scholarly journals Photoproduction of Pion Pairs at Moderate Energies

1977 ◽  
Vol 30 (6) ◽  
pp. 577
Author(s):  
T Chandramohan ◽  
K Venkatesan ◽  
P Achuthan

The problem of the production of pion pairs in photon-nucleon collisions is studied with the help of a new Lagrangian model. Using a relativistic covariant and gauge-invariant scattering amplitude based on a phenomenological Lagrangian, the differential and total cross sections are calculated for unpolarized and linearly polarized photons. The production amplitude incorporates terms involving 8(700), p(770), f(1260) and A(1236) resonances in addition to the nucleon and pion exchanges.

1997 ◽  
Vol 27 (3) ◽  
Author(s):  
V. P. Likhachev ◽  
M. N. Martins ◽  
Yu. A. Kasatkin ◽  
M. T. F. da Cruz ◽  
J. D. T. Arruda-Neto ◽  
...  

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Kenji Aoki ◽  
Daisuke Jido

Abstract We revisit the $KN$ scattering amplitude in order to investigate the possibility of the existence of a broad resonance in the $I=0$$KN$ channel around the energy of 1617 MeV with 305 MeV width. We use the chiral unitary model to describe the $KN$ scattering amplitudes and determine the model parameters so as to reproduce the differential cross sections of the $K^{+}N$ scatterings and the $I=0$ and 1 total cross sections up to $p_{\rm lab} = 800$ MeV/c, from which inelastic contributions start to be significant. Performing analytic continuation of the determined amplitude to the complex energy plane, we find a pole for a broad resonance state. We point out that the rapid increase appearing in the $I=0$ total cross section around $p_{\rm lab}=500$ MeV/c is a hint of the possible broad resonance of strangeness $S=+1$.


Particles ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 57-69 ◽  
Author(s):  
I. M. Dremin

Recent experimental results about the energy behavior of the total cross sections, the share of elastic and inelastic contributions to them, the peculiar shape of the differential cross section and our guesses about the behavior of real and imaginary parts of the elastic scattering amplitude are discussed. The unitarity condition relates elastic and inelastic processes. Therefore it is used in the impact-parameter space to get some information about the shape of the interaction region of colliding protons by exploiting new experimental data. The obtained results are described.


2005 ◽  
Vol 20 (06) ◽  
pp. 1286-1294
Author(s):  
KYUNGSIK KANG

The gauge/string-gravity duality correspondence opened renewed hope and possibility to address some of the fundamental and non-perturbative QCD problems of in particle physics, such as hadron spectrum and Regge behavior of the scattering amplitude at high energies. One of the most fundamental and long-standing problems is the high energy behavior of the total cross-sections. According to a series of exhaustive tests by the COMPETE group, (1) total cross sections have a universal Heisenberg behavior in energy corresponding to the maximal energy behavior allowed by the Froissart bound, i.e., A+B ln 2(s/s0) with B~0.32 mb and s0~34.41 GeV2 for all reactions, and (2). The factorization relation among σpp,even, σγp and σγγ is well satisfied by experiments. I discuss the recent interesting application of the gauge/string-gravity duality of AdS/CFT correspondence with a deformed background metric so as to break the conformal symmetry that lead to the Heisenberg behavior of rising total cross sections, and present some preliminary results on the high energy QCD from Planckian scattering in AdS and black-hole production.


1970 ◽  
Vol 24 (17) ◽  
pp. 955-959 ◽  
Author(s):  
H. H. Bingham ◽  
W. B. Fretter ◽  
K. C. Moffeit ◽  
W. J. Podolsky ◽  
M. S. Rabin ◽  
...  

2011 ◽  
Vol 26 (27n28) ◽  
pp. 4755-4771 ◽  
Author(s):  
L. L. JENKOVSZKY ◽  
A. I. LENGYEL ◽  
D. I. LONTKOVSKYI

A simple model for elastic diffractive hadron scattering, reproducing the dip-bump structure is used to analyze pp and [Formula: see text] scattering. The main emphasis is on the delicate and nontrivial dynamics in the dip-bump region, near t = -1 GeV 2. The simplicity of the model and the expected smallness of the absorption corrections enables one the control of various contributions to the scattering amplitude, in particular the interplay between the C-even and C-odd components of the amplitude, as well as their relative contribution, changing with s and t. The role of the nonlinearity of the Regge trajectories is scrutinized. The ratio of the real to imaginary parts of the forward amplitude, the ratio of elastic to total cross-sections and the inelastic cross-section are calculated. Predictions for the LHC energy region, where most of the existing models will be either confirmed or ruled out, are presented.


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.


1992 ◽  
Vol 07 (28) ◽  
pp. 2559-2565 ◽  
Author(s):  
SAUL BARSHAY ◽  
PATRICK HEILIGER ◽  
DIETER REIN

A new structure for the high-energy diffractive scattering amplitude is derived in two complementary ways (one of them recently revealed as due to Richard Feynman). Total cross-sections increase, due to a blackening of the interaction and also due to an effect which leads to an increase in the effective interaction area at fixed opacity. These features are dynamically related to the dominant high-energy process of multiparticle production.


1976 ◽  
Vol 54 (17) ◽  
pp. 1741-1748 ◽  
Author(s):  
J-S. Tsai ◽  
L. Lebow ◽  
D. A. L. Paul

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.


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