The paper by Zvi Bern, Lance Dixon, David C. Dunbar, David A. Kosower, and others identifies a large class of one-loop amplitudes for massless particles that can be constructed via unitarity from tree amplitudes without any ambiguities. This class includes one-loop amplitudes for massless supersymmetric gauge theories, as well as many non-supersymmetric amplitudes that can be rearranged to take advantage of this result. The authors demonstrate that all color-ordered amplitudes in massless supersymmetric gauge theories with trivial superpotential are cut-constructible. They apply this method to compute the one-loop maximally helicity-violating $n$-gluon amplitudes in $N = 1$ supersymmetric gauge theory and the six-gluon amplitudes in $N = 4$ super-Yang-Mills theory for all helicity configurations. The paper also discusses the use of collinear limits and recursive techniques to handle amplitudes that are not cut-constructible, such as scalar-loop contributions to $n$-gluon amplitudes. The authors provide explicit examples and detailed proofs to support their findings.The paper by Zvi Bern, Lance Dixon, David C. Dunbar, David A. Kosower, and others identifies a large class of one-loop amplitudes for massless particles that can be constructed via unitarity from tree amplitudes without any ambiguities. This class includes one-loop amplitudes for massless supersymmetric gauge theories, as well as many non-supersymmetric amplitudes that can be rearranged to take advantage of this result. The authors demonstrate that all color-ordered amplitudes in massless supersymmetric gauge theories with trivial superpotential are cut-constructible. They apply this method to compute the one-loop maximally helicity-violating $n$-gluon amplitudes in $N = 1$ supersymmetric gauge theory and the six-gluon amplitudes in $N = 4$ super-Yang-Mills theory for all helicity configurations. The paper also discusses the use of collinear limits and recursive techniques to handle amplitudes that are not cut-constructible, such as scalar-loop contributions to $n$-gluon amplitudes. The authors provide explicit examples and detailed proofs to support their findings.