Speaker
Description
Can alpha particles be the basic building blocks of atomic nuclei? The conventional mean-field picture with nucleons as basic degrees of freedom is considered to dominate, particularly in the ground state of the doubly magic nucleus 16O. On the other hand, alpha cluster theories have predicted their existence in the ground state of 16O [1, 2, 3]. Recently, proton-induced alpha-knockout reactions have been established as an effective probe for studying alpha clusters in the nuclei [4]. The reaction cross section of 16 O(p, pα) is a good measure for the number of alpha clusters.
We performed an experiment at RCNP using a 400 MeV proton beam incident on an oxygen-containing target. A double-arm spectrometer analyzed the energies and momenta of recoil protons and alpha particles emitted by the 16 O(p, pα)12 C reaction.
The measured alpha separation energy spectrum and its yield provide direct evidence of alpha clusters in the ground state of ^{16}O. Furthermore, the spectrum reveals three distinct peaks, each corresponding to different types of alpha cluster motion inside the nucleus. Ongoing analysis of the momentum distribution of alpha clusters in ^{16}O will further clarify their motion.
we will discuss the experimental results of the 16O(p,pα)12C reaction and their interpretation.
[1] D.M. Brink et. al, Phys.Lett.B. 33, 143-146 (1970)
[2] R. Bujker and F. Iachello, Phys.Rev.Lett. 112, 152501 (2014).
[3] E. Epelbaum et. al, Phys.Rev.Lett. 112, 102501 (2014).
[4] J. Tanaka, Z.H. Yang et. al, Science 371, 260-264 (2021).
| Type of contribution | poster |
|---|---|
| Are you a student or postdoc? | yes |
