### Abstract

We model the effects of a large number of zero modes for N_{f} species of quarks at finite vacuum angle θ, using a matrix model with Gaussian weights constrained by the topological susceptibility and compressibility. The quenched free energy exhibits a cusp at θ <π that is sensitive to the accuracy of the numerical analysis and the maximum density of winding modes. Our results bear much in common with recent lattice simulations by Schierholz and others. The unquenched free energy exhibits similar sensitivities, but for small quark masses or a large density of zero modes the results are in agreement with those derived using anomalous Ward identities and effective Lagrangians.

Original language | English |
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Title of host publication | Acta Physica Polonica B |

Pages | 1297-1315 |

Number of pages | 19 |

Volume | 32 |

Edition | 4 |

Publication status | Published - 2001 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Acta Physica Polonica B*(4 ed., Vol. 32, pp. 1297-1315)

**θ Vacuum : A matrix model.** / Janik, Romuald A.; Nowak, Maciej A.; Papp, G.; Zahed, Ismail.

Research output: Chapter in Book/Report/Conference proceeding › Chapter

*Acta Physica Polonica B.*4 edn, vol. 32, pp. 1297-1315.

}

TY - CHAP

T1 - θ Vacuum

T2 - A matrix model

AU - Janik, Romuald A.

AU - Nowak, Maciej A.

AU - Papp, G.

AU - Zahed, Ismail

PY - 2001

Y1 - 2001

N2 - We model the effects of a large number of zero modes for Nf species of quarks at finite vacuum angle θ, using a matrix model with Gaussian weights constrained by the topological susceptibility and compressibility. The quenched free energy exhibits a cusp at θ <π that is sensitive to the accuracy of the numerical analysis and the maximum density of winding modes. Our results bear much in common with recent lattice simulations by Schierholz and others. The unquenched free energy exhibits similar sensitivities, but for small quark masses or a large density of zero modes the results are in agreement with those derived using anomalous Ward identities and effective Lagrangians.

AB - We model the effects of a large number of zero modes for Nf species of quarks at finite vacuum angle θ, using a matrix model with Gaussian weights constrained by the topological susceptibility and compressibility. The quenched free energy exhibits a cusp at θ <π that is sensitive to the accuracy of the numerical analysis and the maximum density of winding modes. Our results bear much in common with recent lattice simulations by Schierholz and others. The unquenched free energy exhibits similar sensitivities, but for small quark masses or a large density of zero modes the results are in agreement with those derived using anomalous Ward identities and effective Lagrangians.

UR - http://www.scopus.com/inward/record.url?scp=31244433537&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=31244433537&partnerID=8YFLogxK

M3 - Chapter

VL - 32

SP - 1297

EP - 1315

BT - Acta Physica Polonica B

ER -