scholarly journals The Chiral Condensate of One-Flavor QCD and the Dirac Spectrum at $\theta=0$

2015 ◽  
Author(s):  
Jacobus Verbaarschot ◽  
Tilo Wettig
Keyword(s):  
Chiral Condensate ◽  
Dirac Spectrum

scholarly journals Stochastic calculation of the Dirac spectrum on the lattice and a determination of chiral condensate in 2 + 1-flavor QCD

2016 ◽  
Vol 2016 (9) ◽  
pp. 093B06 ◽  
Author(s):  
Guido Cossu ◽  
Hidenori Fukaya ◽  
Shoji Hashimoto ◽  
Takashi Kaneko ◽  
Jun-Ichi Noaki
Keyword(s):  
Chiral Condensate ◽  
Dirac Spectrum

scholarly journals Chiral condensate and Dirac spectrum of one-and two-flavor QCD at nonzero θ-angle

2018 ◽  
Vol 175 ◽  
pp. 04004 ◽  
Author(s):  
Mario Kieburg ◽  
Jacobus Verbaarschot ◽  
Tilo Wettig
Keyword(s):  
Dirac Operator ◽  
Quark Mass ◽  
Imaginary Axis ◽  
Chiral Condensate ◽  
Dirac Spectrum ◽  
Quark Masses ◽  
Zero Modes

In previous work we showed that the chiral condensate of one-flavor QCD exhibits a Silver Blaze phenomenon when the quark mass crosses m = 0: the chiral condensate remains constant while the quark mass crosses the spectrum of the Dirac operator, which is dense on the imaginary axis. This behavior can be explained in terms of exponentially large cancellations between contributions from the zero modes and from the nonzero modes when the quark mass is negative. In these proceedings we show that a similar Silver Blaze phenomenon takes places for QCD with one flavor and arbitrary θ- angle, and for QCD with two flavors with different quark masses m1 and m2. In the latter case the chiral condensate remains constant when m1 crosses zero at fixed m2 > 0 until the Dashen point m1 = –m2 is reached, where the chiral condensate has a discontinuity. In terms of contributions from the Dirac spectrum the shift of the discontinuity from m1 = 0 to m1 = -m2 also arises from exponentially large cancellations between the zero and nonzero modes when m1m2 < 0. All calculations are performed in the microscopic or ε-domain of QCD. Results for arbitrary θ-angle are discussed as well.

scholarly journals The chiral condensate from the Dirac spectrum in BSM gauge theories

2014 ◽  
Author(s):  
Kieran Holland ◽  
Zoltan Fodor ◽  
Julius Kuti ◽  
Daniel Nogradi ◽  
Chik Him Wong
Keyword(s):  
Gauge Theories ◽  
Chiral Condensate ◽  
Dirac Spectrum

scholarly journals CHIRAL SYMMETRY BREAKING AT NONZERO CHEMICAL POTENTIAL

2006 ◽  
Vol 21 (04) ◽  
pp. 859-864 ◽  
Author(s):  
J. C. Osborn ◽  
K. Splittorff ◽  
J. J. M. Verbaarschot
Keyword(s):  
Partition Function ◽  
Symmetry Breaking ◽  
Dirac Operator ◽  
Chiral Symmetry ◽  
Chemical Potential ◽  
Chiral Symmetry Breaking ◽  
Chiral Condensate ◽  
Zero Temperature ◽  
Dirac Spectrum

We consider chiral symmetry breaking at nonzero chemical potential and discuss the relation with the spectrum of the Dirac operator. We solve the so called Silver Blaze Problem that the chiral condensate at zero temperature does not depend on the chemical potential while this is not the case for the Dirac spectrum and the weight of the partition function.

scholarly journals Determination of the chiral condensate from QCD Dirac spectrum on the lattice

2011 ◽  
Vol 83 (7) ◽  
Author(s):  
H. Fukaya ◽  
S. Aoki ◽  
T. W. Chiu ◽  
S. Hashimoto ◽  
T. Kaneko ◽  
...  
Keyword(s):  
Chiral Condensate ◽  
Dirac Spectrum

scholarly journals Dirac spectrum and chiral condensate for QCD at fixed θ angle

2019 ◽  
Vol 99 (7) ◽  
Author(s):  
M. Kieburg ◽  
J. J. M. Verbaarschot ◽  
T. Wettig
Keyword(s):  
Chiral Condensate ◽  
Dirac Spectrum

scholarly journals POSSIBILITY OF FORMING A LARGE DCC IN ULTRA-RELATIVISTIC HEAVY-ION COLLISIONS

2000 ◽  
Vol 15 (15) ◽  
pp. 2269-2288
Author(s):  
SANATAN DIGAL ◽  
RAJARSHI RAY ◽  
SUPRATIM SENGUPTA ◽  
AJIT M. SRIVASTAVA
Keyword(s):  
Three Dimensional ◽  
Thermal Fluctuations ◽  
Heavy Ion ◽  
High Energy ◽  
Chiral Condensate ◽  
Relativistic Heavy Ion Collisions ◽  
Maximum Temperature ◽  
Chiral Field ◽  
Heavy Nuclei ◽  
True Vacuum

We demonstrate the possibility of forming a single, large domain of disoriented chiral condensate (DCC) in a heavy-ion collision. In our scenario, rapid initial heating of the parton system provides a driving force for the chiral field, moving it away from the true vacuum and forcing it to go to the opposite point on the vacuum manifold. This converts the entire hot region into a single DCC domain. Subsequent rolling down of the chiral field to its true vacuum will then lead to emission of a large number of (approximately) coherent pions. The requirement of suppression of thermal fluctuations to maintain the (approximate) coherence of such a large DCC domain, favors three-dimensional expansion of the plasma over the longitudinal expansion even at very early stages of evolution. This also constrains the maximum temperature of the system to lie within a window. We roughly estimate this window to be about 200–400 MeV. These results lead us to predict that extremely high energy collisions of very small nuclei (possibly hadrons) are better suited for observing signatures of a large DCC. Another possibility is to focus on peripheral collisions of heavy nuclei.

Light front Hamiltonian for boson form of QED (1 + 1) in Pauli–Villars regularization

2019 ◽  
Vol 34 (21) ◽  
pp. 1950113
Author(s):  
V. A. Franke ◽  
M. Yu. Malyshev ◽  
S. A. Paston ◽  
E. V. Prokhvatilov ◽  
M. I. Vyazovsky
Keyword(s):  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Chiral Condensate ◽  
Light Front ◽  
Coupling Constants ◽  
Hamiltonian Approach ◽  
Chiral Perturbation ◽  
Dimensional Models ◽  
Villars Regularization ◽  
Ultraviolet Regularization

Light front (LF) Hamiltonian for QED in [Formula: see text] dimensions is constructed using the boson form of this model with additional Pauli–Villars-type ultraviolet regularization. Perturbation theory, generated by this LF Hamiltonian, is proved to be equivalent to usual covariant chiral perturbation theory. The obtained LF Hamiltonian depends explicitly on chiral condensate parameters which enter in a form of some renormalization of coupling constants. The obtained results can be useful when one attempts to apply LF Hamiltonian approach for [Formula: see text]-dimensional models like QCD.

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