Fri·May 17, 2024Friday·May 17, 2024

1. 01*

   The 3He(\vec n,p)3H parity-conserving asymmetry

   M. Viviani🇮🇹 · S. Baeßler🇺🇸 · L. Barrón-Palos🇲🇽 · N. Birge🇺🇸 · J.D. Bowman · J. Calarco · V. Cianciolo🇺🇸 · C.E. Coppola · C.B. Crawford🇺🇸 · G. Dodson🇺🇸 · N. Fomin🇺🇸 · I. Garishvili🇺🇸 and 19 other authors

   Recently, the n${}^3$He collaboration reported a measurement of the parity-violating (PV) proton directional asymmetry $A_{\mathrm{PV}}=(1.55\pm 0.97(\mathrm{st}\mathrm{at})\pm 0.24(\mathrm{sys}))\times 10^{-8}$ in the capture reaction of ${}^3$He$(\vec{n},\mathrm{p}){}^3$H at meV incident neutron energies. The result increased the limited inventory of precisely measured and calculable PV observables in few-body systems required to further understand the structure of hadronic weak interaction. In this letter, we report the experimental and theoretical investigation of a parity conserving (PC) asymmetry $A_{\mathrm{PC}}$ in the same reaction (the first ever measured PC observable at meV neutron energies). As a result of S- and P-wave mixing in the reaction, the $A_{\mathrm{PC}}$ is inversely proportional to the neutron wavelength $\lambda$. The experimental value is $(\lambda \times A_{\mathrm{PC}})\equiv \beta =(-1.97\pm 0.28(\mathrm{stat})\pm 0.12(\mathrm{sys}))\times 10^{-6}$ Amstrongs. We present results for a theoretical analysis of this reaction by solving the four-body scattering problem within the hyperspherical harmonic method. We find that in the ${}^3$He$(\vec{n},\mathrm{p}){}^3$H reaction, $A_{\mathrm{PC}}$ depends critically on the energy and width of the close $0^{-}$ resonant state of ${}^4$He, resulting in a large sensitivity to the spin-orbit components of the nucleon-nucleon force and even to the three-nucleon force. The analysis of the accurately measured $A_{\mathrm{PC}}$ and $A_{\mathrm{PV}}$ using the same few-body theoretical models gives essential information needed to interpret the PV asymmetry in the ${}^3$He$(\vec{n},\mathrm{p}){}^3$H reaction.

   nucl-exnucl-th1 citation
2. 02*

   Three-body forces and Efimov physics in nuclei and atoms

   Shimpei Endo🇯🇵 · Evgeny Epelbaum🇩🇪 · Pascal Naidon🇯🇵 · Yusuke Nishida🇯🇵 · Kimiko Sekiguchi🇯🇵 · Yoshiro Takahashi🇯🇵

   This review article presents historical developments and recent advances in our understanding on the three-body forces and Efimov physics, from an interdisciplinary viewpoint encompassing nuclear physics and cold atoms. Theoretical attempts to elucidate the three-body force with the chiral effective field theory are explained, followed by an overview of experiments aimed at observing signatures of the nuclear three-body force. Some recent experimental and theoretical works in the field of cold atoms devoted to measuring and engineering three-body forces among atoms are also presented. As a phenomenon arising from the three-body effect, Efimov physics in both cold atoms and nuclear systems is reviewed.

   ↳ nucl-thcond-mat.quant-gasnucl-exEPJA(2025)·21 citations
3. 03*

   A study of the fine-structure constant dependence of radiative capture in Halo-EFT

   Ulf-G. Meißner🇩🇪 · Bernard Ch. Metsch🇩🇪 · Helen Meyer🇩🇪

   We study the fine-structure constant dependence of the rates of some selected radiative capture reactions within the framework of so-called Halo Effective Field Theory in order to assess the adequacy of some assumptions made on the Coulomb penetrability. We find that this dependence deviates from that implied by a parameterization of the cross sections of this effect via a simple penetration factor. Some features of this fine-structure dependence are discussed, in particular its potential impact on the abundances of the light elements in primordial nucleosynthesis.

   ↳ nucl-thastro-ph.COhep-phhep-th+1EPJA(2024)·2 citations
4. 04*

   Locating the critical point for the hadron to quark-gluon plasma phase transition from finite-size scaling of proton cumulants in heavy-ion collisions

   Agnieszka Sorensen🇺🇸 · Paul Sorensen🇺🇸

   We perform a finite-size scaling analysis of net-proton number cumulants in Au+Au collisions at center-of-mass energies between $\sqrt{s_{\mathrm{NN}}}=2.4$ GeV and 54.4 GeV to search for evidence of a critical point in the QCD phase diagram. In our analysis, we use both susceptibility and Binder cumulants which we extract from the second and fourth moments of the net-proton number distributions. We take measurements in different rapidity bin widths, corresponding to different subvolumes of the system, as probes of different length scales. We use model simulations to verify the applicability of this approach, then apply it to data and find evidence for a critical point near the baryon chemical potential of ${\mu }_B\approx 625$ MeV and temperature of $T\approx 140$ MeV. The Binder cumulants, also analyzed in varying rapidity bin widths, provide complementary evidence for a critical point in a similar region. This is the first analysis of experimental data to locate the critical point in a range consistent with theoretical predictions.

   ↳ nucl-thnucl-ex37 citations
5. 05*

   Designing the system to measure the depth-dose profile of a proton beam using CsI(Tl) scintillator

   P. Boontueng · N. Ritjoho🇨🇭 · P. Phumara · T. Sanghangthum · P. Thongjerm · S. Wonglee · W. Pornroongruengchok · C. Kobdaj🇹🇭

   In this work, the standard CsI(Tl) scintillator was used to determine the characteristics of a proton beam. By irradiating the scintillator with a proton beam, it was able to subsequently measure the emitted light using a spectrometer. This work presents the dose response of a scintillator and its use to measure the depth-dose profile of a proton beam. The measurement of the dose response showed that the emission light of the scintillator depended on the total dose of the proton beam. For the design of the depth-dose measurement, the setup of the water phantom included a scintillator and a water tank. The depth-dose profile was determined through varying the water depth at various positions along the path of the proton beam until the end of the Bragg peak region. To compare the measured depth-dose profile, the deposited energy was simulated and fitted Birks constant for collecting quenching. Furthermore, the recommended measurement design suggested using a thin scintillator, as it resulted in a narrower shape of the depth-dose profile. Based on experiment and simulation data, a standard CsI(Tl) scintillator was promising for determining the characteristic proton beam.

   ↳ physics.med-phnucl-ex0 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.