Nuclear Theory·nucl-th

Thursday·June 24, 2021

7 papers—4 primary·3 cross-listed

05
[Submitted on 22 Jun 2021] (cross-list from hep-ph)
Phenomenological mass model for exotic hadrons and predictions for masses of non-strange dibaryons as hexaquarks
Christoffer Beiming🇸🇪 · Jesper Grönroos🇸🇪 · Tommy Ohlsson🇸🇪
We investigate the mass spectra of exotic hadrons known as hexaquarks in the form of dibaryons. We use a phenomenological model based on an extended version of the Gürsey-Radicati mass formula for hadrons to include non-charmed baryons, charmed baryons, and non-strange dibaryons to be able to predict masses of potential dibaryon states. We perform six numerical fits of this model to input data for three different sets of masses of baryons and dibaryons. We find that the model can fit some of the data sets well, especially the sets including charmed baryons and non-strange dibaryons, and observe that the predicted mass of one of the dibaryons is close to the measured mass of the observed hexaquark candidate $d^{*} (2380)$ reported by the WASA-at-COSY experiment. The predicted mass of the deuteron is slightly larger than its measured mass. Finally, for the data sets including charmed baryon and non-strange dibaryon masses, we find that the predicted masses of potential dibaryon states are all in the range from 1900 MeV to 3700 MeV.
Comments:
6 pages, 3 figures. Final version published in Nucl. Phys. B
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2106.11978 [pdf]
NPB(2022)·9 citations
06
[Submitted on 22 Jun 2021] (cross-list from hep-th)
Classicalization and unitarization of wee partons in QCD and Gravity: The CGC-Black Hole correspondence
Gia Dvali🇩🇪 · Raju Venugopalan🇺🇸
We discuss a remarkable correspondence between the description of Black Holes as highly occupied condensates of $N$ weakly interacting gravitons and that of Color Glass Condensates (CGCs) as highly occupied gluon states. In both cases, the dynamics of "wee partons" in Regge asymptotics is controlled by emergent semi-hard scales that lead to perturbative unitarization and classicalization of $2 \to N$ particle amplitudes at weak coupling. In particular, they attain a maximal entropy permitted by unitarity, bounded by the inverse coupling $α$ of the respective constituents. Strikingly, this entropy is equal to the area measured in units of the Goldstone constant corresponding to the spontaneous breaking of Poincaré symmetry by the corresponding graviton or gluon condensate. In gravity, the Goldstone constant is the Planck scale, and gives rise to the Bekenstein-Hawking entropy. Likewise, in the CGC, the corresponding Goldstone scale is determined by the onset of gluon screening. We point to further similarities in Black Hole formation, thermalization and decay, to that of the Glasma matter formed from colliding CGCs in ultrarelativistic nuclear collisions, which decays into a Quark-Gluon Plasma.
Comments:
20 pages; typos fixed, references added, small clarifications to text
Subjects:
High Energy Physics — Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2106.11989 [pdf]
PRD(2022)·73 citations
07
[Submitted on 23 Jun 2021] (cross-list from hep-ph)
$η^{(^{'})} \to π^{+} π^{-} γ^{(*)}$ in large- $N_{c}$ chiral perturbation theory
Patricia Bickert🇩🇪 · Stefan Scherer🇩🇪
We present a calculation of the decays $η^{(^{'})} \to π^{+} π^{-} γ^{(*)}$ at the one-loop level up to and including next-to-next-to-leading order (NNLO) in large- $N_{c}$ chiral perturbation theory. The numerical evaluation of the results is performed successively at LO, NLO, and NNLO, fitting the relevant low-energy constants to the available experimental data. We discuss the widths and decay spectra of $η^{(^{'})} \to π^{+} π^{-} γ$ as well as $η^{(^{'})} \to π^{+} π^{-} l^{+} l^{-}$ , with $l = e, μ$ .
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2106.12482 [pdf]
PRD(2021)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Phenomenological mass model for exotic hadrons and predictions for masses of non-strange dibaryons as hexaquarks

Classicalization and unitarization of wee partons in QCD and Gravity: The CGC-Black Hole correspondence

η(′)→π+π−γ(∗) in large-Nc​ chiral perturbation theory

Affiliations

$η^{(^{'})} \to π^{+} π^{-} γ^{(*)}$ in large- $N_{c}$ chiral perturbation theory