Quite a few new physics beyond the Standard Model predict
long-lived particles, which have a flight length of more than
O(1) mm at the collision point of the LHC.
In order to search the long-lived particles, the ATLAS
experiment has developed dedicated technique to reconstruct
the displaced vertex, and has searched long-lived gluino
up to 1500 GeV in the context of the supersymmetric theories [1].

Toward the 13 TeV collision from this month, we have considered
a new scenario which makes "low" mass displaced vertex with
an invariant mass of O(10) GeV, which is favoured from gaugino
coannihilation process for bino-dark matter [2].
We would like to discuss on the discovery potential of this
scenario in this seminar.

[1] http://arxiv.org/abs/1504.05162
[2] http://arxiv.org/abs/1504.00504