We discuss a model for soft gluon re-summation based on a statistical description of independent emissions during inelastic collisions. The model is applied to estimate Survival Probabilities at the LHC. A comparison with other models and experimental data is presented.
In this paper we present a two channel model with the goal of reproducing the soft scattering data available in the ISR-Tevatron energy range, and extend the model results to LHC and Cosmic Rays energies. A characteristic feature of the model is that we represent the sum of all diffractive final states at a vertex, by a single diffractive state. Our two main results are: (i) The approach of the elastic scattering amplitude to the black disc bound is very slow, reaching it at energies far higher than the GZK ankle cutoff. (ii) Our predicted survival probability for Higgs exclusive central diffractive production at the LHC is 0.7%, which is considerably smaller than our previous estimate. The above features are compatible with a parton-like model in which the traditional soft Pomeron is replaced by an amplitude describing the partonic system, which issaturated in the soft (long distance) limit.
The Bloch-Nordsieck model for the parton distribution of hadrons in impact parameter space, constructed using soft gluon summation, is investigated in detail. Its dependence upon the infrared structure of the strong coupling constant $alpha_s$ is discussed, both for finite as well as singular, but integrable, $alpha_s$. The formalism is applied to the prediction of total proton-proton and proton-antiproton cross-sections, where screening, due to soft gluon emission from the initial valence quarks, becomes evident.
Inclusion of down to zero-momentum gluons and their k_t resummation is shown to quench the too fast rise of the mini jet cross section and thereby obtain realistic total cross-sections.
The production rate and kinematic distributions of isolated photon pairs produced in hadron interactions are studied. The effects of the initial-state multiple soft-gluon emission to the scattering subprocesses q-qbar, qg, and gg to gamma gamma X are resummed with the Collins-Soper-Sterman soft gluon resummation formalism. The effects of fragmentation photons from qg to gamma q, followed by q to gamma X, are also studied. The results are compared with data from the Fermilab Tevatron collider. A prediction of the production rate and kinematic distributions of the diphoton pair in proton-nucleon reactions is also presented.
With quark-antiquark annihilation and creation in the first Born approximation, we study the reactions: $K bar {K} to K bar {K}^ast, ~K bar{K} to K^* bar{K}, ~pi K to pi K^ast, ~pi K to rho K, ~pi pi to K bar{K}^ast, ~pi pi to K^ast bar{K}, ~pi pi to K^ast bar{K}^ast, ~pi rho to K bar{K}, ~pi rho to K^ast bar{K}^ast, ~rho rho to K^ast bar{K}^ast, ~K bar{K}^ast to rho rho$, and $K^* bar{K} to rho rho$. Unpolarized cross sections for the reactions are obtained from transition amplitudes that are composed of mesonic quark-antiquark relative-motion wave functions and the transition potential for quark-antiquark annihilation and creation. From a quark-antiquark potential that is equivalent to the transition potential, we prove that the total spin of the two final mesons may not equal the total spin of the two initial mesons. Based on flavor matrix elements, cross sections for some isospin channels of reactions can be obtained from the other isospin channels of reactions. Remarkable temperature dependence of the cross sections is found.
Giulia Pancheri
,Yogendra. N. Srivastava
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(2018)
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"A Democratic Resummation Procedure of Soft Gluon Emission for Hadronic Inelastic Cross-sections and Survival Probabilities"
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Giulia Pancheri Dr.
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