Abstract
The mass spectrum of 1 + 1-dimensional SU(N) gauge theory coupled to a Majorana fermion in the adjoint representation has been studied in the large N limit using Light-Cone Quantization. Here we extend this approach to theories with small values of N, exhibiting explicit results for N = 2, 3, and 4. In the context of Discretized Light-Cone Quantization, we develop a procedure based on the Cayley-Hamilton theorem for determining which states of the large N theory become null at finite N. For the low-lying bound states, we find that the squared masses divided by g2N, where g is the gauge coupling, have very weak dependence on N. The coefficients of the 1/N2 corrections to their large N values are surprisingly small. When the adjoint fermion is massless, we observe exact degeneracies that we explain in terms of a Kac-Moody algebra construction and charge conjugation symmetry. When the squared mass of the adjoint fermion is tuned to g2N/π, we find evidence that the spectrum exhibits boson-fermion degeneracies, in agreement with the supersymmetry of the model at any value of N.
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Dempsey, R., Klebanov, I.R., Lin, L.L. et al. Adjoint Majorana QCD2 at finite N. J. High Energ. Phys. 2023, 107 (2023). https://doi.org/10.1007/JHEP04(2023)107
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DOI: https://doi.org/10.1007/JHEP04(2023)107