Initial-State Radiation in Inclusive Photon Spectroscopy from Electron-Positron Annihilation

Exclusive hyperon-antihyperon production provides a unique insight for understanding of the intrinsic dynamics when strangeness is involved. In this paper, we review the results of ΛΛ¯ production via different reactions from various experiments, e.g., via p¯p annihilation from the LEAR experiment PS185, via electron-positron annihilation using the energy scan method at the CLEO-c and BESIII experiments and the initial-state-radiation approach utilized at the BaBar experiment. The production cross section of ΛΛ¯ near the threshold is sensitive to QCD based prediction. Experimental high precision data for p¯p→Λ¯Λ close to the threshold region is obtained. The cross section of e+e−→ΛΛ¯ is measured from its production threshold to high energy. A non-zero cross section for e+e−→ΛΛ¯ near threshold is observed at BaBar and BESIII, which is in disagreement with the pQCD prediction. However, more precise data is needed to confirm this observation. Future experiments, utilizing p¯p reaction such as PANDA experiment or electron-positron annihilation such as the BESIII and BelleII experiments, are needed to extend the experimental data and to understand the ΛΛ¯ production.

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Electroweak Effects in e+e−→ZH Process

Symmetry ◽

10.3390/sym13071256 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1256

Author(s):

Andrej Arbuzov ◽

Serge Bondarenko ◽

Lidia Kalinovskaya ◽

Renat Sadykov ◽

Vitaly Yermolchyk

Keyword(s):

Structure Function ◽

Cross Section ◽

Higher Order ◽

Initial State Radiation ◽

Event Generator ◽

Radiative Corrections ◽

Initial State ◽

Electron Positron ◽

Electroweak Radiative Corrections ◽

State Radiation

Electroweak radiative corrections to the cross-section of the process e+e−→ZH are considered. The complete one-loop electroweak radiative corrections are evaluated with the help of the SANC system. Higher-order contributions of the initial-state radiation are computed in the QED structure function formalism. Numerical results are produced by a new version of the ReneSANCe event generator and MCSANCee integrator for the conditions of future electron-positron colliders. The resulting theoretical uncertainty in the description of this process is estimated.

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Final-state radiation in electron-positron annihilation into a pion pair

The European Physical Journal C ◽

10.1140/epjc/s2004-02109-7 ◽

2005 ◽

Vol 40 (1) ◽

pp. 41-54 ◽

Cited By ~ 23

Author(s):

S. Dubinsky ◽

A. Korchin ◽

N. Merenkov ◽

G. Pancheri ◽

O. Shekhovtsova

Keyword(s):

Positron Annihilation ◽

Pion Pair ◽

Final State ◽

Final State Radiation ◽

Electron Positron Annihilation ◽

Electron Positron ◽

State Radiation

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Time-like Proton Form Factors with Initial State Radiation Technique

Symmetry ◽

10.3390/sym14010091 ◽

2022 ◽

Vol 14 (1) ◽

pp. 91

Author(s):

Dexu Lin ◽

Alaa Dbeyssi ◽

Frank Maas

Keyword(s):

Experimental Studies ◽

Form Factors ◽

Initial State Radiation ◽

Initial State ◽

Radiation Process ◽

Electron Positron ◽

Born Cross Section ◽

State Radiation ◽

Radiation Technique ◽

Proton Form Factors

Electromagnetic form factors are fundamental quantities describing the internal structure of hadrons. They can be measured with scattering processes in the space-like region and annihilation processes in the time-like region. The two regions are connected by crossing symmetry. The measurements of the proton electromagnetic form factors in the time-like region using the initial state radiation technique are reviewed. Recent experimental studies have shown that initial state radiation processes at high luminosity electron-positron colliders can be effectively used to probe the electromagnetic structure of hadrons. The BABAR experiment at the B-factory PEP-II in Stanford and the BESIII experiment at BEPCII (an electron positron collider in the τ-charm mass region) in Beijing have measured the time-like form factors of the proton using the initial state radiation process e+e−→pp¯γ. The two kinematical regions where the photon is emitted from the initial state at small and large polar angles have been investigated. In the first case, the photon is in the region not covered by the detector acceptance and is not detected. The Born cross section and the proton effective form factor have been measured over a wide and continuous range of the the momentum transfer squared q2 from the threshold up to 42 (GeV/c)2. The ratio of electric and magnetic form factors of the proton has been also determined. In this report, the theoretical aspect and the experimental studies of the initial state radiation process e+e−→pp¯γ are described. The measurements of the Born cross section and the proton form factors obtained in these analyses near the threshold region and in the relatively large q2 region are examined. The experimental results are compared to the predictions from theory and models. Their impact on our understanding of the nucleon structure is discussed.

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Initial state radiation correction and its effect on data-taking scheme for σB(e+e−→ ZH) measurement

International Journal of Modern Physics A ◽

10.1142/s0217751x19501185 ◽

2019 ◽

Vol 34 (21) ◽

pp. 1950118

Author(s):

Shuang Han ◽

Gang Li ◽

Xiang Zhou ◽

Quan-Lin Jie

Keyword(s):

Cross Section ◽

Correction Factor ◽

Line Shape ◽

Initial State Radiation ◽

Text Line ◽

Initial State ◽

Electron Positron ◽

Born Cross Section ◽

State Radiation ◽

Shape Uncertainty

The measurement of Born cross-section of [Formula: see text] process is one of the major goals of the future Circular Electron Positron Collider, which may reach a precision of 0.5% at 240 GeV. Such unprecedented precision must be guaranteed by both theoretical and experimental sides, such as the calculations of high order corrections, the knowledge of the [Formula: see text] line shape. Uncertainty of the radiative correction factor at 240 GeV caused by the [Formula: see text] line shape is evaluated in this work. Therefore, dedicated data-taking schemes are proposed in order to precisely calculate the ISR correction factor.

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