The (K-,p) reaction on nuclei with in-flight kaons
A. Ramos, V. K. Magas, J. Yamagata-Sekihara, S. Hirenzaki, E. Oset
备注：
To appear in the proceedings of the 10th International Conference on Hypernuclear and Strange Particle Physics, Tokai, Ibaraki (Japan), 14-18 September, 2009
We perform a theoretical study of the spectrum of protons with kinetic energies of around 600 MeV, emitted following the interaction of 1 GeV/c kaons with nuclei. A recent experimental analysis of this (K-,p) reaction on 12C, based on the dominant quasielastic process, has suggested a deeply attractive kaon nucleus potential. Our Monte Carlo simulation considers, in addition, the one-and two-nucleon K- absorption processes producing hyperons that decay into πN pairs. We find that this kaon in-flight reaction is not well suited to determine the kaon optical potential due, essentially, to the limited sensitivity of the cross section to its strength, but also to unavoidable uncertainties from the coincidence requirement applied in the experiment. A shallow kaon nucleus optical potential obtained in chiral models is perfectly compatible with the observed spectrum.
The properties of kaonic nuclei are studied using a two-dimensional Skyrme-Hartree-Fock model with a $KN$ Skyrme force. We focus in particular on the instability of the solutions for a too strong $KN$ interaction, which determines a maximum value of the kaon binding in this approach. We then analyze the change of the deformation properties of several core-deformed nuclei caused by the added kaon, and find a shrinking of the core and in some cases a complete loss of deformation.
Based on our Faddeev-Yakubowsky calculations of four-body kaonic nuclear systems it was revealed that the structure of K-K-pp is well approximated by two Lambda*=K-p's with strong mutual attraction. It is vitally important to study this nucleus, as it is an essential gateway toward multi-Lambda* nuclei. Two experimental proposals are presented: i) production of K-K-pp by p+p reactions at T_p = 7 GeV, and ii) search for K-K-pp from the invariant mass of M(Lambda-Lambda) around 2.6 GeV/c2 in high-energy HI reactions.
在扭曲波脉冲近似下研究了准自由反应A $(γ, K Y)$ B.为此，我们提出了一个修正的树级模型的基本K介子光生，包括强子形状因子符合规范不变性，使用SU（3）的玻恩耦合值和使用共振符合多通道分析。独家准自由K介子光生核的潜力，揭示超子核相互作用的细节进行检查。对于所有六个产生通道，获得了符合截面、光子不对称性和超子极化及其对模型成分的敏感性的详细预测。在选定的运动学条件下，这些观测量对超子-核末态相互作用敏感。一些偏振观测量被发现是不敏感的失真的影响，使它们成为理想的工具，寻找可能的介质修改的基本振幅。
$K^-$ optical potentials relevant to calculations of $K^-$ nuclear quasi-bound states were developed within several chiral meson-baryon coupled-channel interaction models. The applied models yield quite different $K^-$ binding energies and widths. Then, the $K^-$ multinucleon interactions were incorporated by a phenomenological optical potential fitted recently to kaonic atom data. Though the applied $K^-$ interaction models differ significantly in the $K^-N$ subthreshold region, our self-consistent calculations of kaonic nuclei across the periodic table lead to conclusions valid quite general…
We investigate the $ϕ$ meson nuclear transparency using some recent theoretical developments on the $ϕ$ in medium self-energy. The inclusion of direct resonant $ϕN$-scattering and the kaon decay mechanisms leads to a $ϕ$ width much larger than in most previous theoretical approaches. The model has been confronted with photoproduction data from CLAS and LEPS and the recent proton induced $ϕ$ production from COSY finding an overall good agreement. The results support the need of a quite large direct $ϕN$-scattering contribution to the self-energy.
We review the present status of the experimental and theoretical developments in the field of strangeness in nuclei and neutron stars. We start by discussing the $\bar K N$ interaction, that is governed by the presence of the $Λ(1405)$. We continue by showing the two-pole nature of the $Λ(1405)$, and the production mechanisms in photon-, pion-, kaon-induced reactions as well as proton-proton collisions, while discussing the formation of $\bar K NN$ bound states. We then move to the theoretical and experimental analysis of the properties of kaons and antikaons in dense nuclear matter, paying a …
Color transparency is studied for the $K^+$ meson produced due to large four-momentum transfer in the $(e,e^\prime)$ reaction on nuclei. The variation of the $K^+$ meson color transparency ($K^+$CT) with the photon virtuality, and kaon momentum is investigated. The calculated results for $K^+$CT are compared with the data reported from Jefferson Laboratory.
The mass and decay width of the $ϕ$ meson in cold nuclear matter are computed in an effective Lagrangian approach. The medium dependence of these properties are obtained by evaluating kaon-antikaon loop contributions to the $ϕ$ self-energy, employing the medium-modified kaon masses, calculated using the quark-meson coupling model. The loop integral is regularized with a dipole form factor, and the sensitivity of the results to the choice of cutoff mass in the form factor is investigated. At normal nuclear matter density we find a downward shift of the $ϕ$ mass by a few percent, while the decay…
Studying the in-medium $ϕ$ meson spectrum through kaons in proton-nucleus reactions
Yonsei University（延世大学）；KEK, High Energy Accelerator Research Organization（高能加速器研究机构）；Japan Atomic Energy Agency（日本原子能机构）；Wigner Research Centre for Physics（维格纳物理研究中心）
Nuclear system with antikaons, so-called kaonic nuclei, has been a longstanding issue in strange nuclear physics and hadron physics, because they might have exotic nature; In particular, they could be a doorway to the dense matter due to the strong attraction between antikaon and nucleon. Among kaonic nuclei, the three-body system composed of two protons and a single $K^-$ meson, $K^-pp$, is the most essential. In this article, we will report on the recent situation of $K^-pp$ studies in both theoretical and experimental sides. Afterwards, we will explain our latest study of the $K^-pp$ with a…
Evidence of isospin-symmetry violation in high-energy collisions of atomic nuclei: Theoretical and Phenomenological considerations
Warsaw University of Technology（华沙理工大学）；Jan Kochanowski University（扬·科哈诺夫斯基大学）；Bogolyubov Institute for Theoretical Physics（博戈柳博夫理论物理研究所）；University of Houston（休斯顿大学）；Kalinga Institute of Industrial Technology（卡林加工业技术学院）
A theoretical investigation is done to clarify the origin of the peak structure observed near the $K^{-} p p$ threshold in the in-flight ${}^{3}\text{He} ( K^{-}, \, Λp ) n$ reaction of the J-PARC E15 experiment, which could be a signal of the lightest kaonic nuclei, that is, the $\bar{K} N N (I=1/2)$ state. For the investigation, we evaluate the $Λp$ invariant mass spectrum assuming two possible scenarios to interpret the experimental peak. One assumes that the $Λ(1405)$ resonance is generated after the emission of an energetic neutron from the absorption of the initial $K^-$, not forming a b…
Hadronic interactions are crucial for the dynamical description of heavy-ion reactions at low collision energies and in the late dilute stages at high collision energies. In particular, the properties and decay channels of resonances are an essential ingredient of hadronic transport approaches. The HADES collaboration measured particle production in collisions of pions with carbon and tungsten nuclei at $E_\text{kin} = 1.7\,\text{GeV}$. Such reactions are of high interest, because they allow to probe the properties of baryonic resonances produced in a much cleaner environment than the usual nu…
