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Joni M. Suorsa

Publications and source records attributed to Joni M. Suorsa.

9 recordsLinked to original sources

Infrared Behaviour of SU(2) Gauge Theory with $N_f$ fundamental flavours

We review our recent results on the infrared behaviour of the SU(2) gauge theory with $N_f$ massless fundamental flavour fermions. We have analyzed the running of the coupling in SU(2) gauge theories with six and eight fermionic flavours using the gradient flow step scaling method. From the running of the coupling, we see a clear indication of an infrared stable fixed point in theories with six and eight flavours. These results are confirmed by our mass spectrum study, where we varied the number of flavours from two to six. We also compute the anomalous dimensions of mass and coupling.

hep-lat

Infrared fixed point of SU(2) gauge theory with six flavors

We compute the running of the coupling in SU(2) gauge theory with six fermions in fundamental representation of the gauge group. We establish an infrared stable fixed point at strong coupling and measure also the anomalous dimension of the fermion mass operator at the fixed point. This theory therefore likely lies close to the boundary of the conformal window and will display novel infrared dynamics if coupled with the electroweak sector of the Standard Model.

hep-lat

Conformal window in SU(2) with fundamental fermions

We present the updated results of the infrared behavior of the SU(2) 6 and 8 fundamental representation fermions. We use the gradient flow method with the Schrödinger functional boundary conditions to measure the running of the coupling in these theories and find fixed points on both. We also measure the mass anomalous dimension from these configurations.

hep-lat

The gradient flow running coupling in SU(2) gauge theory with $N_f=8$ fundamental flavors

We study the evolution of the coupling in SU(2) gauge field theory with $N_f=8$ fundamental fermion flavors on the lattice. This model is expected to have an infrared fixed point at high coupling. We use HEX-smeared Wilson-clover action, and measure the gradient flow running coupling with Dirichlet boundary conditions. Extrapolating our results to continuum, we find an infrared fixed point at $g^2=8.24(59)^{+0.97}_{-1.64}$, with statistical and systematic error estimates. We also measure the anomalous dimension of the quark mass operator, and find its value at the fixed point $γ\approx 0.15 \pm 0.02$.

hep-lat

Mass anomalous dimension of SU(2) using the spectral density method

SU(2) with N_f = 6 and N_f = 8 are believed to have an infrared conformal fixed point. We use the spectral density method cross referenced with the mass step scaling method to evaluate the coupling constant dependence of the mass anomalous dimension for massless HEX smeared, clover improved Wilson fermions with Schrödinger functional boundary conditions.

hep-lat

Gradient flow running coupling in SU(2) Nf=6 flavors

We present preliminary results of the running of the coupling in SU(2) gauge theory with 6 massless fundamental representation fermion flavors. We measure the coupling using the gradient flow method with Schrödinger functional boundary conditions. The results are consistent with the perturbation theory in the weak coupling and we see an indication of an infrared fixed point at strong coupling.

hep-lat

Gradient flow and IR fixed point in SU(2) with Nf=8 flavors

We study the running of the coupling in SU(2) gauge theory with 8 massless fundamental representation fermion flavours, using the gradient flow method with the Schrödinger functional boundary conditions. Gradient flow allows us to measure robust continuum limit for the step scaling function. The results show a clear indication of infrared fixed point consistent with perturbation theory.

hep-lat

Investigating the Sharpe-Singleton scenario on the lattice by direct eigenvalue computation

We investigate the phase structure of lattice QCD with dynamical Wilson fermions. Wilson chiral perturbation theory predicts that the Aoki phase and the Sharpe-Singleton scenario manifest themselves in very distinct behavior of the Wilson Dirac eigenvalue spectrum. To test this prediction we perform a direct calculation of the eigenvalues of the non-Hermitian Wilson Dirac operator in dynamical lattice simulations. Moreover, we demonstrate an unexpected quark mass dependence on the shape of the eigenvalue distribution in the positive quark mass side.

hep-lat