We study the pion-nucleon P33 and P11 scattering, where the Delta and the Roper resonances are seen, respectively. We use the Lippmann-Schwinger equation extended to couple to a one-body state, and investigate nature of these resonances by taking and omitting a one-baryon state into account. We see validity and puzzle of the standard quark model interpretation, for the Delta and the Roper reson...

We study electromagnetic properties of the nucleon and Roper resonance in a chiral quark-diquark model including two kinds of diquarks needed to describe the nucleon: scalar and axial-vector diquarks. The nucleon and Roper resonance are described as superpositions of two quark-diquark bound states of a quark and a scalar diquark and of a quark and an axial-vector diquark. Electromagnetic form f...

Amos Golan Department of Economics, American University, Roper 200, 4400 Massachusetts Ave., NW, Washington, DC 20016, USA.

Ground-penetrating radar (GPR) has been extensively utilized in deep-space exploration. However, GPR modeling commonly employs simplified antenna models and carrier-free impulse signals, resulting reduced accuracy interpretability. In this paper, we addressed these limitations by combining a tilted monopole linear frequency modulation continuous wave (LFMCW) to simulate real conditions. Additio...