2018 Impact factor 4.843
Particles and Fields


Eur. Phys. J. C 19, 129-136
DOI: 10.1007/s100520100549

Hadronic cross-sections in $\gamma \gamma$ processes and the next Linear Collider

R.M. Godbole1 and G. Pancheri2

1  Centre for Theoretical Studies, Indian Institute of Science, Bangalore 560 012, India
2  Laboratori Nazionali di Frascati dell'INFN, Via E. Fermi 40, 00044, Frascati, Italy

rohini@cts.iisc.ernet.in
Giulia.Pancheri@lnf.infn.it

(Received: 21 October 2000 / Published online: 23 February 2001 -© Springer-Verlag 2001)

Abstract
In this note we address the issue of theoretical estimates of the hadronic cross-sec tions for $\gamma \gamma$ processes. We compare the predictions of the mini-jet model with data as well as other models, highlighting the band of uncertainties in the theoretical predictions, as well as those in the final values of the $\sigma (\gamma \gamma \rightarrow {\mathrm{hadrons}}) $ extracted from the data. We find that the rise of $\sigma_{\gamma \gamma}^{\mathrm{tot}}$ with energy shown in the latest $\gamma \gamma$ data is in tune with the faster rise expected in the eikonal mini-jet models (EMM). We present an estimate of the accuracy with which this cross-sec tion needs to be measured, in order to distinguish between the different theoretical models which try to "explain"the rise of total cross-sec tions with energy. We find that the precision of measurement required to distinguish the EMM-type models from the proton-like models, for $ 300 < s^{1/2}_{\gamma \gamma} < 500 $ GeV, is $\lesssim 20\% $, whereas to distinguish between various proton-like models or among the different parametrisations of the EMM, a precision of $\lesssim 8$-9% or $\lesssim 6$-7% , respectively, is required. We also comment briefly on the implications of these predictions for hadronic backgrounds at the next linear collider (NLC) to be run in the $\gamma \gamma$ mode or e+e- mode.



© Società Italiana di Fisica, Springer-Verlag 2001