We analyse the sensitivity of all experimentally observable asymmetries and energy distributions for the neutron β − -decay with a polarized neutron and unpolarised decay proton and electron and the lifetime of the neutron to contributions of order 10 −4 of interactions beyond the Standard model (SM). Since the asymmetries and energy distributions are expressed in terms of the correlation coefficients of the neutron β − -decay, in order to obtain a theoretical background for the analysis of contributions beyond the SM we revise the calculation of the correlation coefficients within the SM. We take into account a complete set of contributions, induced to next-to-leading order in the large proton mass expansion by the "weak magnetism" and the proton recoil, and the radiative corrections of order (α/π), calculated to leading order in the large proton mass expansion. We confirm the results, obtained in literature. The contributions of interactions beyond the SM we analyse 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-Kobayashi-Maskawa (CKM) matrix element.

We report on precision resonance spectroscopy measurements of quantum states of ultracold neutrons confined above the surface of a horizontal mirror by the gravity potential of the Earth. Resonant transitions between several of the lowest quantum states are observed for the first time. These measurements demonstrate, that Newton's inverse square law of Gravity is understood at micron distances on an energy scale of 10 −14 eV. At this level of precision we are able to provide constraints on any possible gravity-like interaction. In particular, a dark energy chameleon field is excluded for values of the coupling constant β > 5.8 × 10 8 at 95% confidence level (C.L.), and an attractive (repulsive) dark matter axion-like spin-mass coupling is excluded for the coupling strength gsgp > 3.7 × 10 −16 (5.3 × 10 −16 ) at a Yukawa length of λ = 20 µm (95% (C.L.).PACS numbers: 12.15. Ji,13.30.Ce,14.20.Dh,23.40.Bw Experiments that rely on frequency measurements can be performed with incredibly high precision. One example is Rabi spectroscopy, a resonance spectroscopy technique to measure the energy eigenstates of quantum systems. It was originally developed by I. Rabi to measure the magnetic moment of molecules [1]. Today, resonance spectroscopy techniques are applied in various fields of science and medicine including nuclear magnetic resonance, masers, and atomic clocks. These methods have opened up the field of low-energy particle physics with studies of particle properties and their fundamental interactions and symmetries. In an attempt to investigate gravity at short distances, we applied the concept of resonance spectroscopy to quantum states of very slow neutrons in the Earth's gravity potential [2]. Here, we present the first precision measurements of gravitational quantum states with this method that we refer to as gravity resonance spectroscopy (GRS). The strength of GRS is that it does not rely on electromagnetic interactions. The use of neutrons as test particles bypasses the electromagnetic background induced by van der Waals and Casimir forces and other polarizability effects.Within this work, we link these new measurements to dark matter and dark energy searches. Observational cosmology has determined the dark matter and dark energy density parameters to an accuracy of two significant figures [3]. While dark energy explains the accelerated expansion of the universe, dark matter is needed in order to describe the rotation curves of galaxies and the largescale structure of the universe. The true nature of dark energy and the content of dark matter remain a mystery, however. The two most obvious candidates for dark energy are either Einstein's cosmological constant [4] or quintessence theories [5,6], where the dynamic vacuum energy changes over time. The resonant frequencies of our quantum states are intimately related to these models. If some as yet undiscovered dark matter or dark energy particles interact with neutrons, this should result in a measurable energy shift of the observed quantum states. One prom...

The cryogenic storage ring CSR Review of Scientific Instruments 87, 063115 (2016); https://doi

We investigate the equivalence between Thirring model and sine-Gordon model in the chirally broken phase of the Thirring model. This is unlike all other available approaches where the fermion fields of the Thirring model were quantized in the chiral symmetric phase. In the path integral approach we show that the bosonized version of the massless Thirring model is described by a quantum field theory of a massless scalar field and exactly solvable, and the massive Thirring model bosonizes to the sine-Gordon model with a new relation between coupling constants. We show that the non-perturbative vacuum of the chirally broken phase in the massless Thirring model can be described in complete analogy with the BCS ground state of superconductivity. The Mermin-Wagner theorem and Coleman's statement concerning the absence of Goldstone bosons in the 1+1-dimensional quantum field theories are discussed. We investigate the current algebra in the massless Thirring model and give a new value of the Schwinger term. We show that the topological current in the sine-Gordon model coincides with the Noether current responsible for the conservation of the fermion number in the Thirring model. This allows to identify the topological charge in the sine-Gordon model with the fermion number. *