A measurement of the J/ψ and ψ(2S) meson production cross sections in pp collisions at data at √s = 7 TeV with the CMS experiment at the LHC. The data correspond to an integrated luminosity of 36.7 pb−1. The two cross sections and their ratio have been measured as a function of the meson transverse momentum pT (up to 70 GeV/c for the J/ψ and to 30 GeV/c for the ψ(2S)) in several rapidity ranges, assuming null polarization in the prompt production. The b-hadron component is then determined from a fit to the decay length distribution. The differential cross- section ratio between the two states is also computed, cancelling out many systematic uncertainties.
Figure | Caption |
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ALLmassfitJpsi_pT12-15_y09-12.pdf | J/ψ mass distribution fit in the bin: 0.9 < abs(y) < 1.2, 12.0 < pT < 15.0 GeV/c. |
ALLmassfitPsip_pT8-9_y0-12.pdf | J/ψ and ψ(2S) mass distribution fit in the bin: abs(y) < 1.2, 8.0 < pT < 9.0 GeV/c. |
XS_all_alsoOld_sg_jpsi.pdf | Measured differential cross section for J/ψ inclusive production as a function of pT for five rapidity bins, plotted with the results published in [4], which extend to a lower pT range. (Multiplicative factors - showing as additive offsets in log scale - are used to achieve a convenient graphical separation of the measurements from different rapidity bins.) |
2D_ALLtimefitJpsi_pT8-9_y0-09_Log.pdf | Projection of a J/ψ two-dimensional fit on the J/ψ decay length dimension in the bin: abs(y) < 0.9, 8.0 < pT < 9.0 GeV/c. The plot below show the distribution of the pulls. |
2D_ALLtimefitPsip_pT12-15_y16-24_Log.pdf | Projection of a J/ψ-ψ(2S) two-dimensional fit on the ψ(2S) decay length dimension in the bin: 1.6 < abs(y) < 2.4, 12.0 < pT < 15.0 GeV/c. The plots below the distributions show the fit pulls. |
XS_all_p_sg_jpsi_teor.pdf | Measured differential cross section for prompt J/ψ production as a function of pT for the different rapidity bins. The yellow and blue coloured histograms indicate the theoretical predictions from NRQCD calculations, the lines are added only for illustrative purposes. |
XS_all_p_sg_psi2s_teor.pdf | Measured differential cross section for prompt ψ(2S) production as a function of pT for the different rapidity bins. The yellow and blue coloured histograms indicate the theoretical predictions from NRQCD calculations, the lines are added only for illustrative purposes. |
XS_all_b_sg_jpsi_teor.pdf | Measured differential cross section for non-prompt J/ψ production as a function of pT for the different rapidity bins. The yellow and blue coloured histograms indicate the theoretical predictions from FONLL calculations, the lines are added only for illustrative purposes. |
XS_all_b_sg_psi2s_teor.pdf | Measured differential cross section for non-prompt ψ(2S) production as a function of pT for the different rapidity bins. The yellow and blue coloured histograms indicate the theoretical predictions from FONLL calculations, the lines are added only for illustrative purposes |
XS_all_p_sg_noAcc_jpsi.pdf | Measured differential cross section for prompt J/psi production as a function of pT for the different rapidity bins. The error bars on data points include all the statistical and systematic contributions except luminosity. The measurements have been offset by the numerical values given in the legend for easier viewing. The results are not corrected for the muon acceptance |
XS_all_p_sg_noAcc_psi2s.pdf | Measured differential cross section for prompt psi(2S) production as a function of pT for the different rapidity bins. The error bars on data points include all the statistical and systematic contributions except luminosity. The measurements have been offset by the numerical values given in the legend for easier viewing. The results are not corrected for the muon acceptance. |
XS_all_b_sg_noAcc_jpsi.pdf | Measured differential cross section for non-prompt J/psi production as a function of pT for the different rapidity bins. The error bars on data points include all the statistical and systematic contributions except luminosity. The measurements have been offset by the numerical values given in the legend for easier viewing. The result is not corrected for the muon acceptance. |
XS_all_b_sg_noAcc_psi2s.pdf | Measured differential cross section for non-prompt psi(2S) production as a function of pT for the different rapidity bins. The error bars on data points include all the statistical and systematic contributions except luminosity. The measurements have been offset by the numerical values given in the legend for easier viewing. The result is not corrected for the muon acceptance. |
bfrac_0-12.pdf | Fitted J/ψ and ψ(2S) b-fractions plotted as a function of pT for abs(y) < 1.2. |
bfrac_12-16.pdf | Fitted J/ψ and ψ(2S) b-fractions plotted as a function of pT for 1.2 < abs(y) < 1.6. |
bfrac_16-24.pdf | Fitted J/ψ and ψ(2S) b-fractions plotted as a function of pT for 1.6 < abs(y) < 2.4. |
PRatio_av.pdf | Measured value of the &psi(2S) to J/&psi differential cross-section ratio, for prompt production, averaged over rapidity and plotted as a function of pT. It also includes the comparison with the NRQCD prediction. The shaded bands show the uncertainties on the theoretical predictions. The error bars give the total uncertainties on the measurements; polarization uncertainties are not included. |
BRatio_av.pdf | Measured value of the &psi(2S) to J/&psi differential cross-section ratio, for non-prompt production, averaged over rapidity and plotted as a function of pT. It also shows the predictions of the theoretical models used to determine BR(B -> &psi(2S) X), after the latter have been rescaled to the fitted value given in Eq. (12). The shaded bands show the uncertainties on the theoretical predictions. The error bars give the total uncertainties on the measurements. |
All results are expressed in nb / (GeV/c).
For the non-prompt J/psi, in order to ease comparison with NLO MC generators we also provide the total cross section in the visible region of the phase space R:
where R is defined by the single muon criteria:
and the J/psi criteria:
Fraction of J/psi from b-hadrons in pT and |y| bins. The b-fraction column shows the statistical and systematic errors.
Fraction of psi(2S) from b-hadrons in pT and |y| bins. The b-fraction column shows the statistical and systematic errors and the b-fraction ratio over the J/psi is also shown.
Cross sections as a function of y and pT, assuming four polarization scenarios, namely fully longitudinal in the Collins-Soper frame (CS_L), fully transverse in the Collins-Soper frame (CS_T), fully longitudinal in the helicity frame (HX_L), fully trasverse in the helicity frame (HX_T). The results are expressed as a difference with respect to the values measured assuming null-polarization and listed in tables above, and are expressed in nb / (GeV/c).
I | Attachment | History | Action | Size | Date | Who | Comment |
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2D_ALLtimefitJpsi_pT8-9_y0-09_Log.pdf | r2 r1 | manage | 24.7 K | 2011-11-23 - 10:20 | RobertoCovarelli | Projection of a J/ψ two-dimensional fit on the lJ/ψ dimension in the bin: |y| < 0.9, 8.0 < pT < 9.0 GeV/c. The plot below show the distribution of the pulls. | |
2D_ALLtimefitPsip_pT12-15_y16-24_Log.pdf | r2 r1 | manage | 24.3 K | 2011-11-23 - 10:20 | RobertoCovarelli | Projection of a J/ψ-ψ(2S) two-dimensional fit on the lψ(2S) dimension in the bin: 1.6 < |y| < 2.4, 12.0 < pT < 15.0 GeV/c. The plots below the distributions show the fit pulls. | |
ALLmassfitJpsi_pT12-15_y09-12.pdf | r2 r1 | manage | 19.4 K | 2011-11-23 - 10:21 | RobertoCovarelli | J/ψ mass distribution fit in the bin: 0.9 < |y| < 1.2, 12.0 < pT < 15.0 GeV/c. | |
ALLmassfitPsip_pT8-9_y0-12.pdf | r2 r1 | manage | 26.4 K | 2011-11-23 - 10:21 | RobertoCovarelli | J/ψ and ψ(2S) mass distribution fit in the bin: |y| < 1.2, 8.0 < pT < 9.0 GeV/c. | |
BRatio_av.pdf | r1 | manage | 16.7 K | 2011-11-23 - 10:40 | RobertoCovarelli | Measured value of the psi(2S) to J/psi differential cross-section ratio, for prompt (left) and non-prompt (right) production, averaged over rapidity and plotted as a function of pT. The left plot also includes the comparison with the NRQCD prediction, while the right plot shows the predictions of the theoretical models used to determine BR(B -> psi(2S) X), after the latter have been rescaled to the fitted value given in Eq.~(12). The shaded bands show the uncertainties on the theoretical predictions. The error bars give the total uncertainties on the measurements; polarization uncertainties are not included. | |
PRatio_av.pdf | r1 | manage | 15.3 K | 2011-11-23 - 10:39 | RobertoCovarelli | Measured value of the psi(2S) to J/psi differential cross-section ratio, for prompt (left) and non-prompt (right) production, averaged over rapidity and plotted as a function of pT. The left plot also includes the comparison with the NRQCD prediction, while the right plot shows the predictions of the theoretical models used to determine BR(B -> psi(2S) X), after the latter have been rescaled to the fitted value given in Eq.~(12). The shaded bands show the uncertainties on the theoretical predictions. The error bars give the total uncertainties on the measurements; polarization uncertainties are not included. | |
XS_all_alsoOld_sg_jpsi.pdf | r2 r1 | manage | 19.7 K | 2011-11-23 - 10:24 | RobertoCovarelli | Measured differential cross section for J/ψ inclusive production as a function of pT for five rapidity bins, plotted with the results published in [4], which extend to a lower pT range. (multiplicative factors - showing as additive offsets in log scale - are used to achieve a convenient graphical separation of the measurements from different rapidity bins.) | |
XS_all_b_sg_jpsi_teor.pdf | r2 r1 | manage | 27.5 K | 2011-11-23 - 10:25 | RobertoCovarelli | Measured differential cross section for non-prompt J/ψ (left) and ψ(2S) (right) pro- duction as a function of pT for the different rapidity bins. The yellow and blue coloured his- tograms indicate the theoretical predictions from FONLL calculations, the lines are added only for illustrative purposes. | |
XS_all_b_sg_noAcc_jpsi.pdf | r1 | manage | 18.1 K | 2011-11-23 - 10:35 | RobertoCovarelli | Measured differential cross section for non-prompt J/psi (left) and psi(2S) (right) production as a function of pT for the different rapidity bins. The error bars on data points include all the statistical and systematic contributions except luminosity. The measurements have been offset by the numerical values given in the legend for easier viewing. The result is not corrected for the muon acceptance. | |
XS_all_b_sg_noAcc_psi2s.pdf | r1 | manage | 16.2 K | 2011-11-23 - 10:36 | RobertoCovarelli | Measured differential cross section for non-prompt J/psi (left) and psi(2S) (right) production as a function of pT for the different rapidity bins. The error bars on data points include all the statistical and systematic contributions except luminosity. The measurements have been offset by the numerical values given in the legend for easier viewing. The result is not corrected for the muon acceptance. | |
XS_all_b_sg_psi2s_teor.pdf | r3 r2 r1 | manage | 18.5 K | 2011-11-23 - 10:59 | RobertoCovarelli | Measured differential cross section for non-prompt ψ(2S) (right) production as a function of pT for the different rapidity bins. The yellow and blue coloured histograms indicate the theoretical predictions from FONLL calculations, the lines are added only for illustrative purposes. | |
XS_all_p_sg_jpsi_teor.pdf | r2 r1 | manage | 28.1 K | 2011-11-23 - 10:26 | RobertoCovarelli | Measured differential cross section for prompt J/ψ production as a function of pT for the different rapidity bins. The yellow and blue coloured histograms indicate the theoretical predictions from NRQCD calculations, the lines are added only for illustrative purposes. | |
XS_all_p_sg_noAcc_jpsi.pdf | r1 | manage | 18.1 K | 2011-11-23 - 10:32 | RobertoCovarelli | Measured differential cross section for prompt J/psi (left) and psi(2S) (right) production as a function of pT for the different rapidity bins. The error bars on data points include all the statistical and systematic contributions except luminosity. The measurements have been offset by the numerical values given in the legend for easier viewing. The results are not corrected for the muon acceptance. | |
XS_all_p_sg_noAcc_psi2s.pdf | r1 | manage | 16.2 K | 2011-11-23 - 10:34 | RobertoCovarelli | Measured differential cross section for prompt J/psi (left) and psi(2S) (right) production as a function of pT for the different rapidity bins. The error bars on data points include all the statistical and systematic contributions except luminosity. The measurements have been offset by the numerical values given in the legend for easier viewing. The results are not corrected for the muon acceptance. | |
XS_all_p_sg_psi2s_teor.pdf | r2 r1 | manage | 18.5 K | 2011-11-23 - 10:27 | RobertoCovarelli | Measured differential cross section for prompt ψ(2S) production as a function of pT for the different rapidity bins. The yellow and blue coloured histograms indicate the theoretical predictions from NRQCD calculations, the lines are added only for illustrative purposes. | |
bfrac_0-12.pdf | r2 r1 | manage | 15.2 K | 2011-11-23 - 10:27 | RobertoCovarelli | Fitted J/ψ and ψ(2S) b-fractions plotted as a function of pT for three rapidity regions: 0 < |y| < 1.2 (top); 1.2 < |y| < 1.6 (middle); 1.6 < |y| < 2.4 (bottom). Fixed offsets have been added to some sets of points for illustrative purposes. | |
bfrac_12-16.pdf | r2 r1 | manage | 14.5 K | 2011-11-23 - 10:28 | RobertoCovarelli | Fitted J/ψ and ψ(2S) b-fractions plotted as a function of pT for three rapidity regions: 0 < |y| < 1.2 (top); 1.2 < |y| < 1.6 (middle); 1.6 < |y| < 2.4 (bottom). Fixed offsets have been added to some sets of points for illustrative purposes. | |
bfrac_16-24.pdf | r2 r1 | manage | 15.7 K | 2011-11-23 - 10:28 | RobertoCovarelli | Fitted J/ψ and ψ(2S) b-fractions plotted as a function of pT for three rapidity regions: 0 < |y| < 1.2 (top); 1.2 < |y| < 1.6 (middle); 1.6 < |y| < 2.4 (bottom). Fixed offsets have been added to some sets of points for illustrative purposes. |