Measurement of Light-Cone Wave Functions by Diffractive Dissociation

Diffractive dissociation of particles can be used to study their light-cone wave functions. Results from Fermilab experiment E791 for diffractive dissociation of 500 GeV/c pi- mesons into di-jets show that the |q qbar> light-cone asymptotic wave function describes the data well for Q^2 ~ 10 (GeV/c)^2 or more.Comment: Talk given at the Recontres de Moriond, QCD and High Energy Hadronic Interactions, Les Arcs, March 2002. 5 pages 4 figure

The Lattice QCD Study of the Three-Nucleon Force

We investigate three-nucleon forces (3NF) from lattice QCD simulations, utilizing the Nambu-Bethe-Salpeter (NBS) wave function to determine two-nucleon forces (2NF) and 3NF on the same footing. Quantum numbers of the three-nucleon (3N) system are chosen to be (I, J^P)=(1/2, 1/2^+) (the triton channel). We consider the simplest geometrical configuration where 3N are aligned linearly with an equal spacing, to reduce the enormous computational cost. Lattice QCD simulations are performed using Nf=2 dynamical clover fermion configurations at the lattice spacing of a = 0.156 fm on a 16^3 x 32 lattice with a large quark mass corresponding to m(\pi) = 1.13 GeV. We find repulsive 3NF at short distance.Comment: Talk given at the 19th Particles and Nuclei International Conference (PANIC11), Boston, USA, 24-29 Jul 2011, 3 pages, 2 figure

Exploring Three Nucleon Forces in Lattice QCD

We study the three nucleon force in Nf=2 dynamical clover fermion lattice QCD, utilizing the Nambu-Bethe-Salpeter wave function of the three nucleon system. Since parity-odd two nucleon potentials are not available in lattice QCD at this moment, we develop a new formulation to extract the genuine three nucleon force which requires only the information of parity-even two nucleon potentials. In order to handle the extremely expensive calculation cost, we consider a specific three-dimensional coordinate configuration for the three nucleons. We find that the linear setup is advantageous, where nucleons are aligned linearly with equal spacings. The lattice calculation is performed with 16^3 x 32 configurations at \beta=1.95, m_\pi=1.13 GeV generated by CP-PACS Collaboration, and the result of the three nucleon force in triton channel is presented.Comment: Talk given at International conference on the structure of baryons (BARYONS'10), Osaka, Japan, 7-11 Dec 2010, 4 pages, 2 figure