PaperPanorama
FAQ

Nuclear Theory·nucl-th

Wednesday·December 18, 2024

8 papers—2 primary·6 cross-listed

All8Primary2Cross-lists6
  1. 03

    Anisotropic jet broadening and jet shape

    Weiyao Ke🇨🇳 · John Terry🇺🇸 · Ivan Vitev🇺🇸

    In this paper, we explore the use of jet substructure as a way of probing phenomena which break the isotropic behavior of jets, such as jet propagation through an anisotropically flowing quark-gluon plasma or spin correlations. We introduce two novel observables for this purpose: the azimuthal-dependent jet broadening and the azimuthal-dependent jet shape, which generalize the traditional isotropic substructure studies. Using Soft-Collinear Effective Theory, we explicitly calculate the jet functions associated with these observables with a standard jet axis and with a Winner-Take-All jet axis in both the resummed and fixed order limits. While our analysis first and foremost establishes the formalism for the azimuthal-dependent jet substructure, it also brings to light new results for jet substructure in the azimuthally integrated case, such as the semi-inclusive jet function and the exclusive jet shape for the Winner-Take-All axis, and the jet broadening in the fixed order region. As an illustrative example for the new formalism we demonstrate that the azimuthal-dependent jet broadening can be used as a direct probe of the transversity parton distribution function in deep inelastic scattering.

    ↳ hep-phhep-exnucl-exnucl-thJHEP(2025)·9 citations
  2. 04

    QCD factorization with multihadron fragmentation functions

    T. C. Rogers🇺🇸 · M. Radici🇮🇹 · A. Courtoy🇲🇽 · T. Rainaldi🇺🇸

    Important aspects of QCD factorization theorems are the properties of the objects involved that can be identified as universal. One example is that the definitions of parton densities and fragmentation functions for different types of hadrons differ only in the identity of the nonperturbative states that form the matrix elements, but are otherwise the same. This leads to independence of perturbative calculations on nonperturbative details of external states. It also lends support to interpretations of correlation functions as encapsulations of intrinsic nonperturbative properties. These characteristics have usually been presumed to still hold true in fragmentation functions even when the observed nonperturbative state is a small-mass cluster of hadrons rather than simply a single isolated hadron. However, the multidifferential aspect of cross sections that rely on these latter types of fragmentation functions complicates the treatment of kinematical approximations in factorization derivations. That has led to recent claims that the operator definitions for fragmentation functions need to be modified from the single hadron case with nonuniversal prefactors. With such concerns as our motivation, we retrace the steps for factorizing the unpolarized semi-inclusive annihilation cross section and confirm that they do apply without modification to the case of a small-mass multihadron observed in the final state. In particular, we verify that the standard operator definition from single hadron fragmentation, with its usual prefactor, remains equally valid for the small-mass -hadron case with the same hard parts and evolution kernels, whereas the more recently proposed definitions with nonuniversal prefactors do not. Our results reaffirm the reliability of most past phenomenological applications of dihadron fragmentation functions.

    ↳ hep-phhep-exnucl-exnucl-thPRD(2025)·18 citations
  3. 05

    Exact charged and rotating toroidal black hole in the Einstein -Skyrme model

    Carla Henríquez-Baez🇨🇱 · Marcela Lagos🇨🇱 · Evelyn Rodríguez🇨🇱 · Aldo Vera🇨🇱

    In this paper, we construct an exact solution of the Einstein -Skyrme model in space-time dimensions describing a charged and rotating black hole with toroidal horizon. Rotation is added by applying an improper coordinate transformation to the known static toroidal black hole with Skyrme hair, while the electric charge is supplemented by considering a gauge field interacting with Einstein gravity. We perform the thermal analysis in the grand canonical ensemble, explicitly showing the role that the flavor number plays. Some discussions about stability are also considered.

    ↳ hep-thgr-qcnucl-thPRD(2025)·4 citations
  4. 06

    Light-by-light scattering in ultraperipheral heavy ion collisions -- new possibilities

    Antoni Szczurek🇵🇱 · Pawel Jucha🇵🇱

    Light-by-light scattering is a relatively new area of experimental physics. Our recent, theoretical research shows that studying two photon measurements in regions with lower transverse momentum () and invariant mass () allows us to observe not only the main contribution of photon scattering, known as fermionic loops but also mechanisms like the VDM-Regge (double-photon hadronic fluctuation). In addition, diphoton measurements at low diphoton masses are crucial for studies of light meson resonance contributions in scattering. We also focus on the interference between different contributions. For future experiments with the ALICE FoCal and ALICE-3 detectors, we have calculated background contamination and have explored possibilities to minimize their impact.

    ↳ hep-phnucl-thActa Phys.Polon.Supp.(2025)·0 citations
  5. 07

    Constraining the three-body bound state via the pole

    Hai-Xiang Zhu🇨🇳 · Lu Meng🇩🇪 · Yao Ma🇨🇳 · Ning Li🇨🇳 · Wei Chen🇨🇳 · Shi-Lin Zhu🇨🇳

    In this study, we propose using the pole position to constrain the existence of the three-body bound state within the one-boson-exchange (OBE) model. The existence of the bound state remains uncertain due to significant variations in the OBE interaction, particularly in the strength of scalar-meson-exchange interactions, which can differ by a factor about 20 between two commonly used OBE models. This discrepancy renders the system highly model-dependent. To address this issue, we constrain the scalar-meson-exchange interaction using the pole position, where the pseudoscalar-meson coupling is well-determined, and the - and -exchange interactions nearly cancel each other out, leaving the coupling constant of the -exchange as the only unknown parameter. Our results indicate that the isospin- bound states exist when is a virtual state of located within approximately MeV of the threshold. However, the three-body bound state is gone when the virtual state pole is more than MeV away from the threshold. Each experimental progress, either on the state or the , can shed light on the nature of the other state. Another significant outcome is a refined set of OBE model parameters calibrated using the pole positions of , , and , rigorously addressing the cutoff dependence. These parameters provide a valuable resource for more accurate calculations of systems involving few-body , and their antiparticles. Additionally, we find no evidence of the three-body resonances after extensive search using a combination of the Gaussian expansion method and the complex scaling method.

    ↳ hep-phhep-exhep-latnucl-thPRD(2025)·14 citations
  6. 08

    Chirally motivated - model in a finite volume

    Peter C. Bruns🇨🇿 · Ales Cieply🇨🇿

    We generalize the chirally motivated coupled channels model to the cubic finite volume and use it to calculate the stationary energy spectrum that appears in a nice agreement with the spectrum obtained in the lattice QCD simulations by the BaSc collaboration. Several other comparisons with the BaSc results are made, in particular relating their pole positions of the meson-baryon scattering matrix to the two-pole picture of generated by our chiral model in the infinite volume.

    ↳ hep-phhep-latnucl-thEPJA(2025)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE