scholarly journals LEADING EFFECTS IN HADROPRODUCTIONS OF ΛcAND D FROM CONSTITUENT QUARK–DIQUARK CASCADE PICTURE

2004 ◽  
Vol 19 (04) ◽  
pp. 599-611 ◽  
Author(s):  
TSUTOMU TASHIRO ◽  
SHIN-ICHI NAKARIKI ◽  
HUJIO NODA ◽  
KISEI KINOSHITA ◽  
SHUXIN LAN

We discuss the hadroproductions of Λc, [Formula: see text], D and [Formula: see text] in the framework of the constituent quark–diquark cascade model taking into account the valence quark annihilation. The spectra of Λcand [Formula: see text] in pA, Σ-A and π-A collisions are well explained by the model using the values of parameters used in hadroproductions of D and [Formula: see text]. It is shown that the role of valence diquark in the incident baryon is important for [Formula: see text] productions as well as for Λcproduction.

2012 ◽  
Vol 21 (01) ◽  
pp. 1250001
Author(s):  
HUJIO NODA ◽  
TSUTOMU TASHIRO ◽  
SHIN-ICHI NAKARIKI

We discuss the relation between the polarization of inclusively produced (anti)hyperons and the incident baryon states in the framework of the constituent quark–diquark cascade model. We assume that there is an intrinsic diquark–antidiquark state in the incident baryon, in which the intrinsic diquark immediately fragments into a non-leading baryon and the antidiquark behaves as a valence constituent. It is also assumed that the valence (anti)diquark in the incident nucleon tends to combine selectively with a spin-down sea quark and, on the other hand, the spin-up valence quark in the projectile is chosen by a sea (anti)diquark in preference to the spin-down valence quark. It is found that the incident spin-1/2 baryon is mainly composed of a spin-0 valence diquark and a valence quark, and contains an intrinsic diquark–antidiquark state with a probability of about 7%.


2007 ◽  
Vol 16 (07n08) ◽  
pp. 2344-2349
Author(s):  
TSUTOMU TASHIRO ◽  
HUJIO NODA ◽  
SHIN-ICHI NAKARIKI ◽  
KAZUMI FUKUMA

We relate the hyperon polarizations in proton-proton and proton-nucleus collisions to the leading particle effect and use the constituent quark-diquark cascade model with SU(6) wave function. We assume that the quantization axis is characterized by the production normal of the leading baryon of the most massive cascade chain and the incident valence diquark tends to pick up a spin down sea quark or conversely a sea diquark preferentially combines with the spin up incident valence quark to form a leading baryon as compared with the spin down valence quark.


2009 ◽  
Vol 24 (27) ◽  
pp. 2167-2174 ◽  
Author(s):  
H. FRITZSCH ◽  
G. ELDAHOUMI

The constituent quarks are interpreted as bound states, which have an internal structure. The quark distributions of the proton are related to those of the constituent quarks. The experiments support this hypothesis. Likewise the spin structure of the proton is related to the spin structure of the constituent quarks. We find that about 30% of the spin of a constituent quark is given by the valence quark, and 70% are provided by the gluons.


1996 ◽  
Vol 11 (38) ◽  
pp. 3021-3034 ◽  
Author(s):  
H. WEIGEL ◽  
L. GAMBERG ◽  
H. REINHARDT

We study nucleon structure functions within the bosonized Nambu-Jona-Lasinio model where the nucleon emerges as a chiral soliton. As examples we present the unpolarized structure functions for the νp and [Formula: see text] scattering and discuss the Gottfried sum rule in the valence quark approximation. This approximation is justified for moderate constituent quark masses (~ 400 MeV) as the valence quark level dominates the predictions of nucleon properties. We find that these structure functions are well localized in the interval 0≤x Bj ≤1 permitting a parton model interpretation.


1998 ◽  
Vol 2 (4) ◽  
pp. 733-740 ◽  
Author(s):  
Tsutomu Tashiro ◽  
Hujio Noda ◽  
Shin-ichi Nakariki ◽  
Kazuo Ishii ◽  
Kisei Kinoshita

2003 ◽  
Vol 18 (08) ◽  
pp. 1391-1395 ◽  
Author(s):  
A. I. SIGNAL

Model calculations of parton distributions are an important way to connect our knowledge of physics at high energy scales with physics at lower energy scales typical of nuclear physics. Earlier work on the spin-independent valence quark distributions has shown that DIS data support a bag radius around 0.8 fm, and highlighted the importance of chiral symmetry and the role of the pion cloud in nucleon structure. Here, that work is extended to the spin-dependent parton distributions. We calculate these distributions in the model and compare with experimental data.


2008 ◽  
Author(s):  
S. I. Sukhoruchkin ◽  
Sigfrido Boffi ◽  
Claudio Ciofi degli Atti ◽  
Mauro Giannini ◽  
Daniele Treleani

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