Studies of dijet transverse momentum balance and pseudorapidity distributions in pPb collisions at sNN=5.02 TeV

Dijet production has been measured in <math><mrow><mi mathvariant="normal">p</mi><mi mathvariant="normal">Pb</mi></mrow></math> collisions at a nucleon–nucleon centre-of-mass energy of 5.02 <math><mrow><mspace width="0.166667em"/><mtext>TeV</mtext></mrow></math> . A data sample corresponding to an integrated luminosity of 35 <math><mrow><mspace width="0.166667em"/><msup><mtext>nb</mtext><mrow><mo>-</mo><mn>1</mn></mrow></msup></mrow></math> was collected using the Compact Muon Solenoid detector at the Large Hadron Collider. The dijet transverse momentum balance, azimuthal angle correlations, and pseudorapidity distributions are studied as a function of the transverse energy in the forward calorimeters ( <math><msubsup><mi>E</mi><mrow><mi mathvariant="normal">T</mi></mrow><mrow><mn>4</mn><mo>&lt;</mo><mo stretchy="false">|</mo><mi mathvariant="italic">η</mi><mo stretchy="false">|</mo><mo>&lt;</mo><mrow><mn>5.2</mn></mrow></mrow></msubsup></math> ). For <math><mrow><mi mathvariant="normal">p</mi><mi mathvariant="normal">Pb</mi></mrow></math> collisions, the dijet transverse momentum ratio and the width of the distribution of dijet azimuthal angle difference are comparable to the same quantities obtained from a simulated <math><mrow><mi mathvariant="normal">p</mi><mi mathvariant="normal">p</mi></mrow></math> reference and insensitive to <math><msubsup><mi>E</mi><mrow><mi mathvariant="normal">T</mi></mrow><mrow><mn>4</mn><mo>&lt;</mo><mo stretchy="false">|</mo><mi mathvariant="italic">η</mi><mo stretchy="false">|</mo><mo>&lt;</mo><mrow><mn>5.2</mn></mrow></mrow></msubsup></math> . In contrast, the mean value of the dijet pseudorapidity is found to change monotonically with increasing <math><msubsup><mi>E</mi><mrow><mi mathvariant="normal">T</mi></mrow><mrow><mn>4</mn><mo>&lt;</mo><mo stretchy="false">|</mo><mi mathvariant="italic">η</mi><mo stretchy="false">|</mo><mo>&lt;</mo><mrow><mn>5.2</mn></mrow></mrow></msubsup></math> , indicating a correlation between the energy emitted at large pseudorapidity and the longitudinal motion of the dijet frame. The pseudorapidity distribution of the dijet system in minimum bias <math><mrow><mi mathvariant="normal">p</mi><mi mathvariant="normal">Pb</mi></mrow></math> collisions is compared with next-to-leading-order perturbative QCD predictions obtained from both nucleon and nuclear parton distribution functions, and the data more closely match the latter.