Wed·Sep 29, 2021Wednesday·September 29, 2021

1. 01*

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

   K.Y. Wu🇨🇳 · S.Y. Chen🇨🇳 · G.A. Sun🇨🇳 · S.M. Peng🇨🇳 · M. Peng🇨🇳 · H. Yan🇨🇳

   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-exPRL(2022)·28 citations
2. 02*

   Search for photoproduction of axion-like particles at GlueX

   GlueX Collaboration: S. Adhikari🇺🇸 · C. S. Akondi🇺🇸 · M. Albrecht🇺🇸 · A. Ali🇩🇪 · M. Amaryan🇺🇸 · A. Asaturyan🇦🇲 · A. Austregesilo🇺🇸 · Z. Baldwin🇺🇸 · F. Barbosa🇺🇸 · J. Barlow🇺🇸 · E. Barriga🇺🇸 · R. Barsotti🇺🇸 and 132 other authors

   We present a search for axion-like particles, $a$, produced in photon-proton collisions at a center-of-mass energy of approximately 4 GeV, focusing on the scenario where the $a$-gluon coupling is dominant. The search uses $a\to \gamma \gamma$ and $a\to {\pi }^{+}{\pi }^{-}{\pi }^0$ decays, and a data sample corresponding to an integrated luminosity of 168 pb${}^{-1}$ collected with the GlueX detector. The search for $a\to \gamma \gamma$ decays is performed in the mass range of $180<m_a<480$ MeV, while the search for $a\to {\pi }^{+}{\pi }^{-}{\pi }^0$ decays explores the $600<m_a<720$ MeV region. No evidence for a signal is found, and 90% confidence-level exclusion limits are placed on the $a$-gluon coupling strength. These constraints are the most stringent to date over much of the mass ranges considered.

   ↳ hep-exnucl-exPRD(2022)·21 citations
3. 03*

   Status of Anomalies and Sterile Neutrino Searches at Nuclear Reactors

   Stefan Schoppmann🇩🇪

   Two anomalies at nuclear reactors, one related to the absolute antineutrino flux, one related to the antineutrino spectral shape, have drawn special attention to the field of reactor neutrino physics during the past decade. Numerous experimental efforts have been launched to investigate the reliability of flux models and to explore whether sterile neutrino oscillations are at the base of the experimental findings. This review aims to provide an overview on the status of experimental searches at reactors for sterile neutrino oscillations and measurements of the antineutrino spectral shape in mid-2021. The individual experimental approaches and results are reviewed. Moreover, global and joint oscillation and spectral shape analyses are discussed. Many experiments allow setting constraints on sterile oscillation parameters, but cannot yet cover the entire relevant parameter space. Others find evidence in favour of certain parameter space regions. In contrast, findings on the spectral shape appear to give an overall consistent picture across experiments and allow narrowing down contributions of certain isotopes.

   ↳ hep-exnucl-exUniverse(2021)·15 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.