Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F46747885%3A24510%2F17%3A00005281" target="_blank" >RIV/46747885:24510/17:00005281 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1140/epjc/s10052-017-4716-x" target="_blank" >http://dx.doi.org/10.1140/epjc/s10052-017-4716-x</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1140/epjc/s10052-017-4716-x" target="_blank" >10.1140/epjc/s10052-017-4716-x</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

Popis výsledku v původním jazyce

Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q2 > 1(GeV/c)2. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam impinging on a polarised 6 LiD target. By analysing the full range in hadron transverse momentum p T , the different p T -dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δ g/ g is evaluated at leading order in pQCD at a hard scale of μ 2 = ⟨ Q 2 ⟩ = 3 (GeV / c) 2 . It is determined in three intervals of the nucleon momentum fraction carried by gluons, x g , covering the range 0.04 < xg < 0.28 and does not exhibit a significant dependence on x g . The average over the three intervals, ⟨ Δ g/ g⟩ = 0.113 ± 0. 038 (stat.) ± 0. 036 (syst.) at ⟨ x g ⟩ ≈ 0.10 , suggests that the gluon polarisation is positive in the measured x g range.

Název v anglickém jazyce

Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

Popis výsledku anglicky

Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q2 > 1(GeV/c)2. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam impinging on a polarised 6 LiD target. By analysing the full range in hadron transverse momentum p T , the different p T -dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δ g/ g is evaluated at leading order in pQCD at a hard scale of μ 2 = ⟨ Q 2 ⟩ = 3 (GeV / c) 2 . It is determined in three intervals of the nucleon momentum fraction carried by gluons, x g , covering the range 0.04 < xg < 0.28 and does not exhibit a significant dependence on x g . The average over the three intervals, ⟨ Δ g/ g⟩ = 0.113 ± 0. 038 (stat.) ± 0. 036 (syst.) at ⟨ x g ⟩ ≈ 0.10 , suggests that the gluon polarisation is positive in the measured x g range.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

<a href="/cs/project/LG13031" target="_blank" >LG13031: Spolupráce ČR s CERN</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

European Physical Journal C

ISSN

1434-6052

e-ISSN

—

Svazek periodika

77

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

12

Strana od-do

—

Kód UT WoS článku

000399153900002

EID výsledku v databázi Scopus

2-s2.0-85016958819