Measurement of spin correlation in top-antitop quark events and search for stop quark pair production in proton-proton collisions at sqrt(s) = 8 TeV using the ATLAS detector

Abstract

A measurement of spin correlation in tt¯ production is presented using data collected with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb−1. The correlation between the top and antitop quark spins is extracted from dilepton tt¯ events by using the difference in azimuthal angle between the two charged leptons in the laboratory frame. In the helicity basis the measured degree of correlation corresponds to Ahelicity=0.38±0.04, in agreement with the Standard Model prediction. A search is performed for pair production of top squarks with masses close to the top quark mass decaying to predominantly right-handed top quarks and a light neutralino, the lightest supersymmetric particle. Top squarks with masses between the top quark mass and 191 GeV are excluded at the 95% confidence level.


Tutti gli autori

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

Titolo volume/Rivista

PHYSICAL REVIEW LETTERS


Anno di pubblicazione

2015

ISSN

0031-9007

ISBN

Non Disponibile


Numero di citazioni Wos

15

Ultimo Aggiornamento Citazioni

28/04/2018


Numero di citazioni Scopus

35

Ultimo Aggiornamento Citazioni

22/04/2018


Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile