Kanji Tanaka

Noncommutative gauge theory on fuzzy sphere from matrix model

We derive a noncommutative U(1) and U(n) gauge theory on the fuzzy sphere from a three-dimensional matrix model by expanding the model around a classical solution of the fuzzy sphere. Chern–Simons term is added in the matrix model to make the fuzzy sphere as a classical solution of the model. Majorana mass term is also added to make it supersymmetric. We consider two large N limits, one corresponding to a gauge theory on a commutative sphere and the other to that on a noncommutative plane. We also investigate stability of the fuzzy sphere by calculating one-loop effective action around classical solutions. In the final part of this paper, we consider another matrix model which gives a supersymmetric gauge theory on the fuzzy sphere. In this matrix model, only Chern–Simons term is added and supersymmetry transformation is modified.

Λ4H formation from K− absorption at rest on4He,7Li,9Be,12C,16O and40Ca targetsformation from K− absorption at rest on4He,7Li,9Be,12C,16O and40Ca targets

SummaryFormation ofΛ4H hypernucleus from stopped K− on4He,7Li,9Be,12C,16O and40Ca was studied by detecting π− from the two-body decay ofΛ4H,Λ4H→He+π−. The formation probabilities ofΛ4H per stopped K− on these target nuclei were measured. From the coincidence measurement with π0 and π±, we found that theΛ4H hyperfragment formation onA>4 nuclei cannot be accounted for by the direct reaction onα cluster,4He(K−, π0)Λ4H, alone.RiassuntoSi studia la formazione dell’ipernucleoΛ4H da K− assorbito a riposo su4He,7Li,9Be,12C,16O e40Ca rivelando π− dal decadimento a due corpi diΛ4H→He+π−. Si misurano le probabilità di formazione diΛ4H mediante K− assorbito a riposo su questi nuclei bersaglio. Dalle misure di coincidenza con π0 e π±, si trova che la formazione di iperframmentiΛ4H su nucleiA>4 non si può spiegare solo con la reazione diretta su clusterα,4He(K−, π0)Λ4H.РеэюмеИсследуется обраэование гиперядерΛ4H при поглошении остановивщегося K− в мищенях4He,7Li,9Be,12C,16O и40Ca. Исследование гиперядерΛ4H основано на детектировании π− иэ двух-частичного распадаΛ4H→He+π−. Иэмеряются вероятности обраэованияΛ4H на один остановивщийся K− в укаэанных выще ядрах. Иэ иэмерений совпадений с π0 и π± мы получаем, что обраэование гиперфрагментаΛ4H наA>4 не может быть общяснено с помошью только прямой реакции на α-кластере,4He(K−, π0)Λ4H.

Λ 4 H formation from K− absorption at rest on4He,7Li,9Be,12C,16O and40Ca targetsformation from K− absorption at rest on4He,7Li,9Be,12C,16O and40Ca targets@@@Обраэование Λ 4 H при поглошении K− в покое в мищенях4He,7Li,9Be,12C,16O и40Caпри поглошении K− в покое в мищенях4He,7Li,9Be,12C,16O и40Ca

SummaryFormation ofΛ4H hypernucleus from stopped K− on4He,7Li,9Be,12C,16O and40Ca was studied by detecting π− from the two-body decay ofΛ4H,Λ4H→He+π−. The formation probabilities ofΛ4H per stopped K− on these target nuclei were measured. From the coincidence measurement with π0 and π±, we found that theΛ4H hyperfragment formation onA>4 nuclei cannot be accounted for by the direct reaction onα cluster,4He(K−, π0)Λ4H, alone.RiassuntoSi studia la formazione dell’ipernucleoΛ4H da K− assorbito a riposo su4He,7Li,9Be,12C,16O e40Ca rivelando π− dal decadimento a due corpi diΛ4H→He+π−. Si misurano le probabilità di formazione diΛ4H mediante K− assorbito a riposo su questi nuclei bersaglio. Dalle misure di coincidenza con π0 e π±, si trova che la formazione di iperframmentiΛ4H su nucleiA>4 non si può spiegare solo con la reazione diretta su clusterα,4He(K−, π0)Λ4H.РеэюмеИсследуется обраэование гиперядерΛ4H при поглошении остановивщегося K− в мищенях4He,7Li,9Be,12C,16O и40Ca. Исследование гиперядерΛ4H основано на детектировании π− иэ двух-частичного распадаΛ4H→He+π−. Иэмеряются вероятности обраэованияΛ4H на один остановивщийся K− в укаэанных выще ядрах. Иэ иэмерений совпадений с π0 и π± мы получаем, что обраэование гиперфрагментаΛ4H наA>4 не может быть общяснено с помошью только прямой реакции на α-кластере,4He(K−, π0)Λ4H.