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Two-photon physics with GALUGA 2.0

Gerhard A. Schuler
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Abstract

An extended version of the Monte Carlo program GALUGA is presented for the computation of two-photon production in $\e^+\e^-$ collisions. Functions implemented for the five $γ^\starγ^\star$ structure functions now include several ansätze of the total hadronic cross section based on the BFKL--Pomeron and various Regge-like models. In addition, structure functions for resonance formation are included with full dependence on the two photon virtualities $Q_1^2$ and $Q_2^2$ as given in the constituent-quark model. The six lowest-lying resonances of each of the C-even mesons with $J^{P}= 0^-$, $0^+$, $1^+$, $2^+$ and $2^-$ are provided. The program can also be used to calculate with exact kinematics the effective two-photon luminosity function. Special emphasis is put on a numerically stable evaluation of all variables over the full $Q_i^2$ range while keeping all dependences on the electron mass and $Q_i^2$.

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Gerhard A. Schuler. 1997-10-28. Two-photon physics with GALUGA 2.0. https://doi.org/10.1016/s0010-4655(97)00127-6

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