scholarly journals New approach to hard corrections in precision QCD for LHC and FCC physics

2016 ◽  
Vol 31 (22) ◽  
pp. 1650126
Author(s):  
B. F. L. Ward
Keyword(s):  
Hadron Collider ◽  
High Energy ◽  
Lepton Pairs ◽  
General Applicability ◽  
New Approach ◽  
Lhc Physics ◽  
Fixed Order ◽  
Obvious Generalization ◽  
Single Formula

We present a new approach to the realization of hard fixed-order corrections in predictions for the processes probed in high energy colliding hadron beam devices, with some emphasis on the large hadron collider (LHC) and the future circular collider (FCC) devices. We show that the usual unphysical divergence of such corrections as one approaches the soft limit is removed in our approach, so that we would render the standard results to be closer to the observed exclusive distributions. We use the single [Formula: see text] production and decay to lepton pairs as our prototypical example, but we stress that the approach has general applicability. In this way, we open another part of the way to rigorous baselines for the determination of the theoretical precision tags for LHC physics, with an obvious generalization to the FCC as well.

scholarly journals Interplay between IR-improved DGLAP-CS theory and the precision of an NLO ME matched parton shower MC in relation to LHCb data

2016 ◽  
Vol 31 (11) ◽  
pp. 1650063 ◽  
Author(s):  
A. Mukhopadhyay ◽  
B. F. L. Ward
Keyword(s):  
Phase Space ◽  
Hadron Collider ◽  
Current Status ◽  
Event Generator ◽  
Lepton Pairs ◽  
Atlas Data ◽  
Theoretical Predictions ◽  
Lhc Physics ◽  
Important Addition ◽  
Single Formula

We use comparison with recent LHCb data on single [Formula: see text] production and decay to lepton pairs as a vehicle to study the current status of the application of our approach of exact amplitude-based resummation in quantum field theory to precision quantum chromodynamics (QCD) calculations, by realistic MC event generator methods, as needed for precision large hadron collider (LHC) physics. This represents an extension of the phase space of our previous studies based on comparison with CMS and ATLAS data, as the pseudo-rapidity range measured by the LHCb for leptons in the data we study is 2.0 [Formula: see text] 4.5 to be compared with [Formula: see text] 4.6(2.4) in our previous CMS(ATLAS) data comparison for the same processes. To be precise, for [Formula: see text] decays, the CMS data had [Formula: see text] 2.1 while, for [Formula: see text] decays, the CMS data had [Formula: see text] 2.1 for both leptons for the [Formula: see text][Formula: see text] spectrum and had one lepton with [Formula: see text] 2.5 and one with [Formula: see text] 4.6 for the [Formula: see text] rapidity spectrum. The analyses we present here with the LHCb data thus represent an important addition to our previous results, as it is essential that theoretical predictions be able to control all of the measured phase space at LHC. The level of agreement between the new theory and the data continues to be a reason for optimism.

Determination of 18O by prompt nuclear reaction analysis: application for measurement of microsamples

1987 ◽  
Vol 63 (3) ◽  
pp. 1296-1302 ◽  
Author(s):  
S. D. Bradshaw ◽  
D. Cohen ◽  
A. Katsaros ◽  
J. Tom ◽  
F. J. Owen
Keyword(s):  
Los Angeles ◽  
Nuclear Reaction ◽  
Biological Fluids ◽  
Total Error ◽  
High Energy ◽  
Alpha Particles ◽  
Nuclear Reaction Analysis ◽  
General Applicability ◽  
Biological Studies

A method is described for the routine determination of 18O concentrations in microsamples of biological fluids. The method utilizes the prompt nuclear reaction 18O(p, alpha o)15N, and 846-keV protons from a 3-MeV Van de Graaff Accelerator are focused on approximately 2,000-A-thick Ta2O5 targets prepared by anodic oxidation from 50-microliter samples of water distilled from blood or other biological fluids. The broad cross section of the resonance peak for this nuclear reaction (47 keV) ensures high yields, especially at small reaction angles, and the high-energy alpha particles produced by the reaction (4 MeV) are readily separated from scattered protons by the use of an aluminized Mylar foil of suitable thickness. Background levels of 18O (0.204 atom%) can be detected with run times of approximately 5–8 min, and the sensitivity of the method is of the order of 0.05 atom %. Experimental error due to sample preparation was found to be 1.7%, and counting errors were close to theoretical limits so that total error was of the order of 2.5%. Duplicate samples were analyzed by use of the 18O(p, alpha o)15N reaction at Lucas Heights, Australia, and the 18O(p,n)18F reaction by the method of Wood et al. (Anal. Chem. 47: 646–650, 1975) at the University of California, Los Angeles, and the agreement was excellent (y = 1.0123x - 0.0123, r = 0.991, P less than 0.001). The theoretical limitations and the general applicability of the method in biological studies designed to estimate the rate of metabolism of free-ranging animals are discussed.

A new approach to the determination of atomic-architecture of amorphous zeolite precursors by high-energy X-ray diffraction technique

2006 ◽  
Vol 8 (2) ◽  
pp. 224-227 ◽  
Author(s):  
Toru Wakihara ◽  
Shinji Kohara ◽  
Gopinathan Sankar ◽  
Seijiro Saito ◽  
Manuel Sanchez-Sanchez ◽  
...  
Keyword(s):  
High Energy ◽  
X Ray Diffraction ◽  
New Approach ◽  
X Ray ◽  
Zeolite Precursors

scholarly journals Combined subleading high-energy logarithms and NLO accuracy for W production in association with multiple jets

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Jeppe R. Andersen ◽  
James A. Black ◽  
Helen M. Brooks ◽  
Emmet P. Byrne ◽  
Andreas Maier ◽  
...  
Keyword(s):  
Phase Space ◽  
Hadron Collider ◽  
High Energy ◽  
Logarithmic Order ◽  
Order Accuracy ◽  
Logarithmic Corrections ◽  
Multiple Jets ◽  
Fixed Order ◽  
Two Jets ◽  
Logarithmic Accuracy

Abstract Large logarithmic corrections in $$ \hat{s}/{p}_t^2 $$ s ̂ / p t 2 lead to substantial variations in the perturbative predictions for inclusive W-plus-dijet processes at the Large Hadron Collider. This instability can be cured by summing the leading-logarithmic contributions in $$ \hat{s}/{p}_t^2 $$ s ̂ / p t 2 to all orders in αs. As expected though, leading logarithmic accuracy is insufficient to guarantee a suitable description in regions of phase space away from the high energy limit.We present (i) the first calculation of all partonic channels contributing at next-to-leading logarithmic order in W-boson production in association with at least two jets, and (ii) bin-by-bin matching to next-to-leading fixed-order accuracy. This new perturbative input is implemented in High Energy Jets, and systematically improves the description of available experimental data in regions of phase space which are formally subleading with respect to $$ \hat{s}/{p}_t^2 $$ s ̂ / p t 2 .

scholarly journals A first determination of parton distributions with theoretical uncertainties

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Rabah Abdul Khalek ◽  
Richard D. Ball ◽  
Stefano Carrazza ◽  
Stefano Forte ◽  
Tommaso Giani ◽  
...  
Keyword(s):  
Covariance Matrix ◽  
Hadron Collider ◽  
Distribution Functions ◽  
Leading Order ◽  
Parton Distribution Functions ◽  
Parton Distributions ◽  
Central Values ◽  
Sources Of Uncertainty ◽  
Fixed Order

Abstract The parton distribution functions (PDFs) which characterize the structure of the proton are currently one of the dominant sources of uncertainty in the predictions for most processes measured at the Large Hadron Collider (LHC). Here we present the first extraction of the proton PDFs that accounts for the missing higher order uncertainty (MHOU) in the fixed-order QCD calculations used in PDF determinations. We demonstrate that the MHOU can be included as a contribution to the covariance matrix used for the PDF fit, and then introduce prescriptions for the computation of this covariance matrix using scale variations. We validate our results at next-to-leading order (NLO) by comparison to the known next order (NNLO) corrections. We then construct variants of the NNPDF3.1 NLO PDF set that include the effect of the MHOU, and assess their impact on the central values and uncertainties of the resulting PDFs.

DETERMINATION OF TOLERANCE LEVELS IN RADIOTHERAPY DOSIMETRY BASED ON STATISTICAL INTERFERENCE

2019 ◽  
Vol 186 (2-3) ◽  
pp. 367-372
Author(s):  
Irena Koniarová ◽  
Lukáš Kotík
Keyword(s):  
Reference Conditions ◽  
Absorbed Dose ◽  
High Energy ◽  
Energy Photon ◽  
New Approach ◽  
Absorbed Dose To Water ◽  
Input Variables ◽  
Radiotherapy Dosimetry ◽  
True Values

Abstract The most important dosimetry quantity that is determined at radiotherapy centers is the absorbed dose to water for external beams. Fixed tolerances for absorbed doses measured under reference conditions with an ionization chamber for high-energy photon and electron beams are usually 2 and 3%, respectively, regardless of uncertainties of the input variables and other conditions during evaluation. In reality, this agreement should be evaluated considering the uncertainties of the input variables because they affect the size of the random deviations of the measurements from their true values. The aim of this work was to develop a new approach to evaluate the agreement between measured and reported values based on statistical interference rather than to use fixed tolerance levels. The proposed method considers different scenarios that can occur during the evaluation of agreement. Because the method is described in general, it can be used in all similar situations when partial uncertainties can be established.

Kinematic Approximations in TED and RHEED Analysis of Reconstructed Surfaces

1990 ◽  
Vol 48 (2) ◽  
pp. 396-397
Author(s):  
L. -M. Peng ◽  
M. J. Whelan
Keyword(s):  
Electron Diffraction ◽  
Kinematic Analysis ◽  
Incident Beam ◽  
High Energy ◽  
Energy Electron ◽  
Great Success ◽  
High Energy Electron ◽  
Kinematic Approximation ◽  
Reconstructed Surfaces

In recent years there has been a trend in the structure determination of reconstructed surfaces to use high energy electron diffraction techniques, and to employ a kinematic approximation in analyzing the intensities of surface superlattice reflections. Experimentally this is motivated by the great success of the determination of the dimer adatom stacking fault (DAS) structure of the Si(111) 7 × 7 reconstructed surface.While in the case of transmission electron diffraction (TED) the validity of the kinematic approximation has been examined by using multislice calculations for Si and certain incident beam directions, far less has been done in the reflection high energy electron diffraction (RHEED) case. In this paper we aim to provide a thorough Bloch wave analysis of the various diffraction processes involved, and to set criteria on the validity for the kinematic analysis of the intensities of the surface superlattice reflections.The validity of the kinematic analysis, being common to both the TED and RHEED case, relies primarily on two underlying observations, namely (l)the surface superlattice scattering in the selvedge is kinematically dominating, and (2)the superlattice diffracted beams are uncoupled from the fundamental diffracted beams within the bulk.

Janus – A New Approach to Air Combat Pilot Training

2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Training System ◽  
Embedded Sensors ◽  
Pilot Training ◽  
New Approach ◽  
Combat Aircraft ◽  
Air Combat ◽  
The Cost

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.

The Dudley Lee Case: A new approach to factual causation and its implications for transformative jurisprudence

2017 ◽  
Vol 30 (1) ◽  
pp. 273-289
Author(s):  
Anmari Meerkotter
Keyword(s):  
Case Note ◽  
Constitutional Court ◽  
Recent Contribution ◽  
New Approach ◽  
State Accountability ◽  
The Law ◽  
Transformative Impact ◽  
Constitutional Jurisprudence ◽  
Law Of Delict

The Constitutional Court (CC) judgment of Lee v Minister of Correction Services 2013 2SA 144 (CC) is a recent contribution to transformative constitutional jurisprudence in the field of the law of delict. This matter turned on the issue of factual causation in the context of wrongful and negligent systemic omissions by the state. In this case note, I explore the law relating to this element of delictual liability with specific regard to the traditional test for factual causation – the conditio sine qua non (‘but-for’) test. In particular, I note the problems occasioned by formalistic adherence to this test in the context of systemic state omissions as evidenced by the SCA judgment in the same matter. I also consider the manner in which English courts have addressed this problem. Thereafter, I analyse the CC’s broader approach to the determination of factual causation as one based on common sense and justice. I argue that this approach endorses a break from a formalistic application of the test and constitutes a step towards an approach which resonates with the foundational constitutional values of freedom, dignity and equality. Furthermore, it presents an appropriate solution to the problems associated with factual causation where systemic omissions are concerned. I then consider the transformative impact of the Lee judgment. In particular, I argue that the broader enquiry favoured by the CC facilitates the realisation of constitutionally guaranteed state accountability, and amounts to an extension of the existing norm of accountability jurisprudence. Hence, I contend that the judgment presents a further effort by the Constitutional Court to effect wholesale the constitutionalisation of the law of delict, as well as a vindicatory tool to be used by litigants who have been adversely affected by systemic state omissions.

Automatic Determination of Optimal FIB Operations for Improved Circuit Probing and Fast Reconfiguration

2000 ◽  
Author(s):  
Romain Desplats ◽  
Timothee Dargnies ◽  
Jean-Christophe Courrege ◽  
Philippe Perdu ◽  
Jean-Louis Noullet
Keyword(s):  
Integrated Circuit ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Semiconductor Devices ◽  
Front Side ◽  
Automatic Determination ◽  
Metal Line ◽  
New Approach ◽  
Metal Layers

Abstract Focused Ion Beam (FIB) tools are widely used for Integrated Circuit (IC) debug and repair. With the increasing density of recent semiconductor devices, FIB operations are increasingly challenged, requiring access through 4 or more metal layers to reach a metal line of interest. In some cases, accessibility from the front side, through these metal layers, is so limited that backside FIB operations appear to be the most appropriate approach. The questions to be resolved before starting frontside or backside FIB operations on a device are: 1. Is it do-able, are the metal lines accessible? 2. What is the optimal positioning (e.g. accessing a metal 2 line is much faster and easier than digging down to a metal 6 line)? (for the backside) 3. What risk, time and cost are involved in FIB operations? In this paper, we will present a new approach, which allows the FIB user or designer to calculate the optimal FIB operation for debug and IC repair. It automatically selects the fastest and easiest milling and deposition FIB operations.

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