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Full-Text Articles in Physics
Long-Range Interactions For Hydrogen Atoms In Excited D States, Chandra M. Adhikari, Ulrich D. Jentschura
Long-Range Interactions For Hydrogen Atoms In Excited D States, Chandra M. Adhikari, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
Pressure shifts inside an atomic beam are among the more theoretically challenging effects in high-precision measurements of atomic transitions. A crucial element in their theoretical analysis is the understanding of long-range interatomic interactions inside the beam. For excited reference states, the presence of quasi-degenerate states leads to additional challenges, due to the necessity to diagonalize large matrices in the quasi-degenerate hyperfine manifolds. Here, we focus on the interactions of hydrogen atoms in reference states composed of an excited nD state (atom A), and in the metastable 2S state (atom B). We devote special attention to the cases n = 3 …
Long-Range Interactions For Hydrogen Atoms In Excited D States, Chandra M. Adhikari, Ulrich D. Jentschura
Long-Range Interactions For Hydrogen Atoms In Excited D States, Chandra M. Adhikari, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
Pressure shifts inside an atomic beam are among the more theoretically challenging effects in high-precision measurements of atomic transitions. A crucial element in their theoretical analysis is the understanding of long-range interatomic interactions inside the beam. For excited reference states, the presence of quasi-degenerate states leads to additional challenges, due to the necessity to diagonalize large matrices in the quasi-degenerate hyperfine manifolds. Here, we focus on the interactions of hydrogen atoms in reference states composed of an excited nD state (atom A), and in the metastable 2S state (atom B). We devote special attention to the cases n = 3 …
Inverse Moment Of The B Meson Quasidistribution Amplitude, Ji Xu, Xi-Ruo Zhang, Shuai Zhao
Inverse Moment Of The B Meson Quasidistribution Amplitude, Ji Xu, Xi-Ruo Zhang, Shuai Zhao
Physics Faculty Publications
We perform a study on the structure of the inverse moment (IM) of quasidistributions, by taking B-meson quasidistribution amplitude (quasi-DA) as an example. Based on a one-loop calculation, we derive the renormalization group equation and velocity evolution equation for the first IM of quasi-DA. We find that, in the large velocity limit, the first IM of B-meson quasi-DA can be factorized into IM as well as logarithmic moments of light-cone distribution amplitude (LCDA), accompanied by short distance coefficients. Our results can be useful either in understanding the patterns of perturbative matching in large momentum effective theory or evaluating inverse …
Positivity And Renormalization Of Parton Densities, John Collins, Ted C. Rogers, Nobuo Sato
Positivity And Renormalization Of Parton Densities, John Collins, Ted C. Rogers, Nobuo Sato
Physics Faculty Publications
There have been recent debates about whether MS parton densities exactly obey positivity bounds (including the Soffer bound) and whether the bounds should be applied as a constraint on global fits to parton densities and on nonperturbative calculations. A recent paper [Candido et al., Can MS parton distributions be negative?, J. High Energy Phys. 11 (2020) 129] appears to provide a proof of positivity in contradiction with earlier work by other authors. We examine their derivation and find that its primary failure is in the apparently uncontroversial statement that bare parton density (or distribution) function (pdfs) are always …