Practical approximation scheme for the pion dynamics in the three-nucleon system

We discuss a working approximation scheme to a recently developed formulation of the coupled piNNN-NNN problem. The approximation scheme is based on the physical assumption that, at low energies, the 2N-subsystem dynamics in the elastic channel is conveniently described by the usual 2N-potential approach, while the explicit pion dynamics describes small, correction-type effects. Using the standard separable-expansion method, we obtain a dynamical equation of the Alt-Grassberger-Sandhas (AGS) type. This is an important result, because the computational techniques used for solving the normal AGS equation can also be used to describe the pion dynamics in the 3N system once the matrix dimension is increased by one component. We have also shown that this approximation scheme treats the conventional 3N problem once the pion degrees of freedom are projected out. Then the 3N system is described with an extended AGS-type equation where the spin-off of the pion dynamics (beyond the 2N potential) is taken into account in additional contributions to the driving term. These new terms are shown to reproduce the diagrams leading to modern 3N-force models. We also recover two sets of irreducible diagrams that are commonly neglected in 3N-force discussions, and conclude that these sets should be further investigated, because a claimed cancellation is questionable.Comment: 18 pages, including 5 figures, RevTeX, Eps

Mentoring in learning development

Learning Development is still a relatively young field (Syska and Buckley, 2022), and despite a growing body of research, it remains strongly practice-oriented. This means that experience, in this case of individual Learning Developers, takes an even more central place than it does in more established fields, and sharing this experience through mentoring takes on a central role. This is why the mentoring working group has developed a Learning Development focused ALDinHE Mentoring Scheme, together with a Certified Mentor recognition that helps experienced mentors be recognised for their contribution to growing and sharing LD knowledge. This mini keynote briefly introduced the Mentoring Scheme and the CeM recognition before exploring the role mentoring can play in the professional development of Learning Developers with the audience. The questions we asked were: What benefits would you expect for mentees? What benefits would you expect for mentors? What kind of experience can be best shared through mentoring

Developing through mentoring or being mentored: ALDinHE’s new mentoring scheme and certified mentor recognition

ALDinHE is launching its new mentoring scheme and mentorship recognition to acknowledge, promote and recognise the importance of mentoring for learning development as a field that does not offer an official route into the profession. This Professional Development session introduced the mentoring scheme, explaining how to get involved, what support mentors and mentees can receive from ALDinHE and what benefits both sides can get from mentoring or being mentored. If you’re new to learning development or keen to develop more experience in a specific area with the help of a mentor, the mentoring scheme will offer you a brilliant framework to broaden your expertise. If you’re an experienced learning developer or have specific expertise you could share, find out how you could become recognised as a Certified Mentor (CeM) in learning development by ALDinHE

Why is the three-nucleon force so odd?

By considering a class of diagrams which has been overlooked also in the most recent literature on three-body forces, we extract a new contribution to the three-nucleon interaction which specifically acts on the triplet odd states of the two nucleon subsystem. In the static approximation, this 3N-force contribution is fixed by the underlying 2N interaction, so in principle there are no free parameters to adjust. The 2N amplitude however enters in the 3NF diagram in a form which cannot be directly accessed or constrained by NN phase-shift analysis. We conclude that this new 3N-force contribution provides a mechanism which implies that the presence of the third nucleon modifies the p-wave (and possibly the f-wave) components of the 2N subsystem in the triplet-isotriplet channels.Comment: 10 Pages, 7 figures, RevTeX, twocolumn, epsf (updated version with minor changes

Coincident energy and angular distributions in xenon 4d_5/2 inner-shell double photoionization

We report on measurements of the triply differential cross section for the 4d(5/2) inner-shell photoionization in xenon followed by N(5)O(2,3)O(2,3) Auger decay using electron-electron coincidence spectroscopy. The experimental setup made it possible to obtain the first coincident angular distributions for the (1D2) and (3P2) final states at a photon energy of 97.45 eV. Relative amplitudes and phases describing the photoionization were estimated from these angular distributions

The one-pion-exchange three-nucleon force and the AyA_y puzzle

We consider a new three-nucleon force generated by the exchange of one pion in the presence of a 2N correlation. The underlying irreducible diagram has been recently suggested by the authors as a possible candidate to explain the puzzle of the vector analyzing powers $A_y$ and $iT_{11}$ for nucleon-deuteron scattering. Herein, we have calculated the elastic neutron-deuteron differential cross section, $A_y$, $iT_{11}$, $T_{20}$, $T_{21}$, and $T_{22}$ below break-up threshold by accurately solving the Alt-Grassberger-Sandhas equations with realistic interactions. We have also studied how $A_y$ evolves below 30 MeV. The results indicate that this new 3NF diagram provides one possible additional contribution, with the correct spin-isospin structure, for the explanation of the origin of this puzzle.Comment: revised version: We have also studied how Ay evolves below 30 MeV, 4 Pages (twocolumn), 2 figures, uses psfig, RevTe

Emerging from the third space chrysalis: Experiences in a non-hierarchical, collaborative research community of practice

This article discusses the creation of a research-focused virtual community of practice (vCoP) for geographically-dispersed third space professionals, motivated by desires for enhanced professional collaboration, visibility and identity. The authors used collaborative autoethnography (CAE) to evaluate their personal reflections as vCoP participants. Data were gathered in two collaborative writing activities and analysed using thematic analysis (TA). The TA identified two connected themes, which capture the vCoP members’ aspirations to transcend their current roles and be research-active through connecting with like-minded professionals. Collaborative writing activities, including authoring this paper, cultivated elements of academic identity such as independence and purpose. A non-hierarchical and supportive vCoP environment allowed the members to work beyond time and institutional constraints to foster the evolution of the community and an emerging sense of professional identity beyond that typically associated with third space roles. The paper offers a model of collaboration that could help groups in similar situations

Emerging from the third space chrysalis: Experiences in a non-hierarchical, collaborative research community of practice

This article discusses the creation of a research-focused virtual community of practice (vCoP) for geographically-dispersed third space professionals, motivated by desires for enhanced professional collaboration, visibility and identity. The authors used collaborative autoethnography (CAE) to evaluate their personal reflections as vCoP participants. Data were gathered in two collaborative writing activities and analysed using thematic analysis (TA). The TA identified two connected themes, which capture the vCoP members’ aspirations to transcend their current roles and be research-active through connecting with like-minded professionals. Collaborative writing activities, including authoring this paper, cultivated elements of academic identity such as independence and purpose. A non-hierarchical and supportive vCoP environment allowed the members to work beyond time and institutional constraints to foster the evolution of the community and an emerging sense of professional identity beyond that typically associated with third space roles. The paper offers a model of collaboration that could help groups in similar situations. Practitioner Notes 1. Virtual Communities of Practice (vCoPs) can help geographically-dispersed third space, or other higher education professionals connect with like-minded colleagues to meet common aspirations and cultivate a sense of shared professional identity. 2. Democratic participation and support from fellow vCoP members promote commitment, creative thinking, motivation and an openness to generating ideas and trying new ways of working 3. Shared activities, such as collaborative writing and reflection, allow a virtual group to work within time and institutional constraints in ways that would not be achievable for each individual working alone. Such collaboration fosters the evolution of the community 4. The model of collaboration developed by this particular vCoP could be used by other groups to address questions in the changing HE landscape that are relevant to them, and plan activities to strengthen their vCoP’s group identity. 5. Collaborative autoethnography is an appropriate methodology to research a particular cultural and communal context where participants act as both the subjects and the researchers