Searching for Heavier Higgs Boson via Di-Higgs Production at LHC Run-2

The LHC discovery of a light Higgs particle $h^0$ (125GeV) opens up new prospect for searching heavier Higgs boson(s) at the LHC Run-2, which will unambiguously point to new physics beyond the standard model (SM). We study the detection of a heavier neutral Higgs boson $H^0$ via di-Higgs production channel at the LHC (14TeV), $H^0 \to h^0h^0 \to WW^*\gamma\gamma$. This directly probes the $Hhh$ cubic Higgs interaction, which exists in most extensions of the SM Higgs sector. For the decay products of final states $WW^*$, we include both pure leptonic mode $WW^* \to \ell\bar{\nu}\bar{\ell}\nu$ and semi-leptonic mode $WW^* \to q\bar{q}'\ell\nu$. We analyze signals and backgrounds by performing fast detector simulation for the full processes $pp \to H \to hh \to WW^*\gamma\gamma \to \ell\bar{\nu}\bar{\ell}\nu\gamma\gamma$ and $pp \to H \to hh \to WW^*\gamma\gamma \to \ell\nu q\bar{q}'\gamma\gamma$, over the mass range $M_H=250-600$GeV. For generic two-Higgs-doublet models (2HDM), we present the discovery reach of the heavier Higgs boson at the LHC Run-2, and compare it with the current Higgs global fit of the 2HDM parameter space.Comment: Phys.Lett.B Final Version. 16pp (9 Figs + 4 Tables). Only minor refinements, references adde

The thermal and electrical properties of the promising semiconductor MXene Hf2CO2

In this work, we investigate the thermal and electrical properties of oxygen-functionalized M2CO2 (M = Ti, Zr, Hf) MXenes using first-principles calculations. Hf2CO2 is found to exhibit a thermal conductivity better than MoS2 and phosphorene. The room temperature thermal conductivity along the armchair direction is determined to be 86.25-131.2 Wm-1K-1 with a flake length of 5-100 um, and the corresponding value in the zigzag direction is approximately 42% of that in the armchair direction. Other important thermal properties of M2CO2 are also considered, including their specific heat and thermal expansion coefficients. The theoretical room temperature thermal expansion coefficient of Hf2CO2 is 6.094x10-6 K-1, which is lower than that of most metals. Moreover, Hf2CO2 is determined to be a semiconductor with a band gap of 1.657 eV and to have high and anisotropic carrier mobility. At room temperature, the Hf2CO2 hole mobility in the armchair direction (in the zigzag direction) is determined to be as high as 13.5x103 cm2V-1s-1 (17.6x103 cm2V-1s-1), which is comparable to that of phosphorene. Broader utilization of Hf2CO2 as a material for nanoelectronics is likely because of its moderate band gap, satisfactory thermal conductivity, low thermal expansion coefficient, and excellent carrier mobility. The corresponding thermal and electrical properties of Ti2CO2 and Zr2CO2 are also provided here for comparison. Notably, Ti2CO2 presents relatively low thermal conductivity and much higher carrier mobility than Hf2CO2, which is an indication that Ti2CO2 may be used as an efficient thermoelectric material.Comment: 26 pages, 5 figures, 2 table

LHC Higgs Signatures from Topflavor Seesaw Mechanism

We study LHC Higgs signatures from topflavor seesaw realization of electroweak symmetry breaking with a minimal gauge extension SU(2) x SU(2) x U(1). This elegant renormalizable construction singles out top quark sector (instead of all other light fermions) to join the new SU(2) gauge force. It predicts extra vector-like spectator quarks (T, B), new gauge bosons (W', Z'), and a pair of neutral Higgs bosons (h, H). We demonstrate that for the lighter Higgs boson h of mass 125GeV, this model predicts modified Higgs signal rates in h --> \gamma\gamma, WW*, ZZ* channels via gluon fusions, in h --> tau tau mode via vector boson fusions, and in h --> bb mode via gauge boson associate productions. We perform a global fit for our theory by including both direct search data (LHC and Tevatron) and indirect precision constraints. We further analyze the LHC discovery potential for detecting the heavier Higgs state H.Comment: PLB published version. Only minor refinements, typos corrected, references adde

Discovering New Gauge Bosons of Electroweak Symmetry Breaking at LHC-8

We study the physics potential of the 8TeV LHC (LHC-8) to discover, during its 2012 run, a large class of extended gauge models or extra dimensional models whose low energy behavior is well represented by an SU(2)^2 x U(1) gauge structure. We analyze this class of models and find that with a combined integrated luminosity of 40-60/fb at the LHC-8, the first new Kaluza-Klein mode of the W gauge boson can be discovered up to a mass of about 370-400 GeV, when produced in association with a Z boson.Comment: PRD final version (only minor refinements showing the consistency with new LHC data), 11 pages, 5 Figs, 2 Table

Magnetic light amplification by stimulated emission of radiation in subwavelength systems of a dielectric cavity and magnetic quantum emitters

We propose a magnetic laser in a subwavelength system consisting of a high-refractive-index dielectric cavity and an active medium formed by magnetic quantum emitters. Stimulated emissions of magnetic quantum emitters induced by their coherent interactions with quantized magnetic fields of a cavity are theoretically considered. The condition to archive such a magnetic laser is obtained. Numerical results show that magnetic lasers are feasible in some realistic systems, for example, a silicon disk of high-quality whispering gallery modes with embedded emitters. Furthermore, the competitions between the electric interaction and magnetic one in terms of their Purcell factors are also considered in some magnetic laser achievable systems. In a wavelength-scale silicon block of a high-order magnetic mode, the ratio of magnetic Purcell factor to the electric one can reach more than ~10^3 large. Our results open up ways to enhanced magnetic light-matter interactions.Comment: 21 pages, 5 figure

Preparation of novel biodegradable pHEMA hydrogel for a tissue engineering scaffold by microwave-assisted polymerization

AbstractObjectiveTo prepare a novel biodegradable poly(2-hydroxyethylmethacrilate) (pHEMA) hydrogel as tissue engineering scaffold.MethodsThe pHEMA hydrogel was synthesized by microwave-assisted polymerization using 2-hydroxyethyl methacrylate (HEMA) as the raw material, potassium persulfate as the initiator, and PCLX as the cross-linking additive. The hydrogels was characterized with FTIR and NMR spectroscopy. The physical and chemical properties of the prepared hydrogel were evaluated, and its degradation performance was tested. The cytotoxicity of the optimum composite hydrogel was measured by an MTT assay to confirm the feasibility of its use in tissue engineering.ResultsThe optimum conditions under which the hydrogel was prepared by microwave-assisted polymerization are as follows: 1.5 g cross-linking additive, 0.3 g initiator, reaction temperature of 80 °C, and microwave power of 800 W. Degradation studies showed good degradation profiles with 75% in 17 days. Additionally, the hydrogels did not elicit any cytotoxic response in in vitro cytotoxic assays.ConclusionA biodegradable pHEMA hydrogel was successfully prepared by microwave-assisted polymerization, as confirmed from FTIR and NMR results. The hydrogel shows promising applications in tissue engineering, and its healing ability and biocompatibility will be evaluated in detail in the future

Thermal Conductivity Performance of Polypropylene Composites Filled with Polydopamine-Functionalized Hexagonal Boron Nitride

Mussel-inspired approach was attempted to non-covalently functionalize the surfaces of boron nitride (BN) with self-polymerized dopamine coatings in order to reduce the interfacial thermal barrier and enhance the thermal conductivity of BN-containing composites. Compared to the polypropylene (PP) composites filled with pristine BN at the same filler content, thermal conductivity was much higher for those filled with both functionalized BN (f-BN) and maleic anhydride grafted PP (PP-g-ma) due to the improved filler dispersion and better interfacial filler-matrix compatibility, which facilitated the development of more thermal paths. Theoretical models were also applied to predict the composite thermal conductivity in which the Nielsen model was found to fit well with the experimental results, and the estimated effective aspect ratio of fillers well corresponded to the degree of filler aggregation as observed in the morphological study

Summary of drug therapy to treat cognitive impairment-induced obstructive sleep apnea

Obstructive sleep apnea (OSA) is a severe sleep disorder associated with intermittent hypoxia and sleep fragmentation. Cognitive impairment is a signifi- cant and common OSA complication often described in such patients. The most commonly utilized methods in clinical OSA treatment are oral appliances and continuous positive airway pressure (CPAP). However, the current therapeutic methods for improving cognitive function could not achieve the expected efficacy in same patients. Therefore, further understanding the molecular mechanism behind cognitive dysfunction in OSA disease will provide new treatment methods and targets. This review briefly summarized the clinical manifestations of cognitive impairment in OSA disease. Moreover, the pathophysiological molecular mechanism of OSA was outlined. Our study concluded that both SF and IH could induce cognitive impairment by multiple signaling pathways, such as oxidative stress activation, inflammation, and apoptosis. However, there is a lack of effective drug therapy for cognitive impairment in OSA. Finally, the therapeutic potential of some novel compounds and herbal medicine was evaluated on attenuating cognitive impairment based on certain preclinical studies