410 research outputs found
Theoretical Foundation of the Nuclear Force in QCD and its applications to Central and Tensor Forces in Quenched Lattice QCD Simulations
We present full accounts of a method to extract nucleon-nucleon (NN)
potentials from the Bethe-Salpter amplitude in lattice QCD. The method is
applied to two nucleons on the lattice with quenched QCD simulations. By
disentangling the mixing between the S-state and the D-state, we obtain central
and tensor potentials in the leading order of the velocity expansion of the
non-local NN potential. The spatial structure and the quark mass dependence of
the potentials are analyzed in detail.Comment: 40 pages, 11 figures. Prog. Theor. Phys. accepted versio
Comment on "Relation between scattering amplitude and Bethe-Salpeter wave function in quantum field theory"
We invalidate the arguments given in [T.Yamazaki and Y.Kuramashi, Phys. Rev.
D96, 114511 (2017)] over the HAL QCD method for hadron-hadron interactions on
the lattice. We also pose questions on the practical usefulness of the method
proposed in this reference.Comment: 3 pages. Version accepted for publication in Physical Review
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
Two routing problems with the limitation of fuel
AbstractTwo routing problems are considered. Although these two are related to each other, one is polynomially solvable and, by contrast, the other is NP-complete. First an efficient solution procedure is developed for the polynomially solvable problem. Then we establish NP-completeness of the other problem
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
Imaging the bone-immune cell interaction in bone destruction
Bone is a highly dynamic organ that is continuously being remodeled by the reciprocal interactions between bone and immune cells. We have originally established an advanced imaging system for visualizing the in vivo behavior of osteoclasts and their precursors in the bone marrow cavity using two-photon microscopy. Using this system, we found that the blood-enriched lipid mediator, sphingosine-1-phosphate, controlled the migratory behavior of osteoclast precursors. We also developed pH-sensing chemical fluorescent probes to detect localized acidification by bone-resorbing osteoclasts on the bone surface in vivo, and identified two distinct functional states of differentiated osteoclasts, “bone-resorptive” and “non-resorptive.” Here, we summarize our studies on the dynamics and functions of bone and immune cells within the bone marrow. We further discuss how our intravital imaging techniques can be applied to evaluate the mechanisms of action of biological agents in inflammatory bone destruction. Our intravital imaging techniques would be beneficial for studying the cellular dynamics in arthritic inflammation and bone destruction in vivo and would also be useful for evaluating novel therapies in animal models of bone-destroying diseases.Hasegawa T., Kikuta J., Ishii M.. Imaging the bone-immune cell interaction in bone destruction. Frontiers in Immunology 10, 596 (2019); https://doi.org/10.3389/fimmu.2019.00596
Coupled channel approach to strangeness S = -2 baryon-bayron interactions in Lattice QCD
The baryon-baryon interactions with strangeness S = -2 with the flavor SU(3)
breaking are calculated for the first time by using the HAL QCD method extended
to coupled channel system in lattice QCD. The potential matrices are extracted
from the Nambu-Bethe-Salpeter wave functions obtained by the 2+1 flavor gauge
configurations of CP-PACS/JLQCD Collaborations with a physical volume of 1.93
fm cubed and with m_pi/m_K = 0.96, 0.90, 0.86. The spatial structure and the
quark mass dependence of the potential matrix in the baryon basis and in the
SU(3) basis are investigated.Comment: 17 pages, 15 figure
Imaging the Bone-Immune Cell Interaction in Bone Destruction
Bone is a highly dynamic organ that is continuously being remodeled by the reciprocal interactions between bone and immune cells. We have originally established an advanced imaging system for visualizing the in vivo behavior of osteoclasts and their precursors in the bone marrow cavity using two-photon microscopy. Using this system, we found that the blood-enriched lipid mediator, sphingosine-1-phosphate, controlled the migratory behavior of osteoclast precursors. We also developed pH-sensing chemical fluorescent probes to detect localized acidification by bone-resorbing osteoclasts on the bone surface in vivo, and identified two distinct functional states of differentiated osteoclasts, “bone-resorptive” and “non-resorptive.” Here, we summarize our studies on the dynamics and functions of bone and immune cells within the bone marrow. We further discuss how our intravital imaging techniques can be applied to evaluate the mechanisms of action of biological agents in inflammatory bone destruction. Our intravital imaging techniques would be beneficial for studying the cellular dynamics in arthritic inflammation and bone destruction in vivo and would also be useful for evaluating novel therapies in animal models of bone-destroying diseases
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