Isospin breaking in octet baryon mass splittings

Abstract

Using an SU(3) flavour symmetry breaking expansion in the quark mass, we determine the QCD component of the nucleon, Sigma and Xi mass splittings of the baryon octet due to up-down (and strange) quark mass differences in terms of the kaon mass splitting. Provided the average quark mass is kept constant, the expansion coefficients in our procedure can be determined from computationally cheaper simulations with mass degenerate sea quarks and partially quenched valence quarks. Both the linear and quadratic terms in the SU(3) flavour symmetry breaking expansion are considered; it is found that the quadratic terms only change the result by a few percent, indicating that the expansion is highly convergent.Comment: 31 pages, 8 figures, published versio

Two-particle elastic scattering in a finite volume including QED

“…The first region generates the power law correction, and the second region is again evaluated using Poisson summation to give the logarithmic contributions. 10 The relation between the scattering parameters and the binding momentum has been used, with terms higher order in the scattering parameters neglected.…”

“…In particular, hadronic spectra and other hadronic observables are now being calculated in the presence of both isospin violation from the light-quark masses and Quantum Electrodynamics (QED) [1][2][3][4][5][6][7][8][9][10][11]. QED plays a critical role in the stability and structure of nuclei, and therefore first principles calculations of nuclear structure require the inclusion of the electromagnetic (EM) interactions among quarks.…”

Neutron and proton EDM with $N_f=2+1$ domain-wall fermion

“…In lattice QCD, we have several procedures to compute EDM non-perturbatively [5,6,7,8,9]. Lattice calculation including θ term is important for the estimate of hadronic contribution to EDM, and furthermore its procedure is also applicable to extension toward BSM operator.…”

Isospin Breaking in the Nucleon Mass and the Sensitivity ofβDecays to New Physics

“…On the other hand, LQCD collaborations are starting to implement isospin breaking effects [18][19][20] or even directly simulating QED together with QCD [21][22][23][24][25][26][27] (for a recent review see Ref. [42]).…”

“…Actually, the isospin corrections to the hadron masses, and in particular to the nucleon mass, are starting to receive much attention. While phenomenological determinations are being revised [17], different lattice collaborations have embarked on the ab initio computation of these effects in pure QCD [18][19][20] or even including QED [21][22][23][24][25][26][27].…”