BUILDING THE GLUON DISTRIBUTION IN NUCLEONS

1993 ◽  
Vol 08 (16) ◽  
pp. 2779-2790 ◽  
Author(s):  
V. BARONE ◽  
M. GENOVESE ◽  
N. N. NIKOLAEV ◽  
E. PREDAZZI ◽  
B. G. ZAKHAROV
Keyword(s):  
Perturbative Qcd ◽  
Gluon Distribution ◽  
Radiative Effect ◽  
Absolute Normalization ◽  
The Absolute ◽  
Good Agreement

We present a direct perturbative QCD calculation of the gluon distribution in nucleons as a QCD radiative effect. We assume that the only infrared regulator is the nucleon's radius which emerges as a natural cutoff. A technique is introduced which allows constructing the glue step by step keeping a careful balance of valence, gluons and sea and obeying all constraints. The absolute normalization and shape of the calculated gluon distribution are in good agreement with the experimental determinations.

scholarly journals HARD-POMERON BEHAVIOR OF THE LONGITUDINAL STRUCTURE FUNCTION FL IN THE NEXT-TO-LEADING ORDER AT LOW x

2009 ◽  
Vol 18 (01) ◽  
pp. 131-140 ◽  
Author(s):  
G. R. BOROUN
Keyword(s):  
Perturbation Theory ◽  
Structure Function ◽  
Perturbative Qcd ◽  
Gluon Distribution ◽  
Analytic Formula ◽  
Leading Order ◽  
Longitudinal Structure ◽  
Longitudinal Structure Function ◽  
Low X

We present an analytic formula to extract the longitudinal structure function in the next-to-leading order of the perturbation theory at low x, from the Regge-like behavior of the gluon distribution and the structure function at this limit. In this approach, the longitudinal structure function has the hard-Pomeron behavior. The determined values are compared with the H1 data and MRST model. All results can consistently be described within the framework of perturbative QCD, which essentially show increases as x decreases.

scholarly journals Absolute Configuration of Cembrane Diterpenoids from Bursera multijuga

2014 ◽  
Vol 9 (9) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Juan D. Hernández-Hernández ◽  
Hugo A. García-Gutiérrez ◽  
Luisa U. Román-Marín ◽  
Yunuen I. Torres-Blanco ◽  
Carlos M. Cerda-García-Rojas ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Absolute Configuration ◽  
2D Nmr ◽  
Vibrational Circular Dichroism ◽  
Conformational Preference ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Absolute ◽  
First Time ◽  
Good Agreement

The stems of Bursera multijuga afforded (-)-(1 S,3 E,7 R,8 R,11 E)-7,8-epoxycembra-3,11-dien-1-ol (1) and its acetate 2, together with cembrene A (3), nephthenol (4), and cembrenol (5). The structures of 1 and 2 were elucidated by 1D and 2D NMR, HRESIMS, and X-ray diffraction. The conformational preference of flexible 1 was studied by molecular modeling at the DFT B3LYP/DGDZVP level of theory. Good agreement between calculated and experimental vibrational circular dichroism curves established the absolute configuration of 1. This is the first time that cembrane derivatives have been isolated from the genus Bursera.

scholarly journals ON THE ABSOLUTE VALUE OF THE NEUTRINO MASS

2011 ◽  
Vol 26 (21) ◽  
pp. 1555-1559 ◽  
Author(s):  
DRAGAN SLAVKOV HAJDUKOVIC
Keyword(s):  
Neutrino Mass ◽  
Neutrino Oscillations ◽  
Upper Bounds ◽  
Neutrino Mixing ◽  
Absolute Value ◽  
The Absolute ◽  
Good Agreement

The neutrino oscillations probabilities depend on mass squared differences; in the case of three-neutrino mixing, there are two independent differences, which have been measured experimentally. In order to calculate the absolute masses of neutrinos, we have conjectured a third relation, in the form of a sum of squared masses. The calculated masses look plausible and are in good agreement with the upper bounds coming from astrophysics.

scholarly journals Determination of the absolute hardness of electrolytically produced copper coatings by application of the Chicot-Lesage composite hardness model

2021 ◽  
pp. 105-105
Author(s):  
Ivana Mladenovic ◽  
Jelena Lamovec ◽  
Dana Vasiljevic-Radovic ◽  
Vesna Radojevic ◽  
Nebojsa Nikolic
Keyword(s):  
Pause Duration ◽  
Atomic Force ◽  
Copper Coatings ◽  
The Absolute ◽  
Hardness Model ◽  
Composite Hardness ◽  
Pulsating Current ◽  
Good Agreement ◽  
Coating Hardness

In this study, a novel procedure based on application of the Chicot?Lesage (C?L) composite hardness model was proposed for determination of an absolute hardness of electrolytically produced copper coatings. The Cu coatings were electrodeposited on the Si(111) substrate by the pulsating current (PC) regime with a variation of the following parameters: the pause duration, the current density amplitude and the coating thickness. The topography of produced coatings was characterized by atomic force microscope (AFM), while a hardness of the coatings was examined by Vickers microindentation test. Applying the C?L model, the critical relative indentation depth (RID)c of 0.14 was determined, which is independent of all examined parameters of the PC regime. This RID value separated the area in which the composite hardness of the Cu coating corresponded to its absolute hardness (RID < 0.14) from the area in which application of the C?L model was necessary for a determination of the absolute coating hardness (RID ? 0.14). The obtained value was in a good agreement with the value already published in the literature.

scholarly journals Conditions Involved in Dating Terrestrial Shells

Radiocarbon ◽  
1980 ◽  
Vol 22 (2) ◽  
pp. 545-555 ◽  
Author(s):  
Jacques Evin ◽  
Joëlle Marechal ◽  
Christiane Pachiaudi ◽  
J J Puissegur
Keyword(s):  
Sample Selection ◽  
Ground Surface ◽  
Hard Water ◽  
Water Effect ◽  
Terrestrial Gastropods ◽  
The Absolute ◽  
Continental Origin ◽  
Absolute Age ◽  
Good Agreement

Mollusks living only on ground surface can be expected to give the most reliable results in 14C dating from carbonates of continental origin. One may assume they have a homogeneous biotope and are not affected by any hard-water effect. In order to verify these assumptions and to test shells as routine dating material, results from terrestrial gastropods are compared with other 14C dates from classic biologic material, such as peat, charcoal, or bone, collected in the same archaeologic or geologic levels in miscellaneous places. Two sites were selected for which other chronologic data, such as prehistoric industries or malacologic diagrams were available.All results indicate older values for 14C shell dates. The discrepancy between “normal” and snail dates amounts to 300 to 1200 14C years and remains the same whatever the absolute age of the sample. All 13C values of perfectly cleaned shells are between —5 to —10%, versus PDB. The initial 14C content of shells that is too low may be different according to species, as suggested by 13C variations.Although fairly constant, this deviation of 14C ages generally makes such samples unreliable for most archaeologic studies, which often need more precise results. However, some measurements were performed on microfauna shells from several Würmian loess to show that dating of shells may be useful in fairly ancient geologic sediments for lack of better carbonaceous samples. Good agreement of some snail dates with expected sediment ages point to the importance of proper sample selection and pretreatment that might be checked by 13C measurements.

Rates of polymerization in the system styrene, p -methoxy-styrene and methyl methacrylate

1954 ◽  
Vol 227 (1168) ◽  
pp. 10-21 ◽  
Keyword(s):  
Methyl Methacrylate ◽  
Total Rate ◽  
Kinetics Of Polymerization ◽  
Component System ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems ◽  
The Absolute ◽  
Kinetics Of ◽  
Good Agreement

A study has been made of the absolute rates of polymerization in a three-component system. Theoretically, it has been shown how to compute the absolute rates if the total rate of initiation is known, provided information is available about the kinetics of polymerization of the three monomers and of the three two-component systems. The system chosen was styrene, p -methoxystyrene and methyl methacrylate, since the necessary two-component systems have already been investigated in detail. Information about the rate of initiation in the chosen mixture was obtained from the radioactive initiator technique. The experimental rates are in good agreement with those calculated from the data of the relevant one - and two-component systems.

scholarly journals The Exclusive Photoproduction of Υ(1S,2S,3S) in pp and pA Collisions at LHC Energies

2017 ◽  
Vol 45 ◽  
pp. 1760057
Author(s):  
Maria Beatriz Gay Ducati ◽  
Fabio Kopp
Keyword(s):  
Experimental Data ◽  
Gluon Distribution ◽  
Saturation Effect ◽  
Peripheral Collisions ◽  
Low X ◽  
Good Agreement ◽  
Upsilon 1S

We presented the exclusive photoproduction of Upsilon(1S,2S,3S) in pp and pA reactions at the LHC energies for Ultra Peripheral Collisions(UPC). It was calculated in the dipole formalism, with the dipoles models: GBW, CGC and b-CGC. The dipole formalism is characterised by a saturation effect, e.g, the mimic gluon distribution becomes saturated at low-x. This approach has shown a good agreement with the experimental data since HERA and with recent data released by LHCb for processes involving [Formula: see text], [Formula: see text], [Formula: see text] for UPC in pp.

scholarly journals Υ(nS)→Bc⁎π,Bc⁎KDecays with Perturbative QCD Approach

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Junfeng Sun ◽  
Yueling Yang ◽  
Qin Chang ◽  
Gongru Lu ◽  
Jinshu Huang
Keyword(s):  
Elementary Particle ◽  
Standard Model ◽  
Perturbative Qcd ◽  
Weak Interactions ◽  
Branching Ratios ◽  
Electromagnetic Decay ◽  
Decay Modes ◽  
The Standard Model ◽  
The Future ◽  
The Absolute

Besides the traditional strong and electromagnetic decay modes,Υ(nS)meson can also decay through the weak interactions within the standard model of elementary particle. With anticipation of copiousΥ(nS)data samples at the running LHC and coming SuperKEKB experiments, the two-body nonleptonic bottom-changingΥ(nS)→Bc⁎π,Bc⁎Kdecays (n=1,2,3) are investigated with perturbative QCD approach firstly. The absolute branching ratios forΥ(nS)→Bc⁎πandBc⁎Kdecays are estimated to reach up to about10-10and10-11, respectively, which might possibly be measured by the future experiments.

scholarly journals The density of seawater as a function of salinity (5 to 70 g kg

2009 ◽  
Vol 6 (1) ◽  
pp. 153-169 ◽  
Author(s):  
F. J. Millero ◽  
F. Huang
Keyword(s):  
Equation Of State ◽  
High Temperatures ◽  
Pure Water ◽  
Standard Errors ◽  
Density Measurements ◽  
The Absolute ◽  
Good Agreement

Abstract. New seawater density measurements were made as a function of temperature (0 to 90°C) and salinity (5 to 70). The measurements (N=230) from 0 to 40°C and Practical Salinity from 0 to 40 were found to be in good agreement (σ=0.0036) with the equation of state of seawater (Millero and Poisson, 1981) made on samples with a known chlorinity (Cl). These results indicate that the Practical Salinities (S) are in agreement to within ±0.003 with the values calculated from the Chlorinity, SCl=1.80655 Cl. The measurements from 25 to 90°C were used to extend the equation of state to high temperatures and salinities. All the relative densities (ρ−ρ0, where ρ0 is the density for pure water) were fitted to equations of the form (ρ−ρ0)/kg m−3 = ASA + BSA0.5 + CSA2 where A, B, and C are functions of temperature and SA (g kg−1) is the absolute salinity, SA=(35.16504/35)S. The fitted results from SA=0 to 50 and 0 to 40°C (N=247) gave standard errors of 0.0037 kg m−3. The fitted results from 25 to 90°C (N=271) gave standard errors of 0.0063 kg m−3 and all the results (N=501) from 0 to 90°C gave standard errors of 0.0062 kg m−3. The earlier density measurements used to determine the equation of state of seawater were combined to derive equations that are valid from 0 to 40°C and 0 to 90°C. The standard errors of these fits are, respectively, 0.0038 kg m−3 (N=713) and 0.0063 kg m−3 (N=962). These new measurements expand the equation of state of seawater to a wider range of temperature (0 to 90°C) and absolute salinity (0 to 70).

scholarly journals Spatiotemporal variations of NO<sub>y</sub> species in the northern latitudes stratosphere measured with the balloon-borne MIPAS instrument

2008 ◽  
Vol 8 (2) ◽  
pp. 4693-4725
Author(s):  
A. Wiegele ◽  
A. Kleinert ◽  
H. Oelhaf ◽  
R. Ruhnke ◽  
G. Wetzel ◽  
...  
Keyword(s):  
Cross Section ◽  
Continuous Measurement ◽  
Temporal Evolution ◽  
Polar Vortex ◽  
Spatiotemporal Distribution ◽  
Spatiotemporal Variations ◽  
Temperature Variations ◽  
Northern Latitudes ◽  
The Absolute ◽  
Good Agreement

Abstract. This paper presents the spatiotemporal distribution of NOy species at altitudes between 14 and 31 km as measured with the MIPAS-B instrument on the morning of 21 March 2003 in northern Scandinavia. At lower altitudes, temperature variations and the distribution of ClONO2 and the tracer N2O reveal the dynamics along the cross section through the edge of the late arctic polar vortex. At higher altitudes, continuous measurement before, during, and after sunrise provides information about photochemistry illustrating the evolution of the photochemically active gases NO2 and N2O5 around sunrise. The measured temporal evolution of NO2 and N2O5 is compared to box modelling that is run along backward calculated trajectories. With regard to NO2, there is a good agreement between the model and observations in terms of quantity but the photochemistry in the model is slightly too slow. The comparison of measured and modelled N2O5, however, reveals significant differences of the absolute quantities pointing at a too slow photochemistry in the model.

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