123013869
An Application of the Glauber Approximation to High Energy Heavy-Ion Collisions. I Theoretical Formulation
119408373
Fluctuation modes in color-superconductors
We investigate fluctuation effects of a gap parameter in color-superconductors. The fluctuation modes in the super phase are described by two scalar fields of diquarks. One of them is a Nambu-Goldstone boson and the other is a diquark boson whose mass is about twice of the gap energy (an extended quasi-supersymmetry). In the normal phase the fluctuation becomes a precursory (soft) mode whose amplitude increases near the critical temperature.
120691222
Superconductivity of Quark Matter at Finite Temperature
117897053
Shear viscosity and spectral function of the quark matter
We discuss the shear viscosity of the quark matter by using the Kubo-Mori formula. It is found that the shear viscosity is expressed in terms of the quark spectral function. If the spectral function is approximated by a modified Bright-Wigner type, the viscosity decreases as the width of the spectral function increases. We also discuss dependence of the shear viscosity on the temperature and the density.
123251544
Thermodynamic Properties of Color Superconducting Quark Matter
Thermodynamics for color superconducting quark matter is investigated on the basis of the one-gluon-exchange model. Thermodynamic quantities are calculated by using a mean field (BCS) approximation. It is shown that there exists a phase transition of second order between the superconducting phase and normal phase. The pressure and density become larger in the superconducting phase. The specific heat and compressibility have a discontinuity at the critical temperature.
118969678
Tetraquark particle in the string model
We discuss the possibility of the existence of tetraquark states made of four quarks in the string (flux tube) model. The new particle is composed of a diquark and an antidiquark which are connected by a color flux. It is shown that the vibrational and rotational excited states of the string explain some non-qq mesons observed experimentally. Moreover we discuss the decay widths of such tetraquarks with the use of the Schwinger mechanism.
18985470
A search for deeply bound kaonic nuclear states
Abstract We have measured proton and neutron energy spectra by means of time-of-flight (TOF) from 4He( K stopped − , p / n ) reactions (KEK PS E471 experiment). In the proton spectrum, a clear mono-energetic peak was observed under semi-inclusive condition, which was assigned to the formation of a strange tribaryon S0(3115) with isospin T = 1 . The mass and width of the state were deduced to be 3117.7 −2.0 +3.8 ( syst . ) ± 0.9 ( stat . ) MeV / c 2 and 21.6 MeV / c 2 , respectively, and its main decay mode was Σ N N . In the neutron spectrum, a mono-energetic peak was found as the result of a detailed analysis, which was assigned to the formation of another kind of strange tribaryon S+(3140). The mass and width of the state were deduced to be 3140.5 −0.8 +3.0 ( syst . ) ± 2.3 ( stat . ) MeV / c 2 and 21.6 MeV / c 2 , respectively, and its main decay mode was Σ ± N N . The isospin of the state is assigned to be 0. The results are compared with recent theoretical calculations.
121515669
Generation of low-energy muons with laser resonant ionization
We have constructed a low-energy muSR spectrometer at RIKEN-RAL muon facility in ISIS, the UK. With low-background of pulsed muon beam, and short pulse width from laser resonant ionization method, it is hoped this instrument will open new possibilities for studies of material sciences with muon beam. It is enphasized that this method is well suited to the facility where intense pulsed proton beam is available.
122815017
Statistical equations and methods applied to the precision muon (g-2) experiment at BNL
Abstract In the muon ( g - 2 ) experiment at Brookhaven National Laboratory, the spin precession frequency ω a is obtained from a standard χ 2 minimization fit applied to the time distribution of decay electrons. The unusually high accuracy ( ∼ 0.5 ppm ) of the experiment puts stringent requirements on the quality of the fit and the level of understanding of the statistical properties of the fitted parameters. We discuss the properties of the fits and their implications on the derived value for ω a , including estimates of the effect of an imperfect fit function, methods of including additional external information to reduce the error, the effects of splitting the data into many smaller subsets of data, applying different weighting methods to the data using energy information, and various tests of data suitability.
52413327
X-ray spectroscopy of kaonic atoms at SIDDHARTA
The X-ray measurements of kaonic atoms play an important role for understanding the low-energy QCD in the strangeness sector. The SIDDHARTA experiment studied the X-ray transitions of 4 light kaonic atoms (H, D, 3 He, and 4 He) using the DAFNE electron-positron collider at LNF (Italy). Most precise values of the shift and width of the kaonic hydrogen 1s state were determined, which have been now used as fundamental information for the low-energy K − p interaction in theoretical studies. An upper limit of the X-ray yield of kaonic deuterium was derived, important for future K − d experiments. The shifts and widths of the kaonic 3 He and 4 He 2p states were obtained, confirming the end of the "kaonic helium puzzle". In this contribution also the plans for new experiments of kaonic deuterium are being presented.
104275874
Spectroscopy of $\eta '$ mesic nuclei using $(p,d)$ reaction