出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We calculate the energy spectrum of closed strings in SUN
gauge theories with N
2
3
4
6
8
in 2
1 dimensions to a high accuracy. We attempt to control all systematic errors, and this allows
us to perform a precise comparison with different theoretical predictions. When we study the dependence
of the string mass on its length L we find that the Nambu-Goto prediction is a very good
approximation down to relatively short lengths, where the Lüscher term alone is insufficient. We
then isolate the corrections to the Lüscher term, and compare them to recent theoretical predictions,
which indeed seem to be mildly preferred by the data. When we take these corrections into
account and extract string tensions from the string masses, we find that their continuum limit is
lower by 2%
1% from the predictions of Karabli, Kim, and Nair. The discrepancy decreases
with N, but when we extrapolate our results to N
¥ we still find a discrepancy of 0
88% which
is a 4
5s effect.
