The Complete Spectrum of the $W_N$ String

• Main Authors: Lu, H, Pope, C. N, Schrans, S, Xu, K. W
• Format: Journal Article
• Language: English
• Published: 23-01-1992
• Subjects: Physics - High Energy Physics - Theory
• DOI: 10.48550/arxiv.hep-th/9201050

Nucl.Phys.B385:99-126,1992 We obtain the complete physical spectrum of the $W_N$ string, for arbitrary
$N$. The $W_N$ constraints freeze $N-2$ coordinates, while the remaining
coordinates appear in the currents only {\it via} their energy-momentum tensor.
The spectrum is then effectively described by a set of ordinary Virasoro-like
string theories, but with a non-critical value for the central charge and a
discrete set of non-standard values for the spin-2 intercepts. In particular,
the physical spectrum of the $W_N$ string includes the usual massless states of
the Virasoro string. By looking at the norms of low-lying states, we find
strong indications that all the $W_N$ strings are unitary.