Measurement of D± s production asymmetry in pp collisions at $$ \sqrt{s}=7 $$ and 8 TeV

Abstract

A bstract The inclusive D s ± production asymmetry is measured in pp collisions collected by the LHCb experiment at centre-of-mass energies of $$ \sqrt{s}=7 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>7</mml:mn> </mml:math> and 8 TeV. Promptly produced D s ± mesons are used, which decay as D s ± → ϕ π ± , with ϕ → K + K − . The measurement is performed in bins of transverse momentum, p T , and rapidity, y , covering the range 2 . 5 &lt; p T &lt; 25 . 0 GeV/c and 2 . 0 &lt; y &lt; 4 . 5. No kinematic dependence is observed. Evidence of nonzero D s ± production asymmetry is found with a significance of 3.3 standard deviations.