arXiv subjects

Ning Liu

Publications and source records attributed to Ning Liu.

At least 253 records · Page 14Linked to original sources

arXiv2015

Flexible Sensory Platform Based on an Electrolyte-Gated Oxide Neuron Transistor

Inspired by the dendritic integration and spiking operation of a biological neuron, flexible oxide-based neuron transistors gated by solid-state electrolyte films are fabricated on flexible plastic substrates for biochemical sensing applications. When a quasi-static dual-gate laterally synergic sensing mode is adopted, the neuron transistor sensor shows a high pH sensitivity of ~105 mV/pH, which is higher than the Nernst limit. Our results demonstrate that single-spike dynamic mode can remarkably improve the pH sensitivity, reduce response/recover time and power consumption. We also find that appropriate depression applied on the sensing gate electrode can further enhance the pH sensitivity and reduce the power consumption. Our flexible neuron transistors provide a new-concept sensory platform for biochemical detection with high sensitivity, rapid response and ultralow power consumption.

cond-mat.mtrl-sci↗

arXiv2015

Higgs boson production and decay at $e^{+}e^{-}$ colliders as a probe of the Left-Right twin Higgs model

In the framework of the Left-Right twin Higgs (LRTH) model, we consider the constrains from the latest search for high-mass dilepton resonances at the LHC and find that the heavy neutral boson $Z_H$ is excluded with mass below 2.76 TeV. Under these constrains, we study the Higgs-Gauge coupling production processes $e^{+}e^{-}\rightarrow ZH$, $e^{+}e^{-}\rightarrow ν_{e}\bar{ν_{e}}H$ and $e^{+}e^{-}\rightarrow e^{+}e^{-}H$, top quark Yukawa coupling production process $e^{+}e^{-}\rightarrow t\bar{t}H$, Higgs self-couplings production processes $e^{+}e^{-}\rightarrow ZHH$ and $e^{+}e^{-}\rightarrow ν_{e}\bar{ν_{e}}HH$ at $e^{+}e^{-}$ colliders. Besides, we study the major decay modes of the Higgs boson, namely $h\rightarrow f\bar{f}$($f=b,c,τ$), $VV^{*}(V=W, Z)$, $gg$, $γγ$. We find that the LRTH effects are sizable so that the Higgs boson processes at $e^{+}e^{-}$ collider can be a sensitive probe for the LRTH model.

hep-ph↗

arXiv2015

Associated production of single top and Higgs at the LHC in the littlest Higgs model with T-parity

In the littlest Higgs model with T-parity (LHT), we study the $t$-channel single top production in association with a Higgs boson at 8 and 14 TeV LHC. We find that the cross section can be enhanced obviously in this model compared to the Standard Model. By performing a simple parton-level simulation through $pp\rightarrow t(\rightarrow \ell^{+}νb)h(\rightarrow b\bar{b})j$ at 14 TeV LHC, we find that the observability of the signal is promising in the favorable parameter space.

hep-ph↗

arXiv2014

Double Higgs production in the littlest Higgs Model with T-parity at high energy $e^{+}e^{-}$ Colliders

In the framework of the littlest Higgs model with T-parity(LHT), we investigate the double Higgs production processes $e^{+}e^{-}\rightarrow ZHH$ and $e^{+}e^{-}\rightarrow ν\barνHH$ at high energy $e^{+}e^{-}$ colliders. We calculate the production cross sections and find that the relative correction at the center-of-mass energy $\sqrt{s}=500$ GeV can maximally reach $-30%$ for the process $e^{+}e^{-}\rightarrow ZHH$ and $-16%$ for the process $e^{+}e^{-}\rightarrow ν\barνHH$ in the allowed parameter space, respectively. These large relative corrections can reach the detection range of the future $e^{+}e^{-}$ colliders so that they can be used to test the LHT effect. The two relevant decay modes $e^{+}e^{-}\rightarrow ZHH \rightarrow l\bar{l} b\bar{b}b\bar{b}$ and $e^{+}e^{-}\rightarrow ν\barνHH\rightarrow ν\barνb\bar{b}b\bar{b}$ are studied and some distributions of the signal and background are displayed.

hep-ph↗

arXiv2014

Impact of top-Higgs couplings on di-Higgs production at future colliders

Measuring the Higgs-self coupling is one of the most crucial goals of the future colliders, such as the LHC Run-II and the ILC-based photon collider. Since the new physics can affects the di-Higgs production not only from the Higgs self-coupling but also from the top-Higgs coupling, we investigate the di-Higgs production in the presence of the non-standard top-Higgs coupling at the LHC and ILC-based photon collider given the recent Higgs data. Due to the changed interference behaviors of the top quark loops with itself or $W$ boson loops, we find that the cross section of di-Higgs production at the LHC-14 TeV and ILC-500 GeV can be respectively enhanced up to nearly 3 and 2 times the SM predictions within 2$σ$ Higgs data allowed parameter region.

hep-ph↗

arXiv2014

Constraining Top partner and Naturalness at the LHC and TLEP

We investigate indirect constraints on the top partner within the minimal fermionic top partner model. By performing a global fit of the latest Higgs data, $B_s \to μ^+μ^-$ measurements and the electroweak precision observables we find that the top partner with the mass up to 830 GeV is excluded at $2σ$ level. Our bound on the top partner mass is much stronger than the bounds obtained from the direct searches at the LHC. Under the current constraints the fine-tuning measure is less than 9% and the branching ratio of $T \to tZ$ is bounded between 14% and 25%. We also find that precise measurements of Higgs couplings at 240 GeV TLEP will constrain the top partner mass in multi-TeV region.

hep-ph↗

arXiv2014

Revisiting Associated Production of 125 GeV Higgs Boson with a Photon at a Higgs Factory

Considering the constraints from the flavor physics, precision electroweak measurements, Higgs data and dark matter detections, we scan over the parameter space of the MSSM and calculate the cross section of $e^+e^- \to h γ$ in the allowed parameter space. Since the loop-induced gauge couplings $hγγ$ and $hZγ$ can simultaneously contribute to the process $e^+e^- \to h γ$, we find the cross section can be sizably enhanced by a light stau, maximally 1.47(1.38) times larger than the SM prediction at $\sqrt{s}=240(350)$ GeV. So with the high luminosity, the measurement of $e^+e^- \to h γ$ may be used to test the anomalous gauge couplings $hγγ$ and $hZγ$ in the MSSM at a Higgs Factory.

hep-ph↗

arXiv2014

Higgs couplings and Naturalness in the littlest Higgs model with T-parity at the LHC and TLEP

Motivated by the recent LHC Higgs data and null results in searches for any new physics, we investigate the Higgs couplings and naturalness in the littlest Higgs model with T-parity. By performing the global fit of the latest Higgs data, electroweak precise observables and $R_{b}$ measurements, we find that the scale $f$ can be excluded up to 600 GeV at $2σ$ confidence level. The expected Higgs coupling measurements at the future collider TLEP will improve this lower limit to above 3 TeV. Besides, the top parnter mass $m_{T_{+}}$ can be excluded up to 880 GeV at $2σ$ confidence level. The future HL-LHC can constrain this mass in the region $m_{T_{+}} < 2.2$ TeV corresponding to the fine-tuning being lager than 1%.

hep-ph↗

arXiv2014

Single Higgs boson production at $e^{+}e^{-}$ colliders in the Littlest Higgs Model with T-parity

In this work, we investigate the Higgs-boson production processes $e^{+}e^{-}\rightarrow ZH$, $e^{+}e^{-}\rightarrow ν_{e}\bar{ν_{e}}H$ and $e^{+}e^{-}\rightarrow e^{+}e^{-}H$ in the littlest Higgs model with T-parity. We present the production cross sections, the relative corrections and some distributions of the final states. In the allowed parameter space, we find that the relative corrections of the three production channels are negative, the relative correction of the $ZH$ production can reach $-7.5\%$ and the relative corrections of the $ν_{e}\bar{ν_{e}}H$ and $e^{+}e^{-}H$ production can both reach $-6.5\%$ for $\sqrt{s}=500$ GeV with the scale $f=$694 GeV.

hep-ph↗

arXiv2014

Full one-loop electroweak corrections to $e^+e^- \to ZHγ$ at a Higgs factory

Motivated by the future precision test of the Higgs boson at an $e^+e^-$ Higgs factory, we calculate the production $e^+e^- \to ZHγ$ in the Standard Model with complete next-to-leading order electroweak corrections. We find that for $\sqrt{s}=240$ (350) GeV the cross section of this production is sizably reduced by the electroweak corrections, which is $1.03$ (5.32) fb at leading order and 0.72 (4.79) fb at next-to-leading order. The transverse momentum distribution of the photon in the final states is also presented.

hep-ph↗

arXiv2014

Probing Light Higgsinos in Natural SUSY from Monojet Signals at the LHC

We investigate a strategy to search for light, nearly degenerate higgsinos within the natural MSSM at the LHC. We demonstrate that the higgsino mass range $μ$ in $100-150$ GeV, which is preferred by the naturalness, can be probed at $2σ$ significance through the monojet search at 14 TeV HL-LHC with 3000 fb$^{-1}$ luminosity. The proposed method can also probe certain region in the parameter space for the lightest neutralino with a high higgsino purity, that cannot be reached by planned direct detection experiments at XENON-1T(2017).

hep-ph↗

arXiv2014

Next-to-leading order QCD corrections to $HZW^{\pm}$ production at 14 TeV LHC

Since the precise study of Higgs gauge couplings is important to test the Standard Model (SM), we calculate the complete next-to-leading order QCD(NLO QCD) correction to the $pp \to HZW^{\pm}$ production in the SM at 14 TeV LHC. Our results show that the NLO QCD correction can enhance the leading-order cross section of $pp \to HZW^{\pm}$ by 45%, when $ m_H $ = 125.3 GeV. We also study the dependence of the LO and NLO corrected cross sections on the renormalization and factorization scale $μ$. Besides, due to the unbalance of parton distribution functions, we investigate the charge asymmetry of $W^{\pm}$ in the production of $pp\to HZW^{\pm}$, which can reach 32.94% for $μ=(m_H+m_Z+m_W)/2$ at 14 TeV LHC.

hep-ph↗

arXiv2014

Top Quark FCNC Decay to 125GeV Higgs boson in the Littlest Higgs Model with T-parity

Motivated by the current observation of a 125 GeV Higgs boson, we calculate $t\rightarrow cH$ and $t\rightarrow cg(γ)H$ in the unitary gauge in the littlest Higgs model with T-parity(LHT). Due to the large contribution from the new mirror fermions, we find that the branching ratios of $t\rightarrow cH$ and $t\rightarrow cgH$ can be greatly enhanced in the LHT model and maximally reach $\mathcal O(10^{-5})$ in the allowed parameter space. When the mirror fermion mass $M_3 > 2(1.5)$ TeV and the cut-off scale $f=500$ GeV, the process of $pp \to t\bar{t} \to 3b +c +\ell+ \slashed E_{T}^{miss}$ can reach $3σ$($5σ$) sensitivity at 8(14) TeV LHC with luminosity $\cal{L}$ $=20(300) fb^{-1}$.

hep-ph↗

arXiv2013

One-loop effects on top pair production in the littlest Higgs model with T-parity at the LHC

In this work, we systematically investigate the one-loop corrections to $t\bar{t}$ production in the littlest Higgs model with T-parity (LHT) at the LHC for $\sqrt{s}=8,14$ TeV. We focus on the effects of LHT particles on $t\bar{t}$ cross section, polarization asymmetries, spin correlation and charge asymmetry at the LHC. We also study the top quark forward-backward asymmetry at Tevatron and its correlations with the LHC observables. We found that: (1) the contributions of the LHT particles to $t\bar{t}$ production can only reach about 1% at the 14 TeV LHC. Meanwhile, the anomalous top quark forward-backward asymmetry at Tevatron is also hardly to be explained in the LHT model. (2) the parity violating asymmetries in $t\bar{t}$ production, such as left-right asymmetry $|A_{LR}|$ and the polarization $|P_t|$ can respectively reach 1.1% and 0.5%, which may have the potential to provide a signal of LHT at the LHC.

hep-ph↗

arXiv2013

Effect of electrode geometry on photovoltaic performance of polymer solar cells

This paper investigates the impact of electrode geometry on the performance of polymer solar cells (PSCs). Four types of negative electrodes with equal area (0.09 cm2) but different shape (round, oval, square, and triangular) are evaluated with respect to short-circuit current density, open-circuit voltage, fill factor, and power conversion efficiency of PSCs. The results show that the device with round electrodes gives the best photovoltaic performance; in contrast, the device with triangular electrodes reveals the worst properties. Maximum almost twice increase in PCE with round electrode is obtained in the devices compared with that of the triangular electrode. As a conclusion, the electrode boundary curvature has a strong influence on the performance of PSCs. The larger curvature, i.e. the sharper electrodes edge, maybe is a negative effector on exciton separation and carrier transport in PSC system.

cond-mat.mtrl-sci↗

arXiv2013

Superconductivity induced by U-doping in the SmFeAsO system

Through partial substitution of Sm by U in SmFeAsO, a different member of the family of iron-based superconductors was successfully synthesized. X-ray diffraction measurements show that the lattice constants along the a and c axes are both squeezed through U doping, indicating a successful substitution of U at the Sm site. The parent compound shows a strong resistivity anomaly near 150 K, associated with spin-density-wave instability.U doping suppresses this instability and leads to a transition to the superconducting state at temperatures up to 49 K. Magnetic measurements confirm the bulk superconductivity in this system. For the sample with a doping level of x = 0.2, the external magnetic field suppresses the onset temperature very slowly, indicating a rather high upper critical field. In addition, the Hall effect measurements show that U clearly dopes electrons into the material.

cond-mat.supr-con↗

arXiv2013

Two-Higgs-doublet model with a color-triplet scalar: a joint explanation for top quark forward-backward asymmetry and Higgs decay to diphoton

The excess of top quark forward-backward asymmetry ($A^t_{FB}$) reported by the Tevatron and the enhancement of the Higgs decay to diphoton observed by the LHC may point to a same origin of new physics. In this note we examined such anomalies in the two-Higgs-doublet model with a color-triplet scalar. We found that under current experimental constraints this model can simultaneously explain both anomalies at $1σ$ level. Also, we examined the Higgs decay $h\to Zγ$ and displayed its correlation with $h\to γγ$. We found that unlike other models, this model predicts a special correlation between $h\to Zγ$ and $h\to γγ$, i.e., the $Zγ$ rate is highly suppressed while the $γγ$ rate is enhanced. This behavior may help to distinguish this model in the future high luminosity run of the LHC.

hep-ph↗

arXiv2013

Complete one-loop effects of SUSY QCD in $b\bar{b}h$ production at the LHC under current experimental constraints

Inspired by the recent LHC Higgs data and null search results of supersymmetry (SUSY), we scan the parameter space of the Minimal Supersymmetric Standard Model (MSSM) with relatively heavy sparticles (1-3 TeV). Then in the parameter space allowed by current collider experiments and dark matter detections, we calculate the complete one-loop SUSY QCD corrections to $pp\to b\bar{b}h$ at the LHC with $\sqrt{s}=14$ TeV and obtain the following observations: (i) For the large values of $\tanβ$ and low values of $m_{A}$, the SUSY QCD effects can be quite large, which, however, have been excluded by the latest results of LHC search for $H/A \to τ^{+}τ^{-}$; (ii) For modest values of $\tanβ$ and $m_{A}$ which so far survived all experimental constraints, the SUSY QCD corrections can maximally reach about -9%.

hep-ph↗