NAKAZAWA Kazuma

NAKAZAWA Kazuma
Title Professor
Division Environmental and Renewable Energy System Division (Ph.D course)
Section Fundamental Science on Environment

Research fields

Most of electromagnetic wave (EM. wave) and a myriad of particles showering down on Earth collide with molecules or atoms in air and emit radiation which consists of particles and EM. wave, again. Since such fresh radiation is almost absorbed by air, human on the ground has been protected from radiation damage. Among produced particles, there are short-lived (~10-10 sec) particles, called "Hyperon", including strange-quark(s). The hyperons are predicted to exist much in Neutron Stars formed after supernova explosion. To understand state and structure of Neutron Stars, it is necessary to know the interaction between hyperons. Thus we find its interaction by measuring masses of nuclei including two hyperons, called Double-Hypernuclei (DH. nuclei). Figure 1 shows the NAGARA event from which the interaction between two hyperons was measured to be weakly attractive inside Helium nucleus. The KISO event shown in Figure 2 informed us the existence of the nucleus in which a particle with two strange-quarks was bound deeply. The detection both of two was the first time in the world. In our course, you can study DH. nuclei of many nuclides, systematically.

Fig.1．NAGARA event. A Xi- hyperon with two strange- quarks produced two hyperons. A DH. nucleus including them was produced and decayed at points A and B, respectively.

Fig.2．KISO event. A Xi- hyperon with two strange-quarks was bound at deeply state of a 14N nucleus at point A, and two hyperons were produced. Each nucleus including a hyperon (tracks #1 and #2) decayed at points B and C.

Research Keywords

Double-Hypernuclei, NAGARA Event

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