Thu·Nov 2, 2023Thursday·November 2, 2023

1. 01*

   Nuclear PDFs After the First Decade of LHC Data

   M. Klasen🇩🇪 · H. Paukkunen🇫🇮

   We present a review of the conceptual basis, present knowledge and recent progress in the field of global analysis of nuclear parton distribution functions (PDFs). After introducing the theoretical foundations and methodological approaches for the extraction of nuclear PDFs from experimental data, we discuss how different measurements in fixed-target and collider experiments provide increasingly precise constraints on various aspects of nuclear PDFs, including shadowing, antishadowing, the EMC effect, Fermi motion, flavor separation, deuteron binding, target-mass and other higher-twist effects. Particular emphasis is given to measurements carried out in proton-lead collisions at the Large Hadron Collider, which have revolutionized the global analysis during the past decade. These measurements include electroweak-boson, jet, light-hadron, and heavy-flavor observables. Finally, we outline the expected impact of the future Electron Ion Collider and discuss the role and interplay of nuclear PDFs with other branches of nuclear, particle and astroparticle physics.

   ↳ hep-phhep-exnucl-exnucl-thAnn.Rev.Nucl.Part.Sci.(2024)·86 citations
2. 02*

   Measuring the Electric and Magnetic Form Factors of Protons and Antiprotons at small $Q^2$ and the charge radii of hadrons

   Stephan Paul🇩🇪

   Charge radii of hadrons are back in the focus since precision spectroscopic measurements in muonic hydrogen revealed a proton charge radius considerably smaller than generally accepted ever since R.~Hofstaedter's pioneering experiments. Recent experimental results also point to an underestimation of systematic uncertainties in most previous measurements. A new method was thus proposed by AMBER at CERN using elastic scattering by very high energy muons using an active hydrogen target. With a simplified setup we may resume elastic scattering of $\pi$ and K mesons on electrons in inverse kinematics, and, for the first time, probe antiprotons with few percent precision for their charge radius. Applying this method also for protons allows a separation of $G_E^p(Q^2)$ and $G_M^p(Q^2)$ down to $Q^2=10^{-3}(GeV/c{)}^2$.

   ↳ hep-exnucl-ex0 citations
3. 03*

   Shell-model study for ${}^{204-210}$Tl isotopes and core excitations across the $Z=82$ and $N=126$ shell gaps

   Bharti Bhoy🇬🇧 · Praveen C. Srivastava🇮🇳

   In the present work, the ${}^{204-210}$Tl isotopes have been investigated by performing large-scale shell-model calculations, including configurations allowing both neutron and proton core excitations across the $Z$ = 82 and $N$ = 126 shell gaps. Inspired by the recent high-spin experimental data, the structure of Tl isotopes has been studied for a considerably large model space. The KHHE interaction has been used for ${}^{204-206}$Tl isotopes, KHH7B interaction for ${}^{204-210}$Tl isotopes, and additionally KHM3Y interaction has been used for ${}^{208}$Tl isotope. The core excitation has been performed using the KHH7B and KHM3Y interactions. The level spectra of ${}^{204-210}$Tl isotopes are comprehensively described and explained by multi-nucleon couplings of single-particle-hole orbitals within the valence space and by core excitations across ${}^{208}$Pb core. The well-known isomeric states are analyzed in terms of the shell model configurations.

   ↳ nucl-thnucl-exNPA(2024)·3 citations
4. 04*

   Polarized fragmenting jet functions in Inclusive and Exclusive Jet Production

   Zhong-Bo Kang🇺🇸 · Hongxi Xing🇨🇳 · Fanyi Zhao🇺🇸 · Yiyu Zhou🇺🇸

   In this work, we present a complete theoretical framework for analyzing the distribution of polarized hadrons within jets, with and without measuring the transverse momentum relative to the standard jet axis. Using soft-collinear effective theory (SCET), we derive the factorization and provide the theoretical calculation of both semi-inclusive and exclusive fragmenting jet functions (FJFs) under longitudinal and transverse polarization. With the polarized FJFs, one gains access to a variety of new observables that can be used for extracting both collinear and transverse momentum dependent parton distribution functions (PDFs) and fragmentation functions (FFs). As examples, we provide numerical results for the spin asymmetry $A_{TU,T}^{\cos ({\varphi }_S-{\hat{\varphi }}_{S_h})}$ from polarized semi-inclusive hadron-in-jet production in polarized $pp$ collisions at RHIC kinematics, where a transversely polarized quark would lead to the transverse spin of the final-state hadron inside the jet and is thus sensitive to the transversity fragmentation functions. Similarly, another spin asymmetry, $A_{TU,L}^{\cos ({\varphi }_q-{\varphi }_S)}$ from polarized exclusive hadron-in-jet production in polarized $ep$ collisions at EIC kinematics would allow us to access the helicity fragmentation functions. These observables demonstrate promising potential in investigating transverse momentum dependent PDFs and FFs and are worthwhile for further measurements.

   ↳ hep-phhep-exnucl-exnucl-thJHEP(2024)·10 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.