scholarly journals A Novel Feature of Valence Quark Distributions in Hadrons

Physics ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 913-923
Author(s):  
Christopher Leon ◽  
Misak M. Sargsian ◽  
Frank Vera
Keyword(s):  
Valence Quark ◽  
Quark Distribution ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Exponential Form ◽  
Similar Relation ◽  
Analytic Behavior ◽  
Model Independent ◽  
Bjorken X ◽  
Parameter Function

Examining the evolution of the maximum of valence quark distribution, qV, weighted by Bjorken x, h(x,t)≡xqV(x,t), it is observed that h(x,t) at the peak becomes a one-parameter function; h(xp,t)=Φ(xp(t)), where xp is the position of the peak, t=logQ2, and Q2 is the resolution scale. This observation is used to derive a new model-independent relation which connects the partial derivative of the valence parton distribution functions (PDFs) in xp to the quantum chromodynamics (QCD) evolution equation through the xp derivative of the logarithm of the function Φ(xp(t)). A numerical analysis of this relation using empirical PDFs results in an observation of the exponential form of the Φ(xp(t))=h(xp,t)=CeDxp(t) for leading to next-to-next leading order approximations of PDFs for the range of Q2, covering four orders in magnitude. The exponent, D, of the observed “height-position” correlation function converges with the increase in the order of approximation. This result holds for all the PDF sets considered. A similar relation is observed also for the pion valence quark distribution, indicating that the obtained relation may be universal for any non-singlet partonic distribution. The observed “height-position” correlation is used also to indicate that no finite number of exchanges can describe the analytic behavior of the valence quark distribution at the position of the peak at fixed Q2.

scholarly journals An analysis of parton distribution functions of the pion and the kaon with the maximum entropy input

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Chengdong Han ◽  
Gang Xie ◽  
Rong Wang ◽  
Xurong Chen
Keyword(s):  
Parton Distribution ◽  
Valence Quark ◽  
Quark Distribution ◽  
Parton Model ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Theoretical Predictions ◽  
Gluon Distributions ◽  
Qcd Analysis ◽  
Mass Dependent

AbstractWe present pion and kaon parton distribution functions from a global QCD analysis of the experimental data within the framework of dynamical parton model. We use the DGLAP equations with parton–parton recombination corrections and the valence input of uniform distribution which maximizes the information entropy. At our input scale $$Q_0^2$$ Q 0 2 , there are no sea quark and gluon distributions. All the sea quarks and gluons of the pion and the kaon are completely generated from the parton splitting processes. The mass-dependent parton splitting kernel is applied for the strange quark distribution in the kaon. The obtained valence quark and sea quark distributions at high $$Q^{2}$$ Q 2 ($$Q^2>5$$ Q 2 > 5 GeV$$^2$$ 2 ) are compatible with the existed experimental measurements. Furthermore, the asymptotic behaviours of parton distribution functions at small and large x have been studied for both the pion and the kaon. Lastly, the first three moments of parton distributions at high $$Q^{2}$$ Q 2 scale are calculated, which are consistent with other theoretical predictions.

scholarly journals Impact of the top quark cross-section data on parton distribution functions

2018 ◽  
Vol 33 (24) ◽  
pp. 1850142 ◽  
Author(s):  
M. Azizi ◽  
A. Khorramian ◽  
H. Abdolmaleki ◽  
S. Paktinat Mehdiabadi
Keyword(s):  
Cross Section ◽  
Top Quark ◽  
Parton Distribution ◽  
Valence Quark ◽  
Quark Distribution ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Top Quark Production ◽  
Quark Production ◽  
The Impact

Recent measurements of top quark pair production cross-section, which is performed at the LHC and the Tevatron collider, are studied using Hessian profiling technique to obtain their impact on the parton distribution functions (PDFs). The top quark production data covers different center-of-mass energies [Formula: see text], 5.02, 7, 8 and 13 TeV in either [Formula: see text] or [Formula: see text] collisions. It is explained how the Hessian profiling method may be used to assess the impact of these new data on PDFs and consequently on their predictions. In this research, the impact of recent measurements of top quark pair cross-sections on different CT14, MMHT2014 and NNPDF3.0 PDF sets is investigated. The analysis results show that the recent top quark production at the LHC and Tevatron data provide significant constraints in particular on the central value, relative uncertainties or both for the [Formula: see text]-quark distribution and the gluon PDFs in both CT14 and MMHT2014 PDF sets and are insensitive to valence-quark PDFs. A small constraint on the [Formula: see text]-sea quark distribution for CT14 PDF is also observed. There is no impact on the NNPDF3.0 PDF set in presence of these data.

scholarly journals Valence-quark distribution functions in the kaon and pion

2016 ◽  
Vol 93 (7) ◽  
Author(s):  
Chen Chen ◽  
Lei Chang ◽  
Craig D. Roberts ◽  
Shaolong Wan ◽  
Hong-Shi Zong
Keyword(s):  
Valence Quark ◽  
Quark Distribution ◽  
Distribution Functions

scholarly journals STRUCTURE FUNCTIONS

2009 ◽  
Vol 24 (06) ◽  
pp. 1069-1086 ◽  
Author(s):  
CRISTINEL DIACONU
Keyword(s):  
Cross Sections ◽  
Structure Functions ◽  
Distribution Functions ◽  
Final States ◽  
Parton Distribution Functions ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Proton Collisions ◽  
Bjorken X ◽  
Proton Proton Collisions

Recent progress in the understanding of the nucleon is presented. The unpolarized structure functions are obtained with unprecedented precision from the combined H1 and ZEUS data and are used to extract proton parton distribution functions via NLO QCD fits. The obtained parametrization displays an improved precision, in particular at low Bjorken x, and leads to precise predictions of cross-sections for LHC phenomena. Recent data from proton–antiproton collisions at Tevatron indicate further precise constraints at large Bjorken x. The flavor content of the proton is further studied using final states with charm and beauty in DIS ep and [Formula: see text] collisions. Data from polarized DIS or proton–proton collisions are used to test the spin structure of the proton and to constrain the polarized parton distributions.

scholarly journals LORENTZ INVARIANCE RELATIONS AND WANDZURA–WILCZEK APPROXIMATION

2009 ◽  
Vol 24 (35n37) ◽  
pp. 2950-2959 ◽  
Author(s):  
T. TECKENTRUP ◽  
A. METZ ◽  
P. SCHWEITZER
Keyword(s):  
Parton Distribution ◽  
Lorentz Invariance ◽  
Distribution Functions ◽  
Complete List ◽  
Parton Distribution Functions ◽  
Sum Rule ◽  
Model Independent

A complete list of the so-called Lorentz invariance relations between parton distribution functions is given and some of their consequences are discussed, such as the Burkhardt-Cottingham sum rule. The violation of these relations is considered in a model independent way. It is shown that several Lorentz invariance relations are not violated in a generalized Wandzura–Wilczek approximation, indicating that numerically their violation may be small.

EXTRACTING GLUON FRAGMENTATION FUNCTIONS IN HADRON-HADRON COLLISIONS

1989 ◽  
Vol 04 (06) ◽  
pp. 1485-1491
Author(s):  
DONGSHENG DU ◽  
YUZHEN GE ◽  
MA LUO
Keyword(s):  
Valence Quark ◽  
Quark Distribution ◽  
Structure Functions ◽  
Distribution Functions ◽  
Pp Collisions ◽  
Fragmentation Functions ◽  
Gluon Fragmentation ◽  
Better Than

Two methods for extracting gluon fragmentation functions in π±p, [Formula: see text] and pp collisions are proposed. The only inputs are valence-quark distribution functions which we know much better than other structure functions and fragmentation functions. So better extraction of gluon fragmentation functions can be obtained.

RECENT PROGRESS ON NUCLEON STRUCTURE WITH LATTICE QCD

2014 ◽  
Vol 25 ◽  
pp. 1460039 ◽  
Author(s):  
HUEY-WEN LIN
Keyword(s):  
Lattice Qcd ◽  
Parton Distribution ◽  
Recent Progress ◽  
Distribution Functions ◽  
Nucleon Structure ◽  
Matrix Elements ◽  
Parton Distribution Functions ◽  
Bjorken X ◽  
Systematic Control ◽  
Made In

I review recent progress made in the calculation of nucleon structure in lattice QCD. Due to space limitations, I will focus on a few specific topics: systematic control of lattice-QCD matrix elements, probing TeV-physics with the aid of nucleon tensor and scalar charges, and Bjorken-x dependence of nucleon parton distribution functions.

scholarly journals Pion and kaon valence-quark parton distribution functions

2011 ◽  
Vol 83 (6) ◽  
Author(s):  
Trang Nguyen ◽  
Adnan Bashir ◽  
Craig D. Roberts ◽  
Peter C. Tandy
Keyword(s):  
Parton Distribution ◽  
Valence Quark ◽  
Distribution Functions ◽  
Parton Distribution Functions
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