scholarly journals An investigation of the $$\alpha _S$$ and heavy quark mass dependence in the MSHT20 global PDF analysis

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
T. Cridge ◽  
L. A. Harland-Lang ◽  
A. D. Martin ◽  
R. S. Thorne
Keyword(s):  
Heavy Quark ◽  
Cross Sections ◽  
Scattering Data ◽  
Data Sets ◽  
Quark Masses ◽  
Heavy Quark Mass ◽  
Pdf Analysis ◽  
Definition Of ◽  
The Individual ◽  
The Masses

AbstractWe investigate the MSHT20 global PDF sets, demonstrating the effects of varying the strong coupling $$\alpha _S(M_Z^2)$$ α S ( M Z 2 ) and the masses of the charm and bottom quarks. We determine the preferred value, and accompanying uncertainties, when we allow $$\alpha _S(M_Z^2)$$ α S ( M Z 2 ) to be a free parameter in the MSHT20 global analyses of deep-inelastic and related hard scattering data, at both NLO and NNLO in QCD perturbation theory. We also study the constraints on $$\alpha _S(M_Z^2)$$ α S ( M Z 2 ) which come from the individual data sets in the global fit by repeating the NNLO and NLO global analyses at various fixed values of $$\alpha _S(M_Z^2)$$ α S ( M Z 2 ) , spanning the range $$\alpha _S(M_Z^2)=0.108$$ α S ( M Z 2 ) = 0.108 to 0.130 in units of 0.001. We make all resulting PDFs sets available. We find that the best fit values are $$\alpha _S(M_Z^2)=0.1203\pm 0.0015$$ α S ( M Z 2 ) = 0.1203 ± 0.0015 and $$0.1174\pm 0.0013$$ 0.1174 ± 0.0013 at NLO and NNLO respectively. We investigate the relationship between the variations in $$\alpha _S(M_Z^2)$$ α S ( M Z 2 ) and the uncertainties on the PDFs, and illustrate this by calculating the cross sections for key processes at the LHC. We also perform fits where we allow the heavy quark masses $$m_c$$ m c and $$m_b$$ m b to vary away from their default values and make PDF sets available in steps of $$\Delta m_c =0.05~\mathrm GeV$$ Δ m c = 0.05 G e V and $$\Delta m_b =0.25~\mathrm GeV$$ Δ m b = 0.25 G e V , using the pole mass definition of the quark masses. As for varying $$\alpha _S(M_Z^2)$$ α S ( M Z 2 ) values, we present the variation in the PDFs and in the predictions. We examine the comparison to data, particularly the HERA data on charm and bottom cross sections and note that our default values are very largely compatible with best fits to data. We provide PDF sets with 3 and 4 active quark flavours, as well as the standard value of 5 flavours.

scholarly journals Heavy-flavor hadro-production with heavy-quark masses renormalized in the $$ \overline{\mathrm{MS}} $$, MSR and on-shell schemes

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
M. V. Garzelli ◽  
L. Kemmler ◽  
S. Moch ◽  
O. Zenaiev
Keyword(s):  
Heavy Quark ◽  
Cross Sections ◽  
Top Quark ◽  
Quark Mass ◽  
Production Cross ◽  
Hadron Collider ◽  
Distribution Functions ◽  
Heavy Flavor ◽  
Parton Distribution Functions ◽  
Heavy Quark Mass

Abstract We present predictions for heavy-quark production at the Large Hadron Collider making use of the $$ \overline{\mathrm{MS}} $$ MS ¯ and MSR renormalization schemes for the heavy-quark mass as alternatives to the widely used on-shell renormalization scheme. We compute single and double differential distributions including QCD corrections at next-to-leading order and investigate the renormalization and factorization scale dependence as well as the perturbative convergence in these mass renormalization schemes. The implementation is based on publicly available programs, MCFM and xFitter, extending their capabilities. Our results are applied to extract the top-quark mass using measurements of the total and differential $$ t\overline{t} $$ t t ¯ production cross-sections and to investigate constraints on parton distribution functions, especially on the gluon distribution at low x values, from available LHC data on heavy-flavor hadro-production.

BACKWARD ANGLE STRUCTURE IN THE 20Ne+28Si QUASIELASTIC SCATTERING

2013 ◽  
Vol 22 (10) ◽  
pp. 1350073 ◽  
Author(s):  
O. SGOUROS ◽  
V. SOUKERAS ◽  
A. PAKOU ◽  
N. PATRONIS ◽  
K. ZERVA ◽  
...  
Keyword(s):  
Cross Sections ◽  
Form Factors ◽  
Scattering Data ◽  
Data Sets ◽  
Quasielastic Scattering ◽  
Particle Form ◽  
Reaction Channels ◽  
Reasonable Description ◽  
Optical Model Analysis ◽  
Backward Angle

New data for the quasielastic scattering of 20 Ne from a 28 Si target at incident energies of 42.5 MeV and 52.3 MeV and for the 28 Si (20 Ne , 24 Mg )24 Mg , 28 Si (20 Ne , 16 O )32S and 28 Si (20 Ne , 12 C )36 Ar transfer reactions at 52.3 MeV are reported. Oscillations are observed in the backward angle quasielastic scattering data at 52.3 MeV and the 28 Si (20 Ne , 12 C )36 Ar transfer cross-sections are of the same magnitude as those for single-α stripping. Coupled reaction channels (CRC) calculations are unable to describe either the quasielastic or the 28 Si (20 Ne , 12 C )36 Ar transfer data assuming a sequential α transfer process with α-particle form factors from the literature. The addition of direct 8 Be cluster transfer can provide a reasonable description of both data sets, but only with much larger spectroscopic factors than suggested by simple structure calculations or the large 8 Be emission thresholds of 20 Ne , 28 Si and 36 Ar , suggesting that the observed structure is of resonance-like origin. An optical model analysis of the quasielastic scattering data is also reported.

scholarly journals Multiloop contributions to the on-shell-$$ \overline{{\mathrm{MS}}}$$ heavy quark mass relation in QCD and the asymptotic structure of the corresponding series: the updated consideration

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
A. L. Kataev ◽  
V. S. Molokoedov
Keyword(s):  
Heavy Quark ◽  
Mass Relation ◽  
Normalization Factor ◽  
Asymptotic Structure ◽  
Quark Masses ◽  
Heavy Quark Mass ◽  
Seventh Order ◽  
Order Of Magnitude ◽  
Effective Charges ◽  
Asymptotic Character

AbstractThe asymptotic structure of the QCD perturbative relation between the on-shell and $$\overline{{\mathrm{MS}}}$$ MS ¯ heavy quark masses is studied. We estimate the five and six-loop contributions to this relation by three different techniques. First, the effective charges motivated approach in two variants is used. Second, the results following from the large-$$\beta _0$$ β 0 approximation are analyzed. Finally, the consequences of applying the asymptotic renormalon-based formula are investigated. We show that all approaches lead to corrections which are qualitatively consistent in order of magnitude. Their sign-alternating character in powers of the number of massless quarks is demonstrated. We emphasize that there is no contradiction in the behavior of the fine structure of the renormalon-based estimates with other approaches if one use the detailed information about the normalization factor included in the renormalon asymptotic formula. The obtained five- and six-loop estimates indicate that in the case of the b-quark the asymptotic character of the studied relation manifests itself above the fourth order of PT, whereas for the t-quark it starts to reveal itself after the seventh order. This allows to conclude that like the running masses, the pole masses of the b and especially t-quark in principle may be used in the phenomenologically-oriented studies.

scholarly journals Skin Doctor: Machine Learning Models for Skin Sensitization Prediction that Provide Estimates and Indicators of Prediction Reliability

2019 ◽  
Vol 20 (19) ◽  
pp. 4833 ◽  
Author(s):  
Anke Wilm ◽  
Conrad Stork ◽  
Christoph Bauer ◽  
Andreas Schepky ◽  
Jochen Kühnl ◽  
...  
Keyword(s):  
Correlation Coefficients ◽  
Applicability Domain ◽  
Support Vector ◽  
Data Sets ◽  
Skin Sensitization ◽  
Prediction Reliability ◽  
Local Lymph Node ◽  
Definition Of ◽  
The Individual ◽  
In Silico Models

The ability to predict the skin sensitization potential of small organic molecules is of high importance to the development and safe application of cosmetics, drugs and pesticides. One of the most widely accepted methods for predicting this hazard is the local lymph node assay (LLNA). The goal of this work was to develop in silico models for the prediction of the skin sensitization potential of small molecules that go beyond the state of the art, with larger LLNA data sets and, most importantly, a robust and intuitive definition of the applicability domain, paired with additional indicators of the reliability of predictions. We explored a large variety of molecular descriptors and fingerprints in combination with random forest and support vector machine classifiers. The most suitable models were tested on holdout data, on which they yielded competitive performance (Matthews correlation coefficients up to 0.52; accuracies up to 0.76; areas under the receiver operating characteristic curves up to 0.83). The most favorable models are available via a public web service that, in addition to predictions, provides assessments of the applicability domain and indicators of the reliability of the individual predictions.

Mass and Mass Loss Measurements on DNA and fd Phage

1972 ◽  
Vol 30 ◽  
pp. 186-187
Author(s):  
Joseph Wall
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Scanning Transmission Electron Microscope ◽  
Scattering Data ◽  
Mass Measurements ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Atomic Scattering ◽  
The Individual ◽  
Scattering Cross Sections

Mass measurements can be done with the scanning transmission electron microscope in a manner similar to the densitometry of conventional microscope plates. Since the measurements are made directly on the microscope output signal, however, there are none of the non-linearities associated with film. The two signals (proportional to normalized elastically and inelastically scattered currents) are recorded directly on digital tape for analysis.Mass can be determined from the scattering data using atomic scattering cross-sections and assuming the cross-section of an object is the sum of the individual atomic cross-sections. Since the elastic and inelastic cross-sections have different dependence on atomic number, it also is possible to estimate the average Z of the object being measured. These calculations are performed using a Nova 800 computer system which is interfaced directly to the microscope.

Benjamín Jarnés: Aspects of the Dehumanized Novel

PMLA ◽  
1961 ◽  
Vol 76 (3) ◽  
pp. 247-253
Author(s):  
Paul Ilie
Keyword(s):  
The State ◽  
Narrative Fiction ◽  
Philosophical Significance ◽  
Individual Personality ◽  
Contemporary Life ◽  
Human Reality ◽  
Benjamin Jarnes ◽  
Definition Of ◽  
The Individual ◽  
The Masses

Ortega has maintained in his Ideas sobre la novela that action is not the essence of a novel, a principle which he corroborates by the fact that most plots are readily forgotten. For Ortega, the novel's essence is pure being or nonaction, manifested by the state of its characters. One of the most conscientious practitioners of Ortegan theory was Benjamín Jarnés, who in Locura y muerte de nadie (Madrid, 1929) wrote a novel revealing human reality stripped of its vital core: action, passion, and sentiment. The process of devoiding reality of its real content while leaving a mere semblance of reality as the remainder is, of course, “dehumanization” in the Ortegan definition of the term. Two further aspects of Jarnés' novel—the absence of a personality in his protagonist and the use of a highly abstract, cerebral language—serve to supplement the meaning of “dehumanization” at least as far as narrative fiction is involved. But Locura y muerte… also commands attention because its author reaches out into areas of cultural and philosophical significance in order to determine the causes of a comparable dehumanization in contemporary life at the same time that he depicts this life fictionally. My procedure in this essay will be to discuss first Jarnés' notion of the interplay between the masses and the individual personality; then, in the light of this, the attitudes underlying his approach to this particular novel; and, finally, the techniques involved in the verbalization of his novel.

scholarly journals Analyzing the Anomalous Dipole Moment Type Couplings of Heavy Quarks with FCNC Interactions at the CLIC

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
A. T. Tasci ◽  
A. Senol ◽  
C. Verep
Keyword(s):  
Dipole Moment ◽  
Standard Model ◽  
Heavy Quark ◽  
Cross Sections ◽  
Linear Collider ◽  
Heavy Quarks ◽  
Decay Modes ◽  
Quark Masses ◽  
Single Production

We examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant standard model decay modes at the compact linear collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities for3σobservation limit.

The Autobiographical Subject and the Death Penalty

2013 ◽  
Vol 35 (2) ◽  
pp. 165-187
Author(s):  
E. S. Burt
Keyword(s):  
Death Penalty ◽  
First Person ◽  
Philosophical Investigation ◽  
The Subject ◽  
Definition Of ◽  
The Individual

Why does writing of the death penalty demand the first-person treatment that it also excludes? The article investigates the role played by the autobiographical subject in Derrida's The Death Penalty, Volume I, where the confessing ‘I’ doubly supplements the philosophical investigation into what Derrida sees as a trend toward the worldwide abolition of the death penalty: first, to bring out the harmonies or discrepancies between the individual subject's beliefs, anxieties, desires and interests with respect to the death penalty and the state's exercise of its sovereignty in applying it; and second, to provide a new definition of the subject as haunted, as one that has been, but is no longer, subject to the death penalty, in the light of the worldwide abolition currently underway.

ГЕРМЕНЕВТИКА ЛИЧНОСТИ КАК МЕТОД СОВРЕМЕННОЙ ПЕРСОНОЛОГИИ

1970 ◽  
Vol 6 (1) ◽  
pp. 32-42
Author(s):  
Елена Старовойтенко
Keyword(s):  
Text Setting ◽  
Research Setting ◽  
Textual Representations ◽  
General Scientific ◽  
Definition Of ◽  
The Individual ◽  
The Continuum

Персонологическая интерпретация текстов предполагает реализацию общенаучных, а также специфических для персонологии, герменевтических установок, к которым относятся: установка на интерпретацию текста как исследование, установка на разнообразие герменевтических действий с текстом, установка на выявление неисследованных содержаний текста, установка на творческое постижение тайн текста, установка на целостное отношение к личности и "Я" автора текста, установка на выявление способности автора быть "практикующим феноменологом", установка на определение места изучаемого текста в континууме текстовых репрезентаций "личности", установка на соотнесение своего понимания текста с другими интерпретациями и их интеграцию, установка на раскрытие сущности авторской "идеи личности", возможное только в единстве интерпретаций, установка на построение и применение герменевтической модели, определяющей процедуру интерпретации как исследования и творчества, установка на определение места проделанного герменевтического поиска в культуре познания и жизни личности, установка на интерпретацию различных видов "текстов личности". Personological interpretation of texts suggests the implementation of the general scientific and also hermeneutical settings specific for Personology which include the setting of the interpretation of the text as a research, setting of a variety of hermeneutical actions with the text, setting to identify unexplored contents of the text, setting of the creative comprehension of the mysteries of the text, setting of the integrity of the attitude of the individual and the "I" of the author of the text, setting to reveal the author's ability to be "practicing phenomenologist", setting of the definition of the place in the text in the continuum of textual representations of the "personality", setting in the correlation of the understanding of the text with other interpretations and their integration, setting of the disclosure of the author's "ideas person" is possible only in the unity of interpretation, setting of the construction and usage of hermeneutical models defining the procedure for the interpretation of both studies and work, the setting to determine the place of hermeneutical research in culture and knowledge of a person's life, setting of the interpretation of various types of "texts of the individual."

¿Quién soy yo? Reflexiones teórico sistémicas acerca de la indentidad individual

2017 ◽  
Vol 1 (1) ◽  
pp. 15-31
Author(s):  
Francisco Xavier Morales
Keyword(s):  
Identity Construction ◽  
Social Systems ◽  
Social Contexts ◽  
Individual Identity ◽  
Contemporary Society ◽  
Self Identity ◽  
Moral Communication ◽  
Identity Based ◽  
Definition Of ◽  
The Individual

The problem of identity is an issue of contemporary society that is not only expressed in daily life concerns but also in discourses of politics and social movements. Nevertheless, the I and the needs of self-fulfillment usually are taken for granted. This paper offers thoughts regarding individual identity based on Niklas Luhmann’s systems theory. From this perspective, identity is not observed as a thing or as a subject, but rather as a “selfillusion” of a system of consciousness, which differentiates itself from the world, event after event, in a contingent way. As concerns the definition  of contents of self-identity, the structures of social systems define who is a person, how he or she should act, and how much esteem he or she should receive. These structures are adopted by consciousness as its own identity structures; however, some social contexts are more relevant for self-identity construction than others. Moral communication increases the probability that structure appropriation takes place, since the emotional element of identity is linked to the esteem/misesteem received by the individual from the interactions in which he or she participates.

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