arXiv subjects

C. T. Willemyns

Publications and source records attributed to C. T. Willemyns.

4 recordsLinked to original sources

arXiv2022

Target normal single-spin asymmetry in inclusive electron-nucleon scattering with two-photon exchange: Analysis using $1/N_c$ expansion

We calculate the target normal single-spin asymmetry caused by two-photon exchange in inclusive electron-nucleon scattering in the resonance region. Our analysis uses the $1/N_c$ expansion of low-energy QCD and combines $N$ and $Δ$ intermediate and final states using the contracted $SU(4)$ spin-flavor symmetry. The normal spin asymmetry obtained in leading-order accuracy in $1/N_c$ has magnitude $\sim 10^{-2}$ and different sign in $ep$ and $en$ scattering. It can be measured in electron scattering at lab energies $\sim$ 0.5-1.5 GeV and provides a clean probe of two-photon exchange dynamics.

hep-ph↗

arXiv2022

Many-quark interactions: Large-$N$ scaling and contribution to baryon masses

Starting from an effective Hamiltonian modelling a baryon made of $N$ identical quarks in the large-$N$ approach of QCD, we obtain analytical formulas allowing to estimate the contributions of multiquark interactions to the baryon mass. The cases of vanishing (mass spectrum) and non-vanishing (baryon melting) temperatures are treated.

hep-ph↗

arXiv2021

Quasi Kepler's third law for quantum many-body systems

The Kepler's third law is a relation between the period and the energy of two classical particles interacting via a gravitational potential. Recent works showed that this law could be extended, at least approximately, to classical three-body systems, or even many-body classical systems. So, a classical quasi Kepler's third law seems to exist. In this paper, approximate analytical solutions are computed for quantum self-gravitating particles with different masses. The results give strong indications in favor of the existence of a quasi Kepler's third law for such systems. The relevance of the proposal is checked with accurate numerical data for the ground state of self-gravitating identical bosons and with numerical estimations for systems with identical particles plus a different one. Connections between the quantum and classical systems are discussed.

physics.gen-ph↗

arXiv2018

Towers of baryons of the ${\cal N}=2$ quark model band in the large $N_c$ limit

We performed a complete analysis of the spectrum of all the states in the ${\cal N}=2$ quark model harmonic oscillator band with $N_f=3$ in the large $N_c$ limit including the often disregarded antisymmetric multiplet $[{\bf 20},1^+]$. We included configuration mixing effects. We found that the states in the $[{\bf 56},L^+]$ and $[{\bf 70},L^+]$ with $L=0,2$ fall into nine towers of degenerate states. We found that nonstrange antisymmetric states fall into three towers and respond to the same structure as the states in the $[{\bf 70},1^-]$ multiplet. We also showed explicitly the compatibility of these results and the scattering resonance picture.

nucl-th↗