53 research outputs found
Universal mass equation for equal-quantum excited-states sets II
No full textWe extend our recent study of the Universal Mass Equation for equal-quantum excited-states sets reported by Roper and Strakovsky (Eur Phys J A 61:102, 2025). The masses of twelve baryon sets and sixteen meson sets, with only two equal-quantum excited states in each set, using Breit-Wigner PDG2024 masses and their uncertainties at fixed for baryons and for mesons, are fitted by a simple one-parameter logarithmic function, , where n is the level of radial excitation. Two accurate masses that start a set are used to calculate four higher masses in the set accurately. It is noted that values for equal-quantum excited-states sets accurately lie on a straight line, whose line parameters can be used to calculate and predict higher mass states for sets that have only one known member
The scattering length based on near-threshold charmoniums photoproduction
No full textUnder the framework of Vector Meson Dominance model, the value of scattering
length can be expressed as a function of the ratio between total cross section
and , where is the ratio between final momentum
and initial momentum and positively correlated
with the center-of-mass energy. Based on the theoretical study of charmoniums
photoproduction within two gluon exchange model and effective pomeron model, we
research the scattering lengths of vector mesons and proton interaction in this
work. Results show that the scattering length
obtained from the two models are close and basically in agreement with the
theoretical prediction of Strakovsky and co-workers. Additionally, we first
calculate the scattering length of -proton interaction in two gluon
exchange model and effective pomeron model as am (1 am =
fm) and am, respectively. This is a little bit
different from the two models and requires precise measurements from subsequent
experiments. In short, our results will provide a theoretical reference for
future studies on characterizing the vector meson-proton scattering length.Comment: 7 pages, 7 figure
NN and 3N Interactions
No full textThis chapter provides a short overview of the Covariant Spectator Theory (CST) and its applications to the study of two- and three-nucleon forces. The basic ideas are illustrated using a simple model where two scalar “nucleons” exchange a scalar meson. Then, the equations needed for the realistic description of NN and 3N scattering and bound states are introduced, and a kernel (or relativistic potential) for use in these equations is chosen. Results recently obtained by adjusting the free parameters in this kernel in order to give high-precision fits to the two-nucleon scattering data are presented. These fits automatically give the correct three-body binding energy without the introduction of any additional forces or parameters. The chapter concludes with a discussion of the implications of these results, and an assessment of our current understanding of two- and three-nucleon forces
K-Long Facility for JLab and its Scientific Potential
No full textOur main interest in creating a secondary high-quality KL-beam is to investigate hyperon spectroscopy through both formation and production processes. We propose to study two-body reactions induced by the KL-beam on the proton target. The experiment should measure both differential cross sections and self-analyzed polarizations of the produced Λ-, Σ-, and Ξ-hyperons using the GlueX detector at the Jefferson Lab Hall D. New data will greatly constrain partial-wave analysis and reduce modeldependent uncertainties in the extraction of strange resonance properties, providing a new benchmark for comparisons with QCD-inspired models and LQCD calculations. The measurements will span c.m. cos θ from −0.95 to 0.95 in c.m. range above W = 1490 MeV and up to 4000 MeV
History of N(1680)
No full textThis paper describes my personal appreciation for some of the great research
achievements of Mitya Diakonov, Vitya Petrov, and Maxim Polyakov and how my own
research career has followed the paths they opened. Among the topics where they
have been the most influential have been the pursuit and study of the exotic
pentaquark. The search for exotics may require a complementary approach, such
as experimental and theoretical activity. Here, I would like to focus on a
story of in which I was involved.Comment: 13 pages, 7 figures; it will come to the Memorial volume of Acta
Physica Polonica B dedicated to Mitya Diakonov, Vitya Petrov, and Maxim
Polyakov; several glitches were fixe
О величине экспериментального значения массы ∆⁺ (1232) резонанса из реакций γp→nπ⁺ (pπ⁰)
No full textThe reliability of the phenomenological estimates for the D⁺(1232) mass is questioned coming from the of π⁺ and π⁰ mesons photoproduction data off proton target till the end of 2001. The origin of an old discrepancy for the D⁺(1232) mass presented in tables of the Particle Data Group is discussed.The author would like to thank I.I. Strakovsky for kindly sending the information about article [14]
О величине экспериментального значения массы ∆⁺ (1232) резонанса из реакций γp→nπ⁺ (pπ⁰)
No full textThe reliability of the phenomenological estimates for the D⁺(1232) mass is questioned coming from the of π⁺ and π⁰ mesons photoproduction data off proton target till the end of 2001. The origin of an old discrepancy for the D⁺(1232) mass presented in tables of the Particle Data Group is discussed.The author would like to thank I.I. Strakovsky for kindly sending the information about article [14]
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No full textThe -p scattering length, , can be extracted from the photoproduction cross section near threshold using the Vector Meson Dominance (VMD) model to relate the reaction to . Such estimates based on experimental data result in values for , which are much lower than most of the theoretical predictions. In this work, we study the relations between the different results, depending on the use of the total or the differential cross sections, and the method of extrapolating the data to threshold in the case of a low-statistics data sample, such as the near threshold photoproduction dataset. We estimate a range for of 0.003–0.025 fm as extracted from experimental data within the VMD model and discuss possible reasons for such lower values compared to the theoretical results
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