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Nuclear Theory·nucl-th

Friday·June 14, 2024

10 papers—4 primary·6 cross-listed

All10Primary4Cross-lists6
  1. 05

    [Submitted on 27 May 2024] (cross-list from astro-ph.HE)

    Ultraheavy Ultrahigh-Energy Cosmic Rays

    B. Theodore Zhang🇯🇵 · Kohta Murase🇺🇸 · Nick Ekanger🇺🇸 · Mukul Bhattacharya🇺🇸 · Shunsaku Horiuchi🇺🇸

    We investigate the propagation of ultraheavy (UH) nuclei as ultrahigh-energy cosmic rays (UHECRs). We show that their energy loss lengths at EeV are significantly longer than those of protons and intermediate-mass nuclei, and that the highest-energy cosmic rays with energies beyond EeV, including the Amaterasu particle, may be UH-UHECRs. For the first time, we derive constraints on the contribution of UH-UHECR sources, and find that the current data are consistent with energy generation rate densities of UHECRs from collapsars and neutron star mergers. Our model predicts that the mean value of the depth of shower maximum is lower than that for iron nuclei beyond 100 EeV, which can be tested with future composition measurements, e.g., AugerPrime and the Global Cosmic Ray Observatory. In addition, the spectral tension between the Telescope Array (TA) and the Pierre Auger Observatory can be alleviated by considering the enhanced contribution of UHECRs -- including UH nuclei -- from a nearby transient.

    Comments:
    10+6 pages, 3+5 figures, 1+2 tables, version published in PRL (submitted on Jun/01/2024), with clarifications and extended descriptions. Conclusions unchanged
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2405.17409 [pdf]
    PRL(2026)·39 citations
  2. 06

    [Submitted on 11 Jun 2024] (cross-list from astro-ph.HE)

    On the potential of probing the neutron star composition in accreting X-ray binaries

    Kaiser Arf🇬🇷 · Kai Schwenzer🇬🇷

    Transiently accreting Low Mass X-Ray Binaries have the potential to probe the core composition of their neutron stars via deep crustal heating caused by nuclear reactions. We statistically assess this deep crustal heating scenario, taking into account the various microphysical and astrophysical uncertainties. We find that despite the sizable uncertainties there is the chance to discriminate different compositional scenarios. Several observed sources statistically challenge a minimal hadronic matter composition, where cooling proceeds exclusively via slow modified Urca reactions. Considering here two exemplary extended uniform compositions, namely ultra-dense hadronic matter with direct Urca emission and ungapped quark matter, we find that they are even within uncertainties distinguishable. We show that although exotic forms of matter are generally only expected in an inner core, which could in principle have any size, sufficiently large astrophysical data sets nonetheless have the potential to statistically discriminate compositional scenarios, in particular when further mass measurements become available.

    Comments:
    15 pages, 3 figures
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    2406.07534 [pdf]
    PRD(2024)·0 citations
  3. 07

    [Submitted on 12 Jun 2024] (cross-list from hep-ph)

    Color Coherence Effects in Dipole-Quark Scattering in the Soft Limit

    Daniel Pablos🇪🇸 · Sergio Sanjurjo🇪🇸

    Color coherence effects play a crucial role in the description of jet evolution at collider experiments. It is well known that the stimulated gluon emission suffered by energetic jets traversing deconfined QCD matter is also affected by color coherence effects. Through multiple soft scatterings with the medium constituents, an antenna will lose its color correlation, causing its legs to behave as independent emitters after the so-called decoherence time. In this work we provide the first computation of the properties of the recoils produced as a result of these soft scatterings between a color coherent dipole and the medium constituents. Our findings reveal that the angular phase-space of these soft recoils is strongly restricted by the opening angle of the dipole itself due to quantum interference effects. In this long wavelength limit, one can effectively consider that interactions take place with each of the legs of the dipole separately, provided that the angular constraints dictated by the corresponding color flow topologies are respected. This is in complete analogy with the case of soft gluon emission in vacuum, where the recoil quark plays the role of the emitted gluon. As a direct phenomenological application we estimate the collisional energy loss rate of a color antenna. Importantly, these results indicate the way in which color coherence effects can be implemented in jet quenching models that account for the recoils from elastic scatterings, improving in this way our description of medium response physics in heavy-ion collisions.

    Comments:
    7 pages, 2 figures, version submitted to journal
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2406.08550 [pdf]
    PRD(2024)·13 citations
  4. 08

    [Submitted on 12 Jun 2024] (cross-list from hep-ph)

    The connection between Nucleon Energy Correlators and Fracture Functions

    Kai-Bao Chen🇨🇳 · Jian-Ping Ma🇨🇳 · Xuan-Bo Tong🇫🇮

    We establish a sum rule that connects fracture functions to nucleon energy-energy correlators~(NEECs) in a one-to-one correspondence. Using this sum rule, we study the energy pattern in the target fragmentation region of deep inelastic scatterings. Through investigations up to twist-3, we express all eighteen energy-pattern structure functions in terms of associated NEECs, elucidating various azimuthal and spin asymmetries critical for nucleon tomography. Additionally, we investigate the perturbative matching of the twist-2 quark NEECs. We demonstrate that the Sivers-type and worm-gear-type quark NEECs match onto twist-3 multi-parton distributions. Our work provides a framework for examining energy-weighted observables through hadron production processes in the target fragmentation region, offering new insights into nucleon tomography.

    Comments:
    42 pages, 2 figures, 1 table
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2406.08559 [pdf]
    JHEP(2024)·24 citations
  5. 09

    [Submitted on 12 Jun 2024] (cross-list from hep-ph)

    FastEEC: Fast Evaluation of N-point Energy Correlators

    Ankita Budhraja🇳🇱 · Wouter J. Waalewijn🇳🇱

    Energy correlators characterize the asymptotic energy flow in scattering events produced at colliders, from which the microscopic physics of the scattering can be deduced. This view of collisions is akin to analyses of the Cosmic Microwave Background, and a range of promising phenomenological applications of energy correlators have been identified, including the study of hadronization, the deadcone effect, measuring and the top quark mass. While -point energy correlators are interesting to study for larger values of , their evaluation is computationally intensive, scaling like , where is the number of particles. In this Letter, we develop a fast, approximate method for their evaluation exploiting that correlations at a given angular scale are insensitive to effects at other (widely-separated) scales. This implies that the energy correlator can be computed on (sub)jets, effectively reducing M. Furthermore, we utilize a dynamical (sub)jet radius that allows us to obtain reliable results without restricting the angular scales being probed. For concreteness we focus on the projected energy correlator, which projects onto the largest separation between the directions. E.g.~for we find a speed up of up to four orders of magnitude, depending on the desired accuracy. We also consider the possibility of raising the energy to a power higher than one in the energy correlator, which has been proposed to reduce soft sensitivity, and further cuts back the required computation time. These higher-power correlators are not collinear safe, but as a byproduct our approach suggests a natural method to regularize them, such that they can be described using perturbation theory. This letter is accompanied by a public code that implements our method.

    Comments:
    10 pages, 4 figures. Associated code available at : https://github.com/abudhraj/FastEEC/releases/tag/0.1
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2406.08577 [pdf]
    PLB(2025)·12 citations
  6. 10

    [Submitted on 13 Jun 2024] (cross-list from hep-lat)

    QCD constraints on isospin-dense matter and the nuclear equation of state

    Ryan Abbott🇺🇸 · William Detmold🇺🇸 · Marc Illa🇺🇸 · Assumpta Parreño🇪🇸 · Robert J. Perry🇪🇸 · Fernando Romero-López🇺🇸 · Phiala E. Shanahan🇺🇸 · Michael L. Wagman🇺🇸

    Understanding the behavior of dense hadronic matter is a central goal in nuclear physics as it governs the nature and dynamics of astrophysical objects such as supernovae and neutron stars. Because of the non-perturbative nature of quantum chromodynamics (QCD), little is known rigorously about hadronic matter in these extreme conditions. Here, lattice QCD calculations are used to compute thermodynamic quantities and the equation of state of QCD over a wide range of isospin chemical potentials with controlled systematic uncertainties. Agreement is seen with chiral perturbation theory when the chemical potential is small. Comparison to perturbative QCD at large chemical potential allows for an estimate of the gap in the superconducting phase, and this quantity is seen to agree with perturbative determinations. Since the partition function for an isospin chemical potential, , bounds the partition function for a baryon chemical potential , these calculations also provide rigorous non-perturbative QCD bounds on the symmetric nuclear matter equation of state over a wide range of baryon densities for the first time.

    Comments:
    17 pages, 14 figures, updated to journal version
    Subjects:
    High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2406.09273 [pdf]
    PRL(2025)·65 citations

Affiliations

first authorsco-authorsvia INSPIRE