The observation possibility of $B_c$ excitations at LHC

Abstract

It is shown that in the decays $B_c(2P)\to B_c^{\ast }{\gamma }^{\mathrm{hard}}$, $B_c(3P)\to B_c^{\ast }{\gamma }^{\mathrm{hard}}$ and $B_c(2S)\to B_c^{\ast }+{\pi }^{+}{\pi }^{-}$ followed by the decay $B_c^{\ast }\to B_c+{\gamma }^{\mathrm{soft}}$ the loss of the soft photon ${\gamma }^{\mathrm{soft}}$ do not wash out peaks from the initial excitations. The relative yields of $B_c^{\ast }$, 2P-wave, and 3P-wave states of $B_c$ meson at LHC are estimated as function of transverse energy of emitted photon ${\gamma }^{\mathrm{hard}}$. It is pointed out, that the decays $B_c(2S)\to B_c(B_c^{\ast })+{\pi }^{+}{\pi }^{-}$ could provide a new information about a $\sigma$ resonance nature.

Comments: The talk given at the XIth International Workshop High Energy Physics and Quantum Field Theory, June 24- June 30, 2013, Saint Petersburg, Russia; to be published in PoS; 8 pages, 3 figures