scholarly journals Scanning of hadra]on cross section at DAΦNE by analysis of the initial-state radiative events

JETP Letters ◽  
1999 ◽  
Vol 69 (11) ◽  
pp. 811-818 ◽  
Author(s):  
M. Konchatnij ◽  
N. P. Merenkov
Keyword(s):  
Cross Section ◽  
Initial State ◽  
Initial State Radiative

scholarly journals Spin-one dark matter and gamma ray signals from the galactic center

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
H. Hernández-Arellano ◽  
M. Napsuciale ◽  
S. Rodríguez
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Gamma Ray ◽  
Galactic Center ◽  
Photon Emission ◽  
Scalar Coupling ◽  
Initial State ◽  
Internal Bremsstrahlung ◽  
Resonance Effects ◽  
State Radiation

Abstract In this work we study the possibility that the gamma ray excess (GRE) at the Milky Way galactic center come from the annihilation of dark matter with a (1, 0) ⊕ (0, 1) space-time structure (spin-one dark matter, SODM). We calculate the production of prompt photons from initial state radiation, internal bremsstrahlung, final state radiation including the emission from the decay products of the μ, τ or hadronization of quarks. Next we study the delayed photon emission from the inverse Compton scattering (ICS) of electrons (produced directly or in the prompt decay of μ, τ leptons or in the hadronization of quarks produced in the annihilation of SODM) with the cosmic microwave background or starlight. All these mechanisms yield significant contributions only for Higgs resonant exchange, i.e. for M ≈ MH /2, and the results depend on the Higgs scalar coupling to SODM, gs. The dominant mechanism at the GRE bump is the prompt photon production in the hadronization of b quarks produced in $$ \overline{D}D\to \overline{b}b $$ D ¯ D → b ¯ b , whereas the delayed photon emission from the ICS of electrons coming from the hadronization of b quarks produced in the same reaction dominates at low energies (ω < 0.3 GeV ) and prompt photons from c and τ , as well as from internal bremsstrahlung, yield competitive contributions at the end point of the spectrum (ω ≥ 30 GeV ). Taking into account all these contributions, our results for photons produced in the annihilation of SODM are in good agreement with the GRE data for gs ∈ [0.98, 1.01] × 10−3 and M ∈ [62.470, 62.505] GeV . We study the consistency of the corresponding results for the dark matter relic density, the spin-independent dark matter-nucleon cross-section σp and the cross section for the annihilation of dark matter into $$ \overline{b}b $$ b ¯ b , τ+τ−, μ+μ− and γγ, taking into account the Higgs resonance effects, finding consistent results in all cases.

scholarly journals Measurement of the e+e−→π+π−π0π0 cross section using initial-state radiation at BABAR

2017 ◽  
Vol 96 (9) ◽  
Author(s):  
J. P. Lees ◽  
V. Poireau ◽  
V. Tisserand ◽  
E. Grauges ◽  
A. Palano ◽  
...  
Keyword(s):  
Cross Section ◽  
Initial State Radiation ◽  
Initial State ◽  
State Radiation

scholarly journals Status of R value measurement at BESIII

2019 ◽  
Vol 212 ◽  
pp. 04005
Author(s):  
Haiming HU
Keyword(s):  
Systematic Error ◽  
Radiative Correction ◽  
Present Status ◽  
Parameter Tuning ◽  
Initial State ◽  
R Value ◽  
Value Measurement ◽  
Area Law ◽  
Initial State Radiative

The dominant systematic error of R value measurement comes from the hadronic generator simulations. This paper reviews the present status of R value measurement from 2.232 to 3.671 GeV at 14 energy points, especially describes the calculations of initial state radiative correction and the issue of the parameter tuning for the Lund area law generator LUARLW.

scholarly journals Open charm studies at Belle

2019 ◽  
Vol 212 ◽  
pp. 09003
Author(s):  
Valentina Zhukova
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Open Charm ◽  
Mass Energy ◽  
Initial State ◽  
Belle Detector ◽  
Section Measurement ◽  
Angular Analysis ◽  
State Radiation ◽  
Radiation Technique

We present the new results of measurements of the exlusive cross sections of the e+ e− annihilation to charmed meson pairs as a function of √ ceneter-of-mass energy from the open charm threashold up to $ \sqrt s = {\rm{6 GeV}} $ using initial state radiation technique. The analysis is based on a data sample collected by the Belle detector with an integrated luminosity of 951 fb−1. The accuracy of the cross section measurement is increased by a factor of 2 in comparison with the first Belle study. We have performed the first angular analysis + −→ D*± D*∓ of the $ {e^{\rm{ + }}}{e^ - } \to {D^{* \pm }}{D^{* \mp }} $ process and decomposed this exclusive cross section into three components corresponding to the different D* helicities.

scholarly journals Stretching of a cylindrical rod of variable cross-section in the theory of small elastic-plastic

2020 ◽  
pp. 78-81
Author(s):  
Николай Ильич Петров
Keyword(s):  
Cross Section ◽  
Axisymmetric Problem ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Initial State ◽  
Plastic Deformations ◽  
Linearized Equations ◽  
Elastic Plastic

В работе рассматривается растяжение бесконечно длинного цилиндрического стержня переменного сечения. Используются результаты решения линеаризированных уравнений теории малых упругопластических деформаций [1-7] в случае осесимметричной задачи. Предполагается, что в начальном состоянии имеет место простое растяжение. We considers the stretching of an infinitely long cylindrical rod of variable cross-section. The results of solving the linearized equations of the theory of small elastic-plastic deformations [1-7] in the case of an axisymmetric problem are used. It is assumed that a simple stretch occurs in the initial state.

scholarly journals CONSOLIDATION ZONES FEATURES FORMATION OF A GROUND AROUND SQUARE SHAPED PILES

2018 ◽  
Vol 1 (50) ◽  
pp. 167-173
Author(s):  
O. V. Malyshev
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Analytical Method ◽  
Lateral Surface ◽  
Analytical Methods ◽  
Rational Design ◽  
Initial State ◽  
Compaction Zone ◽  
Analytical Expressions ◽  
Efficiency And Reliability

Necessity to resolve the problem of concerning the analytical dimensions definition and constructing forms of compacted zones of ground around the lateral surface of square cross section pile in normal to pile axis direction are shown in this article. Various analytical methods of ground compacted zones radius determination around cylindrical elements driven into the ground considering its initial state were analyzed. Graph-analytical method of ground compaction zones construction around square cross-section piles was developed. Efficiency of the developed methodology and analytical expressions using possibility to determine the radius of compaction zone of a ground around the driven or jacked-in elements is confirmed by comparing obtained solutions with the experimental data. The developed methodology allows increasing the efficiency and reliability of piles and pile foundations use due to their rational design.

scholarly journals Hadron Form Factors at BESIII

2018 ◽  
Vol 46 ◽  
pp. 1860027
Author(s):  
Zhaoxia Meng
Keyword(s):  
Cross Section ◽  
Center Of Mass ◽  
Polar Angle ◽  
Form Factors ◽  
Angle Distribution ◽  
Initial State ◽  
Fundamental Information ◽  
Born Cross Section ◽  
Effective Form ◽  
State Radiation

Form factors of hadron provide fundamental information about its structure and dynamics. They constitute a rigorous test of non-perturbative QCD as well as of phenomenological models. Based on data samples collected with BESIII detector at BEPCII collider, born cross section of [Formula: see text] and proton effective form factors are measured at 12 center-of-mass energies between 2.2324 and 3.671 GeV. The ratio [Formula: see text]s are extracted by fitting polar angle distribution of proton for data samples with large statistics. For data between 3.773 and 4.6 GeV, we use initial state radiation (ISR) method to study [Formula: see text] by tagged or un-tagged ISR photon, where the pair cross section, effective form factors and [Formula: see text]s are obtained from proton pair threshold to about 3 GeV. For [Formula: see text] and [Formula: see text], the pair cross section and [Formula: see text] form factors are measured near threshold. With data scanned in 2015 from 2-3.08 GeV, charged Kaon pair cross section and form factors are measured at 21 center-of-mass energies.

scholarly journals Development of a technological complex for thermofriction hardening of products with a circular cross section

2021 ◽  
pp. 65
Author(s):  
Оleg Volkov ◽  
Valeria Subbotinа ◽  
Anna Fedorenko
Keyword(s):  
Cross Section ◽  
High Efficiency ◽  
Circular Cross Section ◽  
Initial State ◽  
Flat Surfaces ◽  
Technological Complex ◽  
High Microhardness ◽  
Different Shapes ◽  
The Cost ◽  
Processing Factors

There are many methods of influencing the structural state of the surface of products of different shapes and different purposes. At the same time, the increase in the relevance of the application of a particular method is closely related to its ability to provide high hardening rates while reducing the cost of such products. The TFН technology has already shown its high efficiency in strengthening surfaces [1]. In addition, studies were conducted on the hardening of surfaces of different profiles [2]. However, the best results are achieved when hardening flat surfaces. In this regard, it is entirely appropriate to conduct research that is related to the development of a technological complex that would include the optimal ratio of processing factors to ensure the necessary level of hardening in the studied objects that have a circular cross-section. Goal. The purpose of this work is to develop a technological complex for processing objects with a circular cross-section. To achieve this goal, metallographic and durometric studies of samples in the initial state and after processing were carried out. At the same time, the changes in the structure and mechanical properties that occur in steel due to processing were studied. Method. The method of thermal friction hardening includes a combined effect of heat and deformation on the treated surface. The peculiarity of this method is the deformation under short-term heating conditions. This makes it possible to further strengthen pre-hardened materials. Results. Under the influence of TFC, significant changes are observed in the structure of cylindrical samples made of 65G steel. This is expressed by the formation of a so-called "white surface layer" in the surface of these samples, which has an ultra-high microhardness [13, 14]. The properties of this layer depend on the initial state of the material, the conditions and modes of conducting TFН.

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