123947708
A Search for Deeply-bound Kaonic Nuclear States by In-flight $^3$He($K^-, n$) Reaction at J-PARC
F. Sakuma, S. Ajimura, G. Beer, H. Bhang, M. Bragadireanu P. Buehler, L. Busso, M. Cargnelli, S. Choi, C. Curceanu S. Enomoto, D. Faso, H. Fujioka, Y. Fujiwara, T. Fukuda C. Guaraldo, T. Hashimoto, R.S. Hayano, T. Hiraiwa, M. Iio M. Iliescu, K. Inoue, Y. Ishiguro, T. Ishikawa, S. Ishimoto T. Ishiwatari, K. Itahashi, M. Iwai, M. Iwasaki, Y. Kato S. Kawasaki, P. Kienle, H. Kou, Y. Ma, J. Marton, Y. Matsuda Y. Mizoi, O. Morra , T. Nagae, H. Noumi, H. Ohnishi, S. Okada H. Outa, K. Piscicchia, M. Poli Lener, A. Romero Vidal Y. Sada, A. Sakaguchi, M. Sato, A. Scordo, M. Sekimoto, H. Shi D. Sirghi, F. Sirghi, K. Suzuki, S. Suzuki, T. Suzuki K. Tanida, H. Tatsuno, M. Tokuda, D. Tomono, A. Toyoda K. Tsukada, O. Vazquez Doce, E. Widmann, B.K. Wuenschek T. Yamaga, T. Yamazaki, H. Yim, Q. Zhang, J. Zmeskal
118375151
Enhancement of muonium emission rate from silica aerogel with a laser-ablated surface
e ) atoms from a laser-processed aerogel surface into vacuumwas studied for the rst time. Laser ablation was used to create hole-like regions withdiameter of about 270 m in a triangular pattern with hole separation in the range of300{500 m. The emission probability for the laser-processed aerogel sample is at leasteight times higher than for a uniform one.
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.
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.
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
121035915
QUARKONIUM AT FINITE TEMPERATURE
We study quarkonium at finite temperature by using a hadron string model. It is shown that as the temperature is increased, the mass of the quarkonium decreases and the slope of the Regge trajectory is changed.
67846515
A Modified Glauber Approximation and the Formation of Shock Waves in High-Energy Heavy Ion Collisions
Coherent features in high energy heavy ion collisions are investigated from a microscopic viewpoint. A modified Glauber approximation which enables us to include the slowing down of the relative motion between the centers of masses of both nuclei is presented. The generation of the shock wave is shown to be suppressed by this slowing down effect. As an application inclusive nucleon spectra and the two-particle correlation are calculated in the case of Ne+U collision at 400 Me V! A. l ) (which are referred to as I hereafter) we investigated a possible microscopic mechanism for shock wave generation in high energy heavy ion collisions. The nuclear excitation induced by a nuclear collision was de­ scribed in terms of phonons. It was shown that as the collision proceeds phonons are coherently excited and show a characteristic feature of the shock wave. In this treatment the action of the projectile on the target was replaced by that of a potential moving with a constant velocity. We may construct this potential by superposing the nucleonic potential between projectile nucleons and the target ones with amplitudes of nucleonic states in both nuclei. To treat both systems equally from a microscopic viewpoint, one of the authors (M.I) proposed a formalism which is essentially an application of the Glauber approximation to the process. 2 ) The assembly of nucleons in the projectile nucleus was assumed to move in a group during the collision and the Glauber approximation was applied to the relative motion between the centers of masses of the projectile and the target nucleus. In this treatment the deceleration of the relative motion due to the nuclear excitation was not taken into account. In this paper we extend the Glauber approximation so as to take into account the slowing down of the relative motion. In § 2 the formulation of the modified Glauber approximation is presented.
123223657
A Vibrational Bag Model for Baryons
Surface monopole vibration of baryons is investigated on the basis of the soliton bag model. We derive a relativistic Lagrangian for the surface motion whose mass parameter is proportional to square of the bag radius. With the use of the WKB approximation, the energy spectra of Pl1 and F" resonances are reproduced by our model fairly well. The static properties of the nucleon are alsO studied in our vibrational bag model and compared with those of the static bag model. Our model predicts that the nucleon consists of the central high·density part and the surrounding low-density part. It is also shown that our model is capable to predict the experimental data as well as the static bag model.
123116586
A Variational Foundation of the Improper Hartree-Bogoliubov Formalism
We give a variational foundation for the improper Hartree-Bogoliubov (HE) formalism by which odd fermion systems can be treated in an analogous way as the formalism of even fermion systems. Because of the difference of the normalization for the improper HE amplitudes from that for the proper ones, the improper HE equation cannot be diagonalized with the conventional BCS ansatz. We decompose the improper liB amplitudes into the amplitudes describing paired and unpaired modes of fermions and the variational procedure is applied to them. We obtain a new form of the improper HE equation with respect to the paired mode amplitudes. It includes the effects of unpaired modes but can be diago­ nalized with the conventional manner.
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.