Matching the Quasi Parton Distribution in a Momentum Subtraction Scheme

The quasi parton distribution is a spatial correlation of quarks or gluons along the $z$ direction in a moving nucleon which enables direct lattice calculations of parton distribution functions. It can be defined with a nonperturbative renormalization in a regularization independent momentum subtraction scheme (RI/MOM), which can then be perturbatively related to the collinear parton distribution in the $\overline{\text{MS}}$ scheme. Here we carry out a direct matching from the RI/MOM scheme for the quasi-PDF to the $\overline{\text{MS}}$ PDF, determining the non-singlet quark matching coefficient at next-to-leading order in perturbation theory. We find that the RI/MOM matching coefficient is insensitive to the ultraviolet region of convolution integral, exhibits improved perturbative convergence when converting between the quasi-PDF and PDF, and is consistent with a quasi-PDF that vanishes in the unphysical region as the proton momentum $P^z\to \infty$, unlike other schemes. This direct approach therefore has the potential to improve the accuracy for converting quasi-distribution lattice calculations to collinear distributions.Comment: 18 pages, 6 figure

Short-Term Impact of Cap-and-Trade Climate Policy and Agricultural Adjustment

Environmental Economics and Policy, International Relations/Trade,

ASSESSING THE IMPACTS OF CAP-AND-TRADE CLIMATE POLICY ON AGRICULTURAL PRODUCERS IN THE NORTHERN PLAINS: A POLICY SIMULATION WITH FARMER PREFERENCES AND ADAPTATION

The purpose of this study is to examine the possible local impacts of cap-and-trade climate policy on agricultural producers in the Northern Plains. This study explicitly considers farmer behavior with respect to agricultural opportunity in carbon offset provision and ability of adaptation to mitigate the production cost impact under a cap-and-trade climate policy. Based on empirically estimated farmer behavior models, a policy simulation with agricultural census data identifies farmer acreage enrollment in carbon offset provision, carbon offset supplies and revenues, the production cost impacts of carbon prices, and impacts on net farm income and their distributions among heterogeneous farmers. Our analysis find that: 1) farmer ex ante preferences in general are biased against participating in carbon credit programs although farmer involvement increases with carbon prices; 2) with the fertilizer industry exempted from cap-and-trade regulation, the production cost impacts would be small, and more than half of the farms or farmland would probably gain for a carbon price higher than $10 per metric ton of carbon; and 3) the production cost impacts with a capped fertilizer industry would be 2 times higher, and more than half of the farms or farmland would lose unless the carbon price could reach beyond$55 per metric ton of carbon. This study sheds some light on agricultural potential to adapt to economy-wide climate change mitigation while providing a bottom-up economic assessment of the costs and benefits of a cap-and-trade climate policy to agricultural producers in the short run.greenhouse gas, cap-and-trade, climate change, agricultural impact, economics, carbon offsets, Agricultural and Food Policy, Environmental Economics and Policy, Land Economics/Use, Resource /Energy Economics and Policy,

Producer Preference for Land-Based Biological Carbon Sequestration in Agriculture: An Economic Inquiry

This study was intended to develop an understanding of producer preference for land-based carbon sequestration in agriculture. We conducted a mail survey to elicit producer choice to provide marketable carbon offsets by participating in different carbon credit programs characterized by varying practices. Based on a quantitative analysis, we found that: 1) the market price for carbon offsets could increase producer participation in carbon sequestration; 2) producers perceived differentially different but correlated private costs for adopting carbon sequestering practices, depending on production attributes; and 3) relatively high carbon prices would be needed to stimulate producer provision of carbon offsets by land-based carbon sequestration activities. A simulation of producer choice with agricultural census data estimated potential carbon offsets supply in the Northern Great Plains region. This study contributes to the economic understanding of agricultural potential for greenhouse gas mitigation.greenhouse gas, carbon sequestration, producer stated preferences, agriculture, economics, carbon offsets, carbon markets, Agricultural and Food Policy, Environmental Economics and Policy, Farm Management, Land Economics/Use, Production Economics, Resource /Energy Economics and Policy, Q54, Q52, Q58,

Identifying the Impact of Weather Variation on Crop Yield in the Northern Plains

weather, production, crop yield, agriculture, economics, Crop Production/Industries, Land Economics/Use, Production Economics, Productivity Analysis, Resource /Energy Economics and Policy,

How Would Cap-and-Trade Climate Policy Affect Agricultural Producers in North Dakota? An Economic Analysis

The purpose of this study is to examine the possible impacts of cap-and-trade climate policy on agricultural producers in North Dakota. In this study, we focused on carbon sequestration potential and production cost impacts of carbon prices, and explicitly considered farmer preferences and adaptation behavior to estimate the benefits and costs of greenhouse gas cap-and-trade. Based on empirically estimated farmer behavior models, a policy simulation with agricultural census data identified farmer acreage allocation for carbon sequestration, carbon offset supplies and revenues, the production cost impacts of carbon prices, and impacts on net farm income and their distributions among heterogeneous farmers. Our analysis found that: 1) farmer ex ante preferences in general were biased against carbon sequestration participation although farmer involvement increased with carbon prices; 2) with the fertilizer industry exempted from cap-and-trade regulation, the production cost impact would be small, and more than half of the farms would gain with a carbon price possibly greater than $10 per metric ton of carbon; and 3) the production cost impact with a capped fertilizer industry would be 2 times higher, and more than half of the farms or farmland would lose unless the carbon price could reach more than$55 per metric ton of carbon.cap-and-trade, climate change, agricultural impacts, economics, carbon sequestration, Agricultural Finance, Financial Economics,

Assessing the Impact of Cap-and-Trade Climate Legislation on Agriculture in the Northern Plains: A Policy Simulation with Farmer Preference and Adaption

cap-and-trade, carbon sequestration, climate change mitigation, agricultural impact, Agricultural and Food Policy, Environmental Economics and Policy, Land Economics/Use, Production Economics, Resource /Energy Economics and Policy,

Existence of negative differential thermal conductance in one-dimensional diffusive thermal transport

We show that in a finite one-dimensional (1D) system with diffusive thermal transport described by the Fourier's law, negative differential thermal conductance (NDTC) cannot occur when the temperature at one end is fixed. We demonstrate that NDTC in this case requires the presence of junction(s) with temperature dependent thermal contact resistance (TCR). We derive a necessary and sufficient condition for the existence of NDTC in terms of the properties of the TCR for systems with a single junction. We show that under certain circumstances we even could have infinite (negative or positive) differential thermal conductance in the presence of the TCR. Our predictions provide theoretical basis for constructing NDTC-based devices, such as thermal amplifiers, oscillators and logic devices

Interplay between spin density wave and π\pi phase shifted superconductivity in the Fe pnictide superconductors

We explore if the phase separation or coexistence of the spin density wave (SDW) and superconductivity (SC) states has any relation to the incommensurability of the SDW in the Fe pnictide superconductors. A systematic method of determining the phase separation or coexistence was employed by computing the anisotropy coefficient $\beta$ from the the 4th order terms of the Ginzburg--Landau (GL) expansion of the free energy close to the tricritical/tetracritical point. It was complemented by the self-consistent numerical iterations of the gap equations to map out the boundaries between the phase separation and coexistence of the SDW and SC phases, and between commensurate (C) and incommensurate (IC) SDW in the temperature--doping plane. Our principal results for the sign reversed $s$-wave pairing SC, in terms of the multicritical temperature, $T_c$, the phase separation/coexistence boundary between the SDW and SC, $T^*$, and the boundary between C/IC SDW, $T_M^*$, are: (a) IC-SDW and SC coexist for $T_c < T^*$ and phase separate otherwise, (b) SDW takes the C form for $T_c>T_M^*$ and IC form for $T_c<T_M^*$, and (c) the thermodynamic first order phase transition intervenes in between the C-SDW and IC-SDW boundary for large $T_M^0$, where $T_M^0$ is the SDW transition temperature at zero doping, $T^*=0.35 ~T_M^0$ and $T_M^*=0.56\ T_M^0$. The intervention makes the phase diagram more complicated than previously reported. By contrast no coexistence was found for the equal sign pairing SC. These results will be compared with the experimental reports in the Fe pnictide superconductors.Comment: 9 pages, 4 figures, Submitted to Phys.Rev.