Effective field theory allows for a systematic and model-independent derivation of the forces between nucleons in harmony with symmetries Quantum Chromodynamics. We review foundations this approach discuss its application light nuclei at various resolution scales. The extension to many-body systems is briefly sketched.

Hadrons are composite particles made of quark and gluons. Interestingly, some excited hadronic states resemble the deuteron viewed as a barely bound neutron-proton system. Such molecules spatially extended systems lying very close to decay thresholds. This work reviews current experimental evidence for related theoretical descriptions, including effective field theories lattice quantum chromodynamics.

We review the implications of spontaneous chiral symmetry breaking in QCD for processes involving one, two or more nucleons.

We perform the first fully consistent analysis of $\mathrm{nd}$ scattering at next-to-next-to-leading order in chiral effective field theory including corresponding three-nucleon force and extending our previous work, where only two-nucleon interaction has been taken into account. The appears this expansion depends on two unknown parameters. These parameters are determined from triton binding energy doublet length. find an improved description various observables relation to next-to-leading...

The Hoyle state plays a crucial role in the hydrogen burning of stars heavier than our sun and production carbon other elements necessary for life. This excited carbon-12 nucleus was postulated by [1] as ingredient fusion three alpha particles to produce at stellar temperatures. Although seen experimentally more half century ago [2,3], nuclear theorists have not yet uncovered nature this from first principles. In letter we report ab initio calculation low-lying states using supercomputer...

We present a nucleon-nucleon potential at fifth order in chiral effective field theory. find substantial improvement the description of phase shifts as compared to fourth-order results utilizing coordinate-space regularization. This provides clear evidence corresponding two-pion exchange contributions with all low-energy constants being determined from pion-nucleon scattering. The fifth-order corrections observables appear be natural size, which confirms good convergence expansion for...

The excited state of the 12C nucleus known as "Hoyle state" constitutes one most interesting, difficult and timely challenges in nuclear physics, it plays a key role production carbon via fusion three alpha particles red giant stars. In this letter, we present ab initio lattice calculations which unravel structure Hoyle state, along with evidence for low-lying spin-2 rotational excitation. For ground first find compact triangular configuration clusters. second "bent-arm" or obtuse We also...

We review recent experimental and theoretical progress in understanding the microscopic details of clustering light nuclei. discuss results on $\alpha$-conjugate systems, molecular structures neutron-rich nuclei, constraints for ab initio theory. then examine nuclear a wide range methods, including resonating group generator coordinate antisymmetrized dynamics, Tohsaki-Horiuchi-Schuck-R\"opke wave function container model, no-core shell model continuum quantum Monte Carlo, lattice effective field

The LHCb Collaboration announced two pentaquark-like structures in the $J/\psi p$ invariant mass distribution. We show that current information on narrow structure at 4.45 GeV is compatible with kinematical effects of rescattering from $\chi_{c1} to p$: First, it located exactly threshold. Second, four-star well-established $\Lambda(1890)$ such a leading Landau singularity triangle diagram can coincidentally appear threshold, and third, there $\chi_{c1}\,p$ threshold but not $\chi_{c0}...

We present a determination of the pion-nucleon (πN) σ term σ_{πN} based on Cheng-Dashen low-energy theorem (LET), taking advantage recent high-precision data from pionic atoms to pin down πN scattering lengths as well constraints analyticity, unitarity, and crossing symmetry in form Roy-Steiner equations perform extrapolation point reliable manner. With isospin-violating corrections included both LET, we obtain σ_{πN}=(59.1±1.9±3.0) MeV=(59.1±3.5) MeV, where first error refers uncertainties...

We present a combined analysis of the electromagnetic form factors nucleon in space- and timelike regions using dispersion theory. Our framework provides consistent description experimental data over full range momentum transfer, line with strictures from analyticity unitarity. The statistical uncertainties extracted are estimated bootstrap method, while systematic errors determined variations spectral functions. also perform high-precision extraction radii find good agreement previous...

In this review recent developments in chiral perturbation theory (CHPT), which is the effective field of standard model below symmetry breaking scale, are considered. The Lagrangian formulated terms pseudoscalar Goldstone bosons (pi, K, eta) briefly discussed. It shown how one can gain insight into ratios light quark masses and to what extent these statements independent. A few selected topics concerning dynamics interactions These pi K scattering, some non-leptonic kaon decays problem...

We review the current status of experimental and theoretical understanding axial nucleon structure at low moderate energies. Topics considered include (quasi)elastic (anti)neutrino-nucleon scattering, charged pion electroproduction off nucleons ordinary as well radiative muon capture on proton.