Nuclear Theory·nucl-th

Friday·February 10, 2023

9 papers—7 primary·2 cross-listed

08
[Submitted on 9 Feb 2023] (cross-list from hep-lat)
Doubly Charmed Tetraquark $T_{cc}^{+}$ from Lattice QCD near Physical Point
Yan Lyu🇨🇳 · Sinya Aoki🇯🇵 · Takumi Doi🇯🇵 · Tetsuo Hatsuda🇯🇵 · Yoichi Ikeda🇯🇵 · Jie Meng🇨🇳
The doubly charmed tetraquark $T_{cc}^{+}$ recently discovered by the LHCb Collaboration is studied on the basis of $(2 + 1)$ -flavor lattice QCD simulations of the $D^{*} D$ system with nearly physical pion mass $m_{π} = 146$ MeV. The interaction of $D^{*} D$ in the isoscalar and $S$ -wave channel, derived from the hadronic spacetime correlation by the HAL QCD method, is attractive for all distances and leads to a near-threshold virtual state with a pole position $E_{pole} = - 59 (_{- 99}^{+ 53}) (_{- 67}^{+ 2})$ keV and a large scattering length $1/ a_{0} = 0.05 (5) (_{- 2}^{+ 2}) fm^{- 1}$ . The virtual state is shown to evolve into a loosely bound state as $m_{π}$ decreases to its physical value by using a potential modified to $m_{π} = 135$ MeV based on the pion-exchange interaction. Such a potential is found to give a semiquantitative description of the LHCb data on the $D^{0} D^{0} π^{+}$ mass spectrum. Future study is necessary to perform physical-point simulations with the isospin-breaking and open three-body-channel effects taken into account.
Comments:
7 pages, 4 figures + supplemental material; v3, match the published version in PRL
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2302.04505 [pdf]
PRL(2023)·141 citations
09
[Submitted on 9 Feb 2023] (cross-list from cond-mat.quant-gas)
BCS-BCS crossover between atomic and molecular superfluids in a Bose-Fermi mixture
Yixin Guo · Hiroyuki Tajima · Tetsuo Hatsuda · Haozhao Liang
We theoretically examine a continuity between atomic and molecular Fermi superfluids in a Bose-Fermi mixture near the Feshbach resonance. Considering a two-channel model describing the Feshbach resonance between Fermi and Bose atoms, we have constructed the mean-field framework based on the perturbative expansion of the Feshbach atom-dimer coupling. The resulting effective Hamiltonian exhibits not only the continuity between atom-atom to molecule-molecule Cooper pairings but also becomes equivalent to the two-band-superconductor model with Suhl-Matthias-Walker type pair-exchange coupling. We demonstrate how these atomic and molecular Fermi superfluids coexist within the two-band-like superfluid theory. The pair-exchange coupling and resulting superfluid gaps are found to be strongly enhanced near the Feshbach resonance due to the interplay between the infrared singularity of Bogoliubov phonons and their Landau damping arising from the coupling with fermions. The pair-exchange coupling can be probed via the observation of the intrinsic Josephson effect between atomic and molecular superfluids.
Comments:
15 pages, 5 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); Superconductivity (cond-mat.supr-con); Nuclear Theory (nucl-th)
arXiv:
2302.04617 [pdf]
PRA(2023)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE

Doubly Charmed Tetraquark Tcc+​ from Lattice QCD near Physical Point

BCS-BCS crossover between atomic and molecular superfluids in a Bose-Fermi mixture

Affiliations

Doubly Charmed Tetraquark $T_{cc}^{+}$ from Lattice QCD near Physical Point