TY - JOUR
T1 - Breakdown of staggered fermions at nonzero chemical potential
AU - Golterman, Maarten
AU - Shamir, Yigal
AU - Svetitsky, Benjamin
PY - 2006
Y1 - 2006
N2 - The staggered-fermion determinant is complex when the quark chemical potential μ is nonzero. Its fourth root, used in simulations with dynamical fermions, will have phase ambiguities that become acute when Reμ is sufficiently large. We show how to resolve these ambiguities, but our prescription only works very close to the continuum limit. We argue that this regime is far from current capabilities. Other procedures require being even closer to the continuum limit, or fail altogether, because of unphysical discontinuities in the measure. At zero temperature the breakdown is expected when Reμmπ/2, where mπ is the pion mass. Estimates of the location of the breakdown at nonzero temperature are less certain.
AB - The staggered-fermion determinant is complex when the quark chemical potential μ is nonzero. Its fourth root, used in simulations with dynamical fermions, will have phase ambiguities that become acute when Reμ is sufficiently large. We show how to resolve these ambiguities, but our prescription only works very close to the continuum limit. We argue that this regime is far from current capabilities. Other procedures require being even closer to the continuum limit, or fail altogether, because of unphysical discontinuities in the measure. At zero temperature the breakdown is expected when Reμmπ/2, where mπ is the pion mass. Estimates of the location of the breakdown at nonzero temperature are less certain.
UR - http://www.scopus.com/inward/record.url?scp=33749439181&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.74.071501
DO - 10.1103/PhysRevD.74.071501
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AN - SCOPUS:33749439181
SN - 1550-7998
VL - 74
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 7
M1 - 071501
ER -