Mon·Dec 26, 2022Monday·December 26, 2022

1. 01*

   Measurement of flavor asymmetry of light-quark sea in the proton with Drell-Yan dimuon production in $p+p$ and $p+d$ collisions at 120 GeV

   J. Dove🇺🇸 · B. Kerns🇺🇸 · C. Leung🇺🇸 · R. E. McClellan🇺🇸 · S. Miyasaka🇯🇵 · D. H. Morton🇺🇸 · K. Nagai🇯🇵 · S. Prasad🇺🇸 · F. Sanftl🇯🇵 · M. B. C. Scott🇺🇸 · A. S. Tadepalli🇺🇸 · C. A. Aidala🇺🇸 and 57 other authors

   Evidence for a flavor asymmetry between the $\bar{u}$ and $\bar{d}$ quark distributions in the proton has been found in deep-inelastic scattering and Drell-Yan experiments. The pronounced dependence of this flavor asymmetry on $x$ (fraction of nucleon momentum carried by partons) observed in the Fermilab E866 Drell-Yan experiment suggested a drop of the $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ ratio in the $x>0.15$ region. We report results from the SeaQuest Fermilab E906 experiment with improved statistical precision for $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ in the large $x$ region up to $x=0.45$ using the 120 GeV proton beam. Two different methods for extracting the Drell-Yan cross section ratios, ${\sigma }^{pd}/2{\sigma }^{pp}$, from the SeaQuest data give consistent results. The $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ ratios and the $\bar{d}\left(x\right)-\bar{u}\left(x\right)$ differences are deduced from these cross section ratios for $0.13<x<0.45$. The SeaQuest and E866/NuSea $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ ratios are in good agreement for the $x\lesssim 0.25$ region. The new SeaQuest data, however, show that $\bar{d}\left(x\right)$ continues to be greater than $\bar{u}\left(x\right)$ up to the highest $x$ value ($x=0.45$). The new results on $\bar{d}\left(x\right)/\bar{u}\left(x\right)$ and $\bar{d}\left(x\right)-\bar{u}\left(x\right)$ are compared with various parton distribution functions and theoretical calculations.

   ↳ hep-phhep-exnucl-exPRC(2023)·22 citations
2. 02*

   $\Xi$-nuclear constraints from ${\Xi }^{-}$ emulsion capture events

   Eliahu Friedman🇮🇱 · Avraham Gal🇮🇱

   All five KEK and J-PARC two-body ${\Xi }^{-}$+${}^A$Z $\to$ ${}_{\Lambda }^{A^{\prime }}$Z'+${}_{\Lambda }^{A^{\prime \prime }}$Z'' capture events in light emulsion nuclei, including KISO and IBUKI in ${}^{14}$N, are consistent with Coulomb-assisted $1p_{{\Xi }^{-}}$ nuclear states. The underlying $\Xi$-nuclear potential is strongly attractive, with nuclear-matter depth $V_{\Xi }$ larger than 20 MeV. The recent ${}^{14}$N capture events KINKA and IRRAWADDY assigned by J-PARC E07 to $1s_{{\Xi }^{-}}$ nuclear states, and implying considerably shallower $V_{\Xi }$, have also another interpretation as $1p_{{\Xi }^0}$ nuclear states.

   ↳ nucl-thhep-phnucl-exEPJ Web Conf.(2022)·5 citations
3. 03*

   The new APD-Based Readout of the Crystal Barrel Calorimeter -- An Overview

   CBELSA/TAPS Collaboration: C. Honisch🇩🇪 · P. Klassen🇩🇪 · J. Müllers🇩🇪 · M. Urban🇩🇪 · F. Afzal🇩🇪 · J. Bieling🇩🇪 · S. Ciupka🇩🇪 · J. Hartmann🇩🇪 · P. Hoffmeister🇩🇪 · M. Lang🇩🇪 · D. Schaab🇩🇪 · C. Schmidt🇩🇪 and 37 other authors

   The Crystal Barrel is an electromagnetic calorimeter consisting of 1380 CsI(Tl) scintillators, and is currently installed at the CBELSA/TAPS experiment where it is used to detect decay products from photoproduction of mesons. The readout of the Crystal Barrel has been upgraded in order to integrate the detector into the first level of the trigger and to increase its sensitivity for neutral final states. The new readout uses avalanche photodiodes in the front-end and a dual back-end with branches optimized for energy and time measurement, respectively. An FPGA-based cluster finder processes the whole hit pattern within less than 100 ns. The important downside of APDs -- the temperature dependence of their gain -- is handled with a temperature stabilization and a compensating bias voltage supply. Additionally, a light pulser system allows the APDs' gains to be measured during beamtimes.

   ↳ physics.ins-detnucl-ex6 citations
4. 04*

   A Method to Load Tellurium in Liquid Scintillator for the Study of Neutrinoless Double Beta Decay

   D.J. Auty🇨🇦 · D. Bartlett🇨🇦 · S.D. Biller🇬🇧 · D. Chauhan🇨🇦 · M. Chen🇨🇦 · O. Chkvorets🇨🇦 · S. Connolly🇨🇦 · X. Dai🇨🇦 · E. Fletcher🇨🇦 · K. Frankiewicz🇺🇸 · D. Gooding🇺🇸 · C. Grant🇺🇸 and 25 other authors

   A method has been developed to load tellurium into liquid scintillator so as to permit searches for neutrinoless double beta decay with high sensitivity. The approach involves the synthesis of an oil-soluble tellurium compound from telluric acid and an organic diol. The process utilises distillable chemicals that can be safely handled underground and affords low radioactive backgrounds, low optical absorption and high light yields at loading levels of at least several percent Te by weight.

   ↳ physics.ins-dethep-exnucl-exNucl.Instrum.Meth.A(2023)·26 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.