Откуда вы вообще взяли, что там в экспериментах вообще наблюдались какие-то "протоны фона", больше тех, что идут из космических лучей? Из пальца высосали?
Из статьи.
Цитата:
The beam associated background sources are complicated. They may mainly come from beam-gas, beam-wall interaction, synchrotron radiation, and lost beam particles. The salient features of the beam associated background are that their tracks are very much along the beam pipe direction, the energy deposited in BSC is small, and most of the tracks are protons.
R-values in Low Energy e+e− Annihilation
Zhengguo Zhao
Institute of High Energy Physics of Chinese Acadmy of Sciences Beijing 100039,P.R.C.
December 24, 2013
Abstract
This presentation briefly summarizes the recent measurements of R-values in low energy e+e− annihilation. The new experiments aimed at reducing the uncertainties in R-values and performed with the upgraded Beijing Spectrom- eter (BESII) at Beijing Electron Positron Collider (BEPC) in Beijing and with CMD-2 and SND at VEEP-2M in Novosibirsk are reviewed and discussed.