Nuclear Theory·nucl-th

Wednesday·December 27, 2023

20 papers—11 primary·9 cross-listed

12
[Submitted on 22 Dec 2023] (cross-list from hep-ph)
Nucleon resonance parameters from Roy-Steiner equations
Martin Hoferichter🇨🇭 · Jacobo Ruiz de Elvira🇪🇸 · Bastian Kubis🇩🇪 · Ulf-G. Meißner🇩🇪
A reliable determination of the pole parameters and residues of nucleon resonances is notoriously challenging, given the required analytic continuation into the complex plane. We provide a comprehensive analysis of such resonance parameters accessible with Roy-Steiner equations for pion-nucleon scattering - a set of partial-wave dispersion relations that combines the constraints from analyticity, unitarity, and crossing symmetry - most prominently of the $Δ (1232)$ resonance. Further, we study the Roper, $N (1440)$ , resonance, which lies beyond the strict domain of validity, in comparison to Padé approximants, comment on the role of subthreshold singularities in the $S$ -wave, and determine the residues of the $f_{0} (500)$ , $ρ (770)$ , and $f_{0} (980)$ resonances in the $t$ -channel process $π π \to N ˉ N$ . The latter allows us to test - for the first time fully model independently in terms of the respective residues - universality of the $ρ (770)$ couplings and the Goldberger-Treiman relation expected if the scalars behaved as dilatons, in both cases revealing large deviations from the narrow-resonance limit.
Comments:
9 pages, 1 figure; journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2312.15015 [pdf]
PLB(2024)·51 citations
13
[Submitted on 22 Dec 2023] (cross-list from hep-ph)
Neutrinoless Double Beta Decay without Vacuum Majorana Neutrino Mass
Lukáš Gráf🇺🇸 · Sudip Jana🇩🇪 · Oliver Scholer🇩🇪 · Nele Volmer🇩🇪
We present a proof-of-concept extension to the Standard Model that can generate a non-vanishing neutrinoless double beta decay ( $0 ν β β$ ) signal without the existence of Majorana neutrinos or lepton number violation in the zero-density vacuum-ground-state Lagrangian. We propose that the $0 ν β β$ can be induced by the capture of an ultralight scalar field, a potential dark matter candidate, that carries two units of lepton number. This makes the observable $0 ν β β$ spectrum indistinguishable from the usual $0 ν β β$ mechanisms by any practical means. We find that a non-zero $0 ν β β$ rate does not require neutrinos to be fundamentally Majorana particles. However, for sizeable decay rates within the range of next-generation experiments, the neutrino will, generally, acquire an (effective) Majorana mass as the scalar field undergoes a transition to the Bose-Einstein condensate phase. We also discuss the distinction between the aforementioned scenario and the case in which the emission of a lepton-number-two scalar leads to $0 ν β β$ , exhibiting discernible qualitative features that make it experimentally distinguishable from the conventional scenario.
Comments:
6 pages + references, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2312.15016 [pdf]
PLB(2024)·15 citations
14
[Submitted on 22 Dec 2023] (cross-list from hep-ph)
Signatures of baryon junctions in semi-inclusive deep inelastic scattering
David Frenklakh🇺🇸 · Dmitri E. Kharzeev🇺🇸 · Wenliang Li🇺🇸
Local gauge invariance of the baryon wave function leads to the emergence of a baryon junction, where three (or $N$ , in $S U (N)$ gauge theory) string operators merge. The existence of baryon junction dramatically affects the dynamics of baryon stopping at high energies, and the corresponding predictions are supported by the recent data from STAR Collaboration at the Relativistic Heavy Ion Collider. Here we outline the ways in which the baryon junctions can be tested in semi-inclusive deep inelasttic scattering at Jefferson Laboratory and the future Electron Ion Collider.
Comments:
4 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2312.15039 [pdf]
PLB(2024)·8 citations
15
[Submitted on 23 Dec 2023] (cross-list from hep-ph)
Hyperorder net baryon number fluctuations in nuclear matter at low temperature
Xinran Yang · Guoyun Shao · Weibo He
We calculate the density fluctuations of net baryon number up to sixth order induced by the interactions of nuclear matter, and explore their relationship with the nuclear liquid-gas phase transition (LGPT), including the stable and metastable phase as well as the region far from the phase transition. The results show that dramatic density fluctuations exist in the vicinity of LGPT, and the hyperorder density fluctuations are more sensitive than the lower order ones to the interactions and structural properties of nuclear matter. The study also indicates that, even far away from the critical region of LGPT, the hadronic interactions can still lead to significant hyperorder density fluctuations. In combination with the chemical freeze-out line fitted from the experimental data, the derived results can be referred to investigate the chiral phase transition, nuclear LGPT, as well as the analysis of related experimental signals.
Comments:
8pages, 6 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2312.15129 [pdf]
PRC(2024)·2 citations
16
[Submitted on 24 Dec 2023] (cross-list from hep-ph)
Phenomenological study of the angle between jet axes in heavy-ion collisions
Jin-Wen Kang🇨🇳 · Sa Wang🇨🇳 · Lei Wang🇨🇳 · Ben-Wei Zhang🇨🇳
This paper presents a phenomenological study on the angle between the Standard and the Winner-Take-All (WTA) jet axes ( $Δ R_{axis}^{WTA - Std}$ ) in high-energy nuclear collisions. The $p$ + $p$ baseline is provided by the Pythia8 event generator. The in-medium jet propagation is simulated by the linear Boltzmann transport (LBT) model, which considers both the elastic and inelastic jet-medium interactions. Our theoretical results calculated by the LBT model show that the $Δ R_{axis}^{WTA - Std}$ distribution in Pb+Pb at $s = 5.02$ TeV is narrower than that in $p$ + $p$ , which agrees well with the recent ALICE measurements. The narrowing of $Δ R_{axis}^{WTA - Std}$ seems to violate the $p_{T}$ -broadening nature of the jet quenching effect, usually explained by the influence of "selection bias". However, the physical details still need to be fully understood. Utilizing a matching-jet method to track the jet evolution in the QGP to remove the selection bias in the Monte Carlo simulations, we observe that the $Δ R_{axis}^{WTA - Std}$ distribution becomes broader due to the jet-medium interactions. At the same time, by rescaling the quark/gluon-jet fractions in Pb+Pb collisions to be the same as that in $p$ + $p$ , we find that the fraction change may not significantly influence the modification pattern of jet $Δ R_{axis}^{WTA - Std}$ . On the other hand, the selected jet sample in A+A collisions has a significantly narrower initial $Δ R_{axis}^{WTA - Std}$ distribution than the $p$ + $p$ baseline, and such a biased comparison between $p$ + $p$ and A+A conceals the actual jet-broadening effect in the experimental measurements. The investigations presented in this paper will deepen our understanding of the relationship between the actual intra-jet modifications in the QGP and the experimental observations.
Comments:
9 pages, 7 figures. Accepted for publication in Phys. Rev. C
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2312.15518 [pdf]
PRC(2025)·8 citations
17
[Submitted on 24 Dec 2023] (cross-list from hep-ph)
The $z_{g}$ distribution for heavy flavour jets in dense quark-gluon plasma
Boris Blok (Technion)🇮🇱 · Chang Wu (Technion)🇮🇱
We study the $z_{g}$ distribution for heavy flavour, i.e. bottom and charm quark, jets propagating through the dense QCD medium. We extend the late emission approximation for Armesto-Salgado-Wiedemann (ASW) formula to heavy flavours. % We consider both the normalised and $N_{jet}$ normalised $z_{g}$ distributions, and the ratio of the latter distributions to the vacuum ones, called the R ratio. We demonstrate that since there is no collinear singularity in the medium, there is no principal need to use the Sudakov safety technique for medium-induced emission (MIE). We see that contrary to the vacuum case, the normalised $z_{g}$ distribution is sensitive to the dead cone angle value. In particular, for the case of $N_{j e t}$ normalised distribution with $θ_{g} \leq θ_{c u t}$ , it is possible to directly probe the dead cone gluons in the medium. Our results can be useful to guide the experimental measurements of the heavy flavour jet substructure in dense QCD medium.
Comments:
42 pages, 31 figures, we slightly changed the name, and corrected the equations for heavy quark jet gluon multiplicities in DLA , some references are also added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2312.15560 [pdf]
PRD(2025)·6 citations
18
[Submitted on 25 Dec 2023] (cross-list from cond-mat.quant-gas)
Non-Hermitian $p$ -wave superfluid and effects of the inelastic three-body loss in a one-dimensional spin-polarized Fermi gas
Hiroyuki Tajima · Yuta Sekino · Daisuke Inotani · Akira Dohi · Shigehiro Nagataki · Tomoya Hayata
We theoretically investigate non-Hermitian $p$ -wave Fermi superfluidity in one-dimensional spin-polarized Fermi gases which is relevant to recent ultracold atomic experiments. Considering an imaginary atom-dimer coupling responsible for the three-body recombination process in the Lindblad formalism, we discuss the stability of the superfluid state against the atomic loss effect. Within the two-channel non-Hermitian BCS-Leggett theory, the atomic loss is characterized by the product of the imaginary atom-dimer coupling and the $p$ -wave effective range. Our results indicate that for a given imaginary atom-dimer coupling, a smaller magnitude of the effective ranges of $p$ -wave interaction is crucial for reaching the non-Hermitian $p$ -wave Fermi superfluid state.
Comments:
9 pages, 3 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el); Superconductivity (cond-mat.supr-con); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2312.15724 [pdf]
PRResearch(2024)·4 citations
19
[Submitted on 25 Dec 2023] (cross-list from hep-ph)
Fermion Masses, Neutrino Mixing and Higgs-Mediated Flavor Violation in 3HDM with $S_{3}$ Permutation Symmetry
K.S. Babu🇺🇸 · Yongcheng Wu🇨🇳 · Shiyuan Xu🇺🇸
The Yukawa and scalar sectors of a general $S_{3}$ -symmetric three-Higgs doublet model (3HDM) are investigated. The Yukawa interactions are constructed in an $S_{3}$ -invariant way, while the scalar potential contains $S_{3}$ soft-breaking terms. Global fits to the quark/lepton masses and CKM/PMNS matrices are performed. Excellent fits to all fermion mass and mixing parameters are obtained. Both normal ordering and inverted ordering of neutrino masses are found to be admissible within the framework, with a prediction for the CP-violation phase, $δ_{C P} ≃ 12 0^{0}$ . The fit results in the Yukawa sector are further investigated, together with the scalar sector, imposing constraints from Higgs-mediated neutral meson mixing and neutron electric dipole moment (EDM). We explore the lowest allowed mass of the heavy Higgs bosons, consistent with these constraints, and find it to be about 17 TeV. The corresponding neutron EDM is around $1.7 \times 1 0^{- 27}$ e-cm, which is within reach of proposed experiments. It is found that the constraints from the $K$ -meson system dominate, while those from the $D$ meson system are marginal.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2312.15828 [pdf]
JHEP(2024)·5 citations
20
[Submitted on 26 Dec 2023] (cross-list from hep-th)
Exact modulated hadronic tubes and layers at finite volume in a cloud of $π$ and $ω$ mesons
Gonzalo Barriga🇨🇱 · Matías Torres🇮🇹 · Aldo Vera🇨🇱
We construct topological soliton solutions describing baryonic tubes and layers with modulation in the $S U (2)$ non-linear sigma model coupled with $ω$ -mesons in $3 + 1$ dimensions. Using appropriate Asäntze for the pionic matter field and the $ω$ -mesons vector potential, the complete set of seven coupled partial differential equations can be solved analytically. These solutions represent modulated tubes and layers at finite volume with arbitrary baryon number, where the modulation of the solitons in one direction is determined by one of the three degrees of freedom of the pionic field, satisfying the equation of a two-dimensional free massless chiral scalar field. As expected, the inclusion of the $ω$ -mesons to the Non-linear sigma model allows to reduce the repulsion energy between baryons, which leads to a flattening of the tubes and layers in one direction, forming a kind of ``nuclear linguine phase''. Also, we show that this construction can be carried out even when higher order terms in the large $N_{c}$ expansion are included -- in particular the Skyrme term -- without spoiling the integrability of the field equations.
Comments:
12 pages, 3 figures
Subjects:
High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2312.16131 [pdf]
NPB(2024)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE