High-resolution spectral radiance measurements were taken by a spectral radiometer on board a heli- copter over the US Oklahoma Southern Great Plain near the Atmospheric Radiation Measurements (ARM) site during August...High-resolution spectral radiance measurements were taken by a spectral radiometer on board a heli- copter over the US Oklahoma Southern Great Plain near the Atmospheric Radiation Measurements (ARM) site during August 1998. The radiometer has a spectral range from 350 nm to 2500 nm at 1 nm resolution The measurements covered several grass and cropland scene types at multiple solar zenith angles. Detailed atmospheric corrections using the Moderate Resolution Transmittance (MODTRAN) radiation model and in-situ sounding and aerosol measurements have been applied to the helicopter measurements in order to re- trieve the surface and top of atmosphere (TOA) Bidirectional Reflectance Distribution Function (BRDF) characteristics. The atmospheric corrections are most significant in the visible wavelengths and in the strong water vapor absorption wavelengths in the near infrared region Adjusting the BRDF to TOA requires a larger correction in the visible channels since Rayleigh scattenng contributes significantly to the TOA reflectance. The opposite corrections to the visible and near infrarred wavelengths can alter the radiance dif- ference and ratio that many remote sensing techniques are based on, such as the normalixed difference vege- tation index (NDVI). The data show that surface BRDFs and spectral albedos are highly sensitive to the veg- etation type and soldr zenith angle while BRDF at TOA depends more on atmospheric conditions and the vi ewing geometry. Comparison with the Clouds and the Earth's Radiant Energy System (CERES) derived clear sky Angular Distribution Model (ADM) for crop and grass scene type shows a standard deviation of 0.08 in broadband anisotropic function at 25°solar zenith angle and 0.15 at 50° solar zenith angle, respectively.展开更多
We explain the framework for calculating next-to-leading-order （NLO） corrections to exclusive processes in the kT factorization theorem, taking πγ^＊→γ as an example. Patrons off-shell by kT^2 are considered in ...We explain the framework for calculating next-to-leading-order （NLO） corrections to exclusive processes in the kT factorization theorem, taking πγ^＊→γ as an example. Patrons off-shell by kT^2 are considered in both the quark diagrams from full QCD and the effective diagrams for the pion wave function. The gauge dependences in the above two sets of diagrams cancel, when deriving the kw-dependent hard kernel as their difference. The light-cone singularities in the kT-dependent pion wave function are regularized by rotating the Wilson lines away from the light cone. Both the large double logarithms In^2 kT and In^2x, x being a parton momentum fraction, arise from the loop correction to the virtual photon vertex, the former being absorbed into the pion wave function, and the latter into a jet function.展开更多
We report the density measurement through e-3He elastic scattering with a 1.23 GeV electron beam in Jefferson Lab experiment E06-010. The extracted 3He density is （9.26±0.06） amagats and the N2/3He ratio is （1...We report the density measurement through e-3He elastic scattering with a 1.23 GeV electron beam in Jefferson Lab experiment E06-010. The extracted 3He density is （9.26±0.06） amagats and the N2/3He ratio is （1.49±0.08）%. In addition, these results are consistent with the deduced target densities based on pressure broadening measurement.展开更多
In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation a...In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation associated with the power expansion of O(∧_(QCD)/m_(c)).In our calculation,we adopt two different models of the D-meson distribution amplitudesφ^(+)_(D,Ⅰ)andφ^(+)_(DⅡ).Within the framework of QCD factorization as well as the dispersion relation,we evaluate the soft contribution up to the next-to-leading logarithmic accuracy and also consider the higher-twist contribution from the two-particle and three-particle distribution amplitudes.Finally,we find that all the sub-leading power contributions are significant atλd(μ0)354 MeV,and the next-to-leading power contributions lead to 143%inφ^(+)_(D,Ⅰ)and 120%inφ^(+)_(DⅡ)corrections to leading power vector form factors with Eγ=0.5 GeV.As the corrections from the higher-twist and local sub-leading power contributions are enhanced with increasing inverse moment,it is difficult to extract an appropriate inverse moment of the D-meson distribution amplitude.The predicted branching fractions are(1.88^(+0.36)_(0.29))×10^(-5)forφ^(+)_(D,Ⅰ)and(2.31^(+0.65)_(-0.54))×10^(-5)forφ^(+)_(DⅡ).展开更多
Applying the effective Lagrangian method,we analyze the radiative contributions of the Kaluza–Klein(KK)modes to the muon magnetic dipole moments in the Appelquist–Cheng–Dobrescu model.Summing over the infinite seri...Applying the effective Lagrangian method,we analyze the radiative contributions of the Kaluza–Klein(KK)modes to the muon magnetic dipole moments in the Appelquist–Cheng–Dobrescu model.Summing over the infinite series composed by the KK towers,we verify the final results satisfying the decoupling theorem in the limit R^(-1)→∞.For the compactification scale R^(-1)=300 GeV,we obtain the electroweak radiative corrections from the KK modes to the muon MDM amount to 6.72×10^(-12) at one loop level.展开更多
The radiance leaving the earth-atmosphere system which can be sensed by a satellite borne radiometer is the sum of radiation emission from the earth surface and each atmospheric level that are transmitted to the top o...The radiance leaving the earth-atmosphere system which can be sensed by a satellite borne radiometer is the sum of radiation emission from the earth surface and each atmospheric level that are transmitted to the top of the atmosphere. The radiation emission from the earth surface and the radiance of each atmospheric level can be separated from the radiance at the top the atmospheric level measured by a satellite borne radiometer. However, it is very difficult to measure the atmospheric radiance, especially the synchronous measurement with the satellite. Thus some atmospheric radiative transfer models have been developed to provide many options for modeling atmospheric radiation transport, such as LOWTRAN, MODTRAN, 6S, FASCODE, LBLRTM, SHARC, and SAMM. Meanwhile, these models can support the detailed detector system design, the optimization and evaluation of satellite mission parameters, and the data processing procedures. As an example, the newly atmospheric radiative transfer models, MODTRAN will be compared with other models after the atmospheric radiative transfer is described. And the atmospheric radiative transfer simulation procedures and their applications to atmospheric transmittance, retrieval of atmospheric elements, and surface parameters, will also be presented.展开更多
文摘High-resolution spectral radiance measurements were taken by a spectral radiometer on board a heli- copter over the US Oklahoma Southern Great Plain near the Atmospheric Radiation Measurements (ARM) site during August 1998. The radiometer has a spectral range from 350 nm to 2500 nm at 1 nm resolution The measurements covered several grass and cropland scene types at multiple solar zenith angles. Detailed atmospheric corrections using the Moderate Resolution Transmittance (MODTRAN) radiation model and in-situ sounding and aerosol measurements have been applied to the helicopter measurements in order to re- trieve the surface and top of atmosphere (TOA) Bidirectional Reflectance Distribution Function (BRDF) characteristics. The atmospheric corrections are most significant in the visible wavelengths and in the strong water vapor absorption wavelengths in the near infrared region Adjusting the BRDF to TOA requires a larger correction in the visible channels since Rayleigh scattenng contributes significantly to the TOA reflectance. The opposite corrections to the visible and near infrarred wavelengths can alter the radiance dif- ference and ratio that many remote sensing techniques are based on, such as the normalixed difference vege- tation index (NDVI). The data show that surface BRDFs and spectral albedos are highly sensitive to the veg- etation type and soldr zenith angle while BRDF at TOA depends more on atmospheric conditions and the vi ewing geometry. Comparison with the Clouds and the Earth's Radiant Energy System (CERES) derived clear sky Angular Distribution Model (ADM) for crop and grass scene type shows a standard deviation of 0.08 in broadband anisotropic function at 25°solar zenith angle and 0.15 at 50° solar zenith angle, respectively.
基金Supported by National Science Council (NSC-95-2112-M-050-MY3)
文摘We explain the framework for calculating next-to-leading-order （NLO） corrections to exclusive processes in the kT factorization theorem, taking πγ^＊→γ as an example. Patrons off-shell by kT^2 are considered in both the quark diagrams from full QCD and the effective diagrams for the pion wave function. The gauge dependences in the above two sets of diagrams cancel, when deriving the kw-dependent hard kernel as their difference. The light-cone singularities in the kT-dependent pion wave function are regularized by rotating the Wilson lines away from the light cone. Both the large double logarithms In^2 kT and In^2x, x being a parton momentum fraction, arise from the loop correction to the virtual photon vertex, the former being absorbed into the pion wave function, and the latter into a jet function.
基金Supported by National Natural Science Foundation of China (11075068, 10775062, 91026021, 11135002)
文摘We report the density measurement through e-3He elastic scattering with a 1.23 GeV electron beam in Jefferson Lab experiment E06-010. The extracted 3He density is （9.26±0.06） amagats and the N2/3He ratio is （1.49±0.08）%. In addition, these results are consistent with the deduced target densities based on pressure broadening measurement.
基金Supported in part by the National Natural Science Foundation of China(1675082,11735010)the Natural Science Foundation of Tianjin(19JCJQJC61100)。
文摘In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation associated with the power expansion of O(∧_(QCD)/m_(c)).In our calculation,we adopt two different models of the D-meson distribution amplitudesφ^(+)_(D,Ⅰ)andφ^(+)_(DⅡ).Within the framework of QCD factorization as well as the dispersion relation,we evaluate the soft contribution up to the next-to-leading logarithmic accuracy and also consider the higher-twist contribution from the two-particle and three-particle distribution amplitudes.Finally,we find that all the sub-leading power contributions are significant atλd(μ0)354 MeV,and the next-to-leading power contributions lead to 143%inφ^(+)_(D,Ⅰ)and 120%inφ^(+)_(DⅡ)corrections to leading power vector form factors with Eγ=0.5 GeV.As the corrections from the higher-twist and local sub-leading power contributions are enhanced with increasing inverse moment,it is difficult to extract an appropriate inverse moment of the D-meson distribution amplitude.The predicted branching fractions are(1.88^(+0.36)_(0.29))×10^(-5)forφ^(+)_(D,Ⅰ)and(2.31^(+0.65)_(-0.54))×10^(-5)forφ^(+)_(DⅡ).
基金Supported by the National Natural Science Foundation of China under Grant No 10975027。
文摘Applying the effective Lagrangian method,we analyze the radiative contributions of the Kaluza–Klein(KK)modes to the muon magnetic dipole moments in the Appelquist–Cheng–Dobrescu model.Summing over the infinite series composed by the KK towers,we verify the final results satisfying the decoupling theorem in the limit R^(-1)→∞.For the compactification scale R^(-1)=300 GeV,we obtain the electroweak radiative corrections from the KK modes to the muon MDM amount to 6.72×10^(-12) at one loop level.
文摘The radiance leaving the earth-atmosphere system which can be sensed by a satellite borne radiometer is the sum of radiation emission from the earth surface and each atmospheric level that are transmitted to the top of the atmosphere. The radiation emission from the earth surface and the radiance of each atmospheric level can be separated from the radiance at the top the atmospheric level measured by a satellite borne radiometer. However, it is very difficult to measure the atmospheric radiance, especially the synchronous measurement with the satellite. Thus some atmospheric radiative transfer models have been developed to provide many options for modeling atmospheric radiation transport, such as LOWTRAN, MODTRAN, 6S, FASCODE, LBLRTM, SHARC, and SAMM. Meanwhile, these models can support the detailed detector system design, the optimization and evaluation of satellite mission parameters, and the data processing procedures. As an example, the newly atmospheric radiative transfer models, MODTRAN will be compared with other models after the atmospheric radiative transfer is described. And the atmospheric radiative transfer simulation procedures and their applications to atmospheric transmittance, retrieval of atmospheric elements, and surface parameters, will also be presented.
