Wed·Oct 30, 2024Wednesday·October 30, 2024

1. 01*

   Effective field theory for radiative corrections to charged-current processes II: Axial-vector coupling

   Vincenzo Cirigliano🇺🇸 · Wouter Dekens🇺🇸 · Emanuele Mereghetti🇺🇸 · Oleksandr Tomalak🇺🇸

   We discuss the hadronic structure-dependent radiative corrections to the axial-vector coupling that controls single-nucleon weak charged-current processes -- commonly denoted by $g_A$. We match the Standard Model at the GeV scale onto chiral perturbation theory at next-to-leading order in the one-nucleon sector, in the presence of electromagnetic and weak interactions. As a result, we provide a representation for the corrections to $g_A$ in terms of infrared finite convolutions of simple kernels with the single-nucleon matrix elements of time-ordered products of two and three quark bilinears (vector, axial-vector, and pseudoscalar). We discuss strategies to determine the required non-perturbative input from data, lattice-QCD (+QED), and possibly hadronic models. This work paves the way for a precise comparison of the values of the ratio $g_A/g_V$ extracted from experiment and from lattice-QCD, which constrain physics beyond the Standard Model.

   ↳ nucl-thhep-exhep-phnucl-exPRD(2025)·22 citations
2. 02*

   Determination of the strong coupling constant and the Collins-Soper kernel from the energy-energy correlator in $e^{+}{e}^{-}$ collisions

   Zhong-Bo Kang🇺🇸 · Jani Penttala🇺🇸 · Congyue Zhang🇺🇸

   We have conducted the first simultaneous global fit of the strong coupling constant ${\alpha }_s$ and the Collins-Soper (CS) kernel using the energy-energy correlators (EEC) of $e^{+}{e}^{-}$ collisions in the back-to-back limit. This analysis, based on the transverse-momentum-dependent (TMD) factorization of EEC at next-to-next-to-next-to-leading logarithmic (${\mathrm{N}}^3\mathrm{LL}$) accuracy, yields ${\alpha }_s$ consistent with the world average. We have tested two different parametrizations for the non-perturbative CS kernel and found both to align with results obtained from lattice QCD and fits on semi-inclusive deep inelastic scattering and Drell-Yan process.

   ↳ hep-phhep-exnucl-exnucl-th37 citations
3. 03*

   Chiral perturbation theory

   Ulf-G. Meißner🇩🇪

   In the limit of vanishing up, down and strange quark masses, QCD exhibits a chiral symmetry. This symmetry is broken spontaneously to its vector subgroup, giving rise to Goldstone bosons. These acquire a small mass through the explicit chiral symmetry breaking for non-vanishing quark masses. The consequences of these broken symmetries can be investigated in a suitably tailored effective field theory called chiral pertubation theory. It admits a perturbative expansion in the external momenta and the Goldstone boson masses and can be systematically analyzed in terms of a loop expansion. The appearing ultraviolet divergences in loop diagrams can be dealt with order-by-order through the Goldstone boson contact interactions. Matter fields like the lowest-lying baryons can also included, leading to a rich and testable phenomenology of low-energy QCD.

   ↳ hep-phhep-exhep-thnucl-ex+1Encyclopedia of Particle Physics(2026)·10 citations
4. 04*

   ALICE Upgrades

   Felix Reidt (for the ALICE collaboration)🇨🇭

   The ALICE collaboration prepares multiple upgrades to further extend the reach of heavy-ion physics at the LHC. For LHC Run 4 (2030-2033), a Forward Calorimeter (FoCal) system combines a high-granularity electromagnetic silicon-tungsten calorimeter with a conventional hadronic calorimeter leading to an excellent two-shower separation for neutral pion reconstruction and photon isolation. Direct photon measurements with FoCal will uniquely constrain the low-x gluon structure of protons and nuclei via forward measurements of direct photons. Additionally, ALICE will employ bent, wafer-scale pixel sensors achieving truly cylindrical tracking layers with very low material budget. These layers will replace the three innermost layers of the Inner Tracking System resulting in an improvement in pointing resolution allowing new measurements of heavy-flavour hadrons and dielectrons. For Run 5 and beyond, a next-generation detector system, ALICE 3, has been conceived to gain unique access to the interaction and thermalization of heavy flavour probes in the QGP as well as to the thermal radiation carrying information about the temperature and the restoration of chiral symmetry. At its core, it combines a high-resolution vertex detector with a large-acceptance silicon pixel tracker. For the identification of particles, a combination of a time-of-flight system, a ring-imaging Cherenkov detector, an electromagnetic calorimeter, a muon identifier, and a dedicated forward detector for ultra-soft photons, are envisaged.

   ↳ physics.ins-dethep-exnucl-exPoS(2025)·3 citations
5. 05*

   Entanglement as a probe of hadronization

   Jaydeep Datta🇺🇸 · Abhay Deshpande🇺🇸 · Dmitri E. Kharzeev🇺🇸 · Charles Joseph Naïm🇺🇸 · Zhoudunming Tu🇺🇸

   Recently, it was discovered that the proton structure at high energies exhibits maximal entanglement. This leads to a simple relation between the proton's parton distributions and the entropy of hadrons produced in high-energy inelastic interactions that has been experimentally confirmed. In this letter, we extend this approach to the production of jets. Here, the maximal entanglement predicts a relation between the jet fragmentation function and the entropy of hadrons produced in jet fragmentation. We test this relation using the ATLAS Collaboration data on jet production at the Large Hadron Collider and find good agreement between the prediction based on maximal entanglement within the jet and the data. This study represents the first use of the quantum entanglement framework in the experimental study of the hadronization process, offering a new perspective on the transition from perturbative to non-perturbative QCD. Our results open the door to a more comprehensive understanding of the quantum nature of hadronization.

   ↳ hep-phhep-exnucl-exnucl-thPRL(2025)·28 citations
6. 06*

   No-quenching baseline for energy loss signals in oxygen-oxygen collisions

   Jannis Gebhard🇩🇪 · Aleksas Mazeliauskas🇩🇪 · Adam Takacs🇩🇪

   In this work, we perform computations of inclusive jet, and semi-inclusive jet-hadron cross sections for minimum bias oxygen-oxygen collisions at RHIC and LHC collision energies. We compute the no-quenching baseline for the jet nuclear modification factor $R_{\mathrm{AA}}$ and jet-, and hadron-triggered semi-inclusive nuclear modification factors $I_{\mathrm{AA}}$. We do this with state-of-the-art nuclear parton distribution functions (nPDFs), next-to-leading-order matrix elements, parton shower, and hadronization. We observe deviations from unity due to cold-nuclear matter effects, even without quenching. We demonstrate that the parton distribution uncertainties constitute a significant obstacle in detecting energy loss in small collision systems. Hadron-triggered observables are particularly sensitive to uncertainties due to correlations between the trigger and analyzed particles. For jet-triggered $I_{\mathrm{AA}}$, there exists a kinematic window in which nPDF and scale uncertainties cancel dramatically while showing little sensitivity to parton shower and hadronization models, addressing a major limiting factor for energy loss discovery in small systems.

   ↳ hep-phnucl-exnucl-thJHEP(2025)·19 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.