Abstract

The production of a Z boson in association with a J/ψ meson in proton--proton collisions probes the production mechanisms of quarkonium and heavy flavour in association with vector bosons, and allows studies of multiple parton scattering. Using 20.3 fb−1 of data collected with the ATLAS experiment at the LHC, in pp collisions at sqrt(s)=8 TeV, the first measurement of associated Z+J/ψ production is presented for both prompt and non-prompt J/ψ production, with both signatures having a significance in excess of 5σ. The inclusive production cross-sections for Z boson production (in μ+μ− or e+e− decay modes) in association with prompt and non-prompt J/ψ(→μ+μ−) are measured relative to the inclusive production rate of Z bosons in the same fiducial volume to be (88±16±6)×10−8 and (157±22±10)×10−8 respectively. Normalised differential production cross-sections are also determined as a function of the J/ψ transverse momentum. The fraction of signal events arising from single and double parton scattering is estimated, and a lower limit of 5.3 (3.7) mb at 68 (95)% confidence level is placed on the effective cross-section regulating double parton interactions.

Autore Pugliese

• Spagnolo Stefania Antonia , Ventura Andrea , Gorini Edoardo

Tutti gli autori

• G. AAD , G. CHIODINI , E. GORINI , M. PRIMAVERA , S. SPAGNOLO , A. VENTURA , ET AL.

Titolo volume/Rivista

THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS

Anno di pubblicazione

2015

ISSN

1434-6044

ISBN

Non Disponibile

Numero di citazioni Wos

11

Ultimo Aggiornamento Citazioni

28/04/2018

Numero di citazioni Scopus

15

Ultimo Aggiornamento Citazioni

28/04/2018

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile