46 research outputs found
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 and MeV, where 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
interaction from 2+1 flavor lattice QCD
We investigate the interaction between baryons in the
channel from 2+1 flavor lattice QCD simulations. On the basis of the HAL QCD
method, the potential is extracted from the Nambu-Bethe-Salpeter
wave function calculated on the lattice by using the PACS-CS gauge
configurations with the lattice spacing fm, the lattice volume
fm and the quark masses corresponding to MeV
and MeV. The potential has a repulsive
core at short distance and an attractive well at intermediate distance.
Accordingly, the phase shift obtained from the potential shows moderate
attraction at low energies. Our data indicate that the system
with the present quark masses may appear close to the unitary limit where the
scattering length diverges.Comment: 9 pages, 4 figures, 1 tabl