We construct a coordinate-space chiral potential, including $\Delta$-isobar intermediate states in its two-pion-exchange component. The contact interactions entering at next-to-leading and next-to-next-to-next-to-leading orders ($Q^2$ $Q^4$, respectively, $Q$ denoting generically the low momentum scale) are rearranged by Fierz transformations to yield terms most quadratic relative operator of two nucleons. low-energy constants multiplying these fitted 2013 Granada database, consisting 2309...

The hyperspherical harmonic (HH) method has been widely applied in recent times to the study of bound states, using Rayleigh-Ritz variational principle, and low-energy scattering processes, Kohn A=3 4 nuclear systems. When wave function system is expanded over a sufficiently large set HH basis functions, containing or not correlation factors, quite accurate results can be obtained for observables interest. In this paper, main aspects are discussed together with its application zero-energy...

A two-nucleon potential and consistent electromagnetic currents are derived in chiral effective field theory $(\ensuremath{\chi}\mathrm{EFT})$ at, respectively, ${Q}^{2}$ (or ${\mathrm{N}}^{2}\mathrm{LO}$) $eQ$ ${\mathrm{N}}^{3}\mathrm{LO}$), where $Q$ generically denotes the low-momentum scale $e$ is electric charge. Dimensional regularization used to renormalize pion-loop corrections. simple expression for magnetic dipole $(M1)$ operator associated with pion loops, consisting of two terms,...

In recent years local chiral interactions have been derived and implemented in quantum Monte Carlo methods order to test what extent the effective field theory framework impacts our knowledge of few- many-body systems. this Letter, we present Green's function calculations light nuclei based on family two-body presented by group a previous paper conjunction with three-body fitted bound- scattering-state observables three-nucleon sector. These include Δ intermediate states their...

We present fully local versions of the minimally nonlocal nucleon-nucleon potentials constructed in a previous paper [Piarulli et al., Phys. Rev. C 91, 024003 (2015)], and use them hypersperical harmonics quantum Monte Carlo calculations ground excited states $^{3}\mathrm{H}$, $^{3}\mathrm{He}$, $^{4}\mathrm{He}$, $^{6}\mathrm{He}$, $^{6}\mathrm{Li}$ nuclei. The long-range part these includes one- two-pion exchange contributions without with $\mathrm{\ensuremath{\Delta}}$ isobars...

Background: The $A=2$ and 3 form factors are among the observables of choice for testing models nuclear interactions associated electromagnetic charge current operators. Here we investigate validity chiral-effective-field-theory ($\ensuremath{\chi}$EFT) approach to describe strong-interaction dynamics in these few-nucleon systems their response probes.Purpose: objectives present work twofold. first is address resolve some differences independent, $\ensuremath{\chi}$EFT derivations up one...

We obtain a minimal form of the two-derivative three-nucleon contact Lagrangian, by imposing all constraints deriving from discrete symmetries, Fierz identities and Poincare' covariance. The resulting interaction, depending on 13 unknown low-energy constants, leads to potential which we give in local configuration space. also consider leading (no-derivative) four-nucleon interaction show that there exists only one independent operator.

The electromagnetic charge operator in a two-nucleon system is derived chiral effective field theory ($\chi$EFT) up to order $e\, Q$ (or N4LO), where $Q$ denotes the low-momentum scale and $e$ electric charge. specific form of N3LO N4LO corrections from, respectively, one-pion-exchange two-pion-exchange depends on off-the-energy-shell prescriptions adopted for non-static terms corresponding potentials. We show that different lead unitarily equivalent potentials accompanying operators. Thus,...

We present a detailed study of the effect different three-nucleon interactions in $p$-$^{3}\mathrm{He}$ elastic scattering at low energies. In particular, two have been considered: one derived from effective field theory next-to-next-to-leading order and more phenomenological point view---the so-called Illinois model. The four-nucleon observables are calculated by using Kohn variational principle hyperspherical harmonics technique, results compared with available experimental data. found...

The Gamow-Teller (GT) matrix element contributing to tritium $\beta$ decay is calculated with trinucleon wave functions obtained from hyperspherical-harmonics solutions of the Schr\"odinger equation chiral two- and three-nucleon interactions including $\Delta$ intermediate states that have recently been constructed in configuration space. Predictions up N3LO expansion axial current (with $\Delta$'s) overestimate empirical value by 1--4 \%. By exploiting relation between low-energy constant...

Two-nucleon axial charge and current operators are derived in chiral effective field theory up to one loop. The derivation is based on time-ordered perturbation accounts for cancellations between the contributions of irreducible diagrams owing nonstatic corrections from energy denominators reducible diagrams. Ultraviolet divergencies associated with loop isolated dimensional regularization. resulting finite conserved limit, while requires renormalization. A complete set contact terms...

The present work deals with ${e}^{+}\text{\ensuremath{-}}{e}^{\ensuremath{-}}$ pair production in the four-nucleon system. We first analyze process as a purely electromagnetic one context of state-of-the-art approach to nuclear strong-interaction dynamics and currents, derived from chiral effective field theory $(\ensuremath{\chi}\mathrm{EFT})$. Next, we examine how exchange hypothetical low-mass boson would impact cross section for such process. consider several possibilities, that this is...

We evaluate the Fermi and Gamow-Teller (GT) matrix elements in tritium $\beta$-decay by including charge-changing weak current corrections up to one loop recently derived nuclear chiral effective field theory ($\chi$ EFT). The trinucleon wave functions are obtained from hyperspherical-harmonics solutions of Schrodinger equation with two- three-nucleon potentials corresponding either $\chi$ EFT (the N3LO/N2LO combination) or meson-exchange phenomenology AV18/UIX combination). find that...

The Hyperspherical Harmonics (HH) method is one of the most accurate techniques to solve quantum mechanical problem for nuclear systems with a number nucleons $A\le 4$. In particular, by applying Rayleigh-Ritz or Kohn variational principle, both bound and scattering states can be addressed, using either local non-local interactions. Thanks this versatility, used test two- three-nucleon components interaction. present review we introduce formalism HH method, states. describe implementation...

The large values of the singlet and triplet two-nucleon scattering lengths locate nuclear system close to unitary limit. This particular position strongly constrains low-energy observables in three-nucleon as depending on one parameter, triton binding energy, introduces correlations sector light nuclei. Here we analyze propagation these infinite matter showing that its saturation properties, equation state β-stable matter, several properties neutron stars, their maximum mass, are well...

Chiral effective field theory allows one to express nuclear physics observables in terms of low-energy constants (LECs), representing at unresolved scales. In this work the authors focus on two-nucleon contact interaction fourth order (N3LO) and use a unitary transformation reduce number involved LECs. This procedure induces three-nucleon ($3N$) depending five unconstrained Those can be used, association with ($2N$) interaction, fit very accurate data polarization low energies, particular...

A combination of finite energy sum rule techniques and chiral perturbation theory (\ensuremath{\chi}PT) is used in order to exploit recent ALEPH data on the non-strange \ensuremath{\tau} vector $(V)$ axial-vector $(A)$ spectral functions with respect an experimental determination \ensuremath{\chi}PT quantity ${L}_{10}.$ constrained fit ${R}_{\ensuremath{\tau},V\ensuremath{-}A}^{(k,l)}$ inverse moments $(l<0)$ positive $(l>~0)$ adjusts simultaneously ${L}_{10}$ nonperturbative power terms...

It is shown that the number of independent operators in nucleon-nucleon parity violating contact Lagrangian at leading order low-momentum expansion can be reduced to five by using Fierz rearrangements nucleon fields.

The magnetic form factors of $^2$H, $^3$H, and $^3$He, deuteron photodisintegration cross sections at low energies, threshold electrodisintegration backward angles in a wide range momentum transfers, are calculated with the chiral two-nucleon (and three-nucleon) interactions including $\Delta$ intermediate states that have recently been constructed configuration space. $A\,$=$\,$3 wave functions obtained from hyperspherical-harmonics solutions Schr\"odinger equation. electromagnetic current...

We construct accurate models of three-nucleon (3N) interaction by fitting, in a hybrid phenomenological approach, the low-energy constants parametrizing subleading 3N contact operators to triton binding energy, n-d scattering lengths, cross section and polarization observables p-d at 2 MeV center-of-mass energy. These lead satisfactory description polarized data whole energy range below deuteron breakup threshold. In particular, long-standing $A_y$ puzzle seems be solved thanks new terms...

Physical systems characterized by a shallow two-body bound or virtual state are governed at large distances continuous-scale invariance, which is broken to discrete one when three more particles come into play. This symmetry induces universal behavior for different systems, independent of the details underlying interaction, rooted in smallness ratio $\ell/a_B \ll 1$, where length $a_B$ associated binding energy system $E_2=\hbar^2/m a_B^2$ and $\ell$ natural given interaction range. Efimov...

${}^{12}{\rm C}$ and ${}^{16}{\rm O}$ nuclei represent essential elements for life on Earth. The study of their formation plays a key role in understanding heavy element nucleosynthesis stellar evolution. In this paper we present the as systems composed $\alpha$-particle clusters using short-range effective field theory approach. fundamental excited states studied are calculated within an ab-initio approach, Hyperspherical Harmonics method. Thanks to two-body potential fine-tuning three-body...