Weise, Christian: Sämtliche Werke, Band 18, Romane II

Weise, Christian; Roloff, Hans-Gert; Susen, Gerd-Hermann

doi:10.1515/9783110903669

Cited by 5 publications

(6 citation statements)

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“…Our derivation, presented in the appendix, agrees in size and sign with [38]. Indeed, the authors of [40] agree now that the sign of the Landau damping term used in [10,38] is the correct one [41]. Nonetheless, a downward mass shift and agreement with the sum rules has already been reported in [10] where the Landau damping term has the same sign as in [38].…”

Section: Introductionsupporting

confidence: 78%

Weighted finite energy sum rules for the omega meson in nuclear matter

Steinmüller

Leupold

2006

Nuclear Physics A

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The possible in-medium changes of the properties of an omega meson placed in cold nuclear matter are constrained by QCD sum rules. It is shown that the sum rules cannot fully determine the in-medium spectral shape of the omega meson. However, for a given parameterization the sum rules can constrain or correlate the hadronic parameters. It is shown that weighted finite energy sum rules provide a proper framework to study directly these constraints/correlations. Two typical parameterizations of possible in-medium omega spectra are analyzed, namely (i) a one-peak structure with arbitrary position and width of the peak and (ii) a structure with two (narrow) peaks, caused by the genuine omega meson and a resonance-hole branch. The sum rules provide for case (i) a mass-width correlation and for case (ii) a correlation between the peak heights and the peak position of the omega branch. It is also analyzed how the obtained results depend on the size of the relevant four-quark operator evaluated with respect to a nucleon. Finally it is argued that a strict vector meson dominance scenario is not compatible with the sum rules.Comment: 14 page

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Section: Introductionsupporting

confidence: 78%

Weighted finite energy sum rules for the omega meson in nuclear matter

Steinmüller

Leupold

2006

Nuclear Physics A

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“…It must be preserved by any viable truncation scheme of the SDE-BSE coupled system. It is the preservation of this identity which proves useful in obtaining the defining characteristics of the octet of pseudoscalar mesons, namely their low mass, their masslessness in the chiral limit, and the hadron mass splittings [2,39] The axial-vector vertex satisfies its own SDE, namely Γ 5µ (k; P ) = γ 5 γ µ + d 4 q (2π) 4 K(k, q; P )χ 5µ (q; P ) , (15) where the appropriate indices are contracted and K(k, q; P ) is the Bethe-Salpeter kernel that appears in the bound state Eq. ( 1).…”

Section: Axial-vector Ward-takahashi Identtiymentioning

confidence: 99%

Charmonia in a contact interaction

2015

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For the flavour-singlet heavy quark system of charmonia, we compute the masses of the ground state mesons in four different channels: pseudo-scalar (ηc(1S)), vector (J/Ψ(1S)), scalar (χc 0 (1P )) and axial vector (χc 1 (1P )), as well as the weak decay constants of the ηc(1S) and J/Ψ(1S) and the charge radius of ηc(1S). The framework for this analysis is provided by a symmetry-preserving Schwinger-Dyson equation (SDEs) treatment of a vector×vector contact interaction (CI). The results found for the meson masses and the weak decay constants, for the spin-spin combinations studied, are in fairly good agreement with experimental data and earlier model calculations based upon Schwinger-Dyson and Bethe-Salpeter equations (BSEs) involving sophisticated interaction kernels. The charge radius of ηc(1S) is consistent with the results from refined SDE studies and lattice Quantum Chromodynamics (QCD).

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“…Meanwhile electropolishing was developed in collaboration with KEK and significant improvements in gradients were realized. The average value improved from ~ 29 MV/m for standard BCP [18] to 35.6 MV/m for electropolished cavities [19]. Figure 9 shows results from vertical tests of several electropolished cavities.…”

Section: A) Ttfmentioning

confidence: 99%

Cavity preparation/assembly techniques and impact on Q, realistic Q-factors in a module, review of modules

Kneisel

2006

Nuclear Instruments and Methods in Physics Research Section A:

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This contribution summarizes the surface preparation procedures for niobium cavities presently used both in laboratory experiments and for modules, such as buffered chemical polishing (BCP), electropolishing (EP), high pressure ultrapure water rinsing (HPR), CO 2 snow cleaning and high temperature heat treatments for hydrogen degassing or postpurification. The impact of surface treatments and the degree of cleanliness during assembly procedures on cavity performance (Q -value and accelerating gradient E acc ) will be discussed.In addition, an attempt will be made to summarize the experiences made in module assemblies in different labs/projects such as DESY (TTF), Jlab (Upgrade) and SNS.

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Weise, Christian: Sämtliche Werke, Band 18, Romane II

Cited by 5 publications

References 0 publications

Weighted finite energy sum rules for the omega meson in nuclear matter

Weighted finite energy sum rules for the omega meson in nuclear matter

Charmonia in a contact interaction

Cavity preparation/assembly techniques and impact on Q, realistic Q-factors in a module, review of modules

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