Measurement of total cross sections (e+, Ne) and (e+, Ar)

1976 ◽  
Vol 54 (17) ◽  
pp. 1741-1748 ◽  
Author(s):  
J-S. Tsai ◽  
L. Lebow ◽  
D. A. L. Paul
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Scattering Amplitude ◽  
Scattering Length ◽  
Forward Scattering Amplitude ◽  
Sum Rule ◽  
Total Cross Sections ◽  
Scattering Lengths ◽  
Momentum Integral

The total cross sections for positrons on neon and argon atoms have been measured in the energy ranges 15 eV to 272.5 eV and 25 eV to 300 eV respectively. The cross sections indicate clearly that Born values will not be reached until at least 3 KeV. Interpolating between the measured and the valid Born regions has allowed an application of the sum rule which connects scattering length. Born forward scattering amplitude, and the momentum-integral over the total cross section. This procedure gives scattering lengths as = −0.53 ± 0.15 Bohr radii for neon and as = −2.8 ± 0.7 Bohr radii for argon; the errors include maximum credible uncertainties in the interpolations.

Pion-nucleon scattering at high energies

1966 ◽  
Vol 289 (1419) ◽  
pp. 500-508 ◽  
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Charge Exchange ◽  
Cross Sections ◽  
Scattering Amplitude ◽  
Forward Scattering Amplitude ◽  
Nucleon Scattering ◽  
Total Cross Sections ◽  
High Energies ◽  
Pion Nucleon

The charge exchange forward scattering amplitude 1.1 1.2 using an interpolation of the total cross sections which includes the results presented by Dr Galbraith at this meeting. From F (-) follows a prediction for the charge exchange forward cross section (c.m. system) 1.3 which will be compared with the experimental data including those presented by Dr Falk-Vairant and Dr Guerriero.

DOUBLE PION PHOTOPRODUCTION EXPERIMENT AT LNS–TOHOKU

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2313-2316 ◽  
Author(s):  
◽  
H. KANDA ◽  
N. CHIGA ◽  
Y. FUJII ◽  
K. FUTATSUKAWA ◽  
...  
Keyword(s):  
Total Cross Section ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Pion Photoproduction ◽  
Total Cross Sections ◽  
Free Proton ◽  
Double Pion ◽  
The Cross

The total cross sections for the π+π− photoproduction on the deuteron were measured in an energy range of 0.8 to 1.1 GeV. The obtained total cross section for the quasi-free π+π− photoproduction on the deuteron was about 60 % of those on the free proton. The cross section for Δ++Δ− photoproduction was derived from the non-quasi-free π+π− photoproduction events. It was smaller than the previous data.

The Scattering of Positrons by Helium: Total Cross Sections up to 270 eV

1975 ◽  
Vol 53 (10) ◽  
pp. 962-967 ◽  
Author(s):  
B. Jaduszliwer ◽  
A. Nakashima ◽  
D. A. L. Paul
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Born Approximation ◽  
Reasonable Agreement ◽  
Experimental Results ◽  
Formation Cross Section ◽  
Sum Rule ◽  
Total Cross Sections ◽  
High Energies

The total cross sections for the scattering of positrons by helium have been measured by the method of transmission in the 16 to 270 eV energy range. The experimental results are higher than those of Canter et al. but are in reasonable agreement with recent results of Griffith et al., and at high energies tend towards Born approximation calculations. The integral of the cross section over positron momentum is smaller than the sum rule estimate made by Bransden et al. A tentative value of (0.034 ± 0.017)πa02 is assigned to the positronium formation cross section at threshold.

Pion-nucleon resonances and their effect upon π ± p total cross sections

1966 ◽  
Vol 289 (1419) ◽  
pp. 521-530 ◽  
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Recent Experiment ◽  
Isotopic Spin ◽  
Spin States ◽  
Total Cross Sections ◽  
Nucleon Resonances ◽  
Pion Nucleon

Precise measurements of the total cross sections of positive and negative π mesons on hydrogen have revealed the presence of structure or enhancements in these cross sections at various momenta up to 3 GeV/ c . The present paper discusses measurements of this type and in particular, a recent experiment to search for structure in the region 3 to 7 GeV/ c , where previous experiments have shown that, if structure were present, it was likely to reveal itself as an amplitude in the total cross section of 1 mb or less. The recent measurements indicate four regions of structure, two in each of the isotopic spin states 3/2 and 1/2. The possible relation of these regions of structure to the formation of pion-nucleon resonances is discussed.

THE SPIN CONTRIBUTION TO THE pp-TOTAL CROSS-SECTION AT HIGH ENERGY

1998 ◽  
Vol 13 (09) ◽  
pp. 1515-1522 ◽  
Author(s):  
E. A. ANDREEVA ◽  
M. N. STRIKHANOV ◽  
S. B. NURUSHEV
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
High Energy ◽  
Spin Projection ◽  
Total Cross Sections ◽  
Spin Effects ◽  
Dependent Term ◽  
Spin Interactions ◽  
200 Gev

The experimental data on the pp-total cross-sections including the spin-dependent parts are analyzed with the goal to determine the contribution of spin interactions at high energies. Based on the Regge model with cuts, the energy dependencies of such contributions are estimated for two spin-dependent terms: (1) the total spin dependent term, σ1 and (2) the spin projection dependent term, σ2. The estimates show that their contributions to the unpolarized total cross section, σ0, decrease with energy from several % around 2 GeV/c to 10-2% around 200 GeV/c. The assumption σ1= -σ2 does not seem to be correct, while the hypothesis 3 σ1=-σ2 is more preferable, especially in the measured energy interval 2-6 GeV. There is a clear indication that the spin effects are sensitive to the pomeron intercept at - t=0 (GeV/c)2. In order to pin down such effects the spin dependent total cross-sections must be measured with precisions better than 10 μb at 200 GeV/c.

η PHOTO-PRODUCTION ON THE DEUTERON AT LNS, TOHOKU UNIVERSITY

2010 ◽  
Vol 19 (12) ◽  
pp. 2393-2399 ◽  
Author(s):  
T. Ishikawa
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Systematic Uncertainty ◽  
Cross Sections ◽  
Energy Region ◽  
Solid Angle ◽  
Total Cross Sections ◽  
Nuclear Science ◽  
Electro Magnetic ◽  
Photo Production

The differential and total cross sections were measured for the γp → ηp and γd → ηpn reactions at Eγ ≤ 1150 MeV by using an electro-magnetic (EM) calorimeter SCISSORS II at the Laboratory of Nuclear Science (LNS), Tohoku University. The total cross section on the deuteron shows a bump around Eγ = 1 GeV , while no bump is observed in the same energy region of that on the proton. This bump is attributed to be a nucleon resonance excited from the neutron, and it is a candidate of anti-decuplet penta-quark baryons with hidden strangeness. It was difficult, however, to detect all the γ's coming from η decay since the solid angle of SCISSORS II was only 12.6% in total. Statistics of the detected η produced events is poor and systematic uncertainty of the obtained cross section is not small due to low acceptance. A new EM calorimeter complex called FOREST with a solid angle of about 4π sr has been constructed. The spin and parity of the relevant resonance are expected to be determined by the experiments with FOREST.

scholarly journals ELASTIC SCATTERING OF PROTONS FROM $\sqrt{s} = 23.5~{\rm GeV}$ to 7 TeV FROM A GENERALIZED BIALAS–BZDAK MODEL

2014 ◽  
Vol 29 (02) ◽  
pp. 1450019 ◽  
Author(s):  
T. CSÖRGŐ ◽  
F. NEMES
Keyword(s):  
Elastic Scattering ◽  
Total Cross Section ◽  
Cross Section ◽  
Scattering Amplitude ◽  
Elastic Cross Section ◽  
Forward Scattering Amplitude ◽  
Proton Proton ◽  
Elastic Proton ◽  
Model Independent ◽  
Total P

The Bialas–Bzdak model of elastic proton–proton scattering is generalized to the case when the real part of the parton–parton level forward scattering amplitude is nonvanishing. Such a generalization enables the model to describe well the dip region of the differential cross-section of elastic scattering at the intersecting storage rings (ISR) energies, and improves significantly the ability of the model to describe also the recent TOTEM data at [Formula: see text] LHC energy. Within this framework, both the increase of the total cross-section, as well as the decrease of the location of the dip with increasing colliding energies, is related to the increase of the quark–diquark distance and to the increase of the "fragility" of the protons with increasing energies. In addition, we present and test the validity of two new phenomenological relations: one of them relates the total p+p cross-section to an effective, model-independent proton radius, while the other relates the position of the dip in the differential elastic cross-section to the measured value of the total cross-section.

Electron Excitation of 21S, 23S, 21P, and 23P States of Helium

1975 ◽  
Vol 53 (20) ◽  
pp. 2289-2295 ◽  
Author(s):  
H. G. P. Lins de Barros ◽  
H. S. Brandi
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Scattering Amplitude ◽  
Theoretical Calculations ◽  
Electron Excitation ◽  
Wave Functions ◽  
Excitation Cross Sections ◽  
Characteristic Values ◽  
The One

Calculations for the total excitation cross sections of the 21S, 23S, 21P, and 23P states of He by electron impact have been carried out assuming the Born–Ochkur approximation for the scattering amplitude and a parametrization previously proposed by the authors for the total cross section. For the atomic wave functions we used LS coupling and obtained the one electron orbitals using the Xα method for three characteristic values of the parameter α. The results are compared with other experimental and theoretical calculations.

scholarly journals Effect of Rapidly Rising Proton?Proton Total Cross Sections on Idealized Extensive Air Showers

1972 ◽  
Vol 25 (6) ◽  
pp. 679
Author(s):  
JA Campbell
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Strong Interaction ◽  
Extensive Air Showers ◽  
Proton Scattering ◽  
Air Showers ◽  
Proton Proton ◽  
Total Cross Sections ◽  
First Time

A simulation of extensive air showers above 1013 eV in which proton?proton scattering takes place partly through a medium-strong interaction is reported. In previous papers the simulation has been shown to be in fair agreement with observational data. The present version includes for the first time the assumption that the total cross section for proton-proton scattering increases with energy, as concluded in a recent paper by Yodh, Pal, and Trefil. The effect of the assumption is to make a noticeably better agreement between the simulation and the data.

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