scholarly journals Lattice QCD study of the elastic and transition form factors of charmed baryons

2021 ◽  
Vol 36 (23) ◽  
pp. 2130013
Author(s):  
K. U. Can

Composite nature of a particle can be probed by electromagnetic interactions and information about their structure is embedded in form factors. Most of the experimental and theoretical efforts on baryon electromagnetic form factors have been focused on nucleon while the data on charmed sector are limited to spectroscopy, and weak and strong decays. Forthcoming experiments with a heavy-hadron physics program at major experimental facilities are expected to provide a wealth of information on charmed baryons, which calls for a better understanding of the heavy-sector dynamics from theoretical grounds. We review the progress in calculating the elastic and transition form factors of charmed baryons in lattice QCD. A collection of static observables, e.g. charge radii, multipole moments, are presented along with the elastic form factors up to [Formula: see text]. As one would expect the charmed baryons are compact in comparison to nucleon and this is due to the presence of valence charm quark(s). The elastic and transition magnetic moments are both suppressed. The lattice results provide predictions for the transition magnetic moments, transition and helicity amplitudes and consequentially the decay widths of some singly and doubly charmed baryons. In general, lattice results are consonant with the qualitative expectations of quark model and heavy-quark symmetry, although there are apparent quantitative differences up to two orders of magnitude in some cases. There are, however, indications that the lattice results can be utilized to improve the model predictions. Nevertheless, discrepancies between the lattice and nonlattice calculations need to be understood better to have a solid insight into the dynamics of the heavy sector. Furthermore, reliably determined charmed baryon observables would be invaluable input to investigate the nature of exotic states, which further emphasizes the importance of rigorous, first-principles calculations to advance our understanding of the dynamics of the heavy quarks and strong interactions.

2005 ◽  
Vol 94 (2) ◽  
Author(s):  
C. Alexandrou ◽  
Ph. de Forcrand ◽  
H. Neff ◽  
J. W. Negele ◽  
W. Schroers ◽  
...  

2014 ◽  
Vol 26 ◽  
pp. 1460090
Author(s):  
◽  
RALF W. GOTHE

Meson-photoproduction measurements and their reaction-amplitude analyses can establish more sensitively, and in some cases in an almost model-independent way, nucleon excitations and non-resonant reaction amplitudes. However, to investigate the strong interaction from explored — where meson-cloud degrees of freedom contribute substantially to the baryon structure — to still unexplored distance scales — where quark degrees of freedom dominate and the transition from dressed to current quarks occurs — we depend on experiments that allow us to measure observables that are probing this evolving non-perturbative QCD regime over its full range. Elastic and transition form factors are uniquely suited to trace this evolution by measuring elastic electron scattering and exclusive single-meson and double-pion electroproduction cross sections off the nucleon. These exclusive measurements will be extended to higher momentum transfers with the energy-upgraded CEBAF beam at JLab to study the quark degrees of freedom, where their strong interaction is responsible for the ground and excited nucleon state formations. After establishing unprecedented high-precision data, the imminent next challenge is a high-quality analysis to extract these relevant electrocoupling parameters for various resonances that then can be compared to state-of-the-art models and QCD-based calculations. Recent results will demonstrate the status of the analysis and of their theoretical descriptions, and an experimental and theoretical outlook will highlight what shall and may be achieved in the new era of the 12-GeV upgraded transition form factor program.


2020 ◽  
Vol 80 (11) ◽  
Author(s):  
June-Young Kim ◽  
Hyun-Chul Kim

AbstractWe investigate the electromagnetic transition form factors of the baryon decuplet to the baryon octet, based on the self-consistent SU(3) chiral quark-soliton model, taking into account the effects of explicit breaking of flavor SU(3) symmetry. We emphasize the $$Q^2$$ Q 2 dependence of the electromagnetic $$N\rightarrow \Delta $$ N → Δ transition form factors and the ratios of E2/M1 and C2/M1 in comparison with the experimental and empirical data. In order to compare the present results of the electromagnetic transition form factors of the $$N\rightarrow \Delta $$ N → Δ with those from lattice QCD, we evaluate the form factors with the pion mass deviated from its physical value. The results of the E2/M1 and C2/M1 ratios are in good agreement with the lattice data. We also present the results of the electromagnetic transition form factors for the decuplet to the octet transitions.


2018 ◽  
Vol 181 ◽  
pp. 01027 ◽  
Author(s):  
Daniel Mohler

I review recent progress in heavy hadron spectroscopy and from ab-initio Lattice QCD calculations.After motivating lattice calculations for heavy-hadrons by contrasting recent LHCb results charmed and doubly-charmed baryons with lattice predictions, selected resultsfrom scattering calculations for heavy-light mesons and for charmonia are presented.I close with a discussion of recent Lattice QCD predictions of explicitlyexotic doubly-heavy states.


2008 ◽  
Vol 77 (8) ◽  
Author(s):  
C. Alexandrou ◽  
G. Koutsou ◽  
H. Neff ◽  
J. W. Negele ◽  
W. Schroers ◽  
...  

2004 ◽  
Vol 69 (11) ◽  
Author(s):  
C. Alexandrou ◽  
Ph. de Forcrand ◽  
Th. Lippert ◽  
H. Neff ◽  
J.W. Negele ◽  
...  

2006 ◽  
Vol 21 (04) ◽  
pp. 720-725 ◽  
Author(s):  
◽  
J. W. Negele ◽  
B. Bistrovic ◽  
R. G. Edwards ◽  
G. Fleming ◽  
...  

The structure of neutrons, protons, and other strongly interacting particles is now being calculated in full, unquenched lattice QCD with quark masses entering the chiral regime. This talk describes selected examples, including the nucleon axial charge, structure functions, electromagnetic form factors, the origin of the nucleon spin, the transverse structure of the nucleon, and the nucleon to Delta transition form factor.


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