Angela Gargano

The 247-keV state in ^{54}Sc, populated in the β decay of ^{54}Ca, is reported here as a nanosecond isomer with a half-life of 26.0(22) ns. The state is interpreted as the 1^{+} member of the πf_{7/2}⊗νf_{5/2} spin-coupled multiplet, which decays to the 3^{+},πf_{7/2}⊗νp_{1/2} ground state. The new half-life corresponds to a pure E2 transition with a strength of 1.93(16) W.u., providing the most precise, unambiguous B(E2) value in the neutron-rich fp region to date for a nucleus with valence protons above Z=20. Notably, it is roughly 4 times larger than the B(E2;1/2^{-}→5/2^{-}) value in ^{55}Ca. The results, as compared to semiempirical and ab initio shell-model calculations, indicate (1) a weak N=34 subshell gap relative to N=32, (2) a large E2 enhancement in Sc as compared to Ca due to 1p-1h proton excitations across Z=28, and (3) empirical effective proton and neutron charges e_{π}=1.30(8)e and e_{ν}=0.452(7)e, respectively, that are in contrast to reports of e_{π}≈1.1-1.15e and e_{ν}≈0.6-0.8e for fp-shell nuclei near N=Z. We demonstrate that these reports are erroneous and that, in fact, a universal set of effective charges can be used across the sd and fp shells.

The three-nucleon force (3NF) plays a crucial role in many-nucleon systems. Specifically, it enhances the spin-orbit (SO) splitting, a key phenomenon in the manifestation of shell structure. However, its detailed mechanism has not been fully understood. Recently, we pointed out that a specific component, called the rank-1 component, originating from the two-pion exchange term of the 3NF, significantly contributes to the SO splitting. In this paper, we present shell-model results obtained by implementing the 3NF derived from chiral effective field theory, and discuss how the rank-1 component enhances the SO splitting in $p$-shell nuclei.

This paper presents a pedagogical intervention targeted at secondary school students developed by two researchers in physics. The project seeks to narrow the gender gap in STEM fields by fostering students’ critical awareness of gender stereotypes and roles, helping them to recognize the influence that gender has on their educational choices and professional aspirations. Unlike other orientation programs, here STEM subjects are not the explicit content, rather the working methodology. Our intervention adopts a project-based learning approach introduced by a board game designed to engage students in the topic. Students are guided in carrying out an autonomous investigation of gender discrepancies within their family, school, and peer contexts through a scientific approach, by administering surveys, gathering and analyzing data, and using gender indicators. The final objective is developing a Gender Report of the school. After presenting the project, we document the project experience in nine schools of the Naples (Italy) area through a qualitative analysis of students’ Reports, focusing on the gender dynamics they have identified, as well as the facilitators’ observations. Our analysis shows that traditional gender roles and stereotypes persist, yet first-hand observation may stimulate students’ critical thinking skills from a gender perspective.

The paper presents a pedagogical intervention targeted at secondary school students developed by two researchers in physics. The project seeks to address the gender gap in STEM fields by fostering students’ critical awareness on gender stereotypes and roles, helping them to recognize the influence that gender has on their educational choices and professional aspirations. Unlike other orientation programs, here STEM subjects are not the explicit content, rather the working methodology. Our intervention adopts a project-based learning approach introduced by a board game designed to engage students in the topic. Students are guided in carrying out an autonomous investigation of gender discrepancies within their family, school, and peer contexts through a scientific approach, by administering surveys, gathering and analyzing data, and using gender indicators. The final objective is developing a Gender Report of the school. After presenting the project, we report a qualitative analysis of students’ Reports focusing on the gender dynamics they have identified. Our analysis shows that traditional gender roles and stereotypes persist, yet first-hand observation may stimulate students’ critical thinking skills from a gender perspective.

The role of three-nucleon forces on structure properties of nuclei is discussed within the realistic shell model. Calculations are performed by employing effective shell-model Hamiltonians derived by way of many-perturbation theory from chiral potentials including the nucleon-nucleon and three-nucleon components. A sketch of the formalism in treating the three-nucleon force is given and some selected results for f p- and p-shell nuclei are shown. Particular attention is devoted to the effects of the three-nucleon force on the monopole component of the effective shell-model interaction by showing how relevant they are in correcting the monopole interaction derived from the nucleon-nucleon force only and correctly describing the formation of shell structure as well as the enhancement in the spin-orbit splitting. A decomposition scheme based on the rank of irreducible tensors forming the three-nucleon force at the next-to-next-to-leading order is also presented to recognize their impact on the spin-orbit enhancement.