Measurement of the inclusive J/ψ polarization at forward rapidity in pp collisions at √s=8 TeV
EUROPEAN PHYSICAL JOURNAL C, cilt.78, sa.7, 2018 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 78 Sayı: 7
- Basım Tarihi: 2018
- Doi Numarası: 10.1140/epjc/s10052-018-6027-2
- Dergi Adı: EUROPEAN PHYSICAL JOURNAL C
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Yıldız Teknik Üniversitesi Adresli: Hayır
Özet
We report on the measurement of the inclusive J/psi polarization parameters in pp collisions at a center of mass energy root s = 8 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.23 pb(-1) J/psi resonances are reconstructed in their di-muon decay channel in the rapidity interval 2.5 < y < 4.0 and over the transverse-momentum interval 2 < pT < 15 GeV/c. The three polarization parameters (lambda(theta), lambda(phi), lambda(theta phi)) are measured as a function of pT both in the helicity and Collins-Soper reference frames. The measured J/psi polarization parameters are found to be compatible with zero within uncertainties, contrary to expectations from all available predictions. The results are compared with the measurement in pp collisions at root s = 7 TeV.