30324247
Deeply bound 1s and 2p pionic states in 205Pb and determination of the s-wave part of the pion-nucleus interaction.
We observed well-separated 1s and 2p pi(-) states in 205Pb in the 206Pb(d,3He) reaction at T(d) = 604.3 MeV. The binding energies and the widths determined are B(1s) = 6.762+/-0.061 MeV, Gamma(1s) = 0.764(+0.154)(-0.171) MeV, B(2p) = 5.110+/-0.045 MeV, and Gamma(2p) = 0.321(-0.062)(+0.060) MeV. They are used to deduce the real and imaginary strengths of the s-wave part of the pion-nucleus interaction, which translates into a positive mass shift of pi(-) in 205Pb.
121882195
Discovery of the repulsive energy shift of the kaonic hydrogen 1s state
Abstract The aim in this manuscript is to clarify the progress in understanding the nature of the K ¯ N interaction at the lowest energy, given by the recent kaonic hydrogen X-ray experiment at KEK [1]. We have observed a clear spectrum showing the kaonic hydrogen K α line, for the first time. The analysis gives the repulsive energy shift to be Δ E (1 s ) = −323 ± 63(statistical) ± 11 (systematic) eV and the energy width to be Λ(1 s ) = 407 ± 208 ± 100 eV. This result is consistent with analyses of the previous low-energy scattering data and resolves the long-standing kaonic hydrogen puzzle.
124123633
SEARCH FOR LORENTZ AND CPT VIOLATION EFFECTS IN MUON SPIN PRECESSION
124815658
Measure of the spatial size for the monopole excitation in proton scattering
122600834
Muon catalyzed fusion experiments on muonic deuterium atom deceleration in thin solid deuterium films
Abstract Muon catalyzed fusion was investigated in a series of thin solid deuterium films by detecting protons from dd fusion. Two different contributions to the total fusion yield resulting from dμ atoms emitted from a primary hydrogen layer and from incident muons directly stopped in the deuterium film itself were observed. The thickness dependence of the fusion yield suggested the importance of molecular effects in dμ elastic scattering in D 2 .
117791711
Radioactive Muonic Atom Studies with Intense Muon Beams
New intense muon beams with flux several orders of magnitude higher than at present muon facilities would allow many novel experimental studies that were until now statistically not feasible. The investigation of the nuclear properties of short‐lived nuclei using muonic atom spectroscopy would become possible. In this paper, the recent progress of a feasibility study at RIKEN‐RAL muon facility using the cold hydrogen film method to produce radioactive muonic atoms is being reported. The first experimental results have just been obtained with stable argon ions implanted in solid deuterium films.
6081502
Mass spectra and decay widths of hadrons in the relativistic string model
A relativistic string model for hadrons is presented. The center-of-mass motion is separated correctly. The vibrational and rotational motions of the string are solved by using the WKB approximation. Moreover, their decay widths are calculated by taking into account the pair creation of quarks inside the string. Both the mass spectra and the decay widths are reproduced fairly well in comparison with experimental data.
121178742
Note on the Occurrence of Shock Waves in High Energy Heavy Ion Collisions
25502171
Rotating Bag Model for Hadrons
The MIT bag model!) has been quite successful in reproducing the observed masses and other static properties of the low-lying hadrons. It is very important to discuss whether or not excited states of the hadrons (resonances) can be explained in the framework of the bag model. A number of excited states have been described successfully by considering collective excitations of the bag.) In particular, Johnson and Thorn) investigated a series of excited states known as the Regge trajectory by using the rotating bag model. They assumed that the rotating bag has stringlike shape with two ends by the centrifugal force and the transverse length is negligible compared with its longitudinal one. From this onedimensional bag model, they succeeded in reproducing the experimental value of the Regge slope very well. Furthermore it was showt: by Wakimaru and one of the present authors (M. I.) that this simple model can explain not only the Regge slope but also the energy spectra of the trajectories.) On the other hand, Eguchi and Migdal et aJ.5) also discussed the excited states by using their string models 'which are independent of the bag model. Any string model which has been proposed is based on the assumption that the shape is stringlike or one-dimensional. Is the assumption of the stringlike shape, however, surely true? section of the stringlike bag, which we call tube, can be given by
18057139
Measurements of Parity-Violation Parameters at SLD
We present direct measurements of the parity-violation parameters A{sub b}, A{sub c}, and A{sub s} at the Z{sup 0} resonance with the SLD detector. The measurements are based on approximately 530 k hadronic Z{sup 0} events collected in 1993-98. Obtained results are A{sub b} = 0.914 {+-} 0.024 (SLD combined: preliminary), A{sub c}, = 0.635 {+-} 0.027 (SLD combined: preliminary), and A{sub s} = 0.895 {+-} 0.066(stat.) {+-} 0.062(sys.).
123025217
Pairing Correlation in Quark Matter
The superconductivity in quark matter is investigated by a generalized mean field approximation. If we assume that two quarks interact each other via the one·gluon exchange potential, attractive force appears in the color·triplet and spin-parallel state. Applying a BCS-like theory to the system, it is shown that we obtain a new superconducting state which is more stable than the normal (Fermi gas) state. We also give the explicit expression of the superconducting state. Recently the possibility of strange quark matter1> has been studied by many authors by using various effective models for QCD. In these approaches2> they have supposed that the ground state of the quark matter is a degenerate Fermi gas state where each quark occupies a single-particle state with definite momentum under the Fermi momentum. We think that this assumption is not so evident. If the interac­ tion between two quarks is attractive and strong enough, the ground state would become a correlated state just like the BCS state in the superconductors rather than the normal state (the Fermi gas state). We will investigate this possibility in this paper. There are several approaches3>.4> to take into account such pairing correlations. They are restricted to the SU(2) quark matter because any two-quark system has color necessarily. In the SU(3), we note that there are three kinds of quark pairs which bear the same color as three kinds of anti-quarks. If such three quark pairs condense in the same way, there may exist a new boson condensate which is a color-singlet state. It is the purpose of this note to discuss such possibility, the color SU(3) superconductivity in the quark matter, by using a mean field approximation. § 2. Attractive force between two quarks First let us consider possibility of appearance of the attractive force between two quarks. We assume the one-gluon exchange potential,5>