  Low-scale string models are phenomenological models in String Theory, in
which the string scale M_s is of the order of TeV. String excited states which
are characteristic modes in low-scale string models can be observed as
resonances in dijet invariant mass distributions at the LHC. If a new heavy
resonance is discovered at the LHC, it is important to investigate whether the
resonance comes from low-scale string models. In this work, two analyses are
performed: One is observing higher spin degeneracy of string excited states by
an angular distribution analysis on the resonance, since the string resonance
consists of several degenerate states with different spins. The other is
observing second string excited states by a search for a second resonance in
dijet invariant mass distributions, since second string excited states have
characteristic masses of sqrt{2} times of masses of first string excited
states. As the result of Monte Carlo simulations assuming the 14 TeV LHC, we
give required luminosities for 5 sigma confirmation in each analysis, in case
of M_s = 4.5, 4.75 and 5 TeV.
