scholarly journals INTERACTION OF TACHYONS WITH MATTER

1999 ◽  
Vol 14 (32) ◽  
pp. 5137-5157 ◽  
Author(s):  
ROMAN TOMASCHITZ
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Energy Levels ◽  
Interaction Mechanism ◽  
Coupling Constant ◽  
Large Impact Parameter ◽  
Hydrogenic Ions ◽  
The Impact ◽  
Static Point ◽  
Classical Cross

A new interaction mechanism of superluminal particles with matter is suggested. Tachyons are described by a real Proca field with negative mass square, coupled to a current of subluminal matter. The potential of a static point source in this field theory is a damped periodic function with 1/r-decay. We treat this potential as a perturbation of the Coulomb potential, and study its effects on cross-sections and energy levels. In the limit of large impact parameter, the periodicity of the potential has a pronounced effect on the classical cross-section, which gets singular at the accumulating extrema of the scattering angle. In this limit we define the cross-section wave mechanically, by semiclassical rainbow scattering. The impact of the tachyon potential on the energy levels of hydrogen and hydrogenic ions is calculated by means of Bohr–Sommerfeld quantization. Estimates for the tachyon mass (3 keV) and the coupling constant of the tachyon potential are derived on the basis of high-precision Lamb shift measurements.

scholarly journals Charged current Drell-Yan production at N3LO

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Claude Duhr ◽  
Falko Dulat ◽  
Bernhard Mistlberger
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Production Cross Section ◽  
Production Cross ◽  
Hadron Collider ◽  
Charge Asymmetry ◽  
Charged Current ◽  
Leading Order ◽  
Neutrino Pair ◽  
The Impact

Abstract We present the production cross section for a lepton-neutrino pair at the Large Hadron Collider computed at next-to-next-to-next-to-leading order (N3LO) in QCD perturbation theory. We compute the partonic coefficient functions of a virtual W± boson at this order. We then use these analytic functions to study the progression of the perturbative series in different observables. In particular, we investigate the impact of the newly obtained corrections on the inclusive production cross section of W± bosons, as well as on the ratios of the production cross sections for W+, W− and/or a virtual photon. Finally, we present N3LO predictions for the charge asymmetry at the LHC.

scholarly journals Application of the EGPT methodology in the analysis of small-sample reactivity worth experiments

2018 ◽  
Vol 4 ◽  
pp. 44 ◽  
Author(s):  
Pierre Leconte ◽  
Jean Tommasi ◽  
Alain Santamarina ◽  
Patrick Blaise ◽  
Paul Ros
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Capture Cross Section ◽  
Reference Sample ◽  
Small Sample ◽  
Capture Cross ◽  
Theoretical Formulation ◽  
Sensitivity Coefficients ◽  
Spectrum Experiment ◽  
The Impact

In the current paper, we investigate the application of the Equivalent Generalized Perturbation Theory (EGPT) to derive trends and associated covariances on the neutron capture cross section of one major fission product for both light water reactors and sodium-cooled fast reactors which is Rhodium-103. To do so, we have considered the ERMINE-V/ZONA1 & ZONA3 fast spectrum experiment and the MAESTRO thermal-spectrum experiment, where samples of these materials were oscillated in the MINERVE facility. In the paper, the theoretical formulation of EPGT is described and its derivation in the special case of the close loop oscillation technique where the reactivity worth is determined thanks to a power control system. A numerical benchmark is presented to assess the relevance of sensitivity coefficients provided by EGPT against direct perturbations where the microscopic cross sections are manually changed before calculating the adjoint and forward flux. The breakdown between direct and indirect contributions in the sensitivity analysis of the sample reactivity worth is presented and discussed, with the impact of using a calibration reference sample to normalize the measured reactivity worth. Finally, the assimilation of integral trends is done with the CONRAD code, using C/E comparisons between TRIPOLI4/JEFF3.2 calculations and experimental results and the sensitivity coefficients provided by the EGPT. Preliminary results of this study are showing that the JEFF3.2 evaluation of 103Rh gives satisfactory agreements in both thermal and fast spectrum experiments and that the combination of them can lead to a significant uncertainty reduction on the capture cross section, from ±5% to ±3% in the resolved resonance range (1 eV–10 keV) and from ±8% to ±5% in the unresolved resonance range (10 keV–1 MeV).

QCD JETS AT HERA I.: O(αs) RADIATIVE CORRECTIONS TO ELECTROWEAK CROSS SECTIONS AND JET RATES

1989 ◽  
Vol 04 (07) ◽  
pp. 1781-1825 ◽  
Author(s):  
JÜRGEN G. KÖRNER ◽  
ERWIN MIRKES ◽  
GERHARD A. SCHULER
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Neutral Current ◽  
High Energy ◽  
Coupling Constant ◽  
Bjorken Scaling ◽  
Born Cross Section ◽  
Wide Range ◽  
Lepton Polarization ◽  
Jet Cross Sections

We present the complete O(αs) corrections to the electroweak cross sections of both neutral current and charged current deep inelastic e±p scattering including lepton polarization effects. Changes in the cross section due to the inclusion of next-to-leading-log (NLL) effects are parametrized by K factors, which are defined as the ratio of the NLL O(αs) cross sections and the Born cross section. Using the standard redefinition scheme of the parton densities, we find that the K factors deviate substantially from unity for small values of the Bjorken-Scaling variable x. We also elaborate on problems that arise when defining jet cross sections in ep scattering and present numerical results for the O(αs) 3-jet and 2-jet rates. We observe that the Q2-dependence of the 3-jet rate is dominated by the running strong coupling constant αs(Q2) allowing for its determination over a wide range in Q2 at high energy ep colliders.

Finite Element Analysis on the Blast Resistant Performance of Multibarrel Tube-Confined Concrete Column in Different Cross-Sections

2013 ◽  
Vol 721 ◽  
pp. 545-550
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Er Gang Xiong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detonation Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Failure Modes ◽  
Circular Cross Section ◽  
Blast Load ◽  
Element Analysis ◽  
The Impact

Based on the finite element analysis software ANSYS/LS-DYNA, this paper numerically analyzed the dynamic performance of MTCCCs with different cross sections under blast load, followed by the study and comparison on the differences of the detonation wave propagation and failure modes between the columns in circular cross section and square cross section. The results show: The blast resistant performance of the circular component is more superior than the square component for its better aerodynamic shape that can greatly reduce the impact of the detonation wave on the column; The main difference of the failure modes between the circular and square cross-sectional components under blast load lies in the different failure mode of the outer steel tube. The simulation results in this paper can provide some references for the blast resisting design of MTCCCs.

scholarly journals Power corrections in a transverse-momentum cut for vector-boson production at NNLO: the qg-initiated real-virtual contribution

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Carlo Oleari ◽  
Marco Rocco
Keyword(s):  
Transverse Momentum ◽  
Cross Section ◽  
Cross Sections ◽  
Vector Boson ◽  
Analytic Form ◽  
Leading Order ◽  
Coupling Constant ◽  
Subtraction Method ◽  
Power Corrections ◽  
Interference Contribution

AbstractWe consider the production of a vector boson (Z, $$W^\pm $$ W ± or $$\gamma ^*$$ γ ∗ ) at next-to-next-to-leading order in the strong coupling constant $$\alpha _\mathrm{S}$$ α S . We impose a transverse-momentum cutoff, $$q_{\mathrm{T}}^{\mathrm{cut}}$$ q T cut , on the vector boson produced in the qg-initiated channel. We then compute the power corrections in the cutoff, up to the second power, of the real-virtual interference contribution to the cumulative cross section at order $$\alpha _\mathrm{S}^2$$ α S 2 . Other terms with the same kinematics, originating from the subtraction method applied to the double-real contribution, have been also considered. The knowledge of such power corrections is a required ingredient in order to reduce the dependence on the transverse-momentum cutoff of the QCD cross sections at next-to-next-to-leading order, when the $$q_{\mathrm{T}}$$ q T -subtraction method is applied. In addition, the study of the dependence of the cross section on $$q_{\mathrm{T}}^{\mathrm{cut}}$$ q T cut allows as well for an understanding of its behaviour in the small transverse-momentum limit, giving hints on the structure at all orders in $$\alpha _\mathrm{S}$$ α S and on the identification of universal patterns. Our result are presented in an analytic form, using the process-independent procedure described in a previous paper for the calculation of the all-order power corrections in $$q_{\mathrm{T}}^{\mathrm{cut}}$$ q T cut .

scholarly journals Evaluation of Flow Resistance Models Based on Field Experiments in a Partly Vegetated Reclamation Channel

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 47 ◽  
Author(s):  
Giuseppe Francesco Cesare Lama ◽  
Alessandro Errico ◽  
Simona Francalanci ◽  
Luca Solari ◽  
Federico Preti ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Flow Resistance ◽  
Field Experiments ◽  
Common Reed ◽  
Cross Sectional ◽  
Riparian Plants ◽  
Water Level Measurements ◽  
The Impact ◽  
Resistance Coefficients

This study presents a methodology for improving the efficiency of Baptist and Stone and Shen models in predicting the global water flow resistance of a reclamation channel partly vegetated by rigid and emergent riparian plants. The results of the two resistance models are compared with the measurements collected during an experimental campaign conducted in a reclamation channel colonized by Common reed (Phragmites australis (Cav.) Trin. ex Steud.). Experimental vegetative Chézy’s flow resistance coefficients have been retrieved from the analysis of instantaneous flow velocity measurements, acquired by means of a downlooking 3-component acoustic Doppler velocimeter (ADV) located at the channel upstream cross section, and by water level measurements obtained through four piezometers distributed along the reclamation channel. The main morphometrical vegetation features (i.e., stem diameters and heights, and bed surface density) have been measured at six cross sections of the vegetated reclamation channel. Following the theoretical assumptions of the divided channel method (DCM), three sub-sections have been delineated in the reference cross section to represent the impact of the partial vegetation cover on the cross sectional variability of the flow field, as observed with the ADV measurements. The global vegetative Chézy’s flow resistance coefficients have been then computed by combining each resistance model with four different composite cross section methods, respectively suggested by Colebatch, Horton, Pavlovskii, and Yen. The comparative analysis between the modeled and the experimental vegetative Chézy’s coefficients has been performed by computing the relative prediction error (εr, expressed in %) under two flow rate regimes. Stone and Shen model combined with the Horton composite cross section method provides vegetative Chézy’s coefficients with the lowest εr.

Cross Section Measurements for the 103Rh(n,n′)103Rhm Reaction from 0.122 to 14.74 MeV

1974 ◽  
Vol 52 (15) ◽  
pp. 1421-1428 ◽  
Author(s):  
D. C. Santry ◽  
J. P. Butler
Keyword(s):  
Neutron Flux ◽  
Cross Section ◽  
Neutron Spectrum ◽  
Cross Sections ◽  
Energy Levels ◽  
Effective Cross Section ◽  
Fission Neutron ◽  
Activation Method ◽  
Excitation Curve ◽  
Fission Neutron Spectrum

Cross sections for the production of 103Rhm were measured by the activation method. At energies below 5.3 MeV the neutron flux was measured with a calibrated neutron long counter, while at higher energies, measurements were made relative to the known cross section for the 32S(n,p)32P reaction. The shape of the Rh excitation curve is discussed in terms of known energy levels in 103Rh. An effective cross section for a 235U fission neutron spectrum calculated from the measured excitation curve is 724 ± 43 mb.

scholarly journals Riverbed Erosion Analysis of Winongo River Using HEC-RAS 5.0.7

2021 ◽  
Vol 933 (1) ◽  
pp. 012026
Author(s):  
P Harsanto ◽  
Nursetiawan ◽  
B P Kamiel ◽  
I Cahyani
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Return Period ◽  
Negative Impact ◽  
Retaining Wall ◽  
Small Rivers ◽  
The People ◽  
Sand And Gravel ◽  
The Impact ◽  
Debris Floods

Abstract Winongo River originates from small rivers on the slopes of Mount Merapi. This creates potential debris floods that will carry material such as sand and gravel, which can cause erosion and sedimentation in rivers. Riverbed erosion is the process of transporting materials on the riverbed that causing the elevation on the riverbed to fall. If the riverbed elevation decreases, it will cause the retaining wall building to become unstable and collaps. If this happens, it will have a negative impact on the people who live along the riverbanks. The impact of erosion and erosion analysis at the bottom of Winongo River is carried out using HEC-RAS 5.0.7. There are 200 cross-sections that had been analyzed. The analysis reveals that the locations have the potential of erosion on the riverbed and the damage that can occur in the riverbank. From the results of the analysis that have been carried out using the 2-year return period (Q2), there are erosion in 9 cross-sections on Winongo River which is located in Bambanglipuro District and Jl. Parangtritis. The depth of erosion that occurs reaches 0.96 m in the cross-section WN 173. The erosion causes damage to the retaining wall, such as cracks, flattening, and collaps.

scholarly journals Determination of Reinforced Concrete Rectangular Sections Having Plastic Moments Equal to all IPE Profiles

2021 ◽  
Vol 7 (4) ◽  
pp. 614-632
Author(s):  
Sayeh Beroual ◽  
Mohamed Laid Samai
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Cross Sections ◽  
Steel Structures ◽  
Structural Elements ◽  
Great Precision ◽  
Design Charts ◽  
Eurocode 2 ◽  
The Impact

The comparison between steel structures and reinforced concrete structures has always been governed by economy and response to earthquake. Steel structures being lighter and are thus more efficient to resist earthquake. On the other hand, they are more expensive (4 to 5 times). Theoretically, two structural elements having the same plastic moment have an equal failure or collapse load. Different profiles of IPE are realized in industry and all their characteristics are determined with a great precision (weight, geometrical characteristics and thus their plastic moment). Determining equivalent rectangular singly reinforced concrete cross-sections is not easy and seems impossible to be solved analytically. To a given profile it may be found a multitude of equivalent rectangular reinforced concrete cross-section (singly and doubly reinforced with different yield strengths and compositions of concrete). To take into consideration all these factors, it is absolutely necessary to construct three axis design charts with an appropriate choice of system of coordinates in order to cover all possible ranges of different parameters. The choice of all these possible rectangular reinforced concrete sections is governed by the plastic performance of these later. They must be under reinforced, allowing plastification of steel before failure in order to permit the redistribution phenomenon in plastic analysis. The exploitation of these different charts has revealed that the absolute majority of these rectangular reinforced concrete cross-section are reasonably well designed and are in conformity with the dimensions used in practice. The results of the present characterization using Eurocode 2 characteristics are compared to those of CP110. The impact does not seem to be very relevant. Doi: 10.28991/cej-2021-03091677 Full Text: PDF

scholarly journals CONSIDERATION OF THE IMPACT OF HIGH HARMONICS WHEN SELECTING THE CONDUCTOR CROSS-SECTIONS OF LINES OF OUTDOOR LIGHTING

2017 ◽  
Vol 60 (6) ◽  
pp. 544-557 ◽  
Author(s):  
V. B. Kozlovskaya ◽  
V. N. Kalechyts
Keyword(s):  
High Pressure ◽  
Cross Section ◽  
Cross Sections ◽  
Operating Mode ◽  
Correct Choice ◽  
Light Sources ◽  
High Harmonics ◽  
Phase Conductors ◽  
Comparison Of The Results ◽  
The Impact

The operating mode of the lighting line depends on the correct choice of conductor cross section. The magnitude of the cross section has an influence on the provision of the required voltage levels on the light sources. The choice of the conductor cross section has been fulfilled based on calculations of the operating mode of the standard line of outdoor lighting specified in the article. Luminaries with high pressure sodium lamps connected through electromagnetic ballasts were used as sources of light. When choosing the conductor cross section of light lines a number of simplifications are commonly used. Attention is paid to the choice of sections without such assumptions: the inductive resistance of conductors is taken into account; the power of the luminaire depends on the voltage level in it. Luminaries with high pressure sodium lamps are the sources of high harmonics. Three variants of calculation are demonstrated depending on the accounting (or non-accounting) of high odd harmonics. The methods of calculating the mode of the lighting line are also presented in the article. The calculation is performed with the aid of Mathcad software. Operating parameters for each phase of the line (i.e. voltage in the items of the scheme, power, currents, power, and voltage losses in all the sections) were determined. The diagrams of the voltage distribution at items of the lighting line for three variants of calculation are plotted for various sections of aluminum conductors. On this basis the choice of the optimum magnitude of the conductor cross section of the lighting line was made. The obtained results of different calculation variants are compared. The comparison of the results obtained with the use of various methods of calculation was made. The impact of high harmonics on the operating mode of the line under consideration has been analyzed. The presence of high harmonics causes an increase of voltage losses, the distortion of sinusoidal voltage. The current of neutral conductor is comparable with the current of phase conductors, besides, the harmonics multiple of 3 are of great importance as they influence on the magnitude of the current.

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