Prospects of Direct Determination of |V_tq| CKM Matrix Elements at the   LHC
  The prospects of measuring the CKM matrix elements |V_tq| with top quarks decays at the LHC are discussed here, with the top quarks produced in the processes pp \rightarrow ttbarX and pp \rightarrow t/tbarX, and the subsequent decays t \rightarrow Ws and/or tbar \rightarrow Wsbar. As for the direct measurement of |V_tb|, there is also a lot of interest in the direct measurements of |V_ts| and |V_td|, as the absolute values of these CKM matrix elements can be modified by approximately a factor 2 from their SM values. Direct determination of these matrix elements will require a good tagging of the t \rightarrow s transition (for |V_ts|) and t \rightarrow d transition (for |V_td|) in the top quark decays, and a very large top quark statistics, which is available at the LHC. Lacking a good tagging for the t \rightarrow d transition, and also because of the small size of the CKM-matrix element, |V_td| = O(10^-2), direct measurements of |V_ts| at the LHC with main emphasis at the centre of mass energy sqrt(s) of 14 TeV/c^2 based on the PLB paper of Ali et al. [1] are shown. Alternative methods for direct |V_tq| determination at the LHC are also reported. 
Theodota Lagouri
hep-ex