arXiv subjects

G. A. Sun

Publications and source records attributed to G. A. Sun.

3 recordsLinked to original sources

arXiv2021

New Experimental Limits on Exotic Spin- and Velocity-dependent Interactions Using Rotationally Modulated Source-masses and an Atomic-magnetometer Array

We conducted laboratory searching for the exotic spin- and velocity-dependent new interactions according to the previously proposed experimental scheme. Two $\sim$6Kg heavy source masses are rotationally modulated at a frequency of 20Hz. Four identical atomic magnetometers are used in an array form to increase the statistics and cancel the common-mode noise. Data processing method based on high precision numerical integration is applied for the four harmonic frequencies of the signal. The rotation direction of the source masses was reversed to flip the signal. Thus the [1,-3,3,-1] weighting method can be applied to remove possible slow drifting further. The experiment method has noise reduction features, and new constraints for Vector-Axial and Axial-Axial were obtained. The new constraints on VA improved by as much as more than four orders, on AA by as much as two orders in the corresponding force range, respectively.

nucl-ex↗

arXiv2018

Constraining New Muonic Interactions Meditated by Axion-Like-Particles

ALPs (Axion Like Particle) beyond the standard model are solutions to several important problems of modern physics. One way to detect these particles is to detect the new interactions they meditate. Many experiments have been performed to search for these new interactions in ranges from $\simμ$m to astrophysical range. At present, nearly all known experiments searching for the ALP-meditated long range new interactions use sources or probes containing protons, neutrons and electrons. Constraints for other fermions such as muons are scarce, though muons might be the most suspicious particles which could take part in new interactions, considering their involvement of several well known puzzles of modern physics. In this work, we discuss the possibility of explaining the anomalous magnetic moment of muons by the long range muonic new interactions mediated by ALPs. We also give a constraint for the scalar-pseudo-scalar(SP) type interaction meditated by muonic ALPs. We propose to further search the muonic SP type interaction by muon spin rotation experiments.

hep-ph↗

arXiv2015

Probe Spin-Velocity Dependent New Interactions by Spin Relaxation Times of Polarized $^{3}He$ Gas

We have constrained possible new interactions which produce nonrelativistic potentials between polarized neutrons and unpolarized matter proportional to $α\vecσ\cdot\vec{v}$ where $\vecσ$ is the neutron spin and $\vec{v}$ is the relative velocity. We use existing data from laboratory measurements on the very long $T_{1}$ and $T_{2}$ spin relaxation times of polarized $^{3}$He gas in glass cells.Using the best available measured $T_{2}$ of polarized $^{3}$He gas atoms as the polarized source and the earth as an unpolarized source, we obtain constraints on two new interactions. We present a new experimental upper bound on possible vector-axial-vector($V_{VA}$) type interactions for ranges between $1\sim10^{8}$m. In combination with previous results, we set the most stringent experiment limits on $g_{V}g_{A}$ ranging from $\simμ$m to $\sim10^{8}$m. We also report what is to our knowledge the first experimental upper limit on the possible torsion fields induced by the earth on its surface. Dedicated experiments could further improve these bounds by a factor of $\sim100$. Our method of analysis also makes it possible to probe many velocity dependent interactions which depend on the spins of both neutrons and other particles which have never been searched for before experimentally.

nucl-ex↗