122785400
Search for Heavy Neutrinos in Kaon Decay
We obtained a new constraint of | u . 1 * * versus m(v.), as shown in Fig.l. Because or the better resolution the lower end of the neutrino mass was reduced to 40 MeV. In Fig.l are also shown other upper limits. One is from R -» j/v done /3/ at SIN. Another comes from the 1 He(jf ,v ) reaction /4/. 1 For the first time we obtained e + spectrum with rejection of the three body decay mode. Hitherto only the e v peak region of 247 MeV/c was known /$/. From the analysis oj; the spectrum we obtained a new constraint, on I U | in a wide mass range between 140 and 350 MeV, as shown in Fig.2. The JL* -> e y experiment /6/ at TRIUMF covers a complementary mass region. A recent experiment to search for neutrino0decays at CERN /?/ gave a new constraint on |U | but the present experiment has yielded a one-order of magnitude better constraint. It should be noted that the deduction of | l I e i l from the CERN experiment requires a model for heavy neutrino decay, while in the present experiment it is given purely kmematically,
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.
124815658
Measure of the spatial size for the monopole excitation in proton scattering
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.
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 .
124123633
SEARCH FOR LORENTZ AND CPT VIOLATION EFFECTS IN MUON SPIN PRECESSION
199687152
Latent Heat in the Chiral Phase Transition
The chiral phase transition of the quark matter is studied in the framework of the QCD-like gauge field theory. The thermodynamical potential is investigated using a variational approach. Latent heat generated in the first-order phase transition is calculated and it is shown that the latent heat is enhanced near the tricritical point and is more than several hundred MeV per quark.
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.
110271540
Compact 8-lead unit for the SC correction coils of the SuperKEKB IR magnet system
In the proposed SuperKEKB interaction region (IR) magnet system 40superconducting (SC) correction coils are designed to perform some specific functions withcurrent of about 50 A. To energize these coils, 80 current leads will be mounted in thecryostats where the stringent spatial constraint and the cryogenic operation require acompact and optimum design. We propose a compact unit to integrate 8 helium vaporcooled leads (4 pairs). The 8 leads are made of brass and consist of two structures for thetransported current and helium vapor, which are designed and simulated by finite elementmodel (FEM). This paper will introduce the material selection and structure details. To equalize the temperature profiles of the individual leads under the different currents and helium flows, some copper blocks are placed between leads. In the cold test, the 8 leadswere operated in the nominal mode and responded safely to some transient situation. This paper will present the thermal and electrical comparison between the experi...
15071400
LCD ROOT simulation and analysis tools
The North American Linear Collider Detector group has developed a simulation program package based on the ROOT system. The package consists of Fast simulation, the reconstruction of the Full simulated data, and physics analysis utilities.
73685731
Flux tube model for glueballs
We calculate the mass spectra and decay widths of glueballs in the flux tube model. The glueball is assumed to be a flux tube ring. The breathing and the rotational motions are investigated using the WKB approximation. The calculated spectrum is consistent with those obtained by lattice QCD. The decay widths are also computed using the Schwinger mechanism, and it is shown that they have rather large values. It is widely believed that the strong interaction is de- scribed by quantum chromodynamics ~QCD !@ 1#. It is, how- ever, very difficult to solve QCD, so that several effective models have been devised to explain the physical properties of many hadrons. The flux tube model @2#, or hadron string model @3,4#, is one such model. According to this model, mesons are made up of a quark and antiquark connected by a color flux tube and baryons are described by a quark and diquark connected by the same flux tube. We showed in a previous paper @5# that various excited states of the hadrons can be explained systematically using such a simple model. On the other hand, recent lattice QCD simulations @6# predict the existence of glueballs, which are composed of only gluons. It is the purpose of this paper to present an intuitive and analytic approach to glueballs using a flux tube model. We assume that the glueball is a closed color flux tube ~flux tube ring !. Moreover, the flux tube that constitutes the ring is assumed to have the same properties as the flux tube that constitutes a meson or a baryon. Consequently, our model has no free parameter. We study the relativistic motion of the closed string and obtain the mass spectrum of the glueballs. This simple picture has already been considered by several authors. In particular, Koma, Suganuma, and Toki @7# studied the relativistic breathing motion analytically with the use of the dual Ginzburg-Landau theory @ 8-1 0#. We study not only the vibrational motion but also the rotational one. Moreover, the decay widths in @7# are also calculated by taking into account qqpair production inside the flux tube ~Schwinger mechanism!. This paper is organized as follows. In the next section, the flux tube model for the glueballs is formulated. Section III is devoted to calculation of the mass spectra and the decay widths of the glueballs. In Sec. IV, the numerical results are presented and some discussion is given.