Mon·Dec 5, 2022Monday·December 5, 2022

1. 01*

   Experimental overview of electromagnetic probes in ultra-relativistic nucleus-nucleus collisions

   Klaus Reygers🇩🇪

   Electromagnetic probes are not affected by hadronization and provide direct information about the space-time evolution of high-energy nucleus-nucleus collisions. In particular, the measurement of thermal radiation from the quark-gluon plasma and the extraction of an effective medium temperature belong to the key objectives in heavy-ion physics. We provide a brief tour of current results and an outlook to future measurements.

   nucl-exActa Phys.Polon.Supp.(2023)·5 citations
2. 02*

   Search for ultralight axion dark matter in a side-band analysis of a 199Hg free-spin precession signal

   C. Abel🇬🇧 · N. J. Ayres🇨🇭 · G. Ban🇫🇷 · G. Bison🇨🇭 · K. Bodek🇵🇱 · V. Bondar🇨🇭 · E. Chanel🇨🇭 · C. B. Crawford🇺🇸 · M. Daum🇨🇭 · B. Dechenaux🇫🇷 · S. Emmenegger🇨🇭 · P. Flaux🇫🇷 and 26 other authors

   Ultra-low-mass axions are a viable dark matter candidate and may form a coherently oscillating classical field. Nuclear spins in experiments on Earth might couple to this oscillating axion dark-matter field, when propagating on Earth's trajectory through our Galaxy. This spin coupling resembles an oscillating pseudo-magnetic field which modulates the spin precession of nuclear spins. Here we report on the null result of a demonstration experiment searching for a frequency modulation of the free spin-precession signal of \magHg in a \SI{1}{\micro\tesla} magnetic field. Our search covers the axion mass range $10^{-16}\text{eV}\lesssim m_a\lesssim 10^{-13}\text{eV}$ and achieves a peak sensitivity to the axion-nucleon coupling of $g_{aNN}\approx 3.5\times 10^{-6}{\text{GeV}}^{-1}$.

   nucl-exhep-exhep-phSciPost Phys.(2023)·25 citations
3. 03*

   Microscopic study of the deformed neutron halo of 31Ne

   R.Takatsu · Y. Suzuki🇯🇵 · W. Horiuchi🇯🇵 · M. Kimura🇯🇵

   The properties of the deformed halo of 31Ne were discussed using the antisymmetrized molecular dynamics plus resonating group method (AMD+RGM). The AMD+RGM calculations describe a large neutron radius for the ground state and reveal that the ground state is dominated by core-excited components. The resonant states were also investigated by applying the analytical continuation of the coupling constant. It was found that the first excited state (the 5/2- state) is also dominated by core-excited components and has a small decay width, whereas the second excited state (the 7/2- state) is dominated by the valence neutron in the $f$-wave coupled to the ground state of 30Ne.

   ↳ nucl-thnucl-exPRC(2023)·12 citations
4. 04*

   Accessing GPDs through the exclusive photoproduction of a photon-meson pair with a large invariant mass

   Goran Duplančić🇭🇷 · Saad Nabeebaccus🇫🇷 · Kornelija Passek-Kumerički🇭🇷 · Bernard Pire🇫🇷 · Lech Szymanowski🇵🇱 · Samuel Wallon🇫🇷

   We study the exclusive photoproduction of a photon-meson pair with a large invariant mass, working in the QCD factorisation framework. Explicitly, we consider a $\rho$-meson or a charged $\pi$ in the final state. This process gives access to chiral-even GPDs as well as chiral-odd GPDs. We focus here on the chiral-even sector. The computation is performed at leading order and leading twist. We discuss the prospects of measuring them in various experiments such as JLab 12-GeV, COMPASS, future EIC and LHC (in ultraperipheral collisions). In particular, the high centre of mass energies available at collider experiments can be used to probe GPDs at small skewness $\xi$. We also compute the polarisation asymmetries with respect to the incoming photon. The results for an alternative distribution amplitude (`holographic' form) are also compared with the predictions obtained with an asymptotic distribution amplitude.

   ↳ hep-phhep-exnucl-exnucl-thActa Phys.Polon.Supp.(2023)·5 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.