Study of double parton scattering in photon + 3 jets final state in proton-proton collision at √s = 7 TeV
You-Hao Chang1*, Paolo Bartalini2, Yuan Chao1, Min-Zu Wang1, Shin-Shan Yu3
1物理系, 台灣大學, 台北市, Taiwan
2物理系, 華中師範大學, 武漢, China
3物理系, 中央大學, 中壢市, Taiwan
* presenting author:張祐豪, email:yuhow@hep1.phys.ntu.edu.tw
Distributions sensitive to double parton scattering are investigated in the photon + 3 jets final state in proton-proton collisions at a centre-of-mass energy of 7 TeV. The data were collected by the CMS experiment at the LHC with an integrated luminosity of 36 pb^-1 in 2010.
A cross section is also measured for a final state with a photon and a jet of transverse momentum Pt > 75 GeV together with 2 jets of Pt > 20 GeV, where the photon and jets are within the fiducial volume of the CMS detector.
The differential cross sections are measured as a function of the difference in azimuthal angles and the transverse momentum balance between the photon-jet pait and the di-jet pair.
Introducing additional contributions from doulbe parton scattering into Monte-Carlo predictions can make them have better agreement with the measured data.


Keywords: CMS, LHC , underlying event, MPI, DPS