Exact chiral symmetry on the lattice: QCD aplications

Guisti, Leonardo

doi:10.1016/s0920-5632(03)01503-2

Cited by 18 publications

(1 citation statement)

References 95 publications

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“…The next to the leading terms should not be included. In particular, it means that the next to the leading contributions which are affected by logarithmic divergencies [36][37][38] and make the quenched quark condensate ill-defined, are avoided. 8 Finally as a last remark we wish to stress an important property of both eqs.…”

Section: Jhep12(2017)104mentioning

confidence: 99%

Spontaneous CP breaking in QCD and the axion potential: an effective Lagrangian approach

Vecchia

Yankielowicz

Veneziano

et al. 2017

J. High Energ. Phys.

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Using the well-known low-energy effective Lagrangian of QCD -valid for small (non-vanishing) quark masses and a large number of colors -we study in detail the regions of parameter space where CP is spontaneously broken/unbroken for a vacuum angle θ = π. In the CP broken region there are first order phase transitions as one crosses θ = π, while on the (hyper)surface separating the two regions, there are second order phase transitions signalled by the vanishing of the mass of a pseudo Nambu-Goldstone boson and by a divergent QCD topological susceptibility. The second order point sits at the end of a first order line associated with the CP spontaneous breaking, in the appropriate complex parameter plane. When the effective Lagrangian is extended by the inclusion of an axion these features of QCD imply that standard calculations of the axion potential have to be revised if the QCD parameters fall in the above mentioned CP broken region, in spite of the fact that the axion solves the strong-CP problem. These last results could be of interest for axionic dark matter calculations if the topological susceptibility of pure YangMills theory falls off sufficiently fast when temperature is increased towards the QCD deconfining transition.

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Section: Jhep12(2017)104mentioning

confidence: 99%

Spontaneous CP breaking in QCD and the axion potential: an effective Lagrangian approach

Vecchia

Yankielowicz

Veneziano

et al. 2017

J. High Energ. Phys.

View full text Add to dashboard Cite

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Light quark masses, chiral condensate and quark–gluon condensate in quenched lattice QCD with exact chiral symmetry

Chiu

Hsieh

2003

Nuclear Physics B

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We determine several quantities in quenched lattice QCD with exact chiral symmetry. For 100 gauge configurations generated with Wilson gauge action at β = 6.0 on the 16 3 × 32 lattice, we compute quenched quark propagators for 13 bare quark masses. The pion decay constant is extracted from the pion propagator, and from which the inverse lattice spacing is determined to be a −1 = 1.979(6) GeV. The parameters (δ, A, B) in the pseudoscalar meson mass formula (14) in quenched chiral perturbation theory (qχPT) to one-loop order are determined. Further, we measure the index (topological) susceptibility of these 100 gauge configurations, χ t = (175 ± 6 MeV) 4 , from which we obtain an estimate of the mass of η ′ in qχPT, and the coefficient of quenched chiral logarithm, both in good agreement with the values determined from the pion masses, as well as with the theoretical estimates. With our values of δ, A, B, the experimental inputs of pion and kaon masses, and the pion decay constant, we determine the light quark masses: m u,d = 4.1 ± 0.3 MeV, and m s = 92 ± 9 MeV, in the MS scheme at scale µ = 2 GeV. Also, we determine the quark condensate qq = −(250 ± 3 MeV) 3 , and the quark-gluon condensate g qσ µν F µν q = −(434±4 MeV) 5 , in the MS scheme at scale 2 GeV.

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