122312808
First results on kaonic hydrogen from the DEAR experiment
Abstract.The objective of DEAR (DAΦNE Exotic Atom Research) is the measurement of the Kα line shift and width, due to the strong interaction, in kaonic hydrogen and a similar measurement - the first one - in kaonic deuterium. The aim is a precision determination of the antikaon-nucleon isospin dependent scattering lengths in order to obtain the kaon nucleon sigma terms. In a first phase, dedicated to the calibration and optimization of the setup, the experiment collected data on kaonic nitrogen: for the first time a complex of three transitions (7 → 6 at 4.6 keV, 6 → 5 at 7.6 keV and 5 → 4 at 14 keV) was measured, and the corresponding yields obtained. The kaonic hydrogen measurement was performed for a total integrated luminosity of about 60 pb-1 in the last months of the 2002 year. Data analyses are in progress, preliminary results being hereby presented, together with those on kaonic nitrogen. PACS: 36.10.-K – 36.10.Gv
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.
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.
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 .
124815658
Measure of the spatial size for the monopole excitation in proton scattering
124123633
SEARCH FOR LORENTZ AND CPT VIOLATION EFFECTS IN MUON SPIN PRECESSION
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.
123071679
Regge trajectories of baryons in the MIT bag model
Abstract We investigate Regge trajectories of baryons in the MIT bag model. It is shown that the energy spectra shown by the trajectories can be described fairly well by the stringlike solutions of the bag model. In particular, three strings with one junction and three ends can explain the delta trajectory better than one string with two ends. The three ends occupied by each quark are assumed to be an equilateral triangle configuration in our calculations.
10122460
First order phase transition in quark matter
We investigate chiral phase transition of the first order in the quark matter. Using the Nambu-Jona-Lasinio model, an equation of state of the quark matter which is similar to the van der Waals's one is obtained. Moreover the specific heat and the compressibility are calculated. It is shown that they are enhanced in the symmetry broken phase, in particular, diverge near the tricritical point.
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.
115798893
Linear Collider vertex detector optimization for Higgs branching ratio measurements
The Higgs branching ratio measurement is a premier goal of the next Linear Collider physics program. Variations of a CCD vertex detector have been studied to assess the impact of inner radius and hit precision on the measurement of the Higgs branching ratios. A small dependence is found when the beampipe radius is varied between 1.2 cm and 2.4 cm, and the hit precision between 3 μm and 5 μm.