Nuclear Theory·nucl-th

Monday·August 16, 2021

5 papers—2 primary·3 cross-listed

01
High-precision nuclear chronometer for the cosmos
X. H. Wu · P. W. Zhao · S. Q. Zhang · J. Meng
Nuclear chronometer, which predicts the ages of the oldest stars by comparing the present and initial abundances of long-lived radioactive nuclides, provides an independent dating technique for the cosmos. A new nuclear chronometer called Th-U-X chronometer is proposed, which imposes stringent constraints on the astrophysical conditions in the $r$ -process simulation by synchronizing the previous Th/X, U/X and Th/U chronometers. The astrophysical uncertainties of nuclear chronometer are significantly reduced from more than $\pm 2$ billion years to within 0:3 billion years by the Th-U-X chronometer. The proposed chronometer is then applied to estimate the ages of the six metal-poor stars with observed uranium abundances, and the predicted ages are compatible with the cosmic age 13.8 billion years predicted from the cosmic microwave background radiation, but in contradictory with the new cosmic age 11.4 billion years from the gravitational lenses measurement.
nucl-thastro-ph.COastro-ph.IMnucl-exApJ(2022)·13 citations
02
The impact of transverse Slavnov-Taylor identities on dynamical chiral symmetry breaking
Luis Albino🇧🇷 · Adnan Bashir🇲🇽 · Bruno El-Bennich🇧🇷 · Eduardo Rojas🇨🇴 · Fernando E. Serna🇧🇷 · Roberto Correa da Silveira🇧🇷
We extend earlier studies of transverse Ward-Fradkin-Green-Takahashi identities in QED, their usefulness to constrain the transverse fermion-boson vertex and their importance for multiplicative renormalizability, to the equivalent gauge identities in QCD. To this end, we consider transverse Slavnov-Taylor identities that constrain the transverse quark-gluon vertex and derive its eight associated scalar form factors. The complete vertex can be expressed in terms of the quark's mass and wave-renormalization functions, the ghost-dressing function, the quark-ghost scattering amplitude and a set of eight form factors. The latter parametrize the hitherto unknown nonlocal tensor structure in the transverse Slavnov-Taylor identity which arises from the Fourier transform of a four-point function involving a Wilson line in coordinate space. We determine the functional form of these eight form factors with the constraints provided by the Bashir-Bermudez vertex and study the effects of this novel vertex on the quark in the Dyson-Schwinger equation using lattice QCD input for the gluon and ghost propagators. We observe significant dynamical chiral symmetry breaking and a mass gap that leads to a constituent mass of the order of 500 MeV for the light quarks. The flavor dependence of the mass and wave-renormalization functions as well as their analytic behavior on the complex momentum plane is studied and as an application we calculate the quark condensate and the pion's weak decay constant in the chiral limit. Both are in very good agreement with their reference values.
nucl-thhep-lathep-phJHEP(2021)·24 citations
03
Forming Molecular States with Hadronic Rescattering
Philip Ilten🇺🇸 · Marius Utheim🇸🇪
A method for modelling the prompt production of molecular states using the hadronic rescattering framework of the general-purpose Pythia event generator is introduced. Production cross sections of possible exotic hadronic molecules via hadronic rescattering at the LHC are calculated for the $χ_{c 1} (3872)$ resonance, a possible tetraquark state, as well as three possible pentaquark states, $P_{c}^{+} (4312)$ , $P_{c}^{+} (4440)$ , and $P_{c}^{+} (4457)$ . For the $P_{c}^{+}$ states, the expected cross section from $Λ_{b}$ decays is compared to the hadronic-rescattering production. The $χ_{c 1} (3872)$ cross section is compared to the fiducial $χ_{c 1} (3872)$ cross-section measurement by LHCb and found to contribute at a level of O(1%). Finally, the expected yields of $P_{c}^{+}$ production from hadronic rescattering during Run 3 of LHCb are estimated. The prompt background is found to be significantly larger than the prompt $P_{c}^{+}$ signal from hadronic rescattering.
↳ hep-phnucl-thEPJA(2022)·29 citations
04
Pole analysis on the doubly charmed meson in $D^{0} D^{0} π^{+}$ mass spectrum
Ling-Yun Dai🇨🇳 · Xiang Sun🇨🇳 · Xian-Wei Kang🇨🇳 · A. P. Szczepaniak🇺🇸 · Jie-Sheng Yu🇨🇳
In this paper we study the scattering amplitudes of $D^{0} D^{0} π^{+}$ - $D^{*+} D^{0}$ coupled channels based on $K$ -matrix within the Chew-Mandelstam formalism. The $D^{0} D^{0} π^{+}$ invariant mass spectrum of LHCb is fitted and the pole parameters of the $T_{cc}^{+}$ are extracted. The analysis of pole behavior suggests that the $T_{cc}^{+}$ may originate from a $D^{*+} D^{0}$ virtual state and is formed as a result of an interplay between an attractive interaction between $D^{0}$ and $D^{*+}$ and coupling to $D^{0} D^{0} π^{+}$ channel.
↳ hep-phnucl-thPRD(2022)·36 citations
05
Mass spectra and decays of open-heavy tetraquark states
Tao Guo🇨🇳 · Jianing Li🇨🇳 · Jiaxing Zhao🇨🇳 · Lianyi He🇨🇳
Open-heavy tetraquark states, especially those contain four different quarks have drawn much attention in both theoretical and experimental fields. In the framework of the improved chromomagnetic interaction (ICMI) model, we complete a systematic study on the mass spectra and possible strong decay channels of the $S$ -wave open-heavy tetraquark states, $q q q ˉ Q ˉ$ ( $q = u, d, s$ and $Q = c, b$ ), with different quantum number $J^{P} = 0^{+}$ , $1^{+}$ , and $2^{+}$ . The parameters in the ICMI model are extracted from the conventional hadron spectra and used directly to predict the mass of tetraquark states. Several compact bound states and narrow resonances are found in both charm-strange and bottom-strange tetraquark sectors, most of them as a product of the strong coupling between the different channels. Our results show the recently discovered four different flavors tetraquark candidates $X_{0} (2900)$ is probably compact $u d s ˉ c ˉ$ state with quantum number $J^{P} = 0^{+}$ . The predictions about $X_{0} (2900)$ and its partners are expected to be better checked with other theories and future experiments.
↳ hep-phnucl-thPRD(2022)·33 citations

Affiliations

first authorsco-authorsvia INSPIRE

High-precision nuclear chronometer for the cosmos

The impact of transverse Slavnov-Taylor identities on dynamical chiral symmetry breaking

Forming Molecular States with Hadronic Rescattering

Pole analysis on the doubly charmed meson in D0D0π+ mass spectrum

Mass spectra and decays of open-heavy tetraquark states

Affiliations

Pole analysis on the doubly charmed meson in $D^{0} D^{0} π^{+}$ mass spectrum