The Experts below are selected from a list of 26691 Experts worldwide ranked by ideXlab platform
Deshan Yang - One of the best experts on this subject based on the ideXlab platform.
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bridging light cone and nrqcd approaches asymptotic behavior of b c electromagnetic form factor
Journal of High Energy Physics, 2011Co-Authors: Yu Jia, Jianxiong Wang, Deshan YangAbstract:This work aims at illustrating that, for a class of leading-twist hard exclusive reactions involving two heavy quarkonia, the light-cone approach, when equipped with the strategy of refactorization of the light-cone distribution amplitude of quarkonium, can be employed to elegantly reproduce the corresponding predictions made in the nonrelativistic QCD (NRQCD) factorization approach, order by order in perturbative expansion. Taking the electromagnetic form factor of the Bc meson at large momentum transfer, Q2, as a concrete example, we compare the results obtained from both NRQCD-based and light-cone-based calculations through the next-to-leading order (NLO) in αs, while at the leading order (LO) in both velocity and 1/Q2 expansion, and explicitly confirm their Mutual Agreement. As a byproduct, we apply our NLO result to explore certain features about the asymptotic behavior of the heavy-light meson form factor. We also address the major theoretical obstacles that prevent us from establishing an analogous equivalence between these two approaches for the double charmonium production process of phenomenological interest, e+e− → J/ψ + ηc.
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bridging light cone and nrqcd approaches asymptotic behavior of b_c electromagnetic form factor
arXiv: High Energy Physics - Phenomenology, 2010Co-Authors: Yu Jia, Jianxiong Wang, Deshan YangAbstract:This work aims at illustrating that, for a class of leading-twist hard exclusive reactions involving two heavy quarkonia, the light-cone approach, when equipped with the strategy of refactorization of the light-cone distribution amplitude of quarkonium, can be employed to elegantly reproduce the corresponding predictions made in the nonrelativistic QCD (NRQCD) factorization approach, order by order in perturbative expansion. Taking the electromagnetic form factor of the $B_c$ meson at large momentum transfer, $Q^2$, as a concrete example, we compare the results obtained from both NRQCD-based and light-cone-based calculations through the next-to-leading order (NLO) in $\alpha_s$, while at the leading order (LO) in both velocity and $1/Q^2$ expansion, and explicitly confirm their Mutual Agreement. As a byproduct, we apply our NLO result to explore certain features about the asymptotic behavior of the heavy-light meson form factor. We also address the major theoretical obstacles that prevent us from establishing an analogous equivalence between these two approaches for the double charmonium production process of phenomenological interest, $e^+e^-\to J/\psi+\eta_c$.
Piero Ugliengo - One of the best experts on this subject based on the ideXlab platform.
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a comparison between plane wave and gaussian type orbital basis sets for hydrogen bonded systems formic acid as a test case
Journal of Chemical Physics, 2007Co-Authors: Sergio Tosoni, Christian Tuma, Joachim Sauer, Bartolomeo Civalleri, Piero UgliengoAbstract:The formic acid molecule, its dimers, and its molecular crystal are adopted as test systems to compare results obtained with plane wave (PW) basis sets and norm-conserving pseudopotentials to all-electron Gaussian-type orbital (GTO) calculations. The CPMD and CRYSTAL06 codes, respectively, are applied with the PBE, PW91, and BLYP density functionals. Hydrogen bonding is the leading interaction in the dimers and the crystal. In the latter, dispersive and weak C–H⋯O interactions are also relevant. Irrespective of the adopted functional, for all considered structures PW and GTO results converge smoothly as a function of the quality of the adopted basis sets to the same values for structures, energies of interaction, and harmonic vibrational features. To achieve a high level of Mutual Agreement the use of GTO basis sets of at least of triple-zeta quality including one set of polarization functions and PW basis sets with a kinetic energy cutoff higher than 110Ry is recommended. Pros and cons of both approaches...
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a comparison between plane wave and gaussian type orbital basis sets for hydrogen bonded systems formic acid as a test case
Journal of Chemical Physics, 2007Co-Authors: Sergio Tosoni, Christian Tuma, Joachim Sauer, Bartolomeo Civalleri, Piero UgliengoAbstract:The formic acid molecule, its dimers, and its molecular crystal are adopted as test systems to compare results obtained with plane wave (PW) basis sets and norm-conserving pseudopotentials to all-electron Gaussian-type orbital (GTO) calculations. The CPMD and CRYSTAL06 codes, respectively, are applied with the PBE, PW91, and BLYP density functionals. Hydrogen bonding is the leading interaction in the dimers and the crystal. In the latter, dispersive and weak C-H...O interactions are also relevant. Irrespective of the adopted functional, for all considered structures PW and GTO results converge smoothly as a function of the quality of the adopted basis sets to the same values for structures, energies of interaction, and harmonic vibrational features. To achieve a high level of Mutual Agreement the use of GTO basis sets of at least of triple-zeta quality including one set of polarization functions and PW basis sets with a kinetic energy cutoff higher than 110 Ry is recommended. Pros and cons of both approaches for studying molecular crystals are also discussed.
Cerdeira F - One of the best experts on this subject based on the ideXlab platform.
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STRAIN DETERMINATION IN INXGA1-XAS/GAAS STRAINED-LAYER SUPERLATTICES BY PHOTOMODULATED REFLECTANCE
Woodbury, 2015Co-Authors: Ck Inoki, Cerdeira F, Vasquezlopez CAbstract:A series of Raman and photoreflectance measurements was performed on several InxGa1-xAs/GaAs strained-layer superlattices of the same period but of different alloy compositions and substrate orientations. In the photoreflectance spectra the photon energy region containing the E1 and E1 + DELTA1 transitions of the GaAs barrier material is analyzed. Both types of measurements are used in order to estimate of the in-plane strain in these layers. The values obtained by both methods are in good Mutual Agreement, thus showing that photoreflectance is an effective method for strain determination.7373266327
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Strain Measurements In Inxga1-xas/gaas Strained-layer Superlattices By Photomodulated Reflectance
2015Co-Authors: Vazquez-lopez C., Cerdeira FAbstract:We performed a series of Raman and photoreflectance measurements on several InxGa1-xAs/GaAs strained layer superlattices of the same period but of different alloy compositions and substrate orientations. Both types of measurements are used in order to estimate the in-plane strain in these layers. The values obtained by both methods are in good Mutual Agreement, thus showing that photoreflectance is an effective method for strain determination. © 1993 Academic Press. All rights reserved.13218
Yu Jia - One of the best experts on this subject based on the ideXlab platform.
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bridging light cone and nrqcd approaches asymptotic behavior of b c electromagnetic form factor
Journal of High Energy Physics, 2011Co-Authors: Yu Jia, Jianxiong Wang, Deshan YangAbstract:This work aims at illustrating that, for a class of leading-twist hard exclusive reactions involving two heavy quarkonia, the light-cone approach, when equipped with the strategy of refactorization of the light-cone distribution amplitude of quarkonium, can be employed to elegantly reproduce the corresponding predictions made in the nonrelativistic QCD (NRQCD) factorization approach, order by order in perturbative expansion. Taking the electromagnetic form factor of the Bc meson at large momentum transfer, Q2, as a concrete example, we compare the results obtained from both NRQCD-based and light-cone-based calculations through the next-to-leading order (NLO) in αs, while at the leading order (LO) in both velocity and 1/Q2 expansion, and explicitly confirm their Mutual Agreement. As a byproduct, we apply our NLO result to explore certain features about the asymptotic behavior of the heavy-light meson form factor. We also address the major theoretical obstacles that prevent us from establishing an analogous equivalence between these two approaches for the double charmonium production process of phenomenological interest, e+e− → J/ψ + ηc.
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bridging light cone and nrqcd approaches asymptotic behavior of b_c electromagnetic form factor
arXiv: High Energy Physics - Phenomenology, 2010Co-Authors: Yu Jia, Jianxiong Wang, Deshan YangAbstract:This work aims at illustrating that, for a class of leading-twist hard exclusive reactions involving two heavy quarkonia, the light-cone approach, when equipped with the strategy of refactorization of the light-cone distribution amplitude of quarkonium, can be employed to elegantly reproduce the corresponding predictions made in the nonrelativistic QCD (NRQCD) factorization approach, order by order in perturbative expansion. Taking the electromagnetic form factor of the $B_c$ meson at large momentum transfer, $Q^2$, as a concrete example, we compare the results obtained from both NRQCD-based and light-cone-based calculations through the next-to-leading order (NLO) in $\alpha_s$, while at the leading order (LO) in both velocity and $1/Q^2$ expansion, and explicitly confirm their Mutual Agreement. As a byproduct, we apply our NLO result to explore certain features about the asymptotic behavior of the heavy-light meson form factor. We also address the major theoretical obstacles that prevent us from establishing an analogous equivalence between these two approaches for the double charmonium production process of phenomenological interest, $e^+e^-\to J/\psi+\eta_c$.
Sergio Tosoni - One of the best experts on this subject based on the ideXlab platform.
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a comparison between plane wave and gaussian type orbital basis sets for hydrogen bonded systems formic acid as a test case
Journal of Chemical Physics, 2007Co-Authors: Sergio Tosoni, Christian Tuma, Joachim Sauer, Bartolomeo Civalleri, Piero UgliengoAbstract:The formic acid molecule, its dimers, and its molecular crystal are adopted as test systems to compare results obtained with plane wave (PW) basis sets and norm-conserving pseudopotentials to all-electron Gaussian-type orbital (GTO) calculations. The CPMD and CRYSTAL06 codes, respectively, are applied with the PBE, PW91, and BLYP density functionals. Hydrogen bonding is the leading interaction in the dimers and the crystal. In the latter, dispersive and weak C–H⋯O interactions are also relevant. Irrespective of the adopted functional, for all considered structures PW and GTO results converge smoothly as a function of the quality of the adopted basis sets to the same values for structures, energies of interaction, and harmonic vibrational features. To achieve a high level of Mutual Agreement the use of GTO basis sets of at least of triple-zeta quality including one set of polarization functions and PW basis sets with a kinetic energy cutoff higher than 110Ry is recommended. Pros and cons of both approaches...
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a comparison between plane wave and gaussian type orbital basis sets for hydrogen bonded systems formic acid as a test case
Journal of Chemical Physics, 2007Co-Authors: Sergio Tosoni, Christian Tuma, Joachim Sauer, Bartolomeo Civalleri, Piero UgliengoAbstract:The formic acid molecule, its dimers, and its molecular crystal are adopted as test systems to compare results obtained with plane wave (PW) basis sets and norm-conserving pseudopotentials to all-electron Gaussian-type orbital (GTO) calculations. The CPMD and CRYSTAL06 codes, respectively, are applied with the PBE, PW91, and BLYP density functionals. Hydrogen bonding is the leading interaction in the dimers and the crystal. In the latter, dispersive and weak C-H...O interactions are also relevant. Irrespective of the adopted functional, for all considered structures PW and GTO results converge smoothly as a function of the quality of the adopted basis sets to the same values for structures, energies of interaction, and harmonic vibrational features. To achieve a high level of Mutual Agreement the use of GTO basis sets of at least of triple-zeta quality including one set of polarization functions and PW basis sets with a kinetic energy cutoff higher than 110 Ry is recommended. Pros and cons of both approaches for studying molecular crystals are also discussed.
