Measurement of quarkonium production at forward rapidity in pp collisions at s=7 TeV

The inclusive production cross sections at forward rapidity of <math><mrow><mi mathvariant="normal">J</mi><mo stretchy="false">/</mo><mi mathvariant="italic">ψ</mi></mrow></math> , <math><mrow><mi mathvariant="italic">ψ</mi><mo stretchy="false">(</mo><mrow><mn>2</mn><mi mathvariant="normal">S</mi></mrow><mo stretchy="false">)</mo></mrow></math> , <math><mi mathvariant="normal">Υ</mi></math> (1S) and <math><mi mathvariant="normal">Υ</mi></math> (2S) are measured in <math><mi mathvariant="normal">pp</mi></math> collisions at <math><mrow><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>7</mn><mspace width="3.33333pt"/><mi mathvariant="normal">TeV</mi></mrow></math> with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb <math><msup><mrow/><mrow><mo>-</mo><mn>1</mn></mrow></msup></math> . Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the <math><mrow><msup><mi mathvariant="italic">μ</mi><mo>+</mo></msup><msup><mi mathvariant="italic">μ</mi><mo>-</mo></msup></mrow></math> invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum <math><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math> and rapidity <math><mi>y</mi></math> , over the ranges <math><mrow><mn>0</mn><mo>&lt;</mo><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub><mo>&lt;</mo><mn>20</mn></mrow></math>  GeV/c for <math><mrow><mi mathvariant="normal">J</mi><mo stretchy="false">/</mo><mi mathvariant="italic">ψ</mi></mrow></math> , <math><mrow><mn>0</mn><mo>&lt;</mo><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub><mo>&lt;</mo><mn>12</mn></mrow></math>  GeV/c for all other resonances and for <math><mrow><mn>2.5</mn><mo>&lt;</mo><mi>y</mi><mo>&lt;</mo><mn>4</mn></mrow></math> . The measured cross sections integrated over <math><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math> and <math><mi>y</mi></math> , and assuming unpolarized quarkonia, are: <math><mrow><msub><mi mathvariant="italic">σ</mi><mrow><mi mathvariant="normal">J</mi><mo stretchy="false">/</mo><mi mathvariant="italic">ψ</mi></mrow></msub><mo>=</mo><mn>6.69</mn><mo>±</mo><mn>0.04</mn><mo>±</mo><mn>0.63</mn></mrow></math>  <math><mi mathvariant="normal">μ</mi></math> b, <math><mrow><msub><mi mathvariant="italic">σ</mi><mrow><mi mathvariant="italic">ψ</mi><mo stretchy="false">(</mo><mrow><mn>2</mn><mi mathvariant="normal">S</mi></mrow><mo stretchy="false">)</mo></mrow></msub><mo>=</mo><mn>1.13</mn><mo>±</mo><mn>0.07</mn><mo>±</mo><mn>0.19</mn></mrow></math>  <math><mi mathvariant="normal">μ</mi></math> b, <math><mrow><msub><mi mathvariant="italic">σ</mi><mrow><mi mathvariant="normal">Υ</mi><mo stretchy="false">(</mo><mrow><mn>1</mn><mi mathvariant="normal">S</mi></mrow><mo stretchy="false">)</mo></mrow></msub><mo>=</mo><mn>54.2</mn><mspace width="0.166667em"/><mo>±</mo><mspace width="0.166667em"/><mn>5.0</mn><mo>±</mo><mn>6.7</mn></mrow></math>  nb and <math><mrow><msub><mi mathvariant="italic">σ</mi><mrow><mi mathvariant="normal">Υ</mi><mo stretchy="false">(</mo><mrow><mn>2</mn><mi mathvariant="normal">S</mi></mrow><mo stretchy="false">)</mo></mrow></msub><mo>=</mo><mn>18.4</mn><mspace width="0.166667em"/><mo>±</mo><mspace width="0.166667em"/><mn>3.7</mn><mspace width="0.166667em"/><mo>±</mo><mspace width="0.166667em"/><mn>2.9</mn></mrow></math>  nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models.