scholarly journals A Fit to the Available e+e-→Λc+Λ-c- cross Section Data Nearby Production Threshold by Means of a Strong Correction to the Coulomb Enhancement Factor

Universe ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 436
Author(s):  
Antonio Amoroso ◽  
Stefano Bagnasco ◽  
Rinaldo Baldini Ferroli ◽  
Ilaria Balossino ◽  
Monica Bertani ◽  
...  
Keyword(s):  
Cross Section ◽  
Enhancement Factor ◽  
Final States ◽  
Cross Section Data ◽  
Initial State ◽  
Final State ◽  
Production Threshold ◽  
Section Data ◽  
State Radiation ◽  
Radiation Technique

There are two available sets of data on the e+e−→Λc+Λ¯c− cross section at energies close to the production threshold, collected by the Belle and by the BESIII Collaborations. The measurement of the former, performed by means of the initial state radiation technique, is compatible with the presence of a resonance, called ψ(4660), observed also in other final states. On the contrary, the latter is measured an almost flat and hence non-resonant cross section in the energy region just above the production threshold, but the data stop before the possible rise in the cross section for the resonant production. We propose an effective model to describe the behavior of the data near this threshold, which is based on a Coulomb-like enhancement factor due to the strong interaction among the final state particles. In the framework of this model, it is possible to describe both datasets.

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.

Ground State Radiation Width of the 10.18 MeV, Jπ = 3−, State in 28Si Deduced From 100 MeV Proton Inelastic Scattering

1974 ◽  
Vol 52 (14) ◽  
pp. 1369-1371
Author(s):  
Y. S. Horowitz
Keyword(s):  
Angular Distribution ◽  
Differential Cross Section ◽  
Cross Section ◽  
Ground State ◽  
Transition Rates ◽  
Cross Section Data ◽  
Section Data ◽  
Proton Inelastic Scattering ◽  
State Radiation ◽  
Mev Protons

Differential cross section data for 100 MeV protons inelastically scattered from 6Li, 9Be, 12C, 24Mg, and 28Si are compared with the corresponding E2 and E3 transition rates and a strong correlation is shown to exist between (dσ/dΩ)max and Γγ0 if the shape of the proton angular distribution is characteristic of single excitation. The persistence of the correlation to transitions with Γγ0/Γγ < 0.1 allows an estimate of Γγ0 = 8.6 ± 5 × 10−4 eV for the 10.18 MeV, Jπ = 3−, level in 28Si.

HADRONIC CROSS SECTION MEASUREMENT AT BES-III

2014 ◽  
Vol 35 ◽  
pp. 1460408
Author(s):  
SVEN SCHUMANN ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Initial State ◽  
Section Data ◽  
Hadronic Cross Section ◽  
Section Measurement ◽  
R Ratio ◽  
State Radiation

Measurements of the R ratio are closely related to two pre quantities, the anomalous magnetic moment of the muon (g - 2), and the value of the electromagnetic fine structure constant [Formula: see text]. Hadronic contributions to both quantities can be derived via dispersion integrals, using experimental R data as input. For the phenomenological evaluations of these contributions, different energy ranges of hadronic cross section data are required. At BES-III, Initial State Radiation (ISR) from an existing Ψ(3770) dataset will be used for measurements of hadronic cross sections below [Formula: see text], while for higher energies a dedicated energy scan program will be performed up to [Formula: see text].

Pooling of Time Series and Cross Section Data

Econometrica ◽  
1969 ◽  
Vol 37 (3) ◽  
pp. 552
Author(s):  
V. K. Chetty
Keyword(s):  
Time Series ◽  
Cross Section ◽  
Cross Section Data ◽  
Section Data

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 Collinear expansion for color singlet cross sections

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Markus A. Ebert ◽  
Bernhard Mistlberger ◽  
Gherardo Vita
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Production Cross ◽  
Gluon Fusion ◽  
Building Blocks ◽  
Color Singlet ◽  
Final State ◽  
Beam Function ◽  
Kinematic Limit ◽  
State Radiation

Abstract We demonstrate how to efficiently expand cross sections for color-singlet production at hadron colliders around the kinematic limit of all final state radiation being collinear to one of the incoming hadrons. This expansion is systematically improvable and applicable to a large class of physical observables. We demonstrate the viability of this technique by obtaining the first two terms in the collinear expansion of the rapidity distribution of the gluon fusion Higgs boson production cross section at next-to-next-to leading order (NNLO) in QCD perturbation theory. Furthermore, we illustrate how this technique is used to extract universal building blocks of scattering cross section like the N-jettiness and transverse momentum beam function at NNLO.

Applications of cross section data for nuclear geochemical well logging

1986 ◽  
Vol 94 (1-4) ◽  
pp. 49-52 ◽  
Author(s):  
R. C. Hertzog ◽  
P. D. Soran ◽  
J. S. Schweitzer
Keyword(s):  
Cross Section ◽  
Well Logging ◽  
Cross Section Data ◽  
Section Data ◽  
Geochemical Well Logging

An Am/Be neutron source and its use in integral tests of differential neutron reaction cross-section data

2010 ◽  
Vol 68 (9) ◽  
pp. 1656-1661 ◽  
Author(s):  
M.S. Uddin ◽  
M.R. Zaman ◽  
S.M. Hossain ◽  
I. Spahn ◽  
S. Sudár ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Source ◽  
Reaction Cross Section ◽  
Reaction Cross ◽  
Cross Section Data ◽  
Section Data ◽  
Neutron Reaction

scholarly journals Unions and Productivity in the Public Sector: A Study of Municipal Libraries

ILR Review ◽  
1983 ◽  
Vol 36 (2) ◽  
pp. 199-213 ◽  
Author(s):  
Ronald G. Ehrenberg ◽  
Daniel R. Sherman ◽  
Joshua L. Schwarz
Keyword(s):  
Public Sector ◽  
Collective Bargaining ◽  
Empirical Analysis ◽  
Cross Section ◽  
Cross Section Data ◽  
The Public ◽  
Section Data ◽  
The Empirical Analysis

This paper develops and illustrates the use of two methodologies to analyze the effect of unions on productivity in the public sector. Although the methodologies are applicable to a wide variety of public sector functions, the focus of the paper is on municipal libraries because of the availability of relevant data. The empirical analysis, which uses 1977 cross-section data on 260 libraries, suggests that collective bargaining coverage has not significantly affected productivity in municipal libraries.

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