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No abstract available

No abstract available

No abstract available

No abstract available

[en] Based solely on such general properties as axiomatic analyticity, crossing symmetry and unitarity, it was recently claimed that a new approach to the problem of constraining scattering amplitudes was developed. However, it is shown that new absolute bounds given in this framework are mainly due to the additional input which itself is one of the outputs one wishes to obtain. Therefore, the new absolute bounds are not valid. (author)

[en] Recently, there has been considerable interest in a grand unified theory (GUT) which unifies the electromagnetic-weak and strong interaction through the gauge principle. This grand unified theory has explained many important questions of high energy physics and shows a possibility to be a really big theory through the combination with the supersysmmetry or supergravity. But there remains many works to be done, especially constructing a realistic model consistent with every experimental and theoretical results. The axion mass and its coupling to ordinary matter are known to be inversely proportional to the large vacuum expectation value fsub(a) of an *(SU(2)x U(1)*)sub(w)-single scalar field. We have searched the grand unified model which contains four mass scales with the proper value consistent with every constraints up to now. It is found that these constraints on four mass scales are indeed a severe one such that a consistent model of SU(7), SU(8), or SU(9) can not be constructed. Even through a model based on a more larger group like SU(11) could be built with proper four mass scales, it seems too complex to be a realistic one. Thus it is a rather natural conclusion that the early universe is not a one of standard cosmology but another one like inflationary universe. (Author)

[en] We have studied the workability of the Archimedes principle realized through the MIT bag model without the approximation of zero gluon mass. In the case of zero limit of the gluon mass, large gluon field is formed inside the quark bag which makes the outside quark mass very large. But this effect is not so magnificent for nonzero inside gluon mass. (Author)

[en] We have studied the implication of new constraint on model construction due to the new cosmological bound of axion coupling to the ordinary matter. It is found that no model of SU(7), SU(8), and SU(9) can be constructed with the four independent stages of symmetry breaking including one stage due to invisible axion. (Author)

[en] It is proved that the logarithmic derivative of the absorptive part of the scattering amplitude with respect to momentum transfer t has an improved rigorous upper bound (7lns)/[2√t (2- √t )] for a sequence of s→infinity. It is also observed that the slope of the Regge trajectory is not only rigorously bounded from above by 7/[2√t (2- √t )], but also by 1/[2√t (2- √t )], if the total cross section increases in any fashion as s→infinity. Here s is energy squared and 0< t<4 (in units of pion mass)