scholarly journals γγ TOTAL CROSS-SECTION AT HIGH ENERGIES

2000 ◽  
Vol 15 (01) ◽  
pp. 9-13 ◽  
Author(s):  
C. BOURRELY ◽  
J. SOFFER ◽  
TAI TSUN WU

We show that the rising total cross-sections σ(γγ→ hadrons) recently observed by the L3 and OPAL collaborations at LEP are fully consistent with the impact-picture for high-energy scattering. The impact picture is then used to predict this γγ total cross-section at higher energies, and confirm the universal increase of total cross-sections including those of pp, [Formula: see text] and γp.

1998 ◽  
Vol 13 (09) ◽  
pp. 1515-1522 ◽  
Author(s):  
E. A. ANDREEVA ◽  
M. N. STRIKHANOV ◽  
S. B. NURUSHEV

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.


2016 ◽  
Vol 31 (10) ◽  
pp. 1650066 ◽  
Author(s):  
F. S. Borcsik ◽  
S. D. Campos

In this paper, one presents a naive parametrization to [Formula: see text] and [Formula: see text] total cross-sections. The main goal of this parametrization is to study the possible fractal structure present in the total cross-section. The result of the fitting procedure shows two different fractal dimensions: a negative (low-energies) and a positive (high-energies). The negative fractal dimension represents the emptiness of the total cross-section structure and the positive represents the filling up process with the energy increase. Hence, the total cross-section presents a multifractal behavior. At low-energies, the odderon exchange may be associated with the negative fractal dimension and at high-energies, the pomeron may be associated with the positive fractal dimension. Therefore, the exchange of odderons and pomerons may be viewed as a transition from a less well-defined to a more well-defined internal structure, depending on the energy.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Roman N. Lee ◽  
Alexey A. Lyubyakin ◽  
Vyacheslav A. Stotsky

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.


2016 ◽  
Vol 31 (23) ◽  
pp. 1650126 ◽  
Author(s):  
Nguyen Suan Han ◽  
Le Anh Dung ◽  
Nguyen Nhu Xuan ◽  
Vu Toan Thang

The derivation of the Glauber type representation for the high energy scattering amplitude of particles of spin 1/2 is given within the framework of the Dirac equation in the Foldy–Wouthuysen (FW) representation and two-component formalism. The differential cross-sections on the Yukawa and Gaussian potentials are also considered and discussed.


1990 ◽  
Vol 05 (24) ◽  
pp. 1983-1991 ◽  
Author(s):  
S. YU. KHLEBNIKOV ◽  
V. A. RUBAKOV ◽  
P. G. TINYAKOV

We study the total cross-section of high energy collisions in the one-instanton sector of purely bosonic theories with instantons. We find that in the limit g2 → 0, E/E sph = fixed , the leading behavior of the total cross-section is σ lot ~ exp [1/g2(−2S0 + F(E/E sph ))], where S0 is the instanton action. In the electroweak theory at E/E sph ≪ 1, the function F(E/E sph ) is determined by the gauge boson part of the instanton configuration and its explicit form is found.


2008 ◽  
Vol 23 (27n30) ◽  
pp. 2313-2316 ◽  
Author(s):  
◽  
H. KANDA ◽  
N. CHIGA ◽  
Y. FUJII ◽  
K. FUTATSUKAWA ◽  
...  

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.


1975 ◽  
Vol 53 (10) ◽  
pp. 962-967 ◽  
Author(s):  
B. Jaduszliwer ◽  
A. Nakashima ◽  
D. A. L. Paul

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.


Sign in / Sign up

Export Citation Format

Share Document