Transverse Momentum Dependent Factorization for Quarkonium Production at Low Transverse Momentum

Quarkonium production in hadron collisions at low transverse momentum $q_\perp \ll M$ with $M$ as the quarkonium mass can be used for probing transverse momentum dependent (TMD) gluon distributions. For this purpose, one needs to establish the TMD factorization for the process. We examine the factorization at the one-loop level for the production of $\eta_c$ or $\eta_b$. The perturbative coefficient in the factorization is determined at one-loop accuracy. Comparing the factorization derived at tree level and that beyond the tree level, a soft factor is, in general, needed to completely cancel soft divergences. We have also discussed possible complications of TMD factorization of p-wave quarkonium production.Comment: Title changed in the journal, published versio

Breakdown of QCD Factorization for P-Wave Quarkonium Production at Low Transverse Momentum

Quarkonium production at low transverse momentum in hadron collisions can be used to extract Transverse-Momentum-Dependent(TMD) gluon distribution functions, if TMD factorization holds there. We show that TMD factorization for the case of P-wave quarkonium with $J^{PC}=0^{++}, 2^{++}$ holds at one-loop level, but is violated beyond one-loop level. TMD factorization for other P-wave quarkonium is also violated already at one-loop.Comment: Published version in Physics Letters B (2014), pp. 103-10

A Modified SPH Method for Dynamic Failure Simulation of Heterogeneous Material

A modified smoothed particle hydrodynamics (SPH) method is applied to simulate the failure process of heterogeneous materials. An elastoplastic damage model based on an extension form of the unified twin shear strength (UTSS) criterion is adopted. Polycrystalline modeling is introduced to generate the artificial microstructure of specimen for the dynamic simulation of Brazilian splitting test and uniaxial compression test. The strain rate effect on the predicted dynamic tensile and compressive strength is discussed. The final failure patterns and the dynamic strength increments demonstrate good agreements with experimental results. It is illustrated that the polycrystalline modeling approach combined with the SPH method is promising to simulate more complex failure process of heterogeneous materials

A novel path planning approach for smart cargo ships based on anisotropic fast marching

Path planning is an essential tool for smart cargo ships that navigate in coastal waters, inland waters or other crowded waters. These ships require expert and intelligent systems to plan safe paths in order to avoid collision with both static and dynamic obstacles. This research proposes a novel path planning approach based on the anisotropic fast marching (FM) method to specifically assist with safe operations in complex marine navigation environments. A repulsive force field is specially produced to describe the safe area distribution surrounding obstacles based on the knowledge of human. In addition, a joint potential field is created to evaluate the travel cost and a gradient descent method is used to search for appropriate paths from the start point to the end point. Meanwhile, the approach can be used to constantly optimize the paths with the help of the expert knowledge in collision avoidance. Particularly, the approach is validated and evaluated through simulations. The obtained results show that it is capable of providing a reasonable and smooth path in a crowded waters. Moreover, the ability of this approach exhibits a significant contribution to the development of expert and intelligent systems in autonomous collision avoidance

Exosomes released by granulocytic myeloid-derived suppressor cells attenuate DSS-induced colitis in mice

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Impacts of Potential China's Environmental Protection Tax Reforms on Provincial Air Pollution Emissions and Economy

China's environmental protection tax (EPT) has been implemented since the beginning of 2018 to control environmental issues (e.g., air pollution). The current EPT law indicates that tax revenues are given to provincial governments without return. However, tax revenue redistribution is the key to achieving a so‐called “double dividend”; that is, an environmental tax could benefit both the environment and economic efficiency. Based on our previous analysis of the effectiveness of the current EPT, we further explore whether the double dividend could be achieved under different tax reforms based on the multiregion and multisectoral computable general equilibrium model. We find that recycling the EPT revenue to reduce household income tax (EPT_Int) is an efficient way to achieve the double dividend, and there is no double dividend if the EPT revenue is compensated by reducing enterprise income tax (EPT_Ent) or by investing in solar power (EPT_Sol). Combining EPT_Int and EPT_Sol could be a better approach if more air pollution emissions reductions are required to achieve the national reduction targets. At the provincial level, recycling the EPT revenues to reduce household income tax could offset the negative effect of environmental tax on the economy and achieve the double dividend in all provinces, especially the provinces with higher emission intensity, such as Shanxi, Hebei, Inner Mongolia, and Guizhou Provinces. This result shows that provinces with high emission intensity may further reduce air pollutant emissions during the post‐EPT era

Analysis of the X(1835)X(1835) as a baryonium state with Bethe-Salpeter equation

In this article, we take the X(1835) as a pseudoscalar baryonium state, and calculate the mass spectrum of the baryon-antibaryon bound states $p\bar{p}$, $\Sigma\bar{\Sigma}$, $\Xi\bar{\Xi}$, and $\Lambda\bar{\Lambda}$ in the framework of the Bethe-Salpeter equation with a phenomenological potential. The numerical results indicate the $p\bar{p}$, $\Sigma\bar{\Sigma}$ and $\Xi\bar{\Xi}$ bound states maybe exist, and the $X(1835)$ can be tentatively identified as the $p\bar{p}$ bound state.Comment: 7 pages, 1 figure, published versio