Nucleon-Nucleon Potential and its Non-locality in Lattice QCD

By the quenched lattice QCD simulation for two nucleons with finite scattering energy, validity of the delivative expansion of the general nucleon-nucleon potential U(r,r') = V(r, {\nabla}_r) \delta^3(r-r') is studied. The relative kinetic energy between two nucleons is introduced through the anti-periodic boundary condition in the spatial directions. On a hypercubic lattice with the lattice spacing a ~ 0.137 fm and the spatial extent L_s ~ 4.4 fm with the pion mass m_{\pi} ~ 530 MeV, the local potentials for two different energies (E ~ 0 MeV and 45 MeV) are compared and found to be identical within statistical errors, which validates the local approximation of U(r,r') up to E=45 MeV for the central and tensor potentials. Central potentials in the spin-singlet channel for different orbital angular momentums (l=0 and l=2) at E ~ 45 MeV are also found to be the same within the errors, which also supports the local approximation.Comment: 15 pages, 16 figure

Energy dependence of nucleon-nucleon potentials from lattice QCD

Thesis (Ph. D. in Science)--University of Tsukuba, (A), no. 5268, 2010.3.25Includes bibliographical reference

Energy dependence of nucleon-nucleon potentials

We investigate the energy dependence of potentials defined through the Bethe-Salpeter wave functions. We analytically evaluate such a potential in the Ising field theory in 2 dimensions and show that its energy dependence is weak at low energy. We then numerically calculate the nucleon-nucleon potential at non-zero energy using quenched QCD with anti-periodic boundary condition. In this case we also observe that the potentials are almost identical at $E\simeq 0$ and $E\simeq 50$ MeV, where $E$ is the center of mass kinetic energy.Comment: 7 pages, 5 figures, talk presented at the XXVI International Symposium on Lattice Field Theory, July 14-19, 2008, Williamsburg, Virginia, US

Baryon-Baryon Interactions in the Flavor SU(3) Limit from Full QCD Simulations on the Lattice

We investigate baryon-baryon (BB) interactions in the 3-flavor full QCD simulations with degenerate quark masses for all flavors. The BB potentials in the orbital S-wave are extracted from the Nambu-Bethe-Salpeter wave functions measured on the lattice. We observe strong flavor-spin dependences of the BB potentials at short distances. In particular, a strong repulsive core exists in the flavor-octet and spin-singlet channel (the 8_s representation), while an attractive core appears in the flavor singlet channel (the 1 representation). We discuss a relation of such flavor-spin dependence with the Pauli exclusion principle in the quark level. Possible existence of an H-dibaryon resonance above the Lambda-Lambda threshold is also discussed.Comment: 16 pages, 4 figures, ptptex.cls use

Osimertinib as treatment for EGFR exon 20 insertion-positive lung adenocarcinoma

A 20-year-old woman was diagnosed with stage 4 lung adenocarcinoma with an epidermal growth factor receptor (EGFR) exon 20 insertion gene mutation. Although the patient underwent chemotherapy, her lesions progressed. Liquid biopsy for EGFR T790M mutation showed negative results. After administering osimertinib, reduction of the lesions at the primary site was observed, and the patient’s respiratory condition improved. Previous reports showing successful treatment of EGFR exon 20 insertion-positive lung adenocarcinoma with the standard osimertinib dose of 80 mg are limited. The present case demonstrated that osimertinib could be a possible treatment option for EGFR exon 20 insertion-positive lung adenocarcinoma

Towards Lattice QCD Baryon Forces at the Physical Point: First Results

Lattice QCD calculations of baryon forces are performed for the first time with (almost) physical quark masses. $N_f = 2+1$ dynamical clover fermion gauge configurations are generated at the lattice spacing of $a \simeq 0.085$ fm on a $(96 a)^4 \simeq (8.2 {\rm fm})^4$ lattice with quark masses corresponding to $(m_\pi, m_K) \simeq (146, 525)$ MeV. Baryon forces are calculated using the time-dependent HAL QCD method. In this report, we study $\Xi\Xi$ and $NN$ systems both in $^1S_0$ and $^3S_1$-$^3D_1$ channels, and the results for the central and tensor forces as well as phase shifts in the $\Xi\Xi$ $(^1S_0)$ channel are presented.Comment: Talk given at the 12th International Conference on Hypernuclear and Strange Particle Physics (HYP2015), Sendai, Japan, 7-12 Sep 2015, 4 pages, 6 figure