scholarly journals Sea Contributions to Spin 1/2 Baryon Structure, Magnetic Moments, and Spin Distribution

1997 ◽  
Vol 12 (10) ◽  
pp. 1861-1874 ◽  
Author(s):  
V. Gupta ◽  
R. Huerta ◽  
G. Sánchez-Colón
Keyword(s):  
Wave Function ◽  
Numerical Analysis ◽  
Quark Model ◽  
Magnetic Moment ◽  
Composite System ◽  
Magnetic Moments ◽  
Spin Distribution ◽  
Quantum Numbers ◽  
Experimental Errors ◽  
Spin Distributions

We treat the baryon as a composite system made out of a "core" of three quarks (as in the standard quark model) surrounded by a "sea" (of gluons and [Formula: see text]-pairs) which is specified by its total quantum numbers like flavor, spin and color. Specifically, we assume the sea to be a flavor octet with spin 0 or 1 but no color. The general wave function for spin 1/2 baryons with such a sea component is given. Application to the magnetic moments is considered. Numerical analysis shows that a scalar (spin 0) sea with an admixture of a vector (spin 1) sea can provide very good fits to the magnetic moment data using experimental errors. These fit also give reasonable values for the spin distributions of the proton and neutron.

scholarly journals SEMILEPTONIC DECAYS, MAGNETIC MOMENTS AND SPIN DISTRIBUTIONS OF SPIN-1/2 BARYONS WITH SEA CONTRIBUTION

1998 ◽  
Vol 13 (24) ◽  
pp. 4195-4212 ◽  
Author(s):  
V. GUPTA ◽  
R. HUERTA ◽  
G. SÁNCHEZ-COLÓN
Keyword(s):  
Reasonable Agreement ◽  
Composite System ◽  
Semileptonic Decay ◽  
Magnetic Moments ◽  
Semileptonic Decays ◽  
Decay Data ◽  
Quantum Numbers ◽  
Experimental Errors ◽  
Spin Distributions

Spin-1/2 baryons are considered as a composite system made out of a "core" of three-quarks surrounded by a "sea" (of gluons and [Formula: see text]-pairs) which is specified by its total quantum numbers. Specifically, we assume this sea to be a flavor octet with spin-0 or 1 but no color. We show our model can provide very good fits to magnetic moments and semileptonic decay data using experimental errors. The predictions for spin distributions are in reasonable agreement with experiment.

scholarly journals MASSES, MAGNETIC MOMENTS, AND SEMILEPTONIC DECAYS OF SPIN-1/2 BARYONS WITH SEA CONTRIBUTION

1998 ◽  
Vol 13 (36) ◽  
pp. 2887-2901
Author(s):  
V. GUPTA ◽  
P. RITTO ◽  
G. SÁNCHEZ-COLÓN
Keyword(s):  
Quark Model ◽  
Reasonable Agreement ◽  
Composite System ◽  
Magnetic Moments ◽  
Semileptonic Decays ◽  
Nucleon Spin ◽  
Quantum Numbers ◽  
Simple Quark Model ◽  
Spin Distributions

The spin-1/2 baryons are pictured as a composite system made out of a "core" of three valence quarks (as in the simple quark model) surrounded by a "sea" (of gluon and [Formula: see text] pairs) which is specified by its total quantum numbers. We assume that the sea is an SU(3) flavor octet with spin 0 or 1 but no color. This model, considered earlier, is used to obtain simultaneous fits for masses, magnetic moments and GA/GV for semileptonic decays. These fits give predictions for nucleon spin distributions in reasonable agreement with experiment.

scholarly journals BARYONS AS SOLITONS IN THREE-DIMENSIONAL QUANTUM CHROMODYNAMICS

1992 ◽  
Vol 07 (32) ◽  
pp. 8001-8019 ◽  
Author(s):  
G. FERRETTI ◽  
S.G. RAJEEV ◽  
Z. YANG
Keyword(s):  
Quantum Chromodynamics ◽  
Quark Model ◽  
Magnetic Moments ◽  
Three Dimensional ◽  
Collective Variables ◽  
Soliton Model ◽  
Quantum Numbers ◽  
Effective Lagrangian ◽  
Quantum Antiferromagnet

We show that baryons of three-dimensional quantum chromodynamics can be understood as solitons of its effective Lagrangian. In the parity-preserving phase we study, these baryons are fermions for odd Nc and bosons for even Nc, never anyons. We quantize the collective variables of the solitons and thereby calculate the flavor quantum numbers. magnetic moments and mass splittings of the baryon. The flavor quantum numbers are in agreement with naive quark model for the low-lying states. The magnetic moments and mass splittings are smaller in the soliton model by a factor of logFπ/Ncmπ. We also show that there is a dibaryon solution that is an analog of the deuteron. These solitons can describe defects in a quantum antiferromagnet.

Analytical solution for magnetic moments of Λ-hypernuclei in a relativistic approach

2019 ◽  
Vol 28 (05) ◽  
pp. 1950033 ◽  
Author(s):  
S. Mohammad Moosavi Nejad ◽  
A. Armat
Keyword(s):  
Wave Function ◽  
Analytical Solution ◽  
Excited States ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Spin Orbital ◽  
Direct Information ◽  
Central Potential ◽  
Highly Sensitive ◽  
Relativistic Approach

The magnetic moments of [Formula: see text]-hypernuclei are the most interesting observables which provide a highly sensitive probe of lambda in the hypernuclei structure and also supply direct information on hyperon–nucleon interactions. In this work, in a relativistic approach we analytically determine the magnetic moment of several [Formula: see text]-hypernuclei such as [Formula: see text], [Formula: see text] and [Formula: see text] in their ground and excited states, i.e., the [Formula: see text], [Formula: see text] and [Formula: see text] states. For our analysis, we consider the central potential of Wood–Saxon and the spin-orbital potential and determine the wave function of hypernuclei. Then, we compute the Dirac, the anomalous and the total magnetic moments of the ground and excited states of [Formula: see text]-hypernuclei.

BARYON MAGNETIC MOMENTS AND SPIN DEPENDENT QUARK FORCES

2002 ◽  
Vol 11 (01) ◽  
pp. 71-81
Author(s):  
GEORGE L. STROBEL
Keyword(s):  
Wave Function ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Mass Difference ◽  
Wave Functions ◽  
Small Current ◽  
Axial Charge ◽  
Strange Quarks ◽  
Quark Masses ◽  
Quark Wave Function

The J=3/2 Δ, J=1/2 nucleon mass difference shows that quark energies can be spin dependent. It is natural to expect that quark wave functions also depend on spin. In the octet, such spin dependent forces lead to different wave functions for quarks with spin parallel or antiparallel to the nucleon spin. A two component Dirac equation wave function is used for the quarks assuming small current quark masses for the u and d quarks. Then, the neutron/proton magnetic moment ratio, the nucleon axial charge, and the spin content of the nucleon can all be simultaneously fit assuming isospin invariance between the u and d quarks, but allowing for spin dependent forces. The breakdown of the Coleman–Glashow sum rule for octet magnetic moments follows naturally in this Dirac approach as the bound quark energy also effects the magnetic moment. Empirically the bound quark energy increases with the number of strange quarks in the system. Allowing the strange quark wave function similar spin dependence predicts the magnetic moments of the octet, in close agreement with experiment. Differences between the octet and decuplet magnetic moments are also explained immediately with spin dependent wave functions.

scholarly journals Spectrosopic Study of Baryons

2021 ◽  
Author(s):  
Zalak Shah ◽  
Ajay Kumar Rai
Keyword(s):  
Wave Function ◽  
Excited States ◽  
Magnetic Moments ◽  
Ground States ◽  
Total Wave Function ◽  
The Other ◽  
Summary Table ◽  
Regge Trajectories ◽  
Quantum Numbers ◽  
The Masses

Baryons are the combination of three quarks(antiquarks) configured by qqq(q¯q¯q¯). They are fermions and obey the Pauli’s principal so that the total wave function must be anti-symmetric. The SU(5) flavor group includes all types of baryons containing zero, one, two or three heavy quarks. The Particle Data Froup (PDG) listed the ground states of most of these baryons and many excited states in their summary Table. The radial and orbital excited states of the baryons are important to calculate, from that the Regge trajectories will be constructed. The quantum numbers will be determined from these slopes and intersects. Thus, we can help experiments to determine the masses of unknown states. The other hadronic properties like decays, magnetic moments can also play a very important role to emphasize the baryons. It is also interesting to determine the properties of exotic baryons nowadays.

scholarly journals OCTET MAGNETIC MOMENTS WITH NULL INSTANTONS AND SEMIBOSONIZED NAMBU–JONA-LASINIO MODEL

1999 ◽  
Vol 14 (36) ◽  
pp. 2525-2529
Author(s):  
ELENA N. BUKINA
Keyword(s):  
Quark Model ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Symmetry Properties ◽  
Meson Cloud ◽  
The Difference

It is shown that the difference between the magnetic moment results in the quark model with null instantons and semibosonized Nambu–Jona-Lasinio model lies in the symmetry properties of the meson cloud contributions.

scholarly journals The Genuine Resonance of Full-Charm Tetraquarks

Universe ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 155
Author(s):  
Xiaoyun Chen
Keyword(s):  
Quark Model ◽  
Bound States ◽  
Expansion Method ◽  
Chiral Quark Model ◽  
Stabilization Method ◽  
Scaling Method ◽  
Resonance States ◽  
Gaussian Expansion Method ◽  
Color Structure ◽  
Quantum Numbers

In this work, the genuine resonance states of full-charm tetraquark systems with quantum numbers JPC=0++,1+−,2++ are searched in a nonrelativistic chiral quark model with the help of the Gaussian Expansion Method. In this calculation, two structures, meson-meson and diquark–antidiquark, as well as their mixing with all possible color-spin configurations, are considered. The results show that no bound states can be formed. However, resonances are possible because of the color structure. The genuine resonances are identified by the stabilization method (real scaling method). Several resonances for the full-charm system are proposed, and some of them are reasonable candidates for the full-charm states recently reported by LHCb.

Baryon magnetic moments in the covariant oscillator quark model with unequal constituent masses

1983 ◽  
Vol 28 (11) ◽  
pp. 2918-2921 ◽  
Author(s):  
Shin Ishida ◽  
Kenji Yamada ◽  
Masuho Oda
Keyword(s):  
Quark Model ◽  
Magnetic Moments

scholarly journals CHIRAL QUARK MODEL (χQM) AND THE NUCLEON SPIN

2004 ◽  
Vol 19 (29) ◽  
pp. 5027-5041 ◽  
Author(s):  
HARLEEN DAHIYA ◽  
MANMOHAN GUPTA
Keyword(s):  
Angular Momentum ◽  
Magnetic Moments ◽  
Distribution Functions ◽  
Gluon Polarization ◽  
Spin Distribution ◽  
Polarization Functions ◽  
Singlet Component ◽  
Configuration Mixing ◽  
The Right ◽  
E866 Data

Using χ QM with configuration mixing, the contribution of the gluon polarization to the flavor singlet component of the total spin has been calculated phenomenologically through the relation [Formula: see text] as defined in the Adler–Bardeen scheme, where ΔΣ on the right-hand side is Q2 independent. For evaluation the contribution of gluon polarization [Formula: see text], ΔΣ is found in the χ QM by fixing the latest E866 data pertaining to [Formula: see text] asymmetry and the spin polarization functions whereas ΔΣ(Q2) is taken to be 0.30±0.06 and αs=0.287±0.020, both at Q2=5 GeV 2. The contribution of gluon polarization Δg' comes out to be 0.33 which leads to an almost perfect fit for spin distribution functions in the χ QM . When its implications for magnetic moments are investigated, we find perfect fit for many of the magnetic moments. If an attempt is made to explain the angular momentum sum rule for proton by using the above value of Δg', one finds the contribution of gluon angular momentum to be as important as that of the [Formula: see text] pairs.

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