Search for technipions in exclusive production of diphotons with large invariant masses at the LHC

Abstract

We focus on exclusive production of neutral technipion ${\tilde{\pi }}^0$ in $pp$ collisions at the LHC, i.e. on $pp\to pp{\tilde{\pi }}^0$ reaction. The dependence of the cross section on parameters of recently proposed vector-like Technicolor model is studied. Characteristic features of the differential distributions are discussed. For not too large technipion masses the diphoton decay channel has the dominant branching fraction. This is also the main reason for an enhanced production of neutral technipions in $\gamma \gamma$-fusion reaction. We discuss potential backgrounds of the QCD and QED origin to the $pp\to pp({\tilde{\pi }}^0\to \gamma \gamma )$ process at large invariant $\gamma \gamma$ masses. We conclude that compared to inclusive case the signal-to-background ratio in the considered exclusive reaction is vary favorable which thereby could serve as a good probe for Technicolor dynamics searches at the LHC.

Comments: 20 pages, 12 figures, 1 table