Wed·Jun 30, 2021Wednesday·June 30, 2021

1. 01*

   Two- and three-particle nonflow contributions to the chiral magnetic effect measurement by spectator and participant planes in relativistic heavy ion collisions

   Yicheng Feng🇺🇸 · Jie Zhao🇺🇸 · Hanlin Li🇨🇳 · Hao-jie Xu🇨🇳 · Fuqiang Wang🇺🇸

   Correlation measurements with respect to the spectator and participant planes in relativistic heavy ion collisions were proposed to extract the chiral magnetic effect (CME) from background dominated azimuthal correlators. This paper investigates the effects of two- and three-particle nonflow correlations on the extracted CME signal fraction, $f_{\text{CME}}$. It is found, guided by a multiphase transport (AMPT) model and the heavy ion jet interaction generator (HIJING) together with experimental data, that the nonflow effects amount to approximately $(4\pm 5)$% and $(-5\pm 3)$% without and with pseudorapidity gaps, respectively, in 20-50% centrality Au+Au collisions at $\sqrt{s_{\text{NN}}}=200\text{ GeV}$.

   nucl-exnucl-thPRC(2022)·33 citations
2. 02*

   Questioning the wobbling interpretation of low-spin bands in $\gamma$-soft nuclei within the interacting boson-fermion model

   K. Nomura🇭🇷 · C. M. Petrache🇫🇷

   An alternative interpretation of the recently reported low-lying excited bands in $\gamma$-soft odd-mass nuclei as wobbling bands is presented in terms of the interacting boson-fermion model. The model Hamiltonian is determined based on the mean-field calculations with the nuclear energy density functionals. The predicted mixing ratios of the $\Delta I=1$ electric quadrupole to magnetic dipole transition rates between yrast bands and those yrare bands previously interpreted as wobbling bands in ${}^{135}$Pr, ${}^{133}$La, ${}^{127}$Xe, and ${}^{105}$Pd are consistently smaller in magnitude than the experimental values on which the wobbling interpretation is based. These calculated mixing ratios indicate predominant magnetic character in agreement with the new experimental data. The earlier wobbling assignments are severely questioned.

   ↳ nucl-thnucl-exPRC(2022)·17 citations
3. 03*

   A Position and Pulse Shape Discriminant p-Terphenyl Detector Module

   D.P. Scriven🇺🇸 · G. Christian · G.V. Rogachev🇺🇸 · C.E. Parker🇺🇸 · L.G. Sobotka🇺🇸 · S. Ahn · G.Chubarian · S. Ota🇯🇵 · E. Aboud🇺🇸 · J. Bishop · E. Koshchiy🇺🇸 · A.G. Thomas🇺🇸

   We present the development of a neutron detector array module made with $\text{para}$-terphenyl, a bright, fast, n/$\gamma$ discriminating crystalline organic scintillator. The module is comprised of 2 cm $\times$ 2 cm $\times$ 2 cm $\text{p}$-terphenyl crystals that have been optically coupled together to create a $\text{pseudo-bar}$ module. While only relying on two photo detectors, the module is capable of distinguishing interactions between up to eight crystals. Furthermore, the module retains the $\text{p}$-terphenyl's pulse shape discrimination (PSD) capability. Together this makes the pseudo-bar module a promising position-sensitive neutron detector. Here we present characteristics of the pseudo-bar module - its timing resolution as well as its pulse shape and position discrimination capabilities, and briefly discuss future plans for utilizing an array of pseudo-bar modules in a useful neutron detector system.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2021)·2 citations
4. 04*

   Fast & accurate emulation of two-body scattering observables without wave functions

   J. A. Melendez🇺🇸 · C. Drischler🇺🇸 · A. J. Garcia🇺🇸 · R. J. Furnstahl🇺🇸 · Xilin Zhang🇺🇸

   We combine Newton's variational method with ideas from eigenvector continuation to construct a fast & accurate emulator for two-body scattering observables. The emulator will facilitate the application of rigorous statistical methods for interactions that depend smoothly on a set of free parameters. Our approach begins with a trial $K$ or $T$ matrix constructed from a small number of exact solutions to the Lippmann--Schwinger equation. Subsequent emulation only requires operations on small matrices. We provide several applications to short-range potentials with and without the Coulomb interaction and partial-wave coupling. It is shown that the emulator can accurately extrapolate far from the support of the training data. When used to emulate the neutron-proton cross section with a modern chiral interaction as a function of 26 free parameters, it reproduces the exact calculation with negligible error and provides an over 300x improvement in CPU time.

   ↳ nucl-thcond-mat.mtrl-scihep-lathep-ph+1PLB(2021)·54 citations
5. 05*

   Spin asymmetries in electron-jet production at the future electron ion collider

   Zhong-Bo Kang🇺🇸 · Kyle Lee🇺🇸 · Ding Yu Shao🇨🇳 · Fanyi Zhao🇺🇸

   We study all the possible spin asymmetries that can arise in back-to-back electron-jet production, $ep\to e+\text{jet}+X$, as well as the associated jet fragmentation process, $ep\to e+\text{jet}(h)+X$, in electron-proton collisions. We derive the factorization formalism for these spin asymmetries and perform the corresponding phenomenology for the kinematics relevant to the future electron ion collider. In the case of unpolarized electron-proton scattering, we also give predictions for azimuthal asymmetries for the HERA experiment. This demonstrates that electron-jet production is an outstanding process for probing unpolarized and polarized transverse momentum dependent parton distribution functions and fragmentation functions.

   ↳ hep-phhep-exnucl-exnucl-thJHEP(2021)·46 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.