STRUCTURE FUNCTION IN NUCLEAR MATTER IN THE NJL MODEL

2003 ◽  
Vol 18 (02n06) ◽  
pp. 384-387
Author(s):  
H. MINEO ◽  
W. BENTZ ◽  
A. W. THOMAS ◽  
N. ISHII ◽  
K. YAZAKI
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Structure Function ◽  
Nuclear Matter ◽  
Structure Functions ◽  
Simple Approximation ◽  
Nucleon Structure ◽  
Confinement Effects ◽  
Njl Model ◽  
Emc Effect

In this work we discuss the EMC effect on the nucleon structure functions in nuclear matter, using a simple approximation to the relativistic Faddeev description of the nucleon in the framework of the Nambu-Jona-Lasinio (NJL) model. We adopt a stable nuclear matter equation of state, calculated in the NJL model, which incorporates confinement effects phenomenologically so as to avoid unphysical thresholds for the decay into quarks. We will compare our results for the EMC ratio in nuclear matter in the NJL model with the parametrized fits to the experimental data.

THE NUCLEON STRUCTURE AND THE EQUATION OF STATE FOR NUCLEAR MATTER

2007 ◽  
Vol 16 (02) ◽  
pp. 608-615
Author(s):  
J. ROŻYNEK
Keyword(s):  
Equation Of State ◽  
Structure Function ◽  
Nuclear Matter ◽  
Mean Field ◽  
Nucleon Structure ◽  
Final State ◽  
Rest Energy ◽  
Relativistic Mean Field ◽  
Quark Contribution ◽  
Nucleon Structure Function

We show the density dependent corrections to the nucleon structure function in the frame of nuclear Relativistic Mean Field (RMF) models. These corrections are connected with the modifications of the parton distribution in nuclei emerging from generalized nuclear Fermi motion and final state interactions between the nucleon and the rest of the nucleus. The medium effects concern the nucleon structure, namely the changes in the nucleon rest energy, the enhancement of sea quark contribution (simulated with "nuclear pions") and the modifications of the transverse parton momentum distribution inside Nuclear Matter (NM). The sea parton distributions are described by the modified cloud of virtual pions in order to saturate the nuclear energy-momentum sum rule. The description of theses features are in good agreement with experimental data; the EMC effect for x > 0.15 and nuclear lepton pair production data has been described essentialy without free parameters. The influence of these medium modifications to the nucleon structure function within the equation of state in RMF models of NM will be discussed.

scholarly journals EFFECT DUE TO COMPOSITENESS OF NUCLEONS IN DEEP INELASTIC LEPTON NUCLEUS SCATTERING

1992 ◽  
Vol 01 (04) ◽  
pp. 809-821 ◽  
Author(s):  
BO-QIANG MA
Keyword(s):  
Structure Function ◽  
Nuclear Structure ◽  
Light Cone ◽  
Degrees Of Freedom ◽  
Structure Functions ◽  
Nucleon Structure ◽  
Nucleon Structure Function ◽  
Nucleus Scattering ◽  
Quark Structure ◽  
Nuclear Structure Functions

The off-shell behaviors of bound nucleons in deep inelastic lepton nucleus scattering are discussed in two scenarios with the basic constituents chosen to be baryon-mesons and quark-gluons respectively in light-cone formalism. It is found that when taking into account the effect due to internal quark structure of nucleons, the derived scaling variable for bound nucleons and the calculated nuclear structure functions are different from those in considering the baryon-mesons as the effective elementary constituents. This implies that the pure baryon-meson descriptions of nuclei give the inaccurate off-shell behavior of the bound nucleon structure function, thereby the quark-gluons seem to be the most appropriate degrees of freedom for nuclear descriptions.

scholarly journals NUCLEAR PARTON DENSITIES AND STRUCTURE FUNCTIONS

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1927-1930 ◽  
Author(s):  
S. ATASHBAR TEHRANI ◽  
ALI N. KHORRAMIAN ◽  
A. MIRJALILI
Keyword(s):  
Experimental Data ◽  
Structure Function ◽  
Nuclear Structure ◽  
Parton Distribution ◽  
Constituent Quark ◽  
Structure Functions ◽  
Constituent Quark Model ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Good Agreement

We calculate nuclear parton distribution functions (PDFs), using the constituent quark model. We find the bounded valon distributions in a nuclear to be related to free valon distributions in a nucleon. By using improved bounded valon distributions for a nuclear with atomic number A and the partonic structure functions inside the valon, we can calculate the nuclear structure function in x space. The results for nuclear structure-function ratio [Formula: see text] at some values of A, are in good agreement with the experimental data.

scholarly journals HARD NON-VACUUM REGGEON IN THE CKMT MODEL

2004 ◽  
Vol 19 (10) ◽  
pp. 755-760
Author(s):  
V. A. ABRAMOVSKY ◽  
A. V. DMITRIEV
Keyword(s):  
Experimental Data ◽  
Structure Function ◽  
Functional Form ◽  
Nucleon Structure ◽  
Photon Virtuality ◽  
Regge Theory ◽  
Incoming Photon ◽  
Nucleon Structure Function

The CKMT model describing the nucleon structure function F2(x,Q2) in the framework of conventional Regge theory with smooth soft-hard pomeron is modified. Smooth soft-hard non-vacuum reggeon dependence on incoming photon virtuality Q2 is introduced. This dependence has the same functional form as the smooth soft-hard functional Q2 dependence for pomeron in original CKMT model. In region of low W2, better agreement with experimental data is observed.

PROPERTIES OF NUCLEONS AND NUCLEAR MATTER IN THE QUARK–DIQUARK MODEL AND EXTENSION TO FINITE DENSITY

2003 ◽  
Vol 18 (08) ◽  
pp. 1409-1412
Author(s):  
W. BENTZ ◽  
H. MINEO ◽  
A. W. THOMAS ◽  
K. YAZAKI
Keyword(s):  
Equation Of State ◽  
Nuclear Matter ◽  
Axial Vector ◽  
Bound State ◽  
Simple Approximation ◽  
Static Properties ◽  
Diquark Model ◽  
Finite Density ◽  
Single Nucleon

We describe the nucleon as a quark-diquark bound state in a simple approximation to the full Faddeev method in the Nambu-Jona-Lasinio model. In the first part of this work, we concentrate on the role of axial vector diquark correlations for the static properties of the nucleon. In the second part, we construct an equation of state of nuclear matter based on the quark-diquark model for the single nucleon.

NUCLEON STRUCTURE FUNCTIONS AT FINITE DENSITY IN THE NJL MODEL

2002 ◽  
Author(s):  
H. MINEO ◽  
W. BENTZ ◽  
A. W. THOMAS ◽  
N. ISHII ◽  
K. YAZAKI
Keyword(s):  
Structure Functions ◽  
Nucleon Structure ◽  
Finite Density ◽  
Njl Model

Relativistic Faddeev description of baryons and nucleon structure function in the NJL model

2000 ◽  
Vol 670 (1-4) ◽  
pp. 48-55 ◽  
Author(s):  
W. Bentz ◽  
H. Mineo ◽  
H. Asami ◽  
K. Yazaki
Keyword(s):  
Structure Function ◽  
Nucleon Structure ◽  
Njl Model ◽  
Nucleon Structure Function

scholarly journals THE MODIFICATION OF THE SCALAR FIELD IN DENSE NUCLEAR MATTER

2010 ◽  
Vol 19 (04) ◽  
pp. 774-780
Author(s):  
JACEK ROŻYNEK
Keyword(s):  
Structure Function ◽  
Nuclear Matter ◽  
Mean Field ◽  
Nuclear Interaction ◽  
Nucleon Structure ◽  
Saturation Point ◽  
Relativistic Mean Field ◽  
Convolution Model ◽  
Dense Nuclear Matter ◽  
Nucleon Structure Function

We show the possible evolution of the nuclear deep inelastic structure function with nuclear density ρ. The nucleon deep inelastic structure function represents distribution of quarks as a function of Björken variable x, which measures the longitudinal fraction of the momentum carried by them during deep inelastic scattering (DIS) of electrons on nuclear targets. The quark localization is proportional to 1/x and this relation introduces the dependence of the nucleon structure function on the nuclear medium. Starting with small density and negative pressure in nuclear matter (NM), we have relatively large inter-nucleon distances and increasing role of nuclear interaction mediated by virtual mesons. When the density approaches the saturation point, ρ = ρ0, we have no longer separate mesons and nucleons but eventually modified nucleon structure function (SF) in the medium. The ratio of the nuclear to the nucleon SF measured at the saturation point is well known as the "EMC effect". For larger density, ρ > ρ0, when the localization of quarks is smaller than 0.3 fm, the nucleons overlap. We argue that nucleon mass should start to decrease in order to satisfy the momentum sum rule (MSR) of DIS. These modifications of the nucleon structure function are calculated in the frame of the nuclear relativistic mean field (RMF) convolution model. The correction to the Fermi energy from a term proportional to the pressure is very important and its inclusion modifies the equation of state (EoS) for the nuclear matter.

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