A search for deviations from the inverse square law of gravity at nm range using a pulsed neutron beam

C Haddock ,Masaaki Kitaguchi,Noriko Oi,Tamaki Yoshioka,Kenji Mishima,Katsuya Hirota,T Shima ,Hirohiko M Shimizu ,W M Snow ,T Ichihara

doi:10.1051/epjconf/201921905002

Abstract

Recently published results and ongoing experimental efforts to search for deviations from the inverse square law of gravity at the nanometer length scale using slow neutron scattering from the noble gases are discussed. Using the pulsed slow neutron beamline BL05 at the Materials and Life Sciences Facility at J-PARC, we measured the neutron momentum transfer (q) dependence of the differential scattering cross section for the noble gases He, Ne, Ar, Kr, and Xe. By comparing to the distributions obtained using pseudo-experimental Monte Carlo simulations and forming ratios between Xe and He, we placed an upper bound on the strength of a new interaction as a function of interaction length λ which improved upon previous results in the region λ < 0.1 nm, and remains competitive in the larger λ region. Additionally we describe how we are using our technique to extract relative values of the total neutron scattering cross sections of the noble gases, as well as how we plan to measure the neutron-electron scattering length using the NOVA instrument on BL21 at J-PARC.

Highlights

The force of gravity is confirmed to follow an inverse-square law (ISL) famously known as “Newton’s Law of Universal Gravitation” and has been verified experimentally down to distances of less than 1 mm [1]
We summarize the results from a dedicated experiment which probed the ISL at the nanometer length scale by analyzing the momentum transfer (q) dependence of neutron-noble gas scattering measurements performed on a cold neutron beamline with a peak velocity of 1534 m/s
When one includes the effects from the interatomic pair potential between gas atoms, small diffraction effects appear [8]. These effects are negligible at our present statistical precision they must be considered when additional data is analyzed to extract the total scattering cross section

Summary

Introduction

The force of gravity is confirmed to follow an inverse-square law (ISL) famously known as “Newton’s Law of Universal Gravitation” and has been verified experimentally down to distances of less than 1 mm [1]. Other theories which try to explain why gravity is so weak compared to the other interactions of Nature produce short-distance modifications to the theory. For weakly-coupled interactions between nucleons and electrons in the nonrelativistic limit, a number of parametrizations of new possible interactions have been developed which are largely model-independent under the assumption that the new interaction is local [3, 4]. These parametrizations typically produce ISL violations with a Yukawa-like exponential falloff with distance multiplied by some power of 1/r , where r is the distance between the nucleons or electrons

Methods

Results

Discussion

Conclusion