We perform a lattice QCD study of the meson decay from the N f ¼ 2 þ 1 full QCD configurations generated with a renormalization group improved gauge action and a nonperturbatively OðaÞ-improved Wilson fermion action. The resonance parameters, the effective ! coupling constant and the resonance mass, are estimated from the P-wave scattering phase shift for the isospin I ¼ 1 two-pion system. The finite size formulas are employed to calculate the phase shift from the energy on the lattice. Our calculations are carried out at two quark masses, m ¼ 410 MeV (m =m ¼ 0:46) and m ¼ 300 MeV (m =m ¼ 0:35), on a 32 3 Â 64 (La ¼ 2:9 fm) lattice at the lattice spacing a ¼ 0:091 fm. We compare our results at these two quark masses with those given in the previous works using N f ¼ 2 full QCD configurations and the experiment.

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Measurements of the azimuthal anisotropy in lead–lead collisions at = 5.02 TeV are presented using a data sample corresponding to 0.49 integrated luminosity collected by the ATLAS experiment at the LHC in 2015. The recorded minimum-bias sample is enhanced by triggers for “ultra-central” collisions, providing an opportunity to perform detailed study of flow harmonics in the regime where the initial state is dominated by fluctuations. The anisotropy of the charged-particle azimuthal angle distributions is characterized by the Fourier coefficients, – , which are measured using the two-particle correlation, scalar-product and event-plane methods. The goal of the paper is to provide measurements of the differential as well as integrated flow harmonics over wide ranges of the transverse momentum, 0.5 60 GeV, the pseudorapidity, 2.5, and the collision centrality 0–80%. Results from different methods are compared and discussed in the context of previous and recent measurements in Pb+Pb collisions at = 2.76 and 5.02 . In particular, the shape of the dependence of elliptic or triangular flow harmonics is observed to be very similar at different centralities after scaling the and values by constant factors over the centrality interval 0–60% and the range 0.5 5 GeV.

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We generate 2 + 1 flavor QCD configurations near the physical point on a 96 4 lattice employing the 6-APE stout smeared Wilson clover action with a nonperturbative c SW and the Iwasaki gauge action at β = 1.82. The physical point is estimated based on the chiral perturbation theory using several data points generated by the reweighting technique from the simulation point, where m π , m K and m Ω are used as physical inputs. The physics results include the quark masses, the hadron spectrum, the pseudoscalar meson decay constants and nucleon sigma terms, using the nonperturbative renormalization factors evaluated with the Schrödinger functional method.

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We study chiral partner structure of four light nucleons, N (939), N (1440), N (1535) and N (1650) using an effective chiral model based on the parity doublet structure. In our model we introduce four chiral representations, (1, 2), (2, 1), (2, 3) and (3, 2) under SU(2)L ⊗ SU(2)R symmetry. We determine the model parameters by fitting them to available experimental values of masses, widths and the axial charge of N (939) together with the axial charges of N (1535) and N (1650) by lattice analyses. We find five groups of solutions: In a group the chiral partner to N (939) is N (1440) having small chiral invariant mass. In another group, the chiral partner is a mixture of N (1535) and N (1650) having a large chiral invariant mass. We claim that off-diagonal elements of axial-charge matrix can be used for distinguishing these groups. We also discuss changes of masses associated with chiral symmetry restoration, which could emerge in high density matter.