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Title: QCD sign problem for small chemical potential

Journal Article · · Physical Review. D, Particles Fields
 [1];  [1]
  1. Niels Bohr Institute, Blegdamsvej 17, DK-2100, Copenhagen O (Denmark)

The expectation value of the complex phase factor of the fermion determinant is computed in the microscopic domain of QCD at nonzero chemical potential. We find that the average phase factor is nonvanishing below a critical value of the chemical potential equal to half the pion mass and vanishes exponentially in the volume for larger values of the chemical potential. This holds for QCD with dynamical quarks as well as for quenched and phase quenched QCD. The average phase factor has an essential singularity for zero chemical potential and cannot be obtained by analytic continuation from imaginary chemical potential or by means of a Taylor expansion. The leading order correction in the p-expansion of the chiral Lagrangian is calculated as well.

OSTI ID:
20929584
Journal Information:
Physical Review. D, Particles Fields, Vol. 75, Issue 11; Other Information: DOI: 10.1103/PhysRevD.75.116003; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
Country of Publication:
United States
Language:
English

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