The helicity amplitudes of the electroexcitation of the Roper resonance on proton are extracted at 1.7 < Q < 4.2 GeV 2 from recent high precision JLab-CLAS cross sections data and longitudinally polarized beam asymmetry for π electroproduction on protons. The analysis is made using two approaches, dispersion relations and unitary isobar model, which give consistent results. It is found that the...

In the excited baryon spectrum, of particular interest is the level order of the positive-parity excited nucleon, so-called the Roper resonance N (1440) and the negative-parity nucleon N(1535). It is worth mentioning that this pattern of the level order between positive and negative-parity excited states can be found universally in the ∆, Σ and flavor-octet Λ channels. It is also interesting to...

We discuss a new description for the Roper resonance, the first nucleon excited state of JP = 1/2+, in a model of strong diquark correlations. Treating the scalarisoscalar and axial-vector–isovector diquarks as independent degrees of freedom, two states having nucleon quantum numbers are constructed. Due to the scalar and axial-vector nature of the diquarks, the two nucleon states have differen...

We study excited states of the nucleon in quenched lattice QCD with the spectral analysis using the maximum entropy method. Our simulations are performed on three lattice sizes 16 × 32, 24 × 32 and 32 × 32, at β = 6.0 to address the finite volume issue. We find a significant finite volume effect on the mass of the Roper resonance for light quark masses. After removing this systematic error, its...

In 2005, the U.S. Supreme Court held the death penalty unconstitutional as applied to juveniles in Roper v. Simmons. The Court reasoned that juveniles were less criminally culpable than adults because they lack maturity, they are more vulnerable to peer influence, and their character is not as well formed as that of adults. Although Roper addressed the imposition of the ultimate punishment of d...