The differential production cross section of the ϕ (1020) meson in s = 7 TeV pp collisions measured with the ATLAS detector

A measurement is presented of the <math><mrow><mi mathvariant="italic">ϕ</mi><mo>×</mo><mi mathvariant="script">BR</mi><mo stretchy="false">(</mo><mi mathvariant="italic">ϕ</mi><mo stretchy="false">→</mo><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>-</mo></msup><mo stretchy="false">)</mo></mrow></math> production cross section at <math><msqrt><mi>s</mi></msqrt></math> = 7 TeV using <math><mrow><mi>p</mi><mi>p</mi></mrow></math> collision data corresponding to an integrated luminosity of 383 <math><mrow><mi mathvariant="normal">μ</mi><msup><mi mathvariant="normal">b</mi><mrow><mo>-</mo><mn>1</mn></mrow></msup></mrow></math> , collected with the ATLAS experiment at the LHC. Selection of <math><mi mathvariant="italic">ϕ</mi></math> (1020) mesons is based on the identification of charged kaons by their energy loss in the pixel detector. The differential cross section is measured as a function of the transverse momentum, <math><msub><mi>p</mi><mrow><mi mathvariant="normal">T</mi><mo>,</mo><mi mathvariant="italic">ϕ</mi></mrow></msub></math> , and rapidity, <math><msub><mi>y</mi><mi mathvariant="italic">ϕ</mi></msub></math> , of the <math><mi mathvariant="italic">ϕ</mi></math> (1020) meson in the fiducial region 500 <math><mrow><mo>&lt;</mo><msub><mi>p</mi><mrow><mi mathvariant="normal">T</mi><mo>,</mo><mi mathvariant="italic">ϕ</mi></mrow></msub><mo>&lt;</mo></mrow></math> 1200 MeV, <math><mrow><mrow><mo stretchy="false">|</mo></mrow><msub><mi>y</mi><mi mathvariant="italic">ϕ</mi></msub><mrow><mo stretchy="false">|</mo><mo>&lt;</mo></mrow></mrow></math> 0.8, kaon <math><mrow><msub><mi>p</mi><mrow><mi mathvariant="normal">T</mi><mo>,</mo><mi>K</mi></mrow></msub><mo>&gt;</mo></mrow></math> 230 MeV and kaon momentum <math><mrow><msub><mi>p</mi><mi>K</mi></msub><mo>&lt;</mo></mrow></math> 800 MeV. The integrated <math><mrow><mi mathvariant="italic">ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></mrow></math> -meson production cross section in this fiducial range is measured to be <math><mrow><msub><mi mathvariant="italic">σ</mi><mi mathvariant="italic">ϕ</mi></msub><mo>×</mo><mi mathvariant="script">BR</mi><mrow><mo stretchy="false">(</mo><mi mathvariant="italic">ϕ</mi><mo stretchy="false">→</mo><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>-</mo></msup><mo stretchy="false">)</mo></mrow></mrow></math> = 570 <math><mo>±</mo></math> 8 (stat) <math><mo>±</mo></math> 66 (syst) <math><mo>±</mo></math> 20 (lumi) <math><mrow><mi mathvariant="normal">μ</mi><mi mathvariant="normal">b</mi></mrow></math> .