Abstract This report was prepared in the context of the LPCC Electroweak Precision Measurements at the LHC WG ( https://lpcc.web.cern.ch/lpcc/index.php?page=electroweak_wg ) and summarizes the ...activity of a subgroup dedicated to the systematic comparison of public Monte Carlo codes, which describe the Drell–Yan processes at hadron colliders, in particular at the CERN Large Hadron Collider (LHC). This work represents an important step towards the definition of an accurate simulation framework necessary for very high-precision measurements of electroweak (EW) observables such as the W boson mass and the weak mixing angle. All the codes considered in this report share at least next-to-leading-order (NLO) accuracy in the prediction of the total cross sections in an expansion either in the strong or in the EW coupling constant. The NLO fixed-order predictions have been scrutinized at the technical level, using exactly the same inputs, setup and perturbative accuracy, in order to quantify the level of agreement of different implementations of the same calculation. A dedicated comparison, again at the technical level, of three codes that reach next-to-next-to-leading-order (NNLO) accuracy in quantum chromodynamics (QCD) for the total cross section has also been performed. These fixed-order results are a well-defined reference that allows a classification of the impact of higher-order sets of radiative corrections. Several examples of higher-order effects due to the strong or the EW interaction are discussed in this common framework. Also the combination of QCD and EW corrections is discussed, together with the ambiguities that affect the final result, due to the choice of a specific combination recipe. All the codes considered in this report have been run by the respective authors, and the results presented here constitute a benchmark that should be always checked/reproduced before any high-precision analysis is conducted based on these codes. In order to simplify these benchmarking procedures, the codes used in this report, together with the relevant input files and running instructions, can be found in a repository at https://twiki.cern.ch/twiki/bin/view/Main/DrellYanComparison .
This report was prepared in the context of the LPCC Electroweak Precision Measurements at the LHC WG ( ) and summarizes the activity of a subgroup dedicated to the systematic comparison of public ...Monte Carlo codes, which describe the Drell-Yan processes at hadron colliders, in particular at the CERN Large Hadron Collider (LHC). This work represents an important step towards the definition of an accurate simulation framework necessary for very high-precision measurements of electroweak (EW) observables such as the W boson mass and the weak mixing angle. All the codes considered in this report share at least next-to-leading-order (NLO) accuracy in the prediction of the total cross sections in an expansion either in the strong or in the EW coupling constant. The NLO fixed-order predictions have been scrutinized at the technical level, using exactly the same inputs, setup and perturbative accuracy, in order to quantify the level of agreement of different implementations of the same calculation. A dedicated comparison, again at the technical level, of three codes that reach next-to-next-to-leading-order (NNLO) accuracy in quantum chromodynamics (QCD) for the total cross section has also been performed. These fixed-order results are a well-defined reference that allows a classification of the impact of higher-order sets of radiative corrections. Several examples of higher-order effects due to the strong or the EW interaction are discussed in this common framework. Also the combination of QCD and EW corrections is discussed, together with the ambiguities that affect the final result, due to the choice of a specific combination recipe. All the codes considered in this report have been run by the respective authors, and the results presented here constitute a benchmark that should be always checked/reproduced before any high-precision analysis is conducted based on these codes. In order to simplify these benchmarking procedures, the codes used in this report, together with the relevant input files and running instructions, can be found in a repository at
Heat-resistant slip coatings of the ZrB
2
–MoSi
2
–SiC system on CCCM were examined for protection of aerospace technology elements from oxidation. The following compositions (mass%) were studied as ...coating materials: 55 ZrB
2
+ 25 MoSi
2
+ 20 SiC (ZSM25), 50 ZrB
2
+ 30 MoSi
2
+ 20 SiC (ZSM30), and 45 ZrB
2
+ 35 MoSi
2
+ 20 SiC (ZSM35). Heat-treatment modes were elaborated for the coatings. The optimal method for producing heat-resistant coatings was selected. The ZSM25 coating was found to satisfy the heat-resistance assessment tests conditions in a Multiplaz 2500-m plasmatron for 20 sec at an angle of 45°, presumably by forming a highly viscous ZrSiO
4
film.
Heat-resistant slip coatings of the ZrB.sub.2-MoSi.sub.2-SiC system on CCCM were examined for protection of aerospace technology elements from oxidation. The following compositions (mass%) were ...studied as coating materials: 55 ZrB.sub.2 + 25 MoSi.sub.2 + 20 SiC (ZSM25), 50 ZrB.sub.2 + 30 MoSi.sub.2 + 20 SiC (ZSM30), and 45 ZrB.sub.2 + 35 MoSi.sub.2 + 20 SiC (ZSM35). Heat-treatment modes were elaborated for the coatings. The optimal method for producing heat-resistant coatings was selected. The ZSM25 coating was found to satisfy the heat-resistance assessment tests conditions in a Multiplaz 2500-m plasmatron for 20 sec at an angle of 45°, presumably by forming a highly viscous ZrSiO.sub.4 film.
Zγγγ → 0 Processes in SANC Bardin, D. Yu; Kalinovskaya, L. V.; Uglov, E. D.
Physics of atomic nuclei,
11/2013, Letnik:
76, Številka:
11
Journal Article
Recenzirano
Odprti dostop
We describe the analytic and numerical evaluation of the
γγ
→
γZ
process cross section and the
Z
→
γγγ
decay rate within the
SANC
system multi-channel approach at the one-loop accuracy level with all ...masses taken into account. The corresponding package for numeric calculations is presented. For checking of the results’ correctness we make a comparison with the other independent calculations.
A review of the SANC computer system intended for theoretical support of experiments at colliders is presented. The system allows the precision predictions to be obtained semiautomatically for a wide ...class of particle interaction processes within the Standard Model. In this case, one considers total contributions of one-loop radiative corrections. Basic elements of the computer system are described, and examples of using the system for the high-precision description of certain processes of the Standard Model particle interactions are given. The MCSANC code developed using the Monte Carlo simulation is presented, which is used to calculate cross sections of a number of processes, investigated at the Large Hadron Collider. The prospects of research development in this field for theoretical support at future hadron and lepton colliders are discussed.
This report was prepared in the context of the LPCC Electroweak Precision Measurements at the LHC WG (https://lpcc.web.cern.ch/lpcc/index.php?page=electroweak_wg) and summarizes the activity of a ...subgroup dedicated to the systematic comparison of public Monte Carlo codes, which describe the Drell–Yan processes at hadron colliders, in particular at the CERN Large Hadron Collider (LHC). This work represents an important step towards the definition of an accurate simulation framework necessary for very high-precision measurements of electroweak (EW) observables such as the W boson mass and the weak mixing angle. All the codes considered in this report share at least next-to-leading-order (NLO) accuracy in the prediction of the total cross sections in an expansion either in the strong or in the EW coupling constant. The NLO fixed-order predictions have been scrutinized at the technical level, using exactly the same inputs, setup and perturbative accuracy, in order to quantify the level of agreement of different implementations of the same calculation. A dedicated comparison, again at the technical level, of three codes that reach next-to-next-to-leading-order (NNLO) accuracy in quantum chromodynamics (QCD) for the total cross section has also been performed. These fixed-order results are a well-defined reference that allows a classification of the impact of higher-order sets of radiative corrections. Several examples of higher-order effects due to the strong or the EW interaction are discussed in this common framework. Also the combination of QCD and EW corrections is discussed, together with the ambiguities that affect the final result, due to the choice of a specific combination recipe. All the codes considered in this report have been run by the respective authors, and the results presented here constitute a benchmark that should be always checked/reproduced before any high-precision analysis is conducted based on these codes. In order to simplify these benchmarking procedures, the codes used in this report, together with the relevant input files and running instructions, can be found in a repository at https://twiki.cern.ch/twiki/bin/view/Main/DrellYanComparison.
We describe the analytic and numerical evaluation of the {gamma}{gamma} {yields} {gamma}Z process cross section and the Z {yields} {gamma}{gamma}{gamma} decay rate within the SANC system ...multi-channel approach at the one-loop accuracy level with all masses taken into account. The corresponding package for numeric calculations is presented. For checking of the results' correctness we make a comparison with the other independent calculations.
This report was prepared in the context of the LPCC
Electroweak Precision Measurements at the LHC WG
(
https://lpcc.web.cern.ch/lpcc/index.php?page=electroweak_wg
) and summarizes the activity of a ...subgroup dedicated to the systematic comparison of public Monte Carlo codes, which describe the Drell–Yan processes at hadron colliders, in particular at the CERN Large Hadron Collider (LHC). This work represents an important step towards the definition of an accurate simulation framework necessary for very high-precision measurements of electroweak (EW) observables such as the
W
boson mass and the weak mixing angle. All the codes considered in this report share at least next-to-leading-order (NLO) accuracy in the prediction of the total cross sections in an expansion either in the strong or in the EW coupling constant. The NLO fixed-order predictions have been scrutinized at the technical level, using exactly the same inputs, setup and perturbative accuracy, in order to quantify the level of agreement of different implementations of the same calculation. A dedicated comparison, again at the technical level, of three codes that reach next-to-next-to-leading-order (NNLO) accuracy in quantum chromodynamics (QCD) for the total cross section has also been performed. These fixed-order results are a well-defined reference that allows a classification of the impact of higher-order sets of radiative corrections. Several examples of higher-order effects due to the strong or the EW interaction are discussed in this common framework. Also the combination of QCD and EW corrections is discussed, together with the ambiguities that affect the final result, due to the choice of a specific combination recipe. All the codes considered in this report have been run by the respective authors, and the results presented here constitute a benchmark that should be always checked/reproduced before any high-precision analysis is conducted based on these codes. In order to simplify these benchmarking procedures, the codes used in this report, together with the relevant input files and running instructions, can be found in a repository at
https://twiki.cern.ch/twiki/bin/view/Main/DrellYanComparison
.
This report was prepared in the context of the LPCC Electroweak Precision Measurements at the LHC WG ( https://lpcc.web.cern.ch/lpcc/index.php?page=electroweak_wg ) and summarizes the activity of a ...subgroup dedicated to the systematic comparison of public Monte Carlo codes, which describe the Drell–Yan processes at hadron colliders, in particular at the CERN Large Hadron Collider (LHC). This work represents an important step towards the definition of an accurate simulation framework necessary for very high-precision measurements of electroweak (EW) observables such as the W boson mass and the weak mixing angle. All the codes considered in this report share at least next-to-leading-order (NLO) accuracy in the prediction of the total cross sections in an expansion either in the strong or in the EW coupling constant. The NLO fixed-order predictions have been scrutinized at the technical level, using exactly the same inputs, setup and perturbative accuracy, in order to quantify the level of agreement of different implementations of the same calculation. A dedicated comparison, again at the technical level, of three codes that reach next-to-next-to-leading-order (NNLO) accuracy in quantum chromodynamics (QCD) for the total cross section has also been performed. These fixed-order results are a well-defined reference that allows a classification of the impact of higher-order sets of radiative corrections. Several examples of higher-order effects due to the strong or the EW interaction are discussed in this common framework. Also the combination of QCD and EW corrections is discussed, together with the ambiguities that affect the final result, due to the choice of a specific combination recipe. All the codes considered in this report have been run by the respective authors, and the results presented here constitute a benchmark that should be always checked/reproduced before any high-precision analysis is conducted based on these codes. In order to simplify these benchmarking procedures, the codes used in this report, together with the relevant input files and running instructions, can be found in a repository at https://twiki.cern.ch/twiki/bin/view/Main/DrellYanComparison .
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