102,114 research outputs found
Excavations and survey at Coats Hill, near Moffat, 1990-1
No full textThis report describes the results of the survey and sample excavations of small cairns,
annular structures and other remains on Coats Hill, near Moffat. The difficulties of assessing
the dates and functions of certain of the structures are discussed. The project formed
part of the archaeological studies for the North Western Ethylene Pipeline (NWEP) Project
for Shell Chemicals UK Ltd, which wholly funded the archaeological work and the publication
of this report
Leptogenesis from low energy CP violation
No full textAbstract We revisit the possibility of producing the observed baryon asymmetry of the Universe via thermal leptogenesis, where CP violation comes exclusively from the low-energy phases of the neutrino mixing matrix. We demonstrate the viability of thermal flavoured leptogenesis across seven orders of magnitude (106 < T (GeV) < 1013), using modern numerical machinery, where the lower bound can be reached only if flavour effects are taken into account and its value depends on the allowed degree of cancellation between the tree-level and radiative contributions to the light neutrino masses. At very high scales (T ≫1012 GeV), we clarify that thermal leptogenesis is sensitive to the low-energy phases, in contradiction with what is usually claimed in the literature. In particular we demonstrate that Majorana-phase leptogenesis is in general viable while Dirac-phase leptogenesis requires some level of fine-tuning
Evidence for antigen presentation by human neutrophils
No full textNeutrophils are the first migrating responders to sterile and infectious inflammation, and act in a powerful but non-specific fashion to kill a wide variety of pathogens. It is now clear that they can also act in a highly discriminating fashion; this is particularly evident in their interactions with other cells of the immune system. It is clear that neutrophils are present during the adaptive immune response, interacting with T cells in complex ways which differ between tissue types and disease state. One of the ways in which this interaction is mediated is by neutrophil expression of HLA molecules and presentation of antigen to T cells. In mice, this is well established to occur with both CD4+ and CD8+ T cells. However, the evidence is less strong with human cells. Here, we assembled available evidence for human neutrophil antigen presentation. We find that the human cells are clearly able to up-regulate HLA-DR and co-stimulatory molecules; are able to process protein antigen into fragments recognised by T cells; are able to enter lymph node T cell zones; and, in vitro, are able to present antigen to memory T cells, inducing proliferation and cytokine production. However, many questions remain, particularly concerning whether the cell-cell interactions can last for sufficient time to trigger naïve T cells. These experiments are now critical as we unravel the complex interactions between these cells and their importance for the development of human immunity
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Invoice from T. C. Moffat, Wheeling, West Virginia, to Stimpson H. Woodward, December 19, 1879
No full textA document from an extensive collection spanning four generations of the Woodward family that operated merchant pig iron companies in West Virginia and Alabama. The collection begins with Stimpson Harvey Woodward (S. H. Woodward), a native of Massachusetts, who moved from Pittsburgh to Wheeling, West Virginia in 1852. He had interests in an iron company as early as 1852 in West Virginia and began Alabama operations in 1869. The family business continued in Alabama until the death of S. H. Woodward's great-grandson in 1965
Erratum: Collinear factorization in wide-angle hadron pair production in e+e- annihilation (Physical Review D (2019) 100 (094014) DOI: 10.1103/PhysRevD.100.094014)
No full textIn our original publication, we presented analytical expressions for the short distance partonic cross sections for dihadron production in e+e- reaction in collinear factorization.
We correct the decomposition of the hadronic tensor and provide minor corrections that do not affect the results of the original publication
Collinear factorization in wide-angle hadron pair production in e+e-annihilation
No full textWe compute the inclusive unpolarized dihadron production cross section in the far from back-to-back region of e+e-annihilation in leading order pQCD using existing fragmentation function fits and standard collinear factorization, focusing on the large transverse momentum region where transverse momentum is comparable to the hard scale (the center-of-mass energy). We compare with standard transverse-momentum-dependent (TMD) fragmentation function-based predictions intended for the small transverse momentum region with the aim of testing the expectation that the two types of calculation roughly coincide at intermediate transverse momentum. We find significant tension, within the intermediate transverse momentum region, between calculations done with existing nonperturbative TMD fragmentation functions and collinear factorization calculations if the center-of-mass energy is not extremely large. We argue that e+e-measurements are ideal for resolving this tension and exploring the large-to-small transverse momentum transition, given the typically larger hard scales (~10 GeV) of the process as compared with similar scenarios that arise in semi-inclusive deep inelastic scattering and fixed-target Drell-Yan measurements
Three-flavored nonresonant leptogenesis at intermediate scales
No full textLeptogenesis can successfully explain the matter-antimatter asymmetry via out-of-equilibrium decays of heavy Majorana neutrinos in the early Universe. In this article, we focus on nonresonant thermal leptogenesis and the possibility of lowering its scale. In order to do so, we calculate the lepton asymmetry produced from the decays of one and two heavy Majorana neutrinos using three-flavored density matrix equations in an exhaustive exploration of the model parameter space. We find regions of the parameter space where thermal leptogenesis is viable at intermediate scales, T∼106 GeV. However, the viability of thermal leptogenesis at such scales requires a certain degree of cancellation between the tree- and one-loop level contribution to the light neutrino mass matrix, and we quantify such fine-tuning
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