Nonleptonic Decays of Charmed Mesons in the Quark Model

title: Electromagnetic Mass Differences of Lowest Lying Hadrons and Behavior of Quarks in Hadrons

title: The Lowest (1/2+ and 0-) Hadron Masses and the Behavior of the Constituent Quarks
abstract: Masses of the lowest lying hadrons and the behavior of constituent quarks are discussed on the analysis of their electromagnetic properties, based on QCD. We find that light quarks (u and d) in the hadrons move with the velocity ::::O.Sc; s quark, with :$0.7c; c quark, with nearly 0.3c. Then we know that the confinement force, no matter what kind of confinement one prefers, does not mainly contribute to the hadron masses. It is also conjectured that Jv,-eJilu-d J;=;[v1,-,11[/Jc-sJ;=;Jv,-rJ/ lt-bl and m,:-::23 GeV on the assumption of the ex­ istence of the next layer. Masses of quarks, of which a hadron is built, are assumed arbitrarily to be from zero to infinity on the argument of various hadronic processes, but the constituent quark masses seem to be mu:-::330 and ms:-::510 (in units of MeV) in the inter­ mediate region at which the magnetic moments and the spectroscopy of hadrons are discussed.ll Can 7r have a mass of an order of one hundred MeV, when it is considered that it is a bound state of such quarks? How do the quarks behave in 7r or other hadrons? This note will con­ tribute to the analysis of the lowest lying hadron masses on the basis of the analysis of the electromagnetic properties by follow­ ing the previous discussions. 2>

title: One Gluon Exchange Contributions to Electromagnetic Mass Differences

title: Nonleptonic Hyperon Decay in the Quark Model
abstract: Nonleptonic hyperon and tr decays are discussed in the nonrelativistic quark model and the SU(6) theory, where we consider the pole diagram for quark. the four-body weak current­ current interaction J1 2 J3 1 and the meson exchange interaction_ We assume two models, and can explain the experiments for parity-violating and parity-conserving amplitudes of nonleptonic hyperon decays. In particular the L1I = 1/2 rule is derived, though the weak current-current interaction J1 2 J3 1 does not satisfy £11 = 1/2. As to the decay of tr two models predict the different ratio of r(SJ~A+K) and r(SJ~S+ll). One is consistent with experiment, the other forbids SJ~A+K.

title: Nonleptonic Decays of Charmed Baryons in the Quark Model

title: Effective System for Simulating Dust Continuum Observations on Distributed Computing Resources
abstract: We present an effective system for simulating dust continuum observations by radiative transfer simulations. By using workflow management system RENKEI-WFT, we utilized distributed computing resources and automated a sequence of computational tasks required for radiative transfer modeling, namely, main radiative transfer simulations, pre-/post-processes, and data transfer between computing resources. Our system simultaneously executes a lot of radiative transfer simulations with different input parameters on distributed computing resources. This capability of our system enables us to conduct effective research by radiative transfer simulation. As a demonstration of our system, we simulated dust continuum observations of protoplanetary disk. We performed hydrodynamic simulation modeling photoevaporating protoplanetary disk irradiated by ultra violet radiation from nearby massive stars. Results of this hydrodynamic simulation were used as input data for radiative transfer simulations. Expected spectral energy distributions and intensity maps were obtained by our system.

title: Phase diagram at finite temperature and quark density in the strong coupling region of lattice QCD for colour SU(3)
abstract: We study the phase diagram of quark matter at finite temperature (T) and chemical potential (μ) in the strong coupling region of lattice QCD for colour SU(3). Baryon has effects to extend the hadron phase to a larger μ direction relative to T c at low temperatures in the strong coupling limit. With the l/g 2 corrections, T c is found to decrease rapidly as g decreases, and the shape of the phase diagram becomes closer to that expected in the real world.

title: Light composite scalar in eight-flavor QCD on the lattice
abstract: In search for a composite Higgs boson (techni-dilaton) in the walking technicolor, we present our preliminary results on the first observation of a light flavor-singlet scalar in a candidate theory for the walking technicolor, the Nf=8 QCD, which was found in our previous paper to have spontaneous chiral symmetry breaking together with remnants of the conformality. Based on simulations with the HISQ-type action on several lattice sizes with various fermion masses, we find evidence of a flavor-singlet scalar meson with mass comparable to that of the Nambu-Goldstone pion in both the small fermion-mass region, where chiral perturbation theory works, and the intermediate fermion-mass region where the hyperscaling relation holds. We further discuss its chiral limit extrapolation in comparison with other states studied in our previous paper: the scalar has a mass much smaller than that of the vector meson, which is compared to the Nambu-Goldstone pion having a vanishing mass in that limit.

title: BROWN-RHO SCALING IN THE STRONG COUPLING LATTICE QCD
abstract: We examine the Brown-Rho scaling for meson masses in the strong coupling limit of lattice QCD with one species of staggered fermion. Analytical expression of meson masses is derived at finite temperature and chemical potential. We find that meson masses are approximately proportional to the equilibrium value of the chiral condensate, which evolves as a function of temperature and chemical potential.

title: Strong Coupling Limit/Region of Lattice QCD
abstract: We study the phase diagram of quark matter and nuclear properties based on the strong coupling expansion of lattice QCD. Both of baryon and finite coupling correction are found to have effects to extend the hadron phase to a larger μ direction relative to Tc. In a chiral RMF model with logarithmic sigma potential derived in the strong coupling limit of lattice QCD, we can avoid the chiral collapse and normal and hypernuclei properties are well described.