arXiv subjects

Natsumi Ikeno

Publications and source records attributed to Natsumi Ikeno.

40 records · Page 3Linked to original sources

arXiv2016

Weak decays of heavy hadrons into dynamically generated resonances

In this review we give a perspective of the theoretical work done recently on the interpretation of results from $B$, $D$, $Λ_b$, $Λ_c$ weak decays into final states that contain interacting hadrons, and how it is possible to obtain additional valuable information that is increasing our understanding of hadron interactions and the nature of many hadronic resonances. The novelty of these processes is that one begins with a clean picture at the quark level which allows one to select the basic mechanisms by means of which the process proceeds. Finally, one has a final state described in terms of quarks. To make contact with the experiments, where mesons and baryons are observed, one must hadronize, creating pairs of $q \bar q$ and writing the new states in terms of mesons and baryons. This concludes the primary hadron production in these processes. After that, the interaction of these hadrons takes place, offering a rich spectrum of resonances and special features from where it is possible to learn much about the interaction of these hadrons and the nature of many resonances in terms of the components of their wave functions.

hep-ph↗

arXiv2013

(d,3He) reaction on odd-neutron nuclear target for the formation of deeply bound pionic atoms

We consider the pionic atom spectroscopy by the (d,3He) reaction on an odd-neutron nuclear target in this article, which has not been investigated so far. In the (d,3He) reaction on the odd-neutron nuclear target, we can observe the pionic states in the even-neutron nucleus with spin-parity 0+. We expect that this pionic state does not have the additional shifts due to the effects of the residual interaction between neutron-hole and pionic states. For the even-neutron nuclear target cases, we may have to take into account the residual interaction effects to deduce the binding energies of the pionic states precisely from the high precision experimental data since the final pionic states are the pion-particle plus neutron-hole states. Thus, in addition to widening the domain of the pionic atom spectroscopy in nuclear chart, the present study of the (d,3He) reaction on the odd-neutron target is considered to be important to deduce extremely precise information on the binding energies of the observed pionic states, and to know the pion properties and aspects of the symmetries of the strong interaction at finite density. We modify the formula of the even-even nuclear target case to study the pionic atom formation spectra on the even-odd nuclear target and show the numerical results of 117Sn target case. This experiment will be performed at RIBF/RIKEN in near future.

nucl-th↗

arXiv2012

$η^\prime$ meson under partial restoration of chiral symmetry in nuclear medium

In-medium modification of the eta' mass is discussed in the context of partial restoration of chiral symmetry in nuclear medium. We emphasize that the U_A(1) anomaly effects causes the eta'-eta mass difference necessarily through the chiral symmetry breaking. As a consequence, the eta' mass is expected to be reduced by order of 100 MeV in nuclear matter where about 30% reduction of chiral symmetry takes place. The strong attraction relating to the eta' mass generation eventually implies that there should be also a strong attractive interaction in the scalar channel of the eta'-N two-body system. We find that the attraction can be strong enough to form a bound state.

nucl-th↗

arXiv2011

Precision Spectroscopy of Deeply Bound Pionic Atoms and Partial Restoration of Chiral Symmetry in Medium

We study theoretically the formation spectra of deeply bound pionic atoms expected to be observed by experiments with high energy resolution at RIBF/RIKEN, and we discuss in detail the possibilities to extract new information on the pion properties at finite density from the observed spectra, which may provide information on partial restoration of chiral symmetry in medium. We find that the non-yrast pionic states such as 2s are expected to be seen in the (d,3He) spectra, which will be helpful to reduce uncertainties of the theoretical calculations in the neutron wave functions in nucleus. The observation of the 2s state with the ground 1s state is also helpful to reduce the experimental uncertainties associated in the calibration of the absolute excitation energy. We find that the nuclear densities probed by atomic pions are quite stable and almost constant for various atomic states and various nuclei. Effects of the pion wave function renormalization to the formation spectra are also evaluated.

nucl-th↗