110 research outputs found

    Design of ternary signals for MIMO identification in the presence of noise and nonlinear distortion

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    A new approach to designing sets of ternary periodic signals with different periods for multi-input multi-output system identification is described. The signals are pseudo-random signals with uniform nonzero harmonics, generated from Galois field GF(q), where q is a prime or a power of a prime. The signals are designed to be uncorrelated, so that effects of different inputs can be easily decoupled. However, correlated harmonics can be included if necessary, for applications in the identification of ill-conditioned processes. A design table is given for q les 31. An example is presented for the design of five uncorrelated signals with a common period N = 168 . Three of these signals are applied to identify the transfer function matrix as well as the singular values of a simulated distillation column. Results obtained are compared with those achieved using two alternative methods

    Role of DNA methylation in head and neck cancer

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    Head and neck cancer (HNC) is a heterogenous and complex entity including diverse anatomical sites and a variety of tumor types displaying unique characteristics and different etilogies. Both environmental and genetic factors play a role in the development of the disease, but the underlying mechanism is still far from clear. Previous studies suggest that alterations in the genes acting in cellular signal pathways may contribute to head and neck carcinogenesis. In cancer, DNA methylation patterns display specific aberrations even in the early and precancerous stages and may confer susceptibility to further genetic or epigenetic changes. Silencing of the genes by hypermethylation or induction of oncogenes by promoter hypomethylation are frequent mechanisms in different types of cancer and achieve increasing diagnostic and therapeutic importance since the changes are reversible. Therefore, methylation analysis may provide promising clinical applications, including the development of new biomarkers and prediction of the therapeutic response or prognosis. In this review, we aimed to analyze the available information indicating a role for the epigenetic changes in HNC

    Search for an invisible muon philic scalar X0X_{0} or vector X1X_{1} via J/ψμ+μ+invisibleJ/\psi\to\mu^+\mu^-+\rm{invisible} decay at BESIII

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    A light scalar X0X_{0} or vector X1X_{1} particles have been introduced as a possible explanation for the (g2)μ(g-2)_{\mu} anomaly and dark matter phenomena. Using (8.998±0.039)×109(8.998\pm 0.039)\times10^9 \jpsi events collected by the BESIII detector, we search for a light muon philic scalar X0X_{0} or vector X1X_{1} in the processes J/ψμ+μX0,1J/\psi\to\mu^+\mu^- X_{0,1} with X0,1X_{0,1} invisible decays. No obvious signal is found, and the upper limits on the coupling g0,1g_{0,1}' between the muon and the X0,1X_{0,1} particles are set to be between 1.1×1031.1\times10^{-3} and 1.0×1021.0\times10^{-2} for the X0,1X_{0,1} mass in the range of 1<M(X0,1)<10001<M(X_{0,1})<1000~MeV/c2/c^2 at 90%\% confidence level.Comment: 9 pages 7 figure

    First Observation of a Three-Resonance Structure in e+ee^+e^-\rightarrow{non-open} Charm Hadrons

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    We report the measurement of the cross sections for e+ee^+e^-\rightarrow{nOCH} (nOCH stands for non-open charm hadrons) with improved precision at center-of-mass energies from 3.645 to 3.871 GeV. We observe for the first time a three-resonance structure in the energy-dependent lineshape of the cross sections, which are R(3760)\mathcal R(3760), R(3780)\mathcal R(3780) and R(3810)\mathcal R(3810) with significances of 9.4σ9.4\sigma, 15.7σ15.7\sigma, and 9.8σ9.8\sigma, respectively. The R(3810)\mathcal R(3810) is observed for the first time. We found two solutions in analysis of the cross sections. For solution I [solution II], we measure the mass, the total width and the product of electronic width and nOCH decay branching fraction to be (3805.8±1.1±2.7)(3805.8 \pm 1.1 \pm 2.7) [(3805.8±1.1±2.7)(3805.8 \pm 1.1 \pm 2.7)] MeV/c2c^2, (11.6±2.6±1.9)(11.6 \pm 2.6 \pm 1.9) [(11.5±2.5±1.8)(11.5 \pm 2.5 \pm 1.8)] MeV, and (10.8±3.2±2.3)(10.8\pm 3.2\pm 2.3) [(11.0±2.9±2.4)(11.0\pm 2.9\pm 2.4)] eV for the R(3810)\mathcal R(3810), respectively. In addition, we measure the branching fractions B(R(3760){\mathcal B}({\mathcal R}(3760)\rightarrow{nOCH})=(24.5±13.4±27.4)%[(6.8±5.4±7.6)%])=(24.5 \pm 13.4 \pm 27.4)\% [(6.8 \pm 5.4 \pm 7.6)\%] for the first time, and B(R(3780){\mathcal B}(\mathcal R(3780)\rightarrow{nOCH})=(11.6±5.8±7.8)%[(10.3±4.5±6.9)%])=(11.6 \pm 5.8 \pm 7.8)\% [(10.3 \pm 4.5 \pm 6.9)\%]. Moreover, we determine the open-charm (OC) branching fraction B(R{\mathcal B}({\mathcal R}(3760)(3760)\rightarrow{OC})=(75.5±13.4±27.4)%[(93.2±5.4±7.6)%])=(75.5 \pm 13.4 \pm 27.4)\% [(93.2 \pm 5.4 \pm 7.6)\%], which supports the interpretation of R(3760)\mathcal R(3760) as an OC pair molecular state, but contained a simple four-quark state component. The first uncertainties are from fits to the cross sections, and the second are systematic

    Measurement of the e+eKS0KL0π0e^{+}e^{-} \to K_{S}^{0} K_{L}^{0} \pi^{0} cross sections from s=\sqrt{s}= 2.000 to 3.080 GeV

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    Based on e+ee^{+}e^{-} collision data collected at center-of-mass energies from 2.000 to 3.080 GeV by the BESIII detector at the BEPCII collider, a partial wave analysis is performed for the process e+eKS0KL0π0e^{+}e^{-}\to K_{S}^{0} K_{L}^{0} \pi^{0}. The results allow the Born cross sections of the process e+eKS0KL0π0e^{+}e^{-}\to K_{S}^{0} K_{L}^{0} \pi^{0}, as well as its subprocesses e+eK(892)0Kˉe^{+}e^{-}\to K^{*}(892)^{0}\bar{K} and K2(1430)0KˉK^{*}_{2}(1430)^{0}\bar{K} to be measured. The Born cross sections for e+eKS0KL0π0e^{+}e^{-}\to K_{S}^{0} K_{L}^{0}\pi^{0} are consistent with previous measurements by BaBar and SND, but with substantially improved precision. The Born cross section lineshape of the process e+eK(892)0Kˉe^{+}e^{-}\to K^{*}(892)^{0}\bar{K} is consistent with a vector meson state around 2.2 GeV with a statistical significance of 3.2σ\sigma. A Breit-Wigner fit determines its mass as MY=(2164.1±9.6±3.1) MeV/c2M_Y=(2164.1\pm9.6\pm3.1)~{\rm{MeV}}/c^{2} and its width as ΓY=(32.4±21.1±1.5) MeV\Gamma_{Y}=(32.4\pm21.1\pm1.5)~\rm{MeV}, where the first uncertainties are statistical and the second ones are systematic, respectively

    Amplitude analysis and branching fraction measurement of the decay D+KS0π+π0π0D^{+} \to K_S^0\pi^+\pi^0\pi^0

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    Using 2.93 fb1\rm{fb}^{-1} of e+ee^+e^- collision data collected with the BESIII detector at the center-of-mass energy 3.773\,GeV, we perform the first amplitude analysis of the decay D+KS0π+π0π0D^+\to K_S^0\pi^+\pi^0\pi^0 and determine the relative magnitudes and phases of different intermediate processes. The absolute branching fraction of D+KS0π+π0π0D^+\to K_S^0\pi^+\pi^0\pi^0 is measured to be (2.888±0.058stat.±0.069syst.)%(2.888\pm0.058_{\rm stat.}\pm0.069_{\rm syst.})\%. The dominant intermediate processes are D+KS0a1(1260)+(ρ+π0)D^+\to K_S^0a_1(1260)^+(\to \rho^+\pi^0) and D+Kˉ0ρ+D^+\to \bar{K}^{*0}\rho^+, with branching fractions of (8.66±1.04stat.±1.39syst.) ⁣× ⁣103(8.66\pm1.04_{\rm stat.}\pm1.39_{\rm syst.})\!\times \!10^{-3} and (9.70±0.81stat.±0.53syst.) ⁣× ⁣103(9.70\pm0.81_{\rm stat.}\pm0.53_{\rm syst.})\!\times \!10^{-3}, respectively

    A coupled-channel analysis of the X(3872)X(3872) lineshape with BESIII data

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    We perform a study of the X(3872)X(3872) lineshape using the data samples of e+eγX(3872)e^+e^-\to\gamma X(3872), X(3872)D0Dˉ0π0X(3872)\to D^0\bar{D}^0 \pi^0 and π+πJ/ψ\pi^+\pi^- J/\psi collected with the BESIII detector. The effects of the coupled-channels and the off-shell D0D^{*0} are included in the parameterization of the lineshape. The lineshape mass parameter is obtained to be MX=(3871.63±0.130.05+0.06)M_{X}=(3871.63\pm 0.13^{+0.06}_{-0.05}) MeV. Two poles are found on the first and second Riemann sheets corresponding to the D0Dˉ0D^{*0}\bar{D}^0 branch cut. The pole location on the first sheet is much closer to the D0Dˉ0D^{*0}\bar{D}^0 threshold than the other, and is determined to be 7.04±0.150.08+0.077.04\pm0.15^{+0.07}_{-0.08} MeV above the D0Dˉ0π0D^0\bar{D}^0\pi^0 threshold with an imaginary part 0.19±0.080.19+0.14-0.19\pm0.08^{+0.14}_{-0.19} MeV

    Updated measurements of the M1 transition ψ(3686)γηc(2S)\psi(3686) \to \gamma \eta_{c}(2S) with ηc(2S)KKˉπ\eta_{c}(2S) \to K \bar{K} \pi

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    Based on a data sample of (27.08±0.14)×108 ψ(3686)(27.08 \pm 0.14 ) \times 10^8~\psi(3686) events collected with the BESIII detector at the BEPCII collider, the M1 transition ψ(3686)γηc(2S)\psi(3686) \to \gamma \eta_{c}(2S) with ηc(2S)KKˉπ\eta_{c}(2S) \to K\bar{K}\pi is studied, where KKˉπK\bar{K}\pi is K+Kπ0K^{+} K^{-} \pi^{0} or KS0K±πK_{S}^{0}K^{\pm}\pi^{\mp}. The mass and width of the ηc(2S)\eta_{c}(2S) are measured to be (3637.8±0.8(stat)±0.2(syst))(3637.8 \pm 0.8 (\rm {stat}) \pm 0.2 (\rm {syst})) MeV/c2c^{2} and (10.5±1.7(stat)±3.5(syst))(10.5 \pm 1.7 (\rm {stat}) \pm 3.5 (\rm {syst})) MeV, respectively. The product branching fraction B(ψ(3686)γηc(2S))×B(ηc(2S)KKˉπ)\mathcal{B}\left(\psi(3686) \rightarrow \gamma \eta_{c}(2 S)\right) \times \mathcal{B}(\eta_{c}(2 S) \rightarrow K \bar{K} \pi) is determined to be (0.97±0.06(stat)±0.09(syst))×105(0.97 \pm 0.06 (\rm {stat}) \pm 0.09 (\rm {syst})) \times 10^{-5}. Using BR(ηc(2S)KKˉπ)=(1.860.49+0.68)%\mathcal{BR}(\eta_{c}(2S)\to K\bar{K}\pi)=(1.86^{+0.68}_{-0.49})\%, we obtain the branching fraction of the radiative transition to be BR(ψ(3686)γηc(2S))=(5.2±0.3(stat)±0.5(syst)1.4+1.9(extr))×104\mathcal{BR}(\psi(3686) \to \gamma \eta_{c}(2S)) = (5.2 \pm 0.3 (\rm {stat}) \pm 0.5 (\rm {syst}) ^{+1.9}_{-1.4} (extr)) \times 10^{-4}, where the third uncertainty is due to the quoted BR(ηc(2S)KKˉπ)\mathcal{BR}(\eta_{c}(2S) \to K\bar{K}\pi)
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