KEK Theory workshop 2019

IR renormalon in a compactified spacetime: the case of the QCD(adj.) on R3×S1

4 Dec 2019, 09:30

40m

Kobayashi Hall, Kenkyu-Honkan bldg. 1F (KEK)

Invited talks

Speaker

Prof. Hiroshi Suzuki

Description

An interesting possibility that the ambiguity in perturbation theory caused by the IR renormalon is cancelled by the instability associated with a semi-classical object called bion has been suggested in the context of the resurgence program of asymptotically-free quantum field theories. To reinforce this picture on the IR renormalon, the understanding of the IR renormalon in a compactified space such as $R^{D-1}\times S^1$ seems to be a basic premise. In this talk, I report our recent analysis on the IR renormalon in the gluon condensate in the $SU(N)$ QCD(adj.) on $R^3\times S^1$ with the $Z_N$ twisted boundary conditions. In the large $N$ limit within the so-called large ${\beta }_0$ approximation, we find that the vacuum polarization of the W-boson, which acquires the twisted momentum from the boundary conditions, gives rise to the renormalon ambiguity that is identical to that in the system in the un-compactified space, $R^4$. This situation is completely different from that in the 2D $C{P}^{N-1}$ model on $R^1\times S^1$ (the analyses on the latter will be presented by Dr. Takaura and Mr. Morikawa).

Presentation materials

Slides

Hiroshi_Suzuki_KEKTH2019.pdf