QCD at Fixed Order: Processes

2018 ◽  
Author(s):  
John Campbell ◽  
Joey Huston ◽  
Frank Krauss
Keyword(s):  
Hadron Collider ◽  
Detailed Comparison ◽  
Theoretical Description ◽  
Higgs Bosons ◽  
Final States ◽  
Collider Physics ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Fixed Order ◽  
The Subject

At the core of any theoretical description of hadron collider physics is a fixed-order perturbative treatment of a hard scattering process. This chapter is devoted to a survey of fixed-order predictions for a wide range of Standard Model processes. These range from high cross-section processes such as jet production to much more elusive reactions, such as the production of Higgs bosons. Process by process, these sections illustrate how the techniques developed in Chapter 3 are applied to more complex final states and provide a summary of the fixed-order state-of-the-art. In each case, key theoretical predictions and ideas are identified that will be the subject of a detailed comparison with data in Chapters 8 and 9.

scholarly journals Meson spectroscopy at VES and COMPASS

2019 ◽  
Vol 212 ◽  
pp. 03010 ◽  
Author(s):  
Dmitry Ryabchikov
Keyword(s):  
Detailed Comparison ◽  
Partial Wave Analysis ◽  
Final States ◽  
Wave Analysis ◽  
Decay Channels ◽  
Diffractive Production ◽  
Meson Spectroscopy ◽  
Narrow State ◽  
The Subject ◽  
Mass Dependent

Diffractive production of π- π- π+ and π- π0 π0 final states is the subject of comprehensive studies performed recently by the VES and the COM-PASS experiments. COMPASS pioneered the application of novel methods of partial-wave analysis: mass-independent PWA inmultiple (m3π, t’)-cells, mass-dependent analysis of spin-density matrices performed simultaneously in all measured t’ bins, the analysis with freed shapes of π+ π- isobars. In addition, COMPASS observed a new narrow state: a1(1420). VES has world-leading data samples on π- π- π+ and π- π0 π0, that yield compatible results and show the potential for a detailed comparison of isospin relations between different decay channels, using the PWA methods with fixed and freed shapes of ππ isobars.

Convection and particle entrainment driven by differential sedimentation

1991 ◽  
Vol 226 ◽  
pp. 349-369 ◽  
Author(s):  
Herbert E. Huppert ◽  
Ross C. Kerr ◽  
John R. Lister ◽  
J. Stewart Turner
Keyword(s):  
Theoretical Description ◽  
Upper And Lower Bounds ◽  
Magma Chambers ◽  
Clear Fluid ◽  
Calculated Density ◽  
Lower Region ◽  
Particle Entrainment ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Differential Sedimentation

When a suspension of small particles is overlain by a clear fluid whose density is greater than that of the interstitial fluid, but less than that of the bulk suspension, the settling of the dense suspended particles can lead to vigorous convection in the overlying fluid. This novel situation is investigated experimentally and theoretically. A sharp interface is observed between the convecting upper region and a stagnant lower region in which there is unimpeded sedimentation at low Reynolds number. There is no transport of fluid from the upper region into the lower, though there is mixing of both buoyant fluid and entrained particles from the lower region into the upper. The interface between the two regions is found to descend at a constant velocity. Systematic laboratory measurements have determined how this velocity depends on the densities of the layers and the distributions of settling velocities of the particles. A theoretical description is developed which calculates the evolution of the density of the lower region due to differential sedimentation of polydisperse particles. Buoyancy arguments based on the calculated density profile are used to place upper and lower bounds on the amount of particle entrainment into the upper layer and on the rate of fall of the interface between the convecting and sedimenting regions. The theoretical predictions are in good agreement with the experimental observations. The analysis of the interaction between convection and sedimentation in the system considered here may be particularly relevant to the description of evolving crystal-rich layers in magma chambers and of silt-laden outflow from rivers, and has a wide range of other industrial, environmental and geological applications.

scholarly journals Search for Heavy Higgs Bosons with the ATLAS Detector

2018 ◽  
Vol 46 ◽  
pp. 1860056
Author(s):  
Jana Schaarschmidt
Keyword(s):  
Large Hadron Collider ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Hadron Collider ◽  
New Physics ◽  
Atlas Detector ◽  
Higgs Bosons ◽  
Final States ◽  
Atlas Experiment

The ATLAS experiment at the Large Hadron Collider performed searches for heavy Higgs bosons, whose presence would establish the existance of new physics. Searches for charged and neutral Higgs bosons are carried out using 8 or 13 TeV data for various production modes and in many different final states. No deviations from Standard Model expectations are observed. Exclusions limits are set on the production cross section and on parameters in various benchmark models.

scholarly journals Improving heavy dijet resonance searches using jet substructure at the LHC

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Aruna Kumar Nayak ◽  
Santosh Kumar Rai ◽  
Tousik Samui
Keyword(s):  
Light Quark ◽  
Hadron Collider ◽  
High Energy ◽  
New Physics ◽  
Higgs Bosons ◽  
Final States ◽  
Jet Substructure ◽  
Charged Higgs Bosons ◽  
Quark Jets ◽  
Positive Step

AbstractThe search for new physics at high energy accelerators has been at the crossroads with very little hint of signals suggesting otherwise. The challenges at a hadronic machine such as the LHC is compounded by the fact that final states are swamped with jets which one needs to understand and unravel. A positive step in this direction would be to separate the jets in terms of their gluonic and quark identities, much in a similar spirit of distinguishing heavy quark jets from light quark jets that has helped in improving searches for both neutral and charged Higgs bosons at the LHC. In this work, we utilise this information using the jet substructure techniques to comment on possible improvements in sensitivity as well as discrimination of new resonances in the all hadronic mode that would be crucial in pinning down new physics signals at HL-LHC, HE-LHC and any future 100 TeV hadron collider.

scholarly journals Jet cross sections at the LHC and the quest for higher precision

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Johannes Bellm ◽  
Andy Buckley ◽  
Xuan Chen ◽  
Aude Gehrmann-De Ridder ◽  
Thomas Gehrmann ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Phenomenological Study ◽  
Hadron Collider ◽  
Scale Dependence ◽  
Leading Order ◽  
Theoretical Predictions ◽  
Fixed Order ◽  
Jet Cross Sections ◽  
Perturbative Corrections

Abstract We perform a phenomenological study of Z plus jet, Higgs plus jet and di-jet production at the Large Hadron Collider. We investigate in particular the dependence of the leading jet cross section on the jet radius as a function of the jet transverse momentum. Theoretical predictions are obtained using perturbative QCD calculations at the next-to and next-to-next-to-leading order, using a range of renormalization and factorization scales. The fixed order predictions are compared to results obtained from matching next-to-leading order calculations to parton showers. A study of the scale dependence as a function of the jet radius is used to provide a better estimate of the scale uncertainty for small jet sizes. The non-perturbative corrections as a function of jet radius are estimated from different generators.

scholarly journals Tau-jet signatures of vectorlike quark decays to heavy charged and neutral Higgs bosons

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Radovan Dermisek ◽  
Enrico Lunghi ◽  
Navin McGinnis ◽  
Seodong Shin
Keyword(s):  
Hadron Collider ◽  
Higgs Doublet ◽  
Higgs Bosons ◽  
Final States ◽  
Type Ii ◽  
Final State ◽  
Quark Decays ◽  
Doublet Model ◽  
Model Independent ◽  
Two Higgs Doublet Model

Abstract We study 4b + 2τ and 4b + 1τ signatures of heavy neutral and charged Higgs bosons originating from cascade decays of pair-produced new quarks. Decays of vectorlike quarks through heavy Higgses can easily dominate in the two Higgs doublet model of type-II, and the studied signatures are common to many possible decay chains. We design search strategies for these final states and discuss the mass ranges of heavy Higgs bosons and new quarks that can be explored at the Large Hadron Collider as functions of branching ratios in a model independent way. We further combine the results with a similar study focusing on decays which lead to a 6b final state and interpret the sensitivity to charged and neutral Higgs bosons and vectorlike quarks in the type-II two Higgs doublet model. We find that the LHC reach for their masses extends to well above 2 TeV in the case of an SU(2) doublet quark and to at least 1.8 TeV for a bottom-like SU(2) singlet quark in the whole range of tan β between 1 and 50.

Typologization of security regulation

2020 ◽  
pp. 20-27
Author(s):  
Denis Tikhomirov
Keyword(s):  
Social Relations ◽  
Scientific Literature ◽  
Legal Regulation ◽  
Procedural Understanding ◽  
Limited Ability ◽  
Methodological Basis ◽  
Wide Range ◽  
The Subject ◽  
Definition Of ◽  
Legal Understanding

The purpose of the article is to typologize terminological definitions of security, to find out the general, to identify the originality of their interpretations depending on the subject of legal regulation. The methodological basis of the study is the methods that made it possible to obtain valid conclusions, in particular, the method of comparison, through which it became possible to correlate different interpretations of the term "security"; method of hermeneutics, which allowed to elaborate texts of normative legal acts of Ukraine, method of typologization, which made it possible to create typologization groups of variants of understanding of the term "security". Scientific novelty. The article analyzes the understanding of the term "security" in various regulatory acts in force in Ukraine. Typological groups were understood to understand the term "security". Conclusions. The analysis of the legal material makes it possible to confirm that the issues of security are within the scope of both legislative regulation and various specialized by-laws. However, today there is no single conception on how to interpret security terminology. This is due both to the wide range of social relations that are the subject of legal regulation and to the relativity of the notion of security itself and the lack of coherence of views on its definition in legal acts and in the scientific literature. The multiplicity of definitions is explained by combinations of material and procedural understanding, static - dynamic, and conditioned by the peculiarities of a particular branch of legal regulation, limited ability to use methods of one or another branch, the inter-branch nature of some variations of security, etc. Separation, common and different in the definition of "security" can be used to further standardize, in fact, the regulatory legal understanding of security to more effectively implement the legal regulation of the security direction.

History of the Study of Apocrypha in Early Medieval England

2020 ◽  
Vol 48 (3-4) ◽  
pp. 13-26
Author(s):  
Brandon W. Hawk
Keyword(s):  
Old Testament ◽  
Medieval England ◽  
Medieval Period ◽  
Early Medieval ◽  
Future Directions ◽  
Early Judaism ◽  
Wide Range ◽  
History Of ◽  
The Subject ◽  
Early English

Literature written in England between about 500 and 1100 CE attests to a wide range of traditions, although it is clear that Christian sources were the most influential. Biblical apocrypha feature prominently across this corpus of literature, as early English authors clearly relied on a range of extra-biblical texts and traditions related to works under the umbrella of what have been called “Old Testament Pseudepigrapha” and “New Testament/Christian Apocrypha." While scholars of pseudepigrapha and apocrypha have long trained their eyes upon literature from the first few centuries of early Judaism and early Christianity, the medieval period has much to offer. This article presents a survey of significant developments and key threads in the history of scholarship on apocrypha in early medieval England. My purpose is not to offer a comprehensive bibliography, but to highlight major studies that have focused on the transmission of specific apocrypha, contributed to knowledge about medieval uses of apocrypha, and shaped the field from the nineteenth century up to the present. Bringing together major publications on the subject presents a striking picture of the state of the field as well as future directions.

Museum Preserves in the Sphere of “Cultural Tourism”: Through the Example of the Cultural Preserves of Tatarstan

2019 ◽  
Vol 9 (4) ◽  
pp. 193-198
Author(s):  
Lyudmila S. Timofeeva ◽  
Albina R. Akhmetova ◽  
Liliya R. Galimzyanova ◽  
Roman R. Nizaev ◽  
Svetlana E. Nikitina
Keyword(s):  
19Th Century ◽  
Art Museum ◽  
Medium Size ◽  
Business Elite ◽  
Wide Range ◽  
The Subject ◽  
Tourist Center ◽  
Regional Authorities ◽  
The 19Th Century ◽  
The City

Abstract The article studies the existence experience of historical cities as centers of tourism development as in the case of Elabuga. The city of Elabuga is among the historical cities of Russia. The major role in the development of the city as a tourist center is played by the Elabuga State Historical-Architectural and Art Museum-Reserve. The object of the research in the article is Elabuga as a medium-size historical city. The subject of the research is the activity of the museum-reserve which contributes to the preservation and development of the historical look of Elabuga and increases its attractiveness to tourists. The tourism attractiveness of Elabuga is obtained primarily through the presence of the perfectly preserved historical center of the city with the blocks of integral buildings of the 19th century. The Elabuga State Historical-Architectural and Art Museum-Reserve, which emerged in 1989, is currently an object of historical and cultural heritage of federal importance. Museum-reserves with their significant territories and rich historical, cultural and natural heritage have unique resources for the implementation of large partnership projects. Such projects are not only aimed at attracting a wide range of tourists, but also stimulate interest in the reserve from the business elite, municipal and regional authorities. The most famous example is the Spasskaya Fair which revived in 2008 in Elabuga. It was held in the city since the second half of the 19th century, and was widely known throughout Russia. The process of the revival and successful development of the fair can be viewed as the creation of a special tourist event contributing to the formation of new and currently important tourism products.

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