Nuclear Theory·nucl-th

Tuesday·December 17, 2024

12 papers—2 primary·10 cross-listed

03
On the negative coupling O(N) model in 2d at high temperature
Paul Romatschke🇺🇸
In this work, I consider N-component scalar quantum field theory in two dimensions interacting with an upside-down quartic potential. Working in the large N limit, the model can be solved non-perturbatively using the saddle-point method for sufficiently strong negative coupling. At high temperature, the O(N) model dimensionally reduces to $P T$ -symmetric quantum mechanics, for which powerful non-perturbative solution methods exist. It is found that the solution from quantum mechanics can be matched by the saddle-point method in quantum field theory when allowing for saddles beyond the principal Riemann sheet. I show that saddle points on non-principal Riemann sheets lead to a fully consistent solution of the 2d negative-coupling O(N) model for all temperatures.
↳ hep-thmath-phmath.MPnucl-thJHEP(2025)·4 citations
04
Neutrinoless double beta decay with light sterile neutrinos: the contact terms
Vincenzo Cirigliano🇺🇸 · Wouter Dekens🇺🇸 · Sebastián Urrutia Quiroga🇺🇸
We study neutrinoless double-beta decay in extensions of the Standard Model that include $n$ right-handed neutrino singlets, with masses $m_{s}$ below the GeV scale. Generalizing recently developed matching methods, we determine the $m_{s}$ dependence of the short-range $nn \to pp$ couplings that appear to leading order in the chiral effective field theory description of neutrinoless double beta decay. We focus on two scenarios, corresponding to the minimal $ν$ SM and left-right symmetric models. We illustrate the impact of our new results in the case of the $ν$ SM, showing a significant impact on the neutrinoless double-beta decay half-life when $m_{s}$ is in the 200-800 MeV range.
↳ hep-phnucl-thJHEP(2025)·10 citations
05
Bottomoniumlike states in proton collisions: Fragmentation and resummation
Francesco Giovanni Celiberto🇪🇸 · Gabriele Gatto🇮🇹
We study the semi-inclusive hadroproduction of doubly bottomed tetraquarks ( $X_{b b ˉ q q ˉ}$ ) as well as fully bottomed ones ( $T_{4 b}$ ), to which we collectively refer as "bottomoniumlike" states. We rely upon the variable-flavor number-scheme fragmentation at leading power, where a single parton perturbatively splits into the corresponding Fock state, which then hadronizes into the color-neutral, observed tetraquark. To this end, we build new sets of DGLAP/HF-NRevo consistent, hadron-structure oriented collinear fragmentation functions, which we name TQHL1.1 and TQ4Q1.1 parametrizations. They extend and supersede the corresponding 1.0 versions recently derived in previous works. The first family describes the fragmentation of doubly heavy tetraquarks and is based on an improved version of the Suzuki model for the heavy-quark channel. The second family depicts the fragmentation of fully heavy tetraquarks and embodies initial-scale inputs for gluon and heavy-quark channels, both of them calculated by the hands of potential nonrelativistic QCD. As a phenomenological application, we provide novel predictions for tetraquark-plus-jet high-energy distributions, computed within the NLL/NLO $^{+}$ hybrid factorization from (sym)JETHAD, at 14 TeV and 100 TeV FCC.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·22 citations
06
Nuclear structure and direct reaction studies in particle- $γ$ coincidence experiments at the FSU John D. Fox Superconducting Linear Accelerator Laboratory
M. Spieker · S. Almaraz-Calderon
Since its foundation in the 1960s, the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University (FSU) pursued research at the forefront of nuclear science. In this contribution, we present recent highlights from nuclear structure and reaction studies conducted at the John D. Fox Superconducting Linear Accelerator Laboratory, also featuring the general experimental capabilities at the laboratory for particle- $γ$ coincidence experiments. Specifically, we focus on light-ion induced reactions measured with the Super-Enge Split-Pole Spectrograph (SE-SPS) and the CATRiNA neutron detectors, respectively. Some results obtained with the CeBrA demonstrator for particle- $γ$ coincidence experiments at the SE-SPS are presented. A highlight from the first experimental campaigns with the combined CLARION2-TRINITY setup, showing that weak reaction channels can be selected, is discussed as well.
↳ nucl-exnucl-thFront.in Phys.(2024)·4 citations
07
Born-Oppenheimer Renormalization group for High Energy Scattering: the Modified BFKL, or where did it all go?
Haowu Duan🇺🇸 · Alex Kovner🇺🇸 · Michael Lublinsky🇮🇱
We continue exploring the Born-Oppenheimer renormalization group generating evolution in frequency of physical observables. In this paper we study the evolution of the total cross section for dilute-dilute scattering retaining only eikonal emissions. We derive and analyze the analog of the BFKL equation in this framework. The frequency evolution has a very strong effect on the solutions of the BO-BFKL equation, slowing down the evolution of the scattering amplitude in a spectacular fashion: the intercept of the Pomeron is decreased by about a factor of three relative to the canonical LO BFKL result. The anomalous dimension is also modified significantly - from the BFKL value of one it goes down to the negative value of $\approx - 0.2$ . Introducing saturation boundary as a proxy for the full saturation dynamics, we find that the dependence of the saturation momentum on rapidity $η$ becomes quite weak with $Q_{s}^{2} \sim e^{a α ˉ_{s} η}$ with $a \approx 0.784$ as opposed to the BFKL value $a = 4.88$ . Our results underscore the necessity to take into account the DGLAP effects in the high energy evolution. This is left for future work.
↳ hep-phhep-thnucl-th1 citation
08
Likelihood of a zero in the proton elastic electric form factor
Peng Cheng🇨🇳 · Zhao-Qian Yao🇪🇸 · Daniele Binosi🇮🇹 · Craig D. Roberts🇨🇳
Working with the $29$ available data on the ratio of proton electric and magnetic form factors, $μ_{p} G_{E}^{p} (Q^{2}) / G_{M}^{p} (Q^{2})$ , and independent of any model or theory of strong interactions, we use the Schlessinger point method to objectively address the question of whether the ratio possesses a zero and, if so, its location. Our analysis predicts that, with 50% confidence, the data are consistent with the existence of a zero in the ratio on $Q^{2} \leq 10.37$ GeV $^{2}$ . The level of confidence increases to $99.9$ \% on $Q^{2} \leq 13.06$ GeV $^{2}$ . Significantly, the likelihood that existing data are consistent with the absence of a zero in the ratio on $Q^{2} \leq 14.49$ GeV $^{2}$ is $1/1$ -million.
↳ hep-phhep-exhep-latnucl-ex+1PLB(2025)·11 citations
09
Quantum-Corrected Holographic Wilson Loop Expectation Values and Super-Yang-Mills Confinement
Xiao-Long Liu🇨🇳 · Cong-Yuan Yue🇨🇳 · Jun Nian🇨🇳 · Wenni Zheng🇨🇳
Confinement is a well-known phenomenon in the infrared regime of (supersymmetric) Yang-Mills theory. While both experimental observations and numerical simulations have robustly confirmed its existence, the underlying physical mechanism remains elusive. Unraveling the theoretical origin of confinement continues to be a profound and longstanding challenge in both physics and mathematics. Motivated by recent advances in quantum Jackiw-Teitelboim gravity, we investigate the Wilson loop expectation values in the large- $N$ limit of $N = 4$ super-Yang-Mills theory at finite chemical potential, employing a holographic approach within the background of an extremal AdS $_{5}$ Reissner-Nordström black brane. Our results reveal that quantum gravitational fluctuations in the near-horizon region significantly modify the holographic Wilson loop expectation values. These values exhibit an area-law behavior, indicative of a confining quark-antiquark potential. Within this framework, our findings suggest that confinement in the super-Yang-Mills theory arises as a consequence of near-horizon quantum gravity fluctuations in the bulk extremal AdS $_{5}$ black brane geometry.
↳ hep-thgr-qchep-phmath-ph+29 citations
10
Isotopic Transparency in Central Xe+Sn Collisions at 100 MeV/nucleon
Arnaud Le Fèvre🇩🇪 · Abdelouahad Chbihi🇫🇷 · Quentin Fable🇫🇷 · Tom Génard🇫🇷 · Jerzy Łukasik🇵🇱 · Wolfgang Trautmann🇩🇪 · Ketel Turzó🇩🇪 · Rémi Bougault🇫🇷 · Sylvie Hudan🇺🇸 · Olivier Lopez🇫🇷 · Walter F. J. Müller🇩🇪 · Carsten Schwarz🇩🇪 and 4 other authors
A new method, based on comparing isotopic yield ratios measured at forward and sideward polar angles and on cross-bombarding heavy nuclei with different neutron-to-proton ratios, is used to quantify the stopping power of nuclear matter in heavy-ion collisions. For central collisions of isotopically separated $^{124, 129}$ Xe+ $^{112, 124}$ Sn at 100~MeV/nucleon bombarding energy, measured with the 4 $π$ multidetector INDRA at GSI, a moderate transparency is deduced for hydrogen isotopes, whereas for heavier fragmentation products with atomic number $Z \geq 3$ a high transparency exceeding 50\% is observed. An anomalously large transparency is found for alpha particles, and possible explanations are presented.
↳ nucl-exnucl-thPLB(2025)·1 citation
11
Non-Radial Oscillation Modes in Hybrid Stars with Hyperons and Delta Baryons
Ishfaq Ahmad Rather🇩🇪 · Kau D. Marquez🇧🇷 · Prashant Thakur🇰🇷 · Odilon Lourenço🇧🇷
We study the effects of hyperons, delta baryons, and quark matter phase transitions on $f$ -mode oscillations in neutron stars. Using the density-dependent relativistic mean-field model (DDME2) for the hadronic phase and the density-dependent quark mass (DDQM) model for the quark phase, we construct hadronic and hybrid equations of state (EoSs) consistent with astrophysical constraints. Including hyperons and delta baryons soften the EoS, reducing maximum mass, while phase transition to the quark matter further softens the EoS, decreasing the speed of sound and hence the maximum mass. We confirm the well-known overestimation of $f$ -mode frequencies by the Cowling approximation (by about 10-30\%) compared to full General Relativity calculation, and show that this discrepancy persists across models including hyperons, $Δ$ baryons, and a phase transition to quark matter. While the discrepancy generally decreases with stellar mass, it increases near the maximum mass in the presence of a phase transition compared to EoSs without this phenomenology. We derive universal relations connecting the frequencies of the $f$ -mode to the average density, compactness, and tidal deformability, finding significant deviations due to hyperons and delta baryons. These deviations could provide distinct observational signatures in gravitational wave data, offering new insights into dense matter physics and advancing gravitational wave asteroseismology of neutron star interiors. Empirical relations for mass-scaled and radius-scaled frequencies are also provided, highlighting the importance of GR calculations for accurate modeling.
↳ astro-ph.HEhep-phnucl-thPRD(2025)·14 citations
12
The causal structure of the quark propagator
Jan M. Pawlowski🇩🇪 · Jonas Wessely🇩🇪
We study the causal structure of the quark propagator with the spectral DSE. The spectral gap equation is solved with the input of the spectral representation of the gluon and a causal STI-construction for the quark-gluon vertex. The latter includes a potential infrared enhancement of the vertex strength of the classical tensor structure that accommodates for the physical strength of chiral symmetry breaking. We find a critical vertex strength, below which the quark has a Källén-Lehmann representation. While the nature of the first singularity does not change above the critical strength, we find that the quark propagator features at least two additional pairs of complex conjugate poles that are located approximately at the sum of quark pole mass and peak position of the quark-gluon coupling. These additional poles lead to violations of causality, if they persist in $S$ -matrix elements. While the vertex strength of the classical tensor structure in full QCD is below the critical one, that of commonly used vertex models, which rely solely on the classical vertex structure, is typically above it. Finally, we discuss how these additional poles could be avoided in full QCD, where part of chiral symmetry breaking is generated by the other tensor structures in the quark-gluon vertex.
↳ hep-phhep-thnucl-thEPJC(2025)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE