The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Michael Klasen - One of the best experts on this subject based on the ideXlab platform.
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Suppression Factors in diffractive photoproduction of dijets
The European Physical Journal C, 2010Co-Authors: Michael Klasen, Gustav KramerAbstract:Now that new publications of H1 data for the diffractive photoproduction of dijets, which overlap with the earlier published H1 data and the recently published data of the ZEUS collaboration, have appeared, we have recalculated the cross sections for this process in next-to-leading order (NLO) of perturbative QCD to see whether they can be interpreted consistently. The results of these calculations are compared to the data of both collaborations. We find that the NLO cross sections disagree with the data, showing that Factorization breaking occurs at that order. If direct and resolved contributions are both suppressed by the same amount, the global Suppression Factor depends on the transverse-energy cut. However, by suppressing only the resolved contribution, also reasonably good agreement with all the data is found with a Suppression Factor independent of the transverse-energy cut.
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NLO QCD analysis of single-diffractive dijet production at the Tevatron
arXiv: High Energy Physics - Phenomenology, 2010Co-Authors: Michael KlasenAbstract:We present the first NLO QCD analysis of single-diffractive dijet production in proton-antiproton collisions. By comparing the ratio of single- and non-diffractive cross sections to data from the Tevatron, the rapidity-gap survival probability is determined as a function of the momentum fraction of the parton in the antiproton. Assuming Regge Factorization, this probability can be interpreted as a Suppression Factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the Suppression Factor in proton-antiproton collisions depends on the momentum fraction of the parton in the Pomeron even at NLO.
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Factorization breaking in single-diffractive dijet production at the Tevatron
Nuclear Physics B - Proceedings Supplements, 2010Co-Authors: Michael KlasenAbstract:We perform a NLO QCD analysis of single-diffractive dijet production in proton-antiproton collisions. By comparing the ratio of single- and non-diffractive cross sections to data from the Tevatron, the rapidity-gap survival probability is determined as a function of the momentum fraction of the parton in the antiproton. Assuming Regge Factorization, this probability can be interpreted as a Suppression Factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the Suppression Factor in proton-antiproton collisions depends on the momentum fraction of the parton in the Pomeron even at NLO.
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Survival probability for diffractive dijet production in pp̄ collisions from next-to-leading order calculations
Physical Review D, 2009Co-Authors: Michael Klasen, Gustav KramerAbstract:We perform next-to-leading order calculations of the single-diffractive and nondiffractive cross sections for dijet production in proton-antiproton collisions at the Tevatron. By comparing their ratio to the data published by the CDF collaboration for two different center-of-mass energies, we deduce the rapidity-gap survival probability as a function of the momentum fraction of the parton in the antiproton. Assuming Regge Factorization, this probability can be interpreted as a Suppression Factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the Suppression Factor in proton-antiproton collisions depends on the momentum fraction of the parton in the Pomeron even at next-to-leading order.
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Survival probability for diffractive dijet production in p-pbar collisions from next-to-leading order calculations
Physical Review D, 2009Co-Authors: Michael Klasen, Gustav KramerAbstract:We perform next-to-leading order calculations of the single-diffractive and non-diffractive cross sections for dijet production in proton-antiproton collisions at the Tevatron. By comparing their ratio to the data published by the CDF collaboration for two different center-of-mass energies, we deduce the rapidity-gap survival probability as a function of the momentum fraction of the parton in the antiproton. Assuming Regge Factorization, this probability can be interpreted as a Suppression Factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the Suppression Factor in proton-antiproton collisions depends on the momentum fraction of the parton in the Pomeron even at next-to-leading order.
Gustav Kramer - One of the best experts on this subject based on the ideXlab platform.
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Suppression Factors in diffractive photoproduction of dijets
The European Physical Journal C, 2010Co-Authors: Michael Klasen, Gustav KramerAbstract:Now that new publications of H1 data for the diffractive photoproduction of dijets, which overlap with the earlier published H1 data and the recently published data of the ZEUS collaboration, have appeared, we have recalculated the cross sections for this process in next-to-leading order (NLO) of perturbative QCD to see whether they can be interpreted consistently. The results of these calculations are compared to the data of both collaborations. We find that the NLO cross sections disagree with the data, showing that Factorization breaking occurs at that order. If direct and resolved contributions are both suppressed by the same amount, the global Suppression Factor depends on the transverse-energy cut. However, by suppressing only the resolved contribution, also reasonably good agreement with all the data is found with a Suppression Factor independent of the transverse-energy cut.
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Survival probability for diffractive dijet production in pp̄ collisions from next-to-leading order calculations
Physical Review D, 2009Co-Authors: Michael Klasen, Gustav KramerAbstract:We perform next-to-leading order calculations of the single-diffractive and nondiffractive cross sections for dijet production in proton-antiproton collisions at the Tevatron. By comparing their ratio to the data published by the CDF collaboration for two different center-of-mass energies, we deduce the rapidity-gap survival probability as a function of the momentum fraction of the parton in the antiproton. Assuming Regge Factorization, this probability can be interpreted as a Suppression Factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the Suppression Factor in proton-antiproton collisions depends on the momentum fraction of the parton in the Pomeron even at next-to-leading order.
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Survival probability for diffractive dijet production in p-pbar collisions from next-to-leading order calculations
Physical Review D, 2009Co-Authors: Michael Klasen, Gustav KramerAbstract:We perform next-to-leading order calculations of the single-diffractive and non-diffractive cross sections for dijet production in proton-antiproton collisions at the Tevatron. By comparing their ratio to the data published by the CDF collaboration for two different center-of-mass energies, we deduce the rapidity-gap survival probability as a function of the momentum fraction of the parton in the antiproton. Assuming Regge Factorization, this probability can be interpreted as a Suppression Factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the Suppression Factor in proton-antiproton collisions depends on the momentum fraction of the parton in the Pomeron even at next-to-leading order.
Takayuki Kubo - One of the best experts on this subject based on the ideXlab platform.
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field limit and nano scale surface topography of superconducting radio frequency cavity made of extreme type ii superconductor
Progress of Theoretical and Experimental Physics, 2015Co-Authors: Takayuki KuboAbstract:The field limit of superconducting radio-frequency cavity made of type II superconductor with a large Ginzburg-Landau parameter is studied with taking effects of nano-scale surface topography into account. If the surface is ideally flat, the field limit is imposed by the superheating field. On the surface of cavity, however, nano-defects almost continuously distribute and suppress the superheating field everywhere. The field limit is imposed by an effective superheating field given by the product of the superheating field for ideal flat surface and a Suppression Factor that contains effects of nano-defects. A nano-defect is modeled by a triangular groove with a depth smaller than the penetration depth. An analytical formula for the Suppression Factor of bulk and multilayer superconductors are derived in the framework of the London theory. As an immediate application, the Suppression Factor of the dirty Nb processed by the electropolishing is evaluated by using results of surface topographic study. The estimated field limit is consistent with the present record field of nitrogen-doped Nb cavities. For a further improvement of field, a surface processing technology that can realize a surface with a smaller slope-angle distribution is necessary. Suppression Factors of surfaces of other bulk and multilayer superconductors, and those after various surface processing technologies can also be evaluated by using the formula.
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field limit and nano scale surface topography of superconducting radio frequency cavity made of extreme type ii superconductor
arXiv: Accelerator Physics, 2014Co-Authors: Takayuki KuboAbstract:The field limit of superconducting radio-frequency cavity made of type II superconductor with a large Ginzburg-Landau parameter is studied with taking effects of nano-scale surface topography into account. If the surface is ideally flat, the field limit is imposed by the superheating field. On the surface of cavity, however, nano-defects almost continuously distribute and suppress the superheating field everywhere. The field limit is imposed by an effective superheating field given by the product of the superheating field for ideal flat surface and a Suppression Factor that contains effects of nano-defects. A nano-defect is modeled by a triangular groove with a depth smaller than the penetration depth. An analytical formula for the Suppression Factor of bulk and multilayer superconductors are derived in the framework of the London theory. As an immediate application, the Suppression Factor of the dirty Nb processed by the electropolishing is evaluated by using results of surface topographic study. The estimated field limit is consistent with the present record field of nitrogen-doped Nb cavities. Suppression Factors of surfaces of other bulk and multilayer superconductors, and those after various surface processing technologies can also be evaluated by using the formula.
Ben-hao - One of the best experts on this subject based on the ideXlab platform.
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Increase of Effective String Tension and Production of Strange Particles
Physics Letters B, 1997Co-Authors: Ben-haoAbstract:The increase of effective string tension as a result of the hard gluon kinks on a string is investigated using a parametrization form. In this form the effective string tension increasing with energies in hadron-hadron collisions is due to the mini-jet (gluon) production in the collisions. The data of the energy dependence of the strange quark Suppression Factor in hh collisions are very well reproduced with this mechanism. Meanwhile, the experimental phenomena of approximate energy independence of the strange quark Suppression Factor in e$^+$e$^-$-annihilations are discussed.
Lei Gao - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation on the Suppression Factor in subcooled boiling flow
Applied Thermal Engineering, 2018Co-Authors: Lin Chen, Pei Zhou, Ronghua Huang, Xi Han, Shiyang Hua, Lei GaoAbstract:Abstract Subcooled boiling flow is the optimal choice for engine cooling system design, as no essential changes in its architecture are required while it is still possible to take advantage of the highest rates of heat transfer associated with nucleate boiling. The Chen's model is widely used for heat transfer coefficient (HTC) prediction in practical application conditions. However, direct validation based on experimental data upon the phenomenon interpreted by ‘Suppression Factor’ in the boiling component of Chen’s model is rarely shown in previous literatures. The present work conducted an experimental study on heat transfer from the bottom side of a rectangular heated block heated by the heating device to the upper side cooled by an internally flowing fluid in a rectangular channel. Tests were operated under representative pressure and temperature conditions with heat transfer coefficient (HTC) obtained in almost all the practical application velocity of flow. Results show that in the fully developed boiling region (FDB) the subcooled boiling heat transfer coefficient decreases as the flow velocity speeds up, which provides direct evidence for the validity of Chen's model. However, the wall heat transfer coefficient predicted by Chen's model doesn’t fit well with the present experimental data. Regarding this, a modified heat transfer model based on Chen style model for subcooled boiling flow is proposed. The HTC predicted by the modified model coincides well with the experimental data for all considered flow conditions in this paper.
