# Investigations of the Few-Nucleon Systems within the LENPIC Project

### Submission summary

 As Contributors: Jacek Golak Preprint link: scipost_201910_00002v4 Date accepted: 2019-12-05 Date submitted: 2019-11-14 Submitted by: Golak, Jacek Submitted to: SciPost Physics Proceedings Proceedings issue: 24th European Few Body Conference (University of Surrey, U.K.) Discipline: Physics Subject area: Nuclear Physics - Theory Approach: Theoretical

### Abstract

Results presented in this contribution are obtained within the Low Energy Nuclear Physics International Collaboration (LENPIC). LENPIC aims to develop chiral nucleon-nucleon and many-nucleon interactions complete through at least the fourth order in the chiral expansion. These interactions will be used together with consistently derived current operators to solve the structure and reactions of light and medium-mass nuclei including electroweak processes. In this contribution the current status of the chiral nuclear forces and current operators will be briefly discussed. A special role played by the calculations of nucleon-deuteron scattering will be explained.

###### Current status:
Publication decision taken: accept

Editorial decision: For Journal SciPost Physics Proceedings: Publish
(status: Editorial decision fixed and (if required) accepted by authors)

### List of changes

(1) page 2, last line (new text after ****)
Unfortunately, the use of such non-local regularization was the source
of finite-cutoff artefacts in the results for higher-energies
elastic nucleon-deuteron scattering [24]. ***** These artefacts appear
for {\em all} non-locally momentum-space regularized 2N potentials
and are a major obstacle to employing such forces in 3N continuum calculations.

(2) page 3, line 8 from bottom (new text after ****)
Calculations described in Ref. [33] showed additionally that combining
N4LO NN potentials with the N2LO 3NF regularized in the same way leads
to similar 3NF effects in nucleon-deuteron
scattering as found with semi-phenomenological nuclear forces. *****
In particular, applications of these forces
does not explain the low energy $A_y$ puzzle [33]. For a detailed comparison
of these chiral potential based predictions to data we refer the reader
to Ref. [33].

(3) page 4, end of section 3 (new text added)

In this contribution, in some measure by definition, we restrict ourselves
to the nuclear forces developed within the LENPIC project. But we are of
course aware of the important contributions made by other groups.
Here we only mention the Moscow (Idaho)-Salamanca
group [38] results, the nuclear forces constructed
by Piarulli et al. [39, 40], by Ekstr\"om et al. [41, 42]
and a very recent family of potentials intended for nuclear structure
calculations [43]. For a more general discussion of the recent
chiral models of the nuclear interactions we refer the reader to Ref. [34].

(4) New references [38]-[43] are added as a consequence of (3).

(5) page 4, new paragraph after
"... fix the low-energy constants in the chiral
electromagnetic and axial currents."

The chiral electroweak current operators are generally not expected
to be used to analyze results of experiments, where electromagnetic
and weak probes transfer a lot of energy and large momenta to a nuclear
system. (See, however, recent predictions for elastic electron-deuteron
scattering in Ref. [54].) That is why first of all we plan to apply chiral
currents to low-energy photodisintegration processes and muon capture
from the lowest atomic orbits, where the energy and momentum transfers
are naturally limited. Calculations based on chiral
forces and currents will be important for the results of electron
scattering experiments planned at the MESA accelerator in Mainz, Germany.

(6) New reference [54] is added as a consequence of (5).

### Submission & Refereeing History

Resubmission scipost_201910_00002v4 on 14 November 2019
Submission scipost_201910_00002v1 on 7 October 2019

## Reports on this Submission

### Report

The report has furtther improved as a consequence of the corrections made and I am very happhy to recommend it for publication.

• validity: high
• significance: high
• originality: high
• clarity: high
• formatting: excellent
• grammar: excellent

### Report

The report has furtther improved as a consequence of the corrections made and I am very happhy to recommend it for publication.

• validity: high
• significance: high
• originality: high
• clarity: high
• formatting: perfect
• grammar: perfect