scholarly journals TWO-PHOTON ANNIHILATION INTO PROTON-ANTIPROTON IN A QUARK-DIQUARK SCHEME

1989 ◽  
Vol 04 (19) ◽  
pp. 5213-5234 ◽  
Author(s):  
M. ANSELMINO ◽  
F. CARUSO ◽  
P. KROLL ◽  
W. SCHWEIGER
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Cross Section ◽  
Electromagnetic Form Factor ◽  
Wave Functions ◽  
Proton Antiproton ◽  
Unpolarized Cross Section ◽  
Two Photon ◽  
Photon Annihilation ◽  
Good Agreement

We consider [Formula: see text] in the framework of the Brodsky-Farrar-Lepage scheme allowing for (scalar) diquarks as quasi-elementary constituents. We compute the unpolarized cross section using different proton wave functions. Their normalization is fixed by computing the electromagnetic form factor of the proton in the same framework. Good agreement with the experimental data can be obtained. Two-photon annihilation into other baryons is also discussed.

Prediction of rms charge radius of proton using proton-proton elastic scattering data at TeV

2021 ◽  
Vol 67 (3 May-Jun) ◽  
pp. 491
Author(s):  
S. Zahra ◽  
B. Shafaq
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Elastic Scattering ◽  
Cross Section ◽  
Charge Radius ◽  
Scattering Data ◽  
Proton Proton ◽  
Proton Elastic Scattering ◽  
Predicted Values ◽  
Good Agreement

Using  proton–proton elastic scattering data  at  TeV and squared four-momentum transfer 0.36 < -t <  0.76 (GeV/c)2 for 13 σBeam distance  and  0.07 < -t <  0.46 (GeV/c)2 for 4.3 σBeam distance, form factor of proton is predicted. Simplest version of Chou–Yang model is employed to extract the form factor by fitting experimental data of differential cross section from TOTEM experiment (for 13σBeamand 4.3 σBeam distance) to a single Gaussian. Root mean square (rms) charge radius of proton is calculated using this form factor.  It is found to be equal to 0.91 fm and 0.90 fm respectively. Which is in good agreement with experimental data and theoretically predicted values.

scholarly journals A study of the process e+ + e−→ e+ + e− + p + p̄ by the two-photon mechanism γγ → pp̄ at high energies

2017 ◽  
Vol 32 (18) ◽  
pp. 1750104 ◽  
Author(s):  
Azad I. Ahmadov
Keyword(s):  
Experimental Data ◽  
Total Cross Section ◽  
Cross Section ◽  
Beam Energy ◽  
Center Of Mass ◽  
Proton Antiproton ◽  
Exclusive Production ◽  
Two Photon ◽  
High Energies ◽  
Energy Formula

In this paper, we consider the exclusive production of proton–antiproton pairs in the interaction between two quasireal photons in [Formula: see text] collision. The differential and total cross-section of the process [Formula: see text] at a beam energy of photons from 2.1 GeV to 4.5 GeV in the center-of-mass and for different values of [Formula: see text] is calculated. At energy [Formula: see text] the total cross-section process of the [Formula: see text] is calculated by the two-photon mechanism. The results are in satisfactory agreement with the experimental data.

scholarly journals Prediction of Rms Charge Radius of Proton Using Proton–Proton Elastic Scattering Data at TeV

2021 ◽  
Vol 67 (3 May-Jun) ◽  
Author(s):  
Sarwat Zahra ◽  
Bushra Shafaq
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
Elastic Scattering ◽  
Cross Section ◽  
Charge Radius ◽  
Scattering Data ◽  
Proton Proton ◽  
Proton Elastic Scattering ◽  
Predicted Values ◽  
Good Agreement

Using  proton–proton elastic scattering data  at  TeV and squared four-momentum transfer 0.36 < -t <  0.76 (GeV/c)2 for 13 σBeam distance  and  0.07 < -t <  0.46 (GeV/c)2 for 4.3 σBeam distance, form factor of proton is predicted. Simplest version of Chou–Yang model is employed to extract the form factor by fitting experimental data of differential cross section from TOTEM experiment (for 13σBeamand 4.3 σBeam distance) to a single Gaussian. Root mean square (rms) charge radius of proton is calculated using this form factor.  It is found to be equal to 0.91 fm and 0.90 fm respectively. Which is in good agreement with experimental data and theoretically predicted values.

scholarly journals Assessing the Instantaneous Stiffness of Cracked Reinforced Concrete Beams Based on a Gradual Change in Strain Distributions

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Chunyu Fu ◽  
Dawei Tong ◽  
Yuyang Wang
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Beams ◽  
Internal Force ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Gradual Change ◽  
Concrete Cracking ◽  
Good Agreement

Concrete cracking causes a gradual change in strain distributions along the cross section height of reinforced concrete beams, which will finally affect their instantaneous stiffness. A method for assessing the stiffness is proposed based on the gradual change, which is considered through modeling different strain distributions for key sections in cracked regions. Internal force equilibria are adopted to find a solution to top strains and neutral axes in the models, and then the inertias of the key sections are calculated to assess the beam stiffness. The proposed method has been validated using experimental results obtained from tests on five reinforced concrete beams. The predicted stiffness and displacements are shown to provide a good agreement with experimental data. The instantaneous stiffness is proven to greatly depend on the crack number and depth. This dependence can be exactly reflected by the proposed method through simulating the gradual change in concrete strain distributions.

Inelastic electric and magnetic electron scattering form factors of 24Mg nucleus: Role of g factors

2017 ◽  
Vol 26 (05) ◽  
pp. 1750032 ◽  
Author(s):  
Anwer A. Al-Sammarraie ◽  
M. L. Inche Ibrahim ◽  
Muna Ahmed Saeed ◽  
Fadhil I. Sharrad ◽  
Hasan Abu Kassim
Keyword(s):  
Experimental Data ◽  
Electron Scattering ◽  
Form Factors ◽  
Wave Functions ◽  
Matrix Elements ◽  
Model Hamiltonian ◽  
Transverse Electron ◽  
Magnetic Electron ◽  
Good Agreement

The electric and magnetic transitions in the [Formula: see text]Mg nucleus are studied based on the calculations of the longitudinal and the transverse electron scattering form factors. The universal sd-shell model Hamiltonian (USDA) is used for calculations. The wave functions of radial single-particle matrix elements are calculated using the Skyrme potential. For the longitudinal form factors, a good agreement is obtained between the calculations and the experimental data. For the transverse form factors, the effective [Formula: see text] factors are made as adjustable parameters in order to describe the experimental data.

The inner shell ionization of atoms by electron impact

1940 ◽  
Vol 36 (1) ◽  
pp. 43-52 ◽  
Author(s):  
E. H. S. Burhop ◽  
H. S. W. Massey
Keyword(s):  
Experimental Data ◽  
Electron Impact ◽  
Cross Section ◽  
Nickel Silver ◽  
Inner Shell Ionization ◽  
Good For ◽  
The Cross ◽  
Shell Ionization ◽  
Good Agreement

Calculations have been made of the cross-section for ionization of the inner shells of atoms by electron impact in the cases of the K-shells of nickel, silver, mercury and of the three L-shells of silver and mercury.The agreement with experiment is reasonably good for the K-shell ionization, but only fair in the case of the rather meagre experimental data available for the L-shell. The values obtained for the relative ionization in the K- and L-shells are in good agreement with those to be expected from experiment.

THEORY OF THE PRESSURE-INDUCED ROTATIONAL SPECTRUM OF HYDROGEN

1959 ◽  
Vol 37 (10) ◽  
pp. 1187-1198 ◽  
Author(s):  
J. Van Kranendonk ◽  
Z. J. Kiss
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Absorption Coefficient ◽  
Pair Distribution Function ◽  
Wave Functions ◽  
Rotational Line ◽  
Induction Effect ◽  
Rotational Spectrum ◽  
Absorption Coefficients ◽  
Good Agreement

The theory of induced infrared absorption developed previously is applied to the pressure-induced rotational spectrum of hydrogen. The intensity of the rotational band is due mainly to the quadrupolar induction effect, and to a small interference effect between the quadrupolar and overlap moments. From the experimental data on the binary absorption coefficients, values of the angle-dependent overlap moments are obtained for H2–He, H2–H2, H2–Ne, H2–N2, and H2–A. A calculation of the overlap moment for pure H2 is presented. Rosen-type wave functions appear to be inadequate for a calculation of the small angle-dependent rotational as well as vibrational overlap moments. The temperature dependence of the binary absorption coefficient is calculated, taking into account the quantum effects in the pair distribution function, and found to be in good agreement with the experimental data. The dependence on the ortho–para ratio is also discussed. The double rotational line S(1) + S(1) has been observed and its intensity measured.

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.

scholarly journals HIGHER TWIST EFFECTS IN PHOTON–PHOTON COLLISIONS

2008 ◽  
Vol 17 (06) ◽  
pp. 1041-1059 ◽  
Author(s):  
A. I. AHMADOV ◽  
I. BOZTOSUN ◽  
A. SOYLU ◽  
E. A. DADASHOV
Keyword(s):  
Wave Function ◽  
Cross Section ◽  
Cross Sections ◽  
Production Cross ◽  
Wave Functions ◽  
Feynman Diagrams ◽  
High Twist ◽  
Higher Twist Effects ◽  
Two Photon ◽  
Pion Wave Function

In this article, we investigate the contribution of the high twist Feynman diagrams to the large-pT single pseudoscalar and vector mesons inclusive production cross section in two-photon collisions and we present the general formulae for the high and leading twist differential cross sections. The pion wave function where two non-trivial Gegenbauer coefficients a2 and a4 have been extracted from the CLEO data, Braun–Filyanov pion wave function, the asymptotic and the Chernyak–Zhitnitsky wave functions are all used in the calculations. For ρ-meson we used the Ball–Braun wave function. The results of the calculations reveal that the high twist cross sections, the ratio R, the dependence transverse momentum pT and the rapidity y of meson in the Φ CLEO (x, Q2) wave function case is very close to the Φ asy (x) asymptotic wave function case. It is shown that the high twist contribution to the cross section depends on the choice of the meson wave functions.

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