patterns of the reference plane in advance. Then only single-shot deformed fringe pattern of the tested object is captured in measurement process.Four moire fringe patterns can be obtained by numerical multiplication between the the AC component of the object pattern and the AC components of the reference patterns respectively. The four low-frequency components corresponding to the moire fringe patterns are calculated by the complex encoding FT (Fourier transform) ,spectrum filtering and inverse FT.Thus the wrapped phase of the object can be determined in the tangent form from the four phase-shifting moire fringe patterns using the four-step phase shifting algorithm.The continuous phase distribution can be obtained by the conventional unwrapping algorithm. Finally, experiments were conducted to prove the validity and feasibility of the proposed method. The results are analyzed and compared with those of Wang method, demonstrating that our method not only can expand the measurement scope, but also can improve accuracy.Comment: 14 pages,5 figures. ams.or

    Probing WL′WHW^\prime_L WH and WR′WHW^\prime_R W H Interaction at LHC

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    Many new physics models predict the existence of TeV-scale charged gauge boson W′W^\prime together with Higgs boson(s). We study the W′WHW^\prime WH interaction and explore the angular distribution of charged lepton to distinguish WR′WHW_R^\prime WH from WL′WHW_L^\prime WH in pp→HW→bbˉlνpp\to HW\to b \bar b l \nu process at the LHC. It is found that a new type forward-backward asymmetry(AFBA_{FB}) relating to the angle between the direction of the charged lepton in WW rest frame and that of the reconstructed W′W^\prime in laboratory frame is useful to investigate the properties of W′WHW^\prime W H interaction. We analyze the Standard Model backgrounds and develop a set of cuts to highlight the signal and suppress the backgrounds at LHC. We find that AFBA_{FB} can reach 0.03(-0.07) for WR′W_R^\prime(WL′W_L^\prime) production at S=14\sqrt{S}=14 TeV

    Natural constraints on the gluon-quark vertex

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    In principle, the strong-interaction sector of the Standard Model is characterised by a unique renormalisation-group-invariant (RGI) running interaction and a unique form for the dressed--gluon-quark vertex, Γμ\Gamma_\mu; but, whilst much has been learnt about the former, the latter is still obscure. In order to improve this situation, we use a RGI running-interaction that reconciles both top-down and bottom-up analyses of the gauge sector in quantum chromodynamics (QCD) to compute dressed-quark gap equation solutions with 1,660,000 distinct Ansaetze for Γμ\Gamma_\mu. Each one of the solutions is then tested for compatibility with three physical criteria and, remarkably, we find that merely 0.55% of the solutions survive the test. Plainly, therefore, even a small selection of observables places extremely tight bounds on the domain of realistic vertex Ansaetze. This analysis and its results should prove useful in constraining insightful contemporary studies of QCD and hadronic phenomena.Comment: 6 pages, 7 figure

    Phase diagram and critical endpoint for strongly-interacting quarks

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    We introduce a method based on the chiral susceptibility, which enables one to draw a phase diagram in the chemical-potential/temperature plane for strongly-interacting quarks whose interactions are described by any reasonable gap equation, even if the diagrammatic content of the quark-gluon vertex is unknown. We locate a critical endpoint (CEP) at (\mu^E,T^E) ~ (1.0,0.9)T_c, where T_c is the critical temperature for chiral symmetry restoration at \mu=0; and find that a domain of phase coexistence opens at the CEP whose area increases as a confinement length-scale grows.Comment: 4 pages, 3 figure
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