AUTHOR=Ceccarelli L. , Gnech A. , Marcucci L. E. , Piarulli M. , Viviani M. 

TITLE=Muon capture on deuteron using local chiral potentials

JOURNAL=Frontiers in Physics

VOLUME=Volume 10 - 2022

YEAR=2023

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2022.1049919

DOI=10.3389/fphy.2022.1049919

ISSN=2296-424X

ABSTRACT=The muon capture reaction
$\mu^- + d \rightarrow n + n + \nu_{\mu}$
in the doublet hyperfine
state is studied using nuclear potentials and consistent
currents derived in chiral effective field theory, which are local and
expressed in coordinate-space (the so-called Norfolk models).
Only the largest contribution due to the
$^1S_0$ $nn$ scattering state is considered. Particular attention is given
to the estimate of the theoretical uncertainty, for which
four sources have been identified:
(i) the model dependence,
(ii) the chiral order convergence for the weak nuclear current,
(iii) the uncertainty in the single-nucleon axial form factor,
and
(iv) the numerical technique adopted to solve the bound and scattering
$A=2$ systems. This last source of uncertainty has turned out
essentially negligible. 
The $^1S_0$ doublet muon capture rate $\Gamma^D(^1S_0)$
has been found to be $\Gamma^D(^1S_0)=255.8(0.6)(4.4)(2.9)$ s$^{-1}$,
where the three errors
come from the first three sources of uncertainty.
The value for $\Gamma^D(^1S_0)$ obtained within this local
chiral framework is compared with previous calculations
and found in very good agreement.