1,015 research outputs found

    Residue theorem and summing over Kaluza-Klein excitations

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    Applying the equations of motion together with corresponding boundary conditions of bulk profiles at infrared and ultraviolet branes, we verify some lemmas on the eigenvalues of Kaluze-Klein modes in framework of warped extra dimension with the custodial symmetry SU(3)c×SU(2)L×SU(2)R×U(1)X×PLRSU(3)_c\times SU(2)_L\times SU(2)_R\times U(1)_X\times P_{LR}. Using the lemmas and performing properly analytic extensions of bulk profiles, we present the sufficient condition for a convergent series of Kaluze-Klein excitations and sum over the series through the residue theorem. The method can also be applied to sum over the infinite series of Kaluze-Klein excitations in unified extra dimension. Additional, we analyze the possible connection between the propagators in five dimensional full theory and the product of bulk profiles with corresponding propagators of exciting Kaluze-Klein modes in four dimensional effective theory, and recover some relations presented in literature for warped and unified extra dimensions respectively. As an example, we demonstrate that the corrections from neutral Higgs to the Wilson coefficients of relevant operators for BXsγB\rightarrow X_s\gamma contain the suppression factor mb3ms/mw4m_b^3m_s/m_{_{\rm w}}^4 comparing with that from other sectors, thus can be neglected safely.Comment: 44 pages, no figur

    Complexity of Government response to Covid-19 pandemic: A perspective of coupled dynamics on information heterogeneity and epidemic outbreak

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    This study aims at modeling the universal failure in preventing the outbreak of COVID-19 via real-world data from the perspective of complexity and network science. Through formalizing information heterogeneity and government intervention in the coupled dynamics of epidemic and infodemic spreading; first, we find that information heterogeneity and its induced variation in human responses significantly increase the complexity of the government intervention decision. The complexity results in a dilemma between the socially optimal intervention that is risky for the government and the privately optimal intervention that is safer for the government but harmful to the social welfare. Second, via counterfactual analysis against the COVID-19 crisis in Wuhan, 2020, we find that the intervention dilemma becomes even worse if the initial decision time and the decision horizon vary. In the short horizon, both socially and privately optimal interventions agree with each other and require blocking the spread of all COVID-19-related information, leading to a negligible infection ratio 30 days after the initial reporting time. However, if the time horizon is prolonged to 180 days, only the privately optimal intervention requires information blocking, which would induce a catastrophically higher infection ratio than that in the counter-factual world where the socially optimal intervention encourages early-stage information spread. These findings contribute to the literature by revealing the complexity incurred by the coupled infodemic-epidemic dynamics and information heterogeneity to the governmental intervention decision, which also sheds insight into the design of an effective early warning system against the epidemic crisis in the future.Comment: This version contains the full-resolution figures for the paper DOI: 10.1007/s11071-023-08427-

    Downregulation of the Adenosine A2b Receptor by RNA Interference Inhibits Hepatocellular Carcinoma Cell Growth

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    To investigate the biological effect of adenosine A2b receptor (A2bR) on the human hepatocellular carcinoma cell line HepG2, three A2bR siRNA constructs were transiently transfected into HepG2 cells. The results showed that A2bR siRNA reduced the levels of A2bR mRNA and protein. In order to further detect the function of A2bR, we established a stable hepatocellular carcinoma cell line (HepG2) expressing siRNA targeting the adenosine A2b receptor. Targeted RNAi significantly inhibited tumor cell growth in vitro, and flow cytometry (FCM) showed that significantly more cells expressing A2bR siRNA were in the G0/G1 phase compared to the untransfected group ((89.56% ± 3.15%) versus (56.19% ± 1.58%), P < 0.01). These results indicated that silencing the expression of adenosine A2b receptor in HepG2 cells can suppress cell growth effectively by blocking the cell cycle. Downregulation of adenosine A2b receptor gene expression with RNA interference could be a new approach to hepatocellular carcinoma therapy

    Branching fractions of BDX0,1(2900)B^-\to D^-X_{0,1}(2900) and their implications

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    The exotic states X0,1(2900)X_{0,1}(2900) with the quark flavor of csuˉdˉcs\bar{u}\bar{d} are recently observed in the mass spectrum of D+KD^+K^- in BDD+KB^-\to D^-D^+K^- by the LHCb collaboration. To explore the nature of X0,1(2900)X_{0,1}(2900), except for analyzing their masses and decay widths as usually did in literatures, the study of their production mechanism in BB-meson weak decays would provide another important information. The amplitude of BDX0,1B^-\to D^- X_{0,1} is non-factorizable. We consider the final-state-interaction effects and calculate them via the rescattering mechanism. The measured branching fractions of BDX0,1B^-\to D^- X_{0,1} are revealed. It is manifested by BΛcΞc()0{B}^-\to \Lambda_c^-\Xi_c^{(\prime)0} and Λb0Pc+K\Lambda_b^0\to P_c^+K^- that the rescattering mechanism can result in the relatively large branching fractions. The similar processes of BπX0,1B^-\to \pi^-X_{0,1} are also analyzed. The isospins of X0,1X_{0,1} can be investigated by BDX0,1±,0B\to DX_{0,1}^{\pm,0} decays.Comment: 12 pages, 10 figures. Version published in EPJC. Additional contributions are added in BπX0,1B\to \pi X_{0,1} in Fig.8. Numerical results of the isospin-partner processes are changed by a factor of 2 in Eqs.(12) and (13

    Polyarylether-based 2D covalent-organic frameworks with in-plane D–A structures and tunable energy levels for energy storage

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    The robust fully conjugated covalent organic frameworks (COFs) are emerging as a novel type of semi-conductive COFs for optoelectronic and energy devices due to their controllable architectures and easily tunable the highest occupied molecular orbital (HOMO) and the lowest occupied molecular orbital (LUMO) levels. However, the carrier mobility of such materials is still beyond requirements due to limited π-conjugation. In this study, a series of new polyarylether-based COFs are rationally synthesized via a direct reaction between hexadecafluorophthalocyanine (electron acceptor) and octahydroxyphthalocyanine (electron donor). These COFs have typical crystalline layered structures, narrow band gaps as low as ≈0.65 eV and ultra-low resistance (1.31 × 10−6 S cm−1). Such COFs can be composed of two different metal-sites and contribute improved carrier mobility via layer-altered staking mode according to density functional theory calculation. Due to the narrow pore size of 1.4 nm and promising conductivity, such COFs and electrochemically exfoliated graphene based free-standing films are fabricated for in-plane micro-supercapacitors, which demonstrate excellent volumetric capacitances (28.1 F cm−3) and excellent stability of 10 000 charge–discharge cycling in acidic electrolyte. This study provides a new approach toward dioxin-linked COFs with donor-acceptor structure and easily tunable energy levels for versatile energy storage and optoelectronic device
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