scholarly journals Regge theory in a holographic dual of QCD in the Veneziano limit

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Artur Amorim ◽  
Miguel S. Costa ◽  
Matti Järvinen
Keyword(s):  
Cross Sections ◽  
Holographic Model ◽  
Meson Spectrum ◽  
Total Cross Sections ◽  
Regge Theory ◽  
Regge Trajectories ◽  
Pseudoscalar Mesons ◽  
Higher Spin ◽  
Spin Fields ◽  
The Masses

Abstract We initiate the study of Regge theory in a bottom-up holographic model for QCD in the Veneziano limit, where the backreaction of the quarks to the gluon dynamics is included. We determine the parameters of the model by carrying out a precise fit to the meson spectrum in QCD. The spectrum for spin-one and pseudoscalar mesons is well reproduced. We then generalise the model to incluce higher spin fields in the bulk trajectories dual to the Pomeron and meson Regge trajectories at the boundary. With this setting, we fit the masses of the mesons with spins J = 2, 3, and 4, as well as the experimental data of the total cross-sections σ(γγ → X), σ(γp → X) and σ(pp → X). For the cross sections we obtain a $$ {\chi}_{\mathrm{d}.\mathrm{o}.\mathrm{f}}^2 $$ χ d . o . f 2 of 0.74 for a total of 199 experimental points.

scholarly journals Higher-spin particles at high-energy colliders

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Juan C. Criado ◽  
Abdelhak Djouadi ◽  
Niko Koivunen ◽  
Martti Raidal ◽  
Hardi Veermäe
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
High Energy ◽  
Effective Field ◽  
Decay Rates ◽  
Theory Approach ◽  
Electron Positron ◽  
Higher Spin ◽  
Feynman Rules ◽  
Spin Fields

Abstract Using an effective field theory approach for higher-spin fields, we derive the interactions of colour singlet and electrically neutral particles with a spin higher than unity, concentrating on the spin-3/2, spin-2, spin-5/2 and spin-3 cases. We compute the decay rates and production cross sections in the main channels for spin-3/2 and spin-2 states at both electron-positron and hadron colliders, and identify the most promising novel experimental signatures for discovering such particles at the LHC. The discussion is qualitatively extended to the spin-5/2 and spin-3 cases. Higher-spin particles exhibit a rich phenomenology and have signatures that often resemble the ones of supersymmetric and extra-dimensional theories. To enable further studies of higher-spin particles at collider and beyond, we collect the relevant Feynman rules and other technical details.

scholarly journals THE POMERON AND ODDERON IN ELASTIC, INELASTIC AND TOTAL CROSS-SECTIONS AT THE LHC

2011 ◽  
Vol 26 (27n28) ◽  
pp. 4755-4771 ◽  
Author(s):  
L. L. JENKOVSZKY ◽  
A. I. LENGYEL ◽  
D. I. LONTKOVSKYI
Keyword(s):  
Simple Model ◽  
Cross Section ◽  
Cross Sections ◽  
Energy Region ◽  
Scattering Amplitude ◽  
Total Cross Sections ◽  
Regge Trajectories ◽  
Relative Contribution ◽  
Main Emphasis

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.

Proton-Proton Total Cross Sections and the Neglect of Masses in Data Fitting in the Regge Region

1981 ◽  
Vol 34 (2) ◽  
pp. 121 ◽  
Author(s):  
Mujahid Kamran
Keyword(s):  
Cross Sections ◽  
Data Fitting ◽  
Exchange Degeneracy ◽  
Interacting Particles ◽  
Proton Proton ◽  
Total Cross Sections ◽  
Regge Region ◽  
The Masses ◽  
Fitting In

It is shown by taking the example of pp total cross .sections that the use of the approximation s ~ 2qs-t while fitting data in the Regge region can be misleading. Several standard fits to O"tot(pp) data are based on the assumption of weak p-f-w-A2 exchange degeneracy (EXD). However, these fits involve the use of the approximation mentioned. We find, quite surprisingly, that it is impossible to fit the O"tot(pp) data in the range 6 ~ Plab ~ 2092 GeVjc using the precise factor 2qs~ in conjunction with weak p-f-w-A2 EXD. OUf investigation shows that O"tot(pp) data alone seem to indicate either a breaking of weak p-f-w-A 2 EXD or the presence of low-lying contributions, or both, provided one does not ignore the masses of the interacting particles in data fitting in the Regge region (Plab ;:;: 5 GeVjc). Caution is therefore urged in the use of such approximations in phenomenological calculations.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

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.

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