scholarly journals A METHOD FOR EXTRACTING THE RESONANCE PARAMETERS FROM EXPERIMENTAL CROSS-SECTIONS

2013 ◽  
Vol 22 (05) ◽  
pp. 1350032 ◽  
Author(s):  
S. A. RAKITYANSKY ◽  
N. ELANDER
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Cross Sections ◽  
Single Channel ◽  
Analytic Structure ◽  
Resonance Parameters ◽  
S Matrix ◽  
Analytic Expressions ◽  
Data Points ◽  
Pseudo Data

Within the proposed method, a set of experimental data points are fitted using a multi-channel S-matrix. Then the resonance parameters are located as its poles on an appropriate sheet of the Riemann surface of the energy. The main advantage of the method is that the S-matrix is constructed in such a way that it has proper analytic structure, i.e. for any number of two-body channels, the branching at all the channel thresholds is represented via exact analytic expressions in terms of the channel momenta. The way the S-matrix is constructed makes it possible not only to locate multi-channel resonances but also to extract their partial widths as well as to obtain the scattering cross-section in the channels for which no data are available. The efficiency of the method is demonstrated by two model examples of a single-channel and a two-channel problems, where known resonance parameters are rather accurately reproduced by fitting the pseudo-data artificially generated using the corresponding potentials.

scholarly journals Color dipole picture of deep inelastic scattering, revisited

2016 ◽  
Vol 31 (30) ◽  
pp. 1650157 ◽  
Author(s):  
Masaaki Kuroda ◽  
Dieter Schildknecht
Keyword(s):  
Experimental Data ◽  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Photoabsorption Cross Section ◽  
Reduced Cross Section ◽  
Color Dipole ◽  
Analytic Expressions ◽  
Dipole Picture

Based upon the color-dipole picture, we provide closed analytic expressions for the longitudinal and the transverse photoabsorption cross-sections at low values of the Bjorken variable of [Formula: see text]. We compare with the experimental data for the longitudinal-to-transverse ratio of the (virtual) photoabsorption cross-section and with our previous fit to the experimental data for the total photoabsorption cross-section. Scaling in terms of the low-[Formula: see text] scaling variable [Formula: see text] is analyzed in terms of the reduced cross-section of deep inelastic scattering.

scholarly journals Testing Compound Nucleus Hypothesis Across the 17O Nucleus Excitation

2019 ◽  
Vol 211 ◽  
pp. 02001 ◽  
Author(s):  
Aloys Nizigama ◽  
Pierre Tamagno ◽  
Olivier Bouland
Keyword(s):  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Center Of Mass ◽  
Ground States ◽  
Mass System ◽  
Resonance Parameters ◽  
Second Stage ◽  
Reference Framework ◽  
Kinetic Transformation

The excited compound nucleus 17O* has been studied over (n,α) and (α,n) cross sections modelling, respectively for 16O and 13C targets in their ground states. The modelling is fulfilled within the Reich-Moore formalism. We were able to calculate the (α,n) cross section by two separate ways: the direct kinematic standard route and by inversion of the (n,α) cross section using the compound nucleus hypothesis. Resonance parameters of the resolved resonance range (0 to 6 MeV) were borrowed from the CIELO project. In a first stage, the modelling is carried out in the referential of the incident particle (either way neutron or α) requesting conversion of the CIELO neutron-type resonance parameters to the α-type. In a second stage, the implementation is uniquely designed in the center of mass system of the excited compound nucleus. The resonance parameters are thus converted in that unique reference framework. The present investigation shows the consistency of the kinetic transformation that relies on the compound nucleus hypothesis.

scholarly journals Resonant states 0+ of the Boron isotope 8B from the Jost-matrix analysis of the partial cross-sections

2019 ◽  
Vol 28 (10) ◽  
pp. 1950083
Author(s):  
S. A. Rakityansky ◽  
S. N. Ershov ◽  
T. J. Tshipi
Keyword(s):  
Experimental Data ◽  
Riemann Surface ◽  
Partial Wave ◽  
Coulomb Interaction ◽  
Cross Sections ◽  
Matrix Analysis ◽  
Analytic Structure ◽  
Square Root ◽  
Excitation Energies ◽  
Resonant States

The available [Formula: see text]-matrix parametrization of experimental data on the excitation functions for the elastic and inelastic [Formula: see text] scattering at the collision energies up to 3.4[Formula: see text]MeV is used to generate the corresponding partial-wave cross-sections in the states with [Formula: see text]. Thus, obtained data are fitted using the semi-analytic two-channel Jost matrix with a proper analytic structure and some adjustable parameters. Then the spectral points are sought as zeros of the Jost matrix determinant (which correspond to the [Formula: see text]-matrix poles) at complex energies. The correct analytic structure makes it possible to calculate the fitted Jost matrix on any sheet of the Riemann surface whose topology involves not only the square-root but also the logarithmic branching caused by the Coulomb interaction. In this way, two overlapping [Formula: see text] resonances at the excitation energies [Formula: see text] and [Formula: see text][Formula: see text]MeV have been found.

Production cross-section of heavy flavored hadrons in pp collision at s = 7 TeV

2019 ◽  
Vol 34 (19) ◽  
pp. 1950150 ◽  
Author(s):  
Muhammad Ajaz ◽  
Irfan Khan ◽  
M. K. Suleymanov
Keyword(s):  
Experimental Data ◽  
Transverse Momentum ◽  
Differential Cross Section ◽  
Cross Section ◽  
Momentum Distribution ◽  
Cross Sections ◽  
Production Cross ◽  
Center Of Mass ◽  
Transverse Momentum Distribution ◽  
Mass Frame

The transverse momentum distribution of the differential production cross-sections of heavy flavored charm hadrons [Formula: see text], [Formula: see text] in pp collisions at 7 TeV are simulated. Predictions of DPMJETIII.17-1, HIJING1.383 and Sibyll2.3c are compared to the differential cross-section measurements of the LHCb experimental data presented in the region of [Formula: see text] and [Formula: see text], where the pp center of mass frame is used to measure the transverse momentum and rapidity. The models reproduce only some regions of [Formula: see text] and/or bins of [Formula: see text] but none of them predict completely all the [Formula: see text] bins over the entire [Formula: see text] range.

Evaluation of Optical Model Potential Using Neutron Induced Cross Section Reaction for Spherical Uranium-238 Isotope up to 20MeV

2015 ◽  
Vol 59 ◽  
pp. 26-34
Author(s):  
Iman Tarik Al-Alawy ◽  
Ronak Ikram Ali
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Optical Model ◽  
Threshold Energy ◽  
Model Potential ◽  
Model Parameters ◽  
Incident Neutron ◽  
Optical Model Potential

The evaluation are based on mainly on the calculations of the nuclear optical model potential and relevant parameters are collected and selected from References Input Parameter Library (RIPL) which is being developed under the international project coordinated by the International Atomic Energy Agency (IAEA). The analyzing of a complete energy range has done starting from threshold energy for each reaction. The cross sections are reproduced in fine steps of incident neutron energy with 0.01MeV intervals with their corresponding errors. The recommended cross sections for available experimental data taken from EXFOR library have been calculated for all the considered neutron induced reactions for U-238 isotopes. The calculated results are analyzed and compared with the experimental data. The optimized optical potential model parameters give a very good agreement with the experimental data over the energy range 0.001-20MeV for neutron induced cross section reactions (n,f), (n,tot), (n,el), (n,inl), (n,2n), (n,3n), and (n,γ) for spherical U-238 target elements.

In-Plane Vibrations of Thick Circular Rings With T or I Cross Sections

1979 ◽  
Vol 46 (2) ◽  
pp. 470-472
Author(s):  
H. Lecoanet ◽  
J. Piranda
Keyword(s):  
Experimental Data ◽  
Eigenvalue Problem ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Circular Rings ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with the problem of eigenfrequencies and eigenvectors for rings whose cross section may be decomposed in basic rectangular cross sections. The solution is derived from a solution of the in-plane eigenvalue problem for rectangular cross-section thick rings. A good agreement between theoretical results and experimental data is obtained.

Axial Loading of Annular Bonded Rubber Blocks

2003 ◽  
Vol 76 (5) ◽  
pp. 1194-1211 ◽  
Author(s):  
J. M. Horton ◽  
G. E. Tupholme ◽  
M. J. C. Gover
Keyword(s):  
Experimental Data ◽  
Stress Distribution ◽  
Closed Form ◽  
Cross Section ◽  
Classical Theory ◽  
Cross Sections ◽  
Axial Loading ◽  
Theory Of Elasticity ◽  
Governing Equations ◽  
Annular Cross Section

Abstract Closed-form expressions are derived using a superposition approach for the axial deflection and stress distribution of axially loaded rubber blocks of annular cross-section, whose ends are bonded to rigid plates. These satisfy exactly the governing equations and conditions based upon the classical theory of elasticity. Readily calculable relationships are derived for the corresponding apparent Young's modulus, Ea, and the modified modulus, Ea′, and their numerical values are compared with the available experimental data. Elementary expressions for evaluating Ea and Ea′ approximately are deduced from these, in forms which are closely analogous to those given previously for blocks of circular and long, thin rectangular cross-sections. The profiles of the deformed lateral surfaces of the block are discussed and it is confirmed that the assumption of parabolic lateral profiles is not valid generally.

scholarly journals Statistical model calculations of the 7Li +11 Β reaction

2019 ◽  
Vol 10 ◽  
pp. 165
Author(s):  
C. Tsabaris ◽  
C. T. Papadopoulos ◽  
R. Vlastou ◽  
A. A. Pakou ◽  
P. A. Assimakopoulos ◽  
...  
Keyword(s):  
Experimental Data ◽  
Statistical Model ◽  
Energy Range ◽  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Reaction Channel ◽  
Model Calculations ◽  
The Individual

The 7Li + 11 Β reaction has been studied in the energy range from a little below to about three times the Coulomb barrier by measuring the cross section of the 7- ray transitions in the residual nuclei produced. Statistical compound nucleus calculations have been performed in order to interpret the experimental data as well as to extract cross sections of the individual exit channels. The statistical compound nucleus theory can reproduce rather well the absolute j - ray and the various reaction channel excitation functions.

scholarly journals Numerical simulation of the transverse flow over spans of girder bridges

2018 ◽  
Vol 18 (4) ◽  
pp. 362-378
Author(s):  
Yu. A. Gosteev ◽  
A. D. Obukhovskiy ◽  
S. D. Salenko
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Cross Section ◽  
Cross Sections ◽  
Aerodynamic Characteristics ◽  
Transverse Flow ◽  
Single Beam ◽  
Weighted Estimates ◽  
Girder Bridges ◽  
The Cross

Introduction. The technique of numerical modeling of the transverse flow over span structures of bridges on the basis of the two-dimensional URANS (Unsteady Reynolds-averaged Navier-Stokes) approach used in the modern methods and software packages for computational fluid dynamics is verified. The work objective was debugging and experimental substantiation of this technique with the use of the database on the aerodynamic characteristics of the cross-sections of span structures of girder bridges of standard shapes pre-developed by the authors.Materials and Methods. A numerical simulation of the transverse flow of low-turbulent (smooth) and turbulent air flows around the bridge structures in a range of practically interesting attack angles is carried out. SST  k − ω turbulence model was used as the closing one. The technique was preliminarily tested on the check problem for the flow of the rectangular crosssection beams. Calculations were carried out using the licensed ANSYS software.Research Results. The calculated dependences on the attack angle of the aerodynamic coefficients of forces (drag and lift) and the moment of the cross sections of the girder bridges of standard shapes are obtained. These data refer to the span structures at the construction phase (without deck and parapets, without parapets) and operation phase, under the conditions of model smooth and turbulent incoming flow. The latter allows us to outline the boundaries for more weighted estimates of the aerodynamic characteristics of thegirder bridges in a real wind current. The best agreement with the experimental data was obtained from the drag of the cross-section. The magnitude of the lifting force is more sensitive to the presence and extent of the separation regions, so its numerical determination is less accurate. The reproduction of the angle-of-attack effect on the aerodynamic moment of the cross-section is the most challenging for the majority of configurations.Discussion and Conclusions. Comparison of the calculated and experimental data indicates the applicability of the URANS approach to the operational prediction of the aerodynamic characteristics of the single-beam span structures. In the case of multi-beam span structures, where the aerodynamic interference between separate girders plays an important role, the URANS approach must apparently give way to more accurate eddy-resolving methods. The results obtained can be used in the aerodynamic analysis of structures and in practice of the relevant design organizations in the field of transport construction.

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