Particle Physics in Birmingham

Particle Physics Seminar

1700 Tuesday 21st Jan. in Poynting LLT
Note changes in date, time, location

(tea, coffee and biscuits served at 16:45)

Measurement of the cross section for prompt J/ψ with W± production at sqrt(s)=7 TeV at ATLAS

Constantinos Melachrinos (University of Chicago)


The process pp → W± J/ψ provides a powerful probe of the production mechanism of charmonium in hadronic collisions, and is also sensitive to multiple parton interactions. Using the 2011 ATLAS dataset of 4.5 fb−1 of sqrt(s) = 7 TeV pp collisions, the first observation is made of the production of W± + prompt J/ψ events in hadronic collisions, using W± → μ νμ and J/ψ → μ+μ. A yield of 27.4 +7.5 -6.5 W± + prompt J/ψ events is observed, with a statistical significance of 5.1σ. The production ratio to inclusive W± boson production is measured, and the double parton scattering contribution is estimated.