Fermion Bags and A New Origin for a Fermion Mass
Abstract
The fermion bag is a powerful idea that helps to solve fermion lattice field theories
using Monte Carlo methods. Some sign problems that had remained unsolved earlier can
be solved within this framework. In this work we argue that the fermion bag also gives
insight into a new mechanism of fermion mass generation, especially at strong couplings
where fermion masses are related to the fermion bag size. On the other hand, chiral
condensates arise due to zero modes in the Dirac operator within a fermion bag. Although
in traditional four-fermion models the two quantities seem to be related, we show
that they can be decoupled. While fermion bags become small at strong couplings, the
ability of zero modes of the Dirac operator within fermion bags to produce a chiral
condensate, can be suppressed by the presence of additional zero modes from other
fermions. Thus, fermions can become massive even without a chiral condensate. This
new mechanism of mass generation was discovered long ago in lattice field theory,
but has remained unappreciated. Recent work suggests that it may be of interest even
in continuum quantum field theory.
Type
Journal articlePermalink
https://hdl.handle.net/10161/9567Collections
More Info
Show full item recordScholars@Duke
Shailesh Chandrasekharan
Professor of Physics
Prof. Chandrasekharan is interested in understanding quantum field theories non-perturbatively
from first principles calculations. His research focuses on lattice formulations of
these theories with emphasis on strongly correlated fermionic systems of interest
in condensed matter, particle and nuclear physics. He develops novel Monte-Carlo algorithms
to study these problems. He is particularly excited about solutions to the notoriously
difficult <a href="http://en.wikipedia.org/wiki/Numerical_si

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info