Beam helicity asymmetries in K+Lambda electroproduction off the proton at low Q(2)
Result description
Beam helicity asymmetries in the (e) over right arrowp -> e'K+Lambda reaction have been measured at unprecedentedly low four-momentum transfers < Q(2)> = 0.05 (GeV/c)(2). At the Mainz Microtron (MAMI), the experiment was performed with a longitudinally polarized beam and an out-of-plane detection of the scattered electron. This experiment probed the associated helicity-dependent structure function d sigma(LT')/d Omega(c.m.)(K), which is sensitive to the details of resonances of the proton. The results were compared to models for kaon electroproduction using effective Lagrangians. The MAMI data is not supporting the Kaon-Maid isobar model, which uses strong longitudinal couplings of the virtual photon to nucleon resonances and predicts a strong peaking of the structure function at forward angles and low Q(2). The data is also in disagreement with a Regge-plus-resonance model that predicts the incorrect sign of the structure function. The combination of the MAMI results with data taken at higher four-momentum transfers measured at Jefferson Lab indicates a smooth transition in Q(2) without significant changes of the interference pattern in the electroproduction process.
Keywords
The result's identifiers
Result code in IS VaVaI
Result on the web
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Beam helicity asymmetries in K+Lambda electroproduction off the proton at low Q(2)
Original language description
Beam helicity asymmetries in the (e) over right arrowp -> e'K+Lambda reaction have been measured at unprecedentedly low four-momentum transfers < Q(2)> = 0.05 (GeV/c)(2). At the Mainz Microtron (MAMI), the experiment was performed with a longitudinally polarized beam and an out-of-plane detection of the scattered electron. This experiment probed the associated helicity-dependent structure function d sigma(LT')/d Omega(c.m.)(K), which is sensitive to the details of resonances of the proton. The results were compared to models for kaon electroproduction using effective Lagrangians. The MAMI data is not supporting the Kaon-Maid isobar model, which uses strong longitudinal couplings of the virtual photon to nucleon resonances and predicts a strong peaking of the structure function at forward angles and low Q(2). The data is also in disagreement with a Regge-plus-resonance model that predicts the incorrect sign of the structure function. The combination of the MAMI results with data taken at higher four-momentum transfers measured at Jefferson Lab indicates a smooth transition in Q(2) without significant changes of the interference pattern in the electroproduction process.
Czech name
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Czech description
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Classification
Type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Result continuities
Project
GA15-04301S: Interactions of hadrons with nucleons and nuclei
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
European Physical Journal A
ISSN
1434-6001
e-ISSN
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Volume of the periodical
53
Issue of the periodical within the volume
10
Country of publishing house
US - UNITED STATES
Number of pages
10
Pages from-to
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UT code for WoS article
000413306000001
EID of the result in the Scopus database
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Basic information
Result type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
OECD FORD
Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Year of implementation
2017