scholarly journals The Masses of Heavy Pentaquarks in Non-Relativistic Bethe-Salpeter Quark Model

2021 ◽  
Vol 68 (1 Jan-Feb) ◽  
Author(s):  
M. Abu-shady ◽  
N. H. Gerish ◽  
M. M. A. Ahmed

The exotic particles such as the pentaquarks are to strengthen understanding of important interactions and the principle of QCD in which pentaquarks contain two heavy- valence quarks. The structure of two bodies including an antiquark and two-diquark is introduced. A new potential for quark interaction is suggested which includes the logarithm potential, the linear potential, and the spin-spin interaction. The suggested potential is included in the framework of spinless of Bethe-Salpeter equation. A comparison with other works is presented which provides a good description of pentaquarks.

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1797-1802 ◽  
Author(s):  
FL. STANCU

Light and heavy pentaquarks are described within a constituent quark model based on a spin-flavor hyperfine interaction. In this model the lowest state acquires positive parity. The masses of the light antidecuplet members are calculated dynamically using a variational method. It is shown that the octet and antidecuplet states with the same quantum numbers mix ideally due to SU (3)F breaking. Masses of the charmed antisextet pentaquarks are predicted within the same model.


2014 ◽  
Vol 29 (22) ◽  
pp. 1450120 ◽  
Author(s):  
Jong-Ping Hsu

We discuss a confining model for quark–antiquark system with a new color SU3 gauge symmetry. New gauge transformations involve non-integrable phase factors and lead to the fourth-order gauge field equations and a linear potential. The massless gauge bosons have non-definite energies, which are not observable because they are permanently confined in quark systems by the linear potential. We use the empirical potentials of charmonium to determine the coupling strength of the color charge gs and find [Formula: see text]. The rules for Feynman diagrams involve propagators with poles of order 2 associated with new gauge fields. The confining quark model may be renormalizable by power counting and compatible with perturbation theory.


2020 ◽  
Vol 80 (11) ◽  
Author(s):  
G. De Conto ◽  
A. C. B. Machado ◽  
J. Montaño ◽  
P. Chimenti

AbstractWe present a model with $$S_3 \otimes \mathbb {Z}_2$$ S 3 ⊗ Z 2 model plus a sterile neutrino and its phenomenological expectations for the production of charged scalars at the compact linear collider. At tree level, our model predicts a total cross section in between 0.1 and $$10^{-5}$$ 10 - 5 pb for the $$e^- e^+ \rightarrow H^+ H^-$$ e - e + → H + H - process, considering all possible mass values for the charged scalar in the CLIC experiment. We also show that this prediction holds regardless of the masses of the other exotic particles and their couplings. We also show that an indirect detection from its effects in the $$e \overline{e} \rightarrow e \overline{e}$$ e e ¯ → e e ¯ + missing energy process is possible under specific conditions, or a direct detection under other circumstances. However, one cannot use this process to study the sterile neutrinos present in this model, given that they have a small influence in the total cross-section for the direct detection of the exotic scalar to be possible.


2010 ◽  
Vol 6 (S276) ◽  
pp. 495-496 ◽  
Author(s):  
Leonardo A. Almeida ◽  
Francisco Jablonski

AbstractQS Vir is an eclipsing cataclysmic variable with 3.618 hrs orbital period. This system has the interesting characteristics that it does not show mass transfer between the components through the L1 Lagrangian point and shows a complex orbital period variation history. Qian et al. (2010) associated the orbital period variations to the presence of a giant planet in the system plus angular momentum loss via magnetic braking. Parsons et al. (2010) obtained new eclipse timings and observed that the orbital period variations associated to a hypothetical giant planet disagree with their measurements and concluded that the decrease in orbital period is part of a cyclic variation with period ~16 yrs. In this work, we present 28 new eclipse timings of QS Vir and suggest that the orbital period variations can be explained by a model with two circumbinary bodies. The best fitting gives the lower limit to the masses M1 sin(i) ~ 0.0086 M⊙ and M2 sin(i) ~ 0.054 M⊙; orbital periods P1 ~ 14.4 yrs and P2 ~ 16.99 yrs, and eccentricities e1 ~ 0.62 and e2~0.92 for the two external bodies. Under the assumption of coplanarity among the two external bodies and the inner binary, we obtain a giant planet with ~0.009 M⊙ and a brown dwarf with ~ 0.056 M⊙ around the eclipsing binary QS Vir.


2005 ◽  
Vol 20 (25) ◽  
pp. 1887-1893 ◽  
Author(s):  
D. EBERT ◽  
R. N. FAUSTOV ◽  
V. O. GALKIN

The masses of the S-wave mesons consisting of the light (u, d, s) quarks are calculated within the constituent quark model. The relativistic Schrödinger-like equation with a confining potential is numerically solved for the complete relativistic [Formula: see text] potential including both spin-independent and spin-dependent terms. The obtained masses of the ground state π, ρ, K, K* and ϕ mesons and their first radial excitations are in a reasonably good overall agreement with experimental data.


Author(s):  
Quan Zhou ◽  
Ming Liu ◽  
Heather Peng ◽  
Wei Qiu

There are challenges in the prediction of low-frequency load and especially the resonant free surface elevation between two bodies in close proximity. Most of the linear potential-flow based seakeeping programs currently used by the industry over-predict the free surface elevation between the vessels/bodies and hence the low-frequency loadings on the hulls. Various methods, such as the lid technique, have been developed to suppress the unrealistic values of low-frequency forces by introducing artificial damping coefficients. However, without the experimental data, it is challenging to specify the coefficients. This paper presents the experimental studies of motions of two bodies with various gaps and the wave elevations between bodies. Model tests were performed at the towing tank of Memorial University. The objective was to provide benchmark data for further numerical studies of the viscous effect on the free surface predictions. The experimental data were compared with numerical solutions based on potential flow methods. The effect of tank walls were examined. Preliminary uncertainty analysis was also carried out.


2003 ◽  
Vol 12 (06) ◽  
pp. 793-807 ◽  
Author(s):  
S. M. GERASYUTA ◽  
V. I. KOCHKIN

Relativistic five-quark equations are found in the framework of the dispersion relation technique. The solutions of these equations using the method based on the extraction of the leading singularities of the amplitudes are obtained. The five-quark amplitudes for the low-lying pentaquarks are calculated under the condition that flavor SU(3) symmetry holds. The poles of the five-quark amplitudes determine the masses of the lowest pentaquarks. The mass spectra of pentaquarks which contain only light quarks are calculated. The calculation of pentaquark amplitudes estimates the contributions of three subamplitudes: molecular subamplitude BM, Mqqq subamplitude and [Formula: see text] subamplitude. The main contributions to the pentaquark amplitude are determined by the subamplitudes, which include the meson states M.


1970 ◽  
Vol 23 (5) ◽  
pp. 615 ◽  
Author(s):  
GB Smith ◽  
LJ Tassie

From the sum rules for hadron scattering, the nucleon form factors, and the masses of the hadrons, the properties of quarks are estimated as: 2 Ge V Jc2 ;:; quark mass ;:; 30 Ge V Jc2, 0�1 fm ;:; range of the quark-quark interaction ;:; 0�25 fm. The hadrons are described by a relativistic independent quark model using the Dirac equation with a potential energy term for the effective interaction.


Author(s):  
Engel Roza

A structure-based view on mesons is given, based upon the concept of an archetype quark, described as a pointlike source producing an energy flux, the spatial description of which is derived from Dirac’s second dipole moment. This enables to conceive the archetype meson (pion) as a structure that behaves as a one-body anharmonic quantum mechanical oscillator. All mesons appear being excitations of the archetype, thereby allowing a calculation of the mass spectrum without the use of empirical parameters for the masses of the quark flavors. This includes a physically comprehensible analysis of the spin-spin interaction between quarks. It also provides a solution for the eta-etaprime puzzle. Next to this, it is shown that quite some particles that are presently regarded as elementary, have a common root and can be traced back to a few archetypes only.


1974 ◽  
Vol 22 ◽  
pp. 93-96
Author(s):  
H. Scholl

The mass of a planet can be determined by the motion of its satellites or by perturbational effects on nearby bodies, such as comets, planets, minor planets. It is well known, for instance, that a body on a nearby orbit which is in close resonance with a planet is suitable for the determination of the planetary mass. In this case the orbital periods of the two bodies are equal or nearly equal to the ratio of small integers (i.e. 1: 1, 2: 1, 3:2).


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