Characteristic length of a Holographic Superconductor with dd-wave gap

After the discovery of the $s$-wave and $p$-wave holographic superconductors, holographic models of $d$-wave superconductor have also been constructed recently. We study analytically the perturbation of the dual gravity theory to calculate the superconducting coherence length $\xi$ of the $d$-wave holographic superconductor near the superconducting phase transition point. The superconducting coherence length $\xi$ divergents as $(1-T/T_c)^{-1/2}$ near the critical temperature $T_c$. We also obtain the magnetic penetration depth $\lambda\propto(T_c-T)^{-1/2}$ by adding a small external homogeneous magnetic field. The results agree with the $s$-wave and $p$-wave models, which are also the same as the Ginzburg-Landau theory.Comment: last version, 10 pages, accepted by PR

Twin Cogenesis

We investigate a cogenesis scenario within the twin Higgs setup which can naturally explain the nature of dark matter, the cosmic coincidence puzzle, little hierarchy problem, leptogenesis and the tiny neutrino masses. Three heavy Majorana neutrinos are introduced to the standard model sector and the twin sector respectively, which explain the tiny neutrino masses and generate the lepton asymmetry and the twin lepton asymmetry at the same time. The twin cogenesis scenario is general and applies to any viable twin Higgs model without hard $\mathbb{Z}_2$ breaking and evading the $\Delta N_{\rm eff}$ constraint. We demonstrate twin cogenesis in two models: fraternal twin Higgs model, and neutrino-philic twin two Higgs doublet model, a newly proposed model to lift the twin neutrino masses with spontaneous $\mathbb{Z}_2$ breaking. The MeV scale dark photon ensures the energy in the twin sector as well as the symmetric component of twin sector particles can be depleted. The lightest twin baryons are the dark matter candidates with masses approximately 5.5~GeV, which explain naturally the amount of dark matter and visible matter in the Universe are of the same order.Comment: 28 pages, 1 figure. Revised version with updated references and minor revisio

Positivity from J-Basis Operators in the Standard Model Effective Field Theory

In the effective field theory (EFT), the positivity bound on dim-8 effective operators tells us that the $s^2$ contribution in the scattering amplitude of 2-to-2 process geometrically corresponds to the convex cone composed of the ultraviolet (UV) states as the external rays. The J-Basis method can provide a complete group theory decomposition of the scattering amplitude on the direct product of the gauge group and the Lorentz group, thus to search for all UV states. Compared to previous methods, which can only perform direct product decomposition on the gauge groups, the J-Basis method greatly improves the strictness of the restrictions and also provides a systematic scheme for calculating the positivity bounds of the dim-8 operators.Comment: 49 pages, 7 figures, 15 table

A complete tree-level dictionary between simplified BSM models and SMEFT (d ≤\leq 7) operators

Finding all possible UV resonances of effective operators is an important task in the bottom-up approach of effective field theory. We present all the tree-level UV resonances for the dimension-5, -6 and -7 operators in the Standard Model effective field theory (SMEFT), and then obtain the correspondence between the UV resonances and the effective operators from the relations among their Wilson coefficients, through the functional matching and operator reduction procedure. This provides a cross-dimension UV/IR dictionary for the SMEFT at tree-level, and the methods used here, especially the on-shell construction of general UV Lagrangian and the systematic reduction of operators, are extendable for UV resonances of $d \geq 8$ operators in SMEFT and other EFTs.Comment: 55 pages, 1 figure, 12 table

Regional Climate Effects of Conversion from Grassland to Forestland in Southeastern China

The land-use and land-cover change (LUCC) is the synthetic result of natural processes and human activities; it largely depends on the surface vegetation conditions, and the mutual conversion among land cover types can accelerate or alleviate the regional and global climate changes. Aiming at analyzing the regional climatic effects of the conversion from grassland to forestland, especially in the long term perspective, we carried out the comparison simulation using the Weather Research and Forecasting (WRF) Model in Fujian province, results indicated that this conversion had a significant influence on the regional climate; the annual average temperature decreased by 0.11°C and the annual average precipitation increased by 46 mm after 11.2% of the grassland was converted into the forestland in the study area from 2000 to 2008. In the future (form 2010 to 2050), the conversion from grassland to forestland is significant under two representative concentration pathways (RCPs) (RCP6 and RCP8.5); the spatial pattern of this conversion under the two scenarios is simulated by dynamic of land system (DLS); then, the regional climate effects of the conversion are simulated using WRF model

Mortality burdens in California due to air pollution attributable to local and nonlocal emissions.

Limited research has been conducted on the contributions of local and nonlocal emission sources to ambient fine particulate matter (PM2.5) and ozone (O3) and their associated mortality. In this study, we estimated the total mortality resulting from long-term PM2.5 and O3 exposures in California in 2012 using multiple concentration response functions (CRFs) and attributed the estimated mortality to different emission groups. The point estimates of PM2.5-associated mortality in California ranged from 12,700 to 26,700, of which 53% were attributable to in-state anthropogenic emissions. Based on new epidemiological evidence, we estimated that O3 could be associated with up to 13,700 deaths from diseases of both the respiratory and cardiovascular systems in California. In addition, 75% of the ambient O3 in California was due to distant emissions outside the western United States, leading to 92% of the O3-associated mortality. Overall, distant emissions lead to greater mortality burdens of air pollution in California than local anthropogenic emissions

Passive Continuous Particle Focusing in a Microchannel with Symmetric Sharp Corner Structures

We report a continuous passive particle focusing method using a novel microchannel with symmetric sharp corners which induce curved streamlines and large centrifugal force on particles. At appropriate flow rate, the centrifugal force generated on particles exceeds the inertial lift force; particles driven by the centrifugal force migrate toward the center of the microchannel, achieving continuous particle focus-ing. With simple structure and operation, this method can be potentially used in particle focusing and ex-traction processes in a variety of lab-on-a chip applications