2,056 research outputs found

    Transverse-momentum-dependent wave functions and Soft functions at one-loop in Large Momentum Effective Theory

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    In large-momentum effective theory (LaMET), the transverse-momentum-dependent (TMD) light-front wave functions and soft functions can be extracted from the simulation of a four-quark form factor and equal-time correlation functions. In this work, using expansion by regions we provide a one-loop proof of TMD factorization of the form factor. For the one-loop validation, we also present a detailed calculation of O(Ξ±s){\cal O}(\alpha_s) perturbative corrections to these quantities, in which we adopt a modern technique for the calculation of TMD form factor based the integration by part and differential equation. The one-loop hard functions are then extracted. Using lattice data from Lattice Parton Collaboration on quasi-TMDWFs, we estimate the effects from the one-loop matching kernel and find that the perturbative corrections depend on the operator to define the form factor, but are less sensitive to the transverse separation. These results will be helpful to precisely extract the soft functions and TMD wave functions from the first-principle in future

    Elucidation of subfamily segregation and intramolecular coevolution of the olfactomedin-like proteins by comprehensive phylogenetic analysis and gene expression pattern assessment

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    AbstractThe categorization of genes by structural distinctions relevant to biological characteristics is very important for understanding of gene functions and predicting functional implications of uncharacterized genes. It was absolutely necessary to deploy an effective and efficient strategy to deal with the complexity of the large olfactomedin-like (OLF) gene family sharing sequence similarity but playing diversified roles in many important biological processes, as the simple highest-hit homology analysis gave incomprehensive results and led to inappropriate annotation for some uncharacterized OLF members. In light of evolutionary information that may facilitate the classification of the OLF family and proper association of novel OLF genes with characterized homologs, we performed phylogenetic analysis on all 116 OLF proteins currently available, including two novel members cloned by our group. The OLF family segregated into seven subfamilies and members with similar domain compositions or functional properties all fell into relevant subfamilies. Furthermore, our Northern blot analysis and previous studies revealed that the typical human OLF members in each subfamily exhibited tissue-specific expression patterns, which in turn supported the segregation of the OLF subfamilies with functional divergence. Interestingly, the phylogenetic tree topology for the OLF domains alone was almost identical with that of the full-length tree representing the unique phylogenetic feature of full-length OLF proteins and their particular domain compositions. Moreover, each of the major functional domains of OLF proteins kept the same phylogenetic feature in defining similar topology of the tree. It indicates that the OLF domain and the various domains in flanking non-OLF regions have coevolved and are likely to be functionally interdependent. Expanded by a plausible gene duplication and domain couplings scenario, the OLF family comprises seven evolutionarily and functionally distinct subfamilies, in which each member shares similar structural and functional characteristics including the composition of coevolved and interdependent domains. The phylogenetically classified and preliminarily assessed subfamily framework may greatly facilitate the studying on the OLF proteins. Furthermore, it also demonstrated a feasible and reliable strategy to categorize novel genes and predict the functional implications of uncharacterized proteins based on the comprehensive phylogenetic classification of the subfamilies and their relevance to preliminary functional characteristics

    QED contributions to the Ξcβˆ’Ξžcβ€²\Xi_c-\Xi_c' mixing

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    We explore the QED corrections to the Ξcβˆ’Ξžcβ€²\Xi_c-\Xi_c^{\prime} mixing within the framework of light-front quark model (LFQM) in the three-quark picture. After explicitly investigating the relation between the Ξcβˆ’Ξžcβ€²\Xi_c-\Xi_c^{\prime} mixing and the flavor SU(3)\rm {SU(3)} and heavy quark symmetry breaking, we derive the QED contributions to the mixing angle. Numerical results indicate the QED contribution is smaller than the one from the mass difference between the strange and up/down quark provided by a recent Lattice QCD analysis. Adding these contributions together we find that at this stage the Ξcβˆ’Ξžcβ€²\Xi_c-\Xi_c^{\prime} mixing is small and still incapable to account for the large SU(3)\rm {SU(3)} symmetry breaking in the semi-leptonic Ξc\Xi_c decays.Comment: 7 pages, 4figure
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