Top-squark study at a future e⁺e^- linear collider

We discuss a potential of studying the production and the decay of the lightest top squark (t̃₁) in the framework of the supersymmetric standard model at a future e⁺e^- collider. In particular, we consider the process t̃₁ → tχ₁ ⁰ (with χ₁⁰ being the lightest neutralino) followed by t → bW. It is shown that, by the study of the angular distribution of the bottom quark (as well as the production cross section of the top squark), properties of χ₁⁰ can be extracted. We also discuss that, if χ₁⁰ is gaugino-like, the neutralino mixing parameters (i.e., the so-called μ-parameter and tan β) may be constrained.