7 pages, 4 figuresInternational audienceWe present phase shift measurements for neutron matter waves in vacuum and in low pressure Helium using a method originally developed for neutron scattering length measurements in neutron interferometry. We search for phase shifts associated with a coupling to scalar fields. We set stringent limits for a scalar chameleon field, a prominent quintessence dark energy candidate. We find that the coupling constant $\beta$ is less than 1.9 $\times10^7$~for $n=1$ at 95\% confidence level, where $n$ is an input parameter of the self--interaction of the chameleon field $\varphi$ inversely proportional to $\varphi^n$

We analyze the sensitivity of all experimentally observable asymmetries and energy distributions for the neutron ${$\beta${}}^{-}$ decay with a polarized neutron and an unpolarized decay proton and electron, and the lifetime of the neutron to contributions of order ${10}^{-4}$ of interactions beyond the standard model (SM). We analyze the contributions of interactions beyond the SM in the linear approximation with respect to the Herczeg phenomenological coupling constants, introduced at the hadronic level. Such an approximation is good enough for the analysis of contributions of order ${10}^{-4}$ of interactions beyond the SM. We show that in such an approximation the correlation coefficients depend only on the axial coupling constant, which absorbs the contributions of the Herczeg left-left and left-right lepton-nucleon current-current interactions (vector and axial-vector interactions beyond the SM), and the Herczeg scalar and tensor coupling constants. In the lifetime of the neutron, in addition to the axial coupling constant, the contributions of the Herczeg left-left and left-right lepton-nucleon current-current interactions (vector and axial-vector interactions beyond the SM) are absorbed by the Cabibbo\char21{}Kobayashi\char21{}Maskawa matrix element.

A symmetry-preserving Dyson-Schwinger equation treatment of a vector-vector contact interaction is used to compute dressed-quark-core contributions to the nucleon $\sigma$-term and tensor charges. The latter enable one to directly determine the effect of dressed-quark electric dipole moments (EDMs) on neutron and proton EDMs. The presence of strong scalar and axial-vector diquark correlations within ground-state baryons is a prediction of this approach. These correlations are active participants in all scattering events and thereby modify the contribution of the singly represented valence quark relative to that of the doubly represented quark. Regarding the proton $\sigma$-term and that part of the proton mass which owes to explicit chiral symmetry breaking, with a realistic $d\text{−}u$ mass splitting, the singly represented $d$ quark contributes 37% more than the doubly represented $u$ quark; and in connection with the proton’s tensor charges, ${\delta }_{T}u$, ${\delta }_{T}d$, the ratio ${\delta }_{T}d/{\delta }_{T}u$ is 18% larger than anticipated from simple quark models. Of particular note, the size of ${\delta }_{T}u$ is a sensitive measure of the strength of dynamical chiral symmetry breaking; and ${\delta }_{T}d$ measures the amount of axial-vector diquark correlation within the proton, vanishing if such correlations are absent.

We derive electric dipole moment (EDM) constraints on possible new macroscopic time-reversal and parity-violating (TVPV) spin-dependent forces. These constraints are compared to those derived from direct searches in fifth-force experiments and from combining laboratory searches with astrophysical bounds on stellar energy loss. For axion-mediated TVPV spin-dependent forces, EDM constraints dominate over fifth-force limits by several orders of magnitude. However, we show that for a generic light scalar, unrelated to the strong $CP$ problem, present bounds from direct fifth-force searches are more stringent than those inferred from EDM limits for the interaction ranges explored by fifth-force experiments. Thus, correlating observations in EDM and fifth-force experiments could help distinguish axions from more generic light scalar scenarios.

We derive the exact analytical solutions to the symmetron field theory equations in the presence of a one- or two-mirror system. The one-dimensional equations of motion are integrated exactly for both systems and their solutions can be expressed in terms of Jacobi elliptic functions. Surprisingly, in the case of two parallel mirrors, the equations of motion generically provide not a unique solution but a discrete set of solutions with increasing number of nodes and energies. The solutions obtained herein can be applied to $q\mathrm{BOUNCE}$ experiments, neutron interferometry and for the calculation of the symmetron-field-induced “Casimir force” in the CANNEX experiment.