Article
Astronomy & Astrophysics
Floriana Giannuzzi, Stefano Nicotri
Summary: The singlet pseudoscalar sector of light mesons was investigated in the soft-wall model, utilizing a bottom-up approach to the AdS/QCD correspondence. The eta' mass arises from the mixing of fields dual to the axial current, pseudoscalar current, and the G (G) over tilde operator. The topological susceptibility was calculated for any quark mass, and the Witten-Veneziano relation was derived in the large Nc limit.
Article
Astronomy & Astrophysics
Z. R. Kordov, R. Horsley, W. Kamleh, Z. Koumi, Y. Nakamura, H. Perlt, P. E. L. Rakow, G. Schierholz, H. Stueben, R. D. Young, J. M. Zanotti
Summary: This study analyzed the light pseudoscalar mesons on a lattice, taking into account the mixing between pi degrees, eta, and eta'. The researchers extracted the masses and flavor compositions of the pseudoscalar meson nonet in a lattice QCD + QED setting around an SU(3)-flavor symmetric point, and observed flavor-symmetry features in the data. One key finding was the observed mass splitting between pi degrees and eta, showing a simple relationship with their corresponding flavor compositions.
Article
Astronomy & Astrophysics
Xiangyu Jiang, Wei Sun, Feiyu Chen, Ying Chen, Ming Gong, Zhaofeng Liu, Renqiang Zhang
Summary: We perform the first lattice study on the mixing of the isoscalar pseudoscalar meson eta and the pseudoscalar glueball Gin the Nf 1/4 2 QCD at the pion mass m pi approximate to 350 MeV. The eta mass is determined to be m eta 1/4 714o6 thorn o16 thorn MeV. Through the Witten-Veneziano relation, this value can be matched to a mass value of similar to 981 MeV for the SU(3) counterpart of eta. Based on a large gauge ensemble, the eta - G mixing energy and the mixing angle are determined to be jxj 1/4 107o15 thorn o2 thorn MeV and j theta j 1/4 3.46o46 thorn degrees from the eta - G correlators that are calculated using the distillation method. We conclude that the eta - G mixing is tiny and the topology induced interaction contributes most of eta mass owing to the QCD UAo1 thorn anomaly.
Article
Physics, Multidisciplinary
Nicolas Lang, David J. Wilson, Hadron Spectrum Collaboration
Summary: We present lattice QCD calculations for D * K scattering amplitudes, and identify low-lying D1 and D * 2 states with different angular momentum and parity. Our analysis of the scattering amplitudes reveals interesting features, including a near-threshold bound state and a narrow resonance peak.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Yu-Shuai Li, Zi-Yue Bai, Xiang Liu
Summary: The investigation of the Upsilon(10753) -> Upsilon(1(3)D(J))(eta) (J = 1, 2, 3) processes shows that these processes have considerable branching ratios, especially for B[Upsilon(10753) -> Upsilon(1(3)D(1))(eta)] and B[Upsilon(10753) -> Upsilon((1)3D(2))(eta)], which may be observed in the Belle II experiment.
Article
Physics, Particles & Fields
Gunnar S. Bali, Vladimir Braun, Sara Collins, Andreas Schaefer, Jakob Simeth
Summary: In this study, the masses, decay constants, and anomalous matrix elements of the eta and eta ' mesons in N-f = 2 + 1 QCD were determined using non-perturbatively improved Wilson fermions. The data are consistent with Chiral Perturbation Theory (ChPT) and give insights into the quark mass dependence, singlet axial Ward identity, and gluonic matrix elements.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Yin Cheng, Qiang Zhao
Summary: Based on the assumption that eta(1405) and eta(1475) are one-state particles, this study investigates the productions and radiative decays of eta(1295) and eta(1405/1475) states. The (K) over bar K* + c.c. meson loops are found to play important roles in the hadronic and radiative decays of these states.
Article
Physics, Multidisciplinary
Jeremy R. Green, Andrew D. Hanlon, Parikshit M. Junnarkar, Hartmut Wittig
Summary: This study presents the first exploration of baryon-baryon interactions in the continuum limit of lattice QCD, revealing unexpectedly large lattice artifacts impacting the binding energy. By applying variational methods and Luscher's finite-volume quantization conditions, scattering phase shifts can be determined from the spectrum, leading to an estimate of the binding energy of the H dibaryon in three-flavor QCD.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Chien-Yeah Seng, Vincenzo Cirigliano, Xu Feng, Mikhail Gorchtein, Luchang Jin, Gerald A. Miller
Summary: Recent estimates suggest that the strong isospin-symmetry breaking (ISB) corrections to the Fermi matrix element in free neutron decay may be one order of magnitude larger than the naive estimate based on a theorem. To investigate this claim, we derive a general expression for the leading ISB correction to hadronic Fermi matrix elements, which can be computed from first principles. Our formalism opens up the possibility of determining this correction in the neutron sector with fully-controlled theory uncertainties.
Article
Astronomy & Astrophysics
Rafel Escribano, Sergi Gonzalez-Solis, Emilio Royo
Summary: The sensitivity of rare decays eta(') -> pi 0 gamma gamma and eta' -> eta gamma gamma to a leptophobic B boson is analyzed. By incorporating B-boson resonance exchange and using experimental data, the constraints on B-boson mass and coupling to Standard Model particles are improved. It is found that identifying the B-boson signature in a specific mass range is challenging, but outside that range, the corresponding signatures may still be observable.
Article
Astronomy & Astrophysics
Shuo Tang, Shaoyang Jia, Pieter Maris, James P. Vary
Summary: This study investigates the semileptonic decay of B-c(0(-)) to charmonia via the bottom-to-charm-quark electroweak current using basis light-front quantization. Weak transition form factors for decays into eta(c) or J/psi are calculated based on initial and final valence light-front wave functions, leading to differential decay width, branching ratios, and observations of unphysical frame dependence. A preferred set of frames is proposed for calculating these form factors based on analysis of the current component.
Article
Physics, Nuclear
Zhen-Hua Zhang
Summary: The influence of the isospin-breaking pi(0)-eta-eta' mixing effect on the CP-asymmetries of B -> K pi processes is examined for the first time. Significant uncertainty is found due to this effect on both the CP-asymmetry sum rule of B -> K pi processes and the CP-asymmetry difference of B+ -> K+pi(0) and B-0 -> K+pi(-), potentially obscuring the significance of the K pi-puzzle. A definitive conclusion is currently unavailable due to the strong non-perturbative phases upon which the correction depends.
Article
Astronomy & Astrophysics
Hsiang-nan Li
Summary: An inverse matrix method is developed to solve resonance masses from a dispersion relation obeyed by a correlation function. The nonperturbative spectral density obtained exhibits resonance structures naturally. The analysis reveals characteristics of different glueballs and proposes a mixing framework including gluonium components for certain mesons.
Article
Astronomy & Astrophysics
Xiang Gao, Andrew D. Hanlon, Nikhil Karthik, Swagato Mukherjee, Peter Petreczky, Philipp Scior, Shuzhe Shi, Sergey Syritsyn, Yong Zhao, Kai Zhou
Summary: In this study, lattice QCD calculations were performed to determine the valence parton distribution function of the pion, using next-to-next-leading-order perturbative QCD matching. The results are in good agreement with global fits to experimental data.
Article
Astronomy & Astrophysics
Ruairi Brett, Chris Culver, Maxim Mai, Andrei Alexandru, Michael Doring, Frank X. Lee
Summary: In this study, a fit of the finite-volume QCD spectrum of three pions at maximal isospin was performed to constrain the three-body force. Results indicate consistency with a constant contact term close to zero for heavier pion mass, while showing statistically significant energy dependence for lighter mass. The findings also suggest the potential to constrain the two-body amplitude with sufficient three-body energy levels.
