The cross-sections and angular distributions of the D—D reactions between 150 and 450 keV

1954 ◽  
Vol 226 (1165) ◽  
pp. 206-216 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Deuteron Beam ◽  
Angular Distributions ◽  
Centre Of Mass ◽  
Mass System ◽  
Gas Target ◽  
Neutron Reaction ◽  
The Cross ◽  
Bombarding Energy

A thin gas target was used and the 3 He and 3 H particles from the reactions were counted in two proportional counters which were rotated to make angles between 20 and 135° (in the centre-of-mass system) with the incident deuteron beam. In contradiction to data previously published for this energy range, the angular distributions of the reactions are different, the asymmetry of the neutron-producing reaction being the greater. The total cross-section of the neutron reaction is greater than that of the proton reaction; the ratio of the cross-sections increases with bombarding energy.

The cross-section and angular distribution of the D-D reactions below 50 keV

1953 ◽  
Vol 216 (1124) ◽  
pp. 57-65 ◽  
Keyword(s):  
Angular Distribution ◽  
Total Cross Section ◽  
Cross Section ◽  
Proportional Counter ◽  
Angular Distributions ◽  
Asymmetry Coefficient ◽  
Gas Target ◽  
The Asymmetry ◽  
The Cross ◽  
Bombarding Energy

A thin gas target was used and the particles from the reactions were detected by a proportional counter. The results show that the total cross-section for the two reactions is the same to within 1%, but that the angular distributions of the products are significantly different. The asymmetry coefficient for the reaction D( d , n ) 3 He is given by 0·31 + 0·0058 E , compared with 0·13 + 0·0047 E for reaction D( d , p ) 3 H, where E is the bombarding energy in kilovolts.

Studies of nuclear collisions involving 8 MeV deuterons by the photographic method III. Angular distribution of the charged particles produced by the bombardment of hydrogen and deuterium

1951 ◽  
Vol 209 (1099) ◽  
pp. 489-501 ◽  
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Cross Sections ◽  
Charged Particles ◽  
Elastic Collision ◽  
Angular Distributions ◽  
Centre Of Mass ◽  
Mass System ◽  
Nuclear Collisions ◽  
Nuclear Processes

Apparatus previously described has been used to study the angular distribution of the charged particles from nuclear processes initiated by 8 MeV deuterons. The experimental technique and the method of obtaining relative values of the yield at different angles in the centre-of-mass system are described. Results of measurements on the elastic collision of deuterons with protons are given, together with an account of the method for obtaining absolute values of cross-sections from the relative values, using the known cross-section for this process measured by other experimenters. Angular distributions obtained for deuterons elastically scattered by deuterons, and for protons from the reaction 2 H ( d , p ) 3 H, are produced, and their interpretation discussed.

scholarly journals PROMPT PHOTON PRODUCTION IN p-p COLLISIONS

1995 ◽  
Vol 10 (20n21) ◽  
pp. 2941-2960 ◽  
Author(s):  
J. CLEYMANS ◽  
E. QUACK ◽  
K. REDLICH ◽  
D.K. SRIVASTAVA
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Cross Sections ◽  
Systematic Study ◽  
Structure Functions ◽  
Photon Production ◽  
Prompt Photon ◽  
Centre Of Mass ◽  
The Cross ◽  
Photon Cross Section

A systematic study of the inclusive photon cross-section in p-p collisions is presented. The dependence of the γ rates on the renormalization and factorization scales is discussed. A comparison is made with experimental data for centre-of-mass energies ranging from 23 GeV to 1.8 TeV. Predictions of the cross-sections are given for two different sets of structure functions for RHIC and LHC energies.

scholarly journals Twist-3 contributions to $$\gamma \gamma \rightarrow \pi ^+\pi ^-,K^+K^-$$ processes in perturbative QCD approach

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
Cong Wang ◽  
Jun-Kang He ◽  
Ming-Zhen Zhou
Keyword(s):  
Perturbative Qcd ◽  
Cross Section ◽  
Cross Sections ◽  
Degrees Of Freedom ◽  
Intermediate Energy ◽  
Angular Distributions ◽  
Experimental Measurements ◽  
Belle Ii ◽  
The Cross ◽  
Near Future

Abstract As one of the simplest hadronic processes, $$\gamma \gamma \rightarrow M^{+}M^{-}$$γγ→M+M- ($$M=\pi ,K$$M=π,K) could be a good testing ground for our understanding of the perturbative and nonperturbative structure of QCD, and will be studied with high precision at BELLE-II in the near future. In this paper, we revisit these processes with twist-3 corrections in the perturbative QCD approach based on the $$k_{T}$$kT factorization theorem, in which transverse degrees of freedom as well as resummation effects are taken into account. The influence of the distribution amplitudes on the cross sections are discussed in detail. Our work shows that not only the transverse momentum effects but also the twist-3 corrections play a significant role in the processes $$\gamma \gamma \rightarrow M^{+}M^{-}$$γγ→M+M- in the intermediate energy region. Especially in the few GeV region, the twist-3 contributions become dominant in the cross sections. And it is noteworthy that both the twist-3 result of the $$\pi ^{+}\pi ^{-}$$π+π- cross section and that of the $$K^{+}K^{-}$$K+K- cross section agree well with the BELLE and ALEPH measurements. For the pion and kaon angular distributions, there still exist discrepancies between our results and the experimental measurements. Possible reasons for these discrepancies are discussed briefly.

Possible structure dependence in the Al reaction

1979 ◽  
Vol 57 (11) ◽  
pp. 1949-1951 ◽  
Author(s):  
M. A. M. Shahabuddin ◽  
J. C. Waddington
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Angular Distributions ◽  
Structure Dependence ◽  
Analyzing Powers ◽  
The Cross ◽  
Back Angle ◽  
Analyzing Power

In the [Formula: see text] Al reaction at Ep = 17.0 MeV, the cross section and analyzing power angular distributions for several Jπ = 5/2+ states are found to be quite different. Except for the ground state, neither the back angle cross sections nor the analyzing powers for these states can be reproduced by cluster DWBA or CCBA calculations. It is thus inferred that this might be due to the dependence of the reaction on the structure of these states.

scholarly journals Dissoziation von H2+ und H3+ beim Stoß an Kr im Energiebereich 6 – 60 keV / Dissociation of H2+ and H3+ by Collision with Kr in the Energy Range between 6 to 60 keV

1976 ◽  
Vol 31 (11) ◽  
pp. 1303-1307 ◽  
Author(s):  
B. Lehmann
Keyword(s):  
Radio Frequency ◽  
Energy Range ◽  
Cross Section ◽  
Charge Exchange ◽  
Cross Sections ◽  
Ion Source ◽  
Energy Curve ◽  
Gas Target ◽  
The Cross

Abstract H2+ and H3+ ions, produced in a H2 plasma of a radio-frequency ion source, were accelerated to 6-60 keV and directed into a gas target of Krypton. The cross sections for the formation of H+ and H- resp. H2+, H+ and H- have been measured. In the case of H+, obtained from the dissociation of H2+, 2 maxima have been found in the present energy range. A third is known to be at about 100 keV. We discuss the applicability of the Massey' adiabatic hypothesis, known from the analysis of charge-exchange experiments, to the maxima in the cross-section vs. energy curve for dissociation experiments.

scholarly journals Measurement of beauty and charm production in pp collisions at $$ \sqrt{s} $$ = 5.02 TeV via non-prompt and prompt D mesons

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
A. Adler ◽  
J. Adolfsson ◽  
...  
Keyword(s):  
Perturbative Qcd ◽  
Cross Section ◽  
Cross Sections ◽  
D Mesons ◽  
Production Cross ◽  
D Meson ◽  
Precise Determination ◽  
Centre Of Mass ◽  
Alice Experiment ◽  
The Cross

Abstract The pT-differential production cross sections of prompt and non-prompt (produced in beauty-hadron decays) D mesons were measured by the ALICE experiment at midrapidity (|y|< 0.5) in proton-proton collisions at $$ \sqrt{s} $$ s = 5.02 TeV. The data sample used in the analysis corresponds to an integrated luminosity of (19.3 ± 0.4) nb−1. D mesons were reconstructed from their decays D0→ K−π+, D+→ K−π+π+, and $$ {\mathrm{D}}_{\mathrm{s}}^{+}\to \upphi {\uppi}^{+}\to {\mathrm{K}}^{-}{\mathrm{K}}^{+}{\uppi}^{+} $$ D s + → ϕ π + → K − K + π + and their charge conjugates. Compared to previous measurements in the same rapidity region, the cross sections of prompt D+ and $$ {\mathrm{D}}_{\mathrm{s}}^{+} $$ D s + mesons have an extended pT coverage and total uncertainties reduced by a factor ranging from 1.05 to 1.6, depending on pT, allowing for a more precise determination of their pT-integrated cross sections. The results are well described by perturbative QCD calculations. The fragmentation fraction of heavy quarks to strange mesons divided by the one to non-strange mesons, fs/(fu + fd), is compatible for charm and beauty quarks and with previous measurements at different centre-of-mass energies and collision systems. The $$ \mathrm{b}\overline{\mathrm{b}} $$ b b ¯ production cross section per rapidity unit at midrapidity, estimated from non-prompt D-meson measurements, is $$ \mathrm{d}{\sigma}_{\mathrm{b}\overline{\mathrm{b}}}/\mathrm{d}y\left|{}_{\left|\mathrm{y}\right|<0.5}=34.5\pm 2.4{\left(\mathrm{stat}\right)}_{-2.9}^{+4.7}\left(\mathrm{tot}.\mathrm{syst}\right)\right. $$ d σ b b ¯ / d y y < 0.5 = 34.5 ± 2.4 stat − 2.9 + 4.7 tot . syst μb. It is compatible with previous measurements at the same centre-of-mass energy and with the cross section pre- dicted by perturbative QCD calculations.

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

scholarly journals Total cross sections of eγ → $$ eX\overline{X} $$ processes with X = μ, γ, e via multiloop methods

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Roman N. Lee ◽  
Alexey A. Lyubyakin ◽  
Vyacheslav A. Stotsky
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Elliptic Integral ◽  
High Energy ◽  
Calculation Methods ◽  
Complete Elliptic Integral ◽  
Total Cross Sections ◽  
Multiloop Calculation ◽  
The Cross ◽  
Analytical Expressions

Abstract Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes e−γ →$$ {e}^{-}X\overline{X} $$ e − X X ¯ with X = μ, γ or e at arbitrary energies. For the first two processes our results are expressed via classical polylogarithms. The cross section of e−γ → e−e−e+ is represented as a one-fold integral of complete elliptic integral K and logarithms. Using our results, we calculate the threshold and high-energy asymptotics and compare them with available results.

scholarly journals Asymptotic Behavior of Stable Structures Made of Beams

2021 ◽  
Author(s):  
Georges Griso ◽  
Larysa Khilkova ◽  
Julia Orlik ◽  
Olena Sivak
Keyword(s):  
Asymptotic Behavior ◽  
Cross Section ◽  
Cross Sections ◽  
Linear Elasticity ◽  
Circular Cross Section ◽  
Linear Elasticity Theory ◽  
Linear Elastic ◽  
The Cross ◽  
Small Rotation ◽  
Stable Structures

AbstractIn this paper, we study the asymptotic behavior of an $\varepsilon $ ε -periodic 3D stable structure made of beams of circular cross-section of radius $r$ r when the periodicity parameter $\varepsilon $ ε and the ratio ${r/\varepsilon }$ r / ε simultaneously tend to 0. The analysis is performed within the frame of linear elasticity theory and it is based on the known decomposition of the beam displacements into a beam centerline displacement, a small rotation of the cross-sections and a warping (the deformation of the cross-sections). This decomposition allows to obtain Korn type inequalities. We introduce two unfolding operators, one for the homogenization of the set of beam centerlines and another for the dimension reduction of the beams. The limit homogenized problem is still a linear elastic, second order PDE.

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