Cross sections and decay rates

1986 ◽  
pp. 83-130
Author(s):  
B. DE WIT ◽  
J. SMITH
Keyword(s):  
Cross Sections ◽  
Decay Rates

scholarly journals Nuclear Physics of the s Process

2008 ◽  
Vol 25 (1) ◽  
pp. 18-29 ◽  
Author(s):  
I. Dillmann ◽  
C. Domingo Pardo ◽  
F. Käppeler ◽  
A. Mengoni ◽  
K. Sonnabend
Keyword(s):  
Cross Sections ◽  
Nuclear Physics ◽  
State Of The Art ◽  
Decay Rates ◽  
Radioactive Isotopes ◽  
Complementary Information ◽  
The Status ◽  
Direct Input ◽  
New Facilities ◽  
Capture Cross Sections

AbstractStarting from a sketch of the s-process concept formulated 50 years ago, the nuclear physics data for s-process calculations are briefly reviewed with emphasis on the status of neutron capture cross sections and beta decay rates. Accurate and comprehensive experimental data are mandatory as direct input for s-process calculations as well as for improving the complementary information from nuclear theory. The current challenges of the field are discussed in the light of new or optimized methods and state-of-the-art facilities, indicating the potential for accurate measurements and the possibility to study cross sections of radioactive isotopes. These opportunities will be considerably enriched by the enormous improvements provided by new facilities.

Saint-Venant Decay Rates for the Rectangular Cross Section Rod

2004 ◽  
Vol 71 (3) ◽  
pp. 429-433 ◽  
Author(s):  
N. G. Stephen ◽  
P. J. Wang
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Transfer Matrix ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Decay Rates ◽  
Elastic Rod ◽  
Cross Sectional ◽  
Element Transfer

A finite element-transfer matrix procedure developed for determination of Saint-Venant decay rates of self-equilibrated loading at one end of a semi-infinite prismatic elastic rod of general cross section, which are the eigenvalues of a single repeating cell transfer matrix, is applied to the case of a rectangular cross section. First, a characteristic length of the rod is modelled within a finite element code; a superelement stiffness matrix relating force and displacement components at the master nodes at the ends of the length is then constructed, and its manipulation provides the transfer matrix, from which the eigenvalues and eigenvectors are determined. Over the range from plane stress to plane strain, which are the extremes of aspect ratio, there are always eigenmodes which decay slower than the generalized Papkovitch-Fadle modes, the latter being largely insensitive to aspect ratio. For compact cross sections, close to square, the slowest decay is for a mode having a distribution of axial displacement reminiscent of that associated with warping during torsion; for less compact cross sections, slowest decay is for a mode characterized by cross-sectional bending, caused by self-equilibrated twisting moment.

scholarly journals Interaction of real and virtual NN̅ pairs in J/ψ decays

2018 ◽  
Vol 181 ◽  
pp. 01020
Author(s):  
Alexander Milstein ◽  
Sergey Salnikov
Keyword(s):  
Experimental Data ◽  
Mass Spectrum ◽  
Invariant Mass ◽  
Cross Sections ◽  
Energy Region ◽  
Mass Spectra ◽  
Optical Potential ◽  
Invariant Mass Spectrum ◽  
Decay Rates ◽  
Angular Distributions

The differential decay rates of the processes J/ψ→pp̅π0, J/ψ→pp̅η, J/ψ→pp̅ω, J/ψ→pp̅ρ, and J/ψ→pp̅γ close to the pp̅ threshold are calculated with the help of the NN̅ optical potential. We use the potential which has been suggested to fit the cross sections of NN̅ scattering together with all other NN̅ experimental data available. The pp̅ nvariant mass spectra of J/ψ decays are in agreement with the available experimental data. The anisotropy of the angular distributions of the decays J/ψ→pp̅π0(η), which appears due to the tensor forces in the NN̅ interaction, is predicted close to the pp̅ threshold. This anisotropy is large enough to be investigated experimentally. Such measurements would allow one to check the accuracy of the model of NN̅ interaction, is predicted close to the pp̅ threshold. This anisotropy is large enough to be investigated experimentally. Such measurements would allow one to check the accuracy of the model of NN̅ interaction. Using our potential and the Green’s function approach we also describe the peak in the η′ π+ π- invariant mass spectrum in the decay J/ψ → γ η′ π+ π- in the energy region near the NN̅ threshold.

scholarly journals Color-octet scalars in Dirac gaugino models with broken R symmetry

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Linda M. Carpenter ◽  
Taylor Murphy
Keyword(s):  
Large Hadron Collider ◽  
Symmetry Breaking ◽  
Supersymmetry Breaking ◽  
Cross Sections ◽  
Hadron Collider ◽  
Scalar Particle ◽  
Decay Rates ◽  
Collider Phenomenology ◽  
Color Octet ◽  
Supersymmetric Models

Abstract In this work we study the collider phenomenology of color-octet scalars (sgluons) in supersymmetric models with Dirac gaugino masses that feature an explicitly broken R symmetry (R-broken models). We construct such models by augmenting minimal R-symmetric models with a fairly general set of supersymmetric and softly supersymmetry-breaking operators that explicitly break R symmetry. We then compute the rates of all significant two-body decays and highlight new features that appear as a result of R symmetry breaking, including enhancements to extant decay rates, novel tree- and loop-level decays, and improved cross sections of single sgluon production. We demonstrate in some detail how the familiar results from minimal R-symmetric models can be obtained by restoring R symmetry. In parallel to this discussion, we explore constraints on these models from the Large Hadron Collider. We find that, in general, R symmetry breaking quantitatively affects existing limits on color-octet scalars, perhaps closing loopholes for light CP-odd (pseudoscalar) sgluons while opening one for a light CP-even (scalar) particle. Qualitatively, however, we find that — much as for minimal R-symmetric models, despite stark differences in phenomenology — scenarios with broken R symmetry and two sgluons below the TeV scale can be accommodated by existing searches.

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