Universality of the p process

Hayakawa, Takehito; Iwamoto, Nancy; Kajino, T.; Shizuma, T.; Umeda, Hiroshi; Nomoto, K.

doi:10.22323/1.028.0113

Cited by 2 publications

(2 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The algorithms we employ is the blocked HMC algorithm [12]. We choose the run-parameters in such a way that the acceptance of the HMC Metropolis test is about 60% ∼ 90%.…”

Section: Setupmentioning

confidence: 99%

Nontrivial center dominance in high temperature QCD

et al. 2016

View full text Add to dashboard Cite

We investigate the properties of quarks and gluons above the chiral phase transition temperature T c , using the RG improved gauge action and the Wilson quark action with two degenerate quarks mainly on a 32 3 × 16 lattice. In the one-loop perturbation theory, the thermal ensemble is dominated by the gauge configurations with effectively Z(3) center twisted boundary conditions, making the thermal expectation value of the spatial Polyakov loop take a non-trivial Z(3) center. This is in agreement with our lattice simulation of high temperature QCD. We further observe that the temporal propagator of massless quarks at extremely high temperature β = 100.0 (T 10 58 T c ) remarkably agrees with the temporal propagator of free quarks with the Z(3) twisted boundary condition for t/L t ≥ 0.2, but differs from that with the Z(3) trivial boundary condition. As we increase the mass of quarks m q , we find that the thermal ensemble continues to be dominated by the Z(3) twisted gauge field configurations as long as m q ≤ 3.0 T and above that the Z(3) trivial configurations come in. The transition is similar to what we found in the departure from the conformal region in the zero-temperature many-flavor conformal QCD on a finite lattice by increasing the mass of quarks.

show abstract

“…The algorithms we employ is the blocked HMC algorithm [12]. We choose the run-parameters in such a way that the acceptance of the HMC Metropolis test is about 60% ∼ 90%.…”

Section: Setupmentioning

confidence: 99%

Nontrivial center dominance in high temperature QCD

et al. 2016

View full text Add to dashboard Cite

show abstract

“…We have performed simulations in the N f = 7 and N f = 16 cases, which we conjecture [7], are the boundaries of the conformal window. The algorithms we employ are the blocked HMC algorithm [8] for N f = 2 N and the RHMC algorithm [9] for N f = 1 in the case N f = 2 N + 1.…”

mentioning

confidence: 99%

Conformal theories with an infrared cutoff

et al. 2013

View full text Add to dashboard Cite

We give a new perspective on the dynamics of conformal theories realized in the SU(N ) gauge theory, when the number of flavors N f is within the conformal window. Motivated by the RG argument on conformal theories with a finite IR cutoff ΛIR, we conjecture that the propagator of a meson GH (t) on a lattice behaves at large t as a power-law corrected Yukawa-type decaying form GH(t) =cH exp (−mHt)/t α H instead of the exponentially decaying form cH exp (−mHt), in the small quark mass region where mH ≤ c ΛIR: mH is the mass of the ground state hadron in the channel H and c is a constant of order 1. The transition between the "conformal region" and the "confining region" is a first order transition. Our numerical results verify the predictions for the N f = 7 case and the N f = 16 case in the SU(3) gauge theory with the fundamental representation.Conformal field theories are ubiquitous in nature and play important roles not only in particle physics beyond the standard model but also in condensed matter physics. Nonperturbative understanding of their dynamics in four-dimensional space-time is ardently desired. In this article, we give a new perspective on the dynamics of conformal theories realized in the SU(N ) gauge theory when the number of flavors N f is within the conformal window [1] by studying meson propagators with a finite infrared (IR) cutoff. Some preliminary results have been presented in [2].Our general argument that follows can be applied to any gauge theories with arbitrary representations as long as they are in the conformal window, but to be specific, we focus on SU(3) gauge theories with N f fundamental fermions ("quarks"). We define the conformal field theory in a constructive way [3]: We employ the Wilson quark action and the standard one-plaquette gauge action on the Euclidean lattice of the size N x = N y = N z = N and N t = rN with aspect ratio r. We impose periodic boundary conditions except for an anti-periodic boundary condition in the time direction for fermion fields. We eventually take the continuum limit by sending the lattice space a → 0 with N → ∞ keeping L = N a fixed. When L = finite, the continuum limit defines a theory with an IR cutoff. The theory is defined by two parameters; the bare coupling constant g 0 and the bare degenerate quark mass m 0 at ultraviolet (UV) cutoff. We also use, instead of g 0 and m 0 , β = 6/g 2 0 and K = 1/2(m 0 a+4). For a later purpose, we define the quark mass m q through Ward-Takahashi identities with renormalization constants being suppressed [2].Let us quickly remind ourselves of the renormalization group (RG) flow when N f is in the conformal window. One important fact is finite size lattices in computer simulation always introduce an IR cutoff Λ IR ∼ 1/(N a). If the IR cutoff were zero, when quarks have tiny masses, the RG trajectory would stay close to the critical line, approaching the IR fixed point and finally would pass away from the IR fixed point to infinity. Therefore the IR behavior is governed by the "confining region". Only on the mass...

show abstract

Universality of the p process

Cited by 2 publications

References 12 publications

Nontrivial center dominance in high temperature QCD

Nontrivial center dominance in high temperature QCD

Conformal theories with an infrared cutoff

Contact Info

Product

Resources

About