Skip to main content

Observation of X(3872) production in pp collisions at \(\sqrt{s}=7\mbox{~TeV}\)

Abstract

Using 34.7 pb−1 of data collected with the LHCb detector, the inclusive production of the X(3872) meson in pp collisions at \(\sqrt{s}=7\mbox{~TeV}\) is observed for the first time. Candidates are selected in the X(3872)→J/ψπ + π decay mode, and used to measure

where σ(ppX(3872)+anything) is the inclusive production cross section of X(3872) mesons with rapidity in the range 2.5–4.5 and transverse momentum in the range 5–20 GeV/c. In addition the masses of both the X(3872) and ψ(2S) mesons, reconstructed in the J/ψπ + π final state, are measured to be

$$m_{X(3872)} = 3871.95 \pm0.48 \ (\mathrm{stat}) \pm0.12 \ (\mathrm {syst})\ \mathrm{MeV}/c^2 $$

and

$$m_{\psi(2S)} = 3686.12\pm0.06 \ (\mathrm{stat}) \pm0.10 \ (\mathrm {syst})\ \mathrm{MeV}/c^2. $$

References

  1. 1.

    S.-K. Choi et al. (Belle collaboration), Observation of a new narrow charmonium state in exclusive B +K ± π + π J/ψ decays. Phys. Rev. Lett. 91, 262001 (2003). arXiv:hep-ex/0309032

    Article  ADS  Google Scholar 

  2. 2.

    D. Acosta et al. (CDF collaboration), Observation of the narrow state X(3872)→J/ψπ + π in \(p\bar{p}\) collisions at \(\sqrt{s}=1.96\mbox{~TeV}\). Phys. Rev. Lett. 93, 072001 (2004). arXiv:hep-ex/0312021

    Article  ADS  Google Scholar 

  3. 3.

    V.M. Abazov et al. (DØ collaboration), Observation and properties of the X(3872) decaying to J/ψπ + π in \(p \bar{p}\) collisions at \(\sqrt{s}= 1.96\mbox{~TeV}\). Phys. Rev. Lett. 93, 162002 (2004). arXiv:hep-ex/0405004

    Article  ADS  Google Scholar 

  4. 4.

    B. Aubert et al. (BaBar collaboration), Study of the B J/ψK π + π decay and measurement of the B X(3872)K branching fraction. Phys. Rev. D 71, 071103 (2005). arXiv:hep-ex/0406022

    ADS  Google Scholar 

  5. 5.

    E. Swanson, The new heavy mesons: a status report. Phys. Rep. 429, 243 (2006). arXiv:hep-ph/0601110

    Article  ADS  Google Scholar 

  6. 6.

    T. Aaltonen et al. (CDF collaboration), Precision measurement of the X(3872) mass in J/ψπ + π decays. Phys. Rev. Lett. 103, 152001 (2009). arXiv:0906.5218

    Article  ADS  Google Scholar 

  7. 7.

    S.-K. Choi et al. (Belle collaboration), Bounds on the width, mass difference and other properties of X(3872)→π + π J/ψ decays. Phys. Rev. D 84, 052004 (2011). arXiv:1107.0163

    Article  ADS  Google Scholar 

  8. 8.

    B. Aubert et al. (BaBar collaboration), A study of BX(3872)K, with X(3872)→J/ψπ + π . Phys. Rev. D 77, 111101 (2008). arXiv:0803.2838

    Article  ADS  Google Scholar 

  9. 9.

    A. Abulencia et al. (CDF collaboration), Measurement of the dipion mass spectrum in X(3872)→J/ψπ + π decays. Phys. Rev. Lett. 96, 102002 (2006). arXiv:hep-ex/0512074

    Article  ADS  Google Scholar 

  10. 10.

    A. Abulencia et al. (CDF collaboration), Analysis of the quantum numbers J PC of the X(3872). Phys. Rev. Lett. 98, 132002 (2007). arXiv:hep-ex/0612053

    Article  ADS  Google Scholar 

  11. 11.

    L. Maiani, F. Piccinini, A.D. Polosa, V. Riquer, Diquark-antidiquarks with hidden or open charm and the nature of X(3872). Phys. Rev. D 71, 014028 (2005). arXiv:hep-ph/0412098

    Article  ADS  Google Scholar 

  12. 12.

    C. Bignamini, B. Grinstein, F. Piccinini, A.D. Polosa, C. Sabelli, Is the X(3872) production cross section at \(\sqrt {s}=1.96\mbox{~TeV}\) compatible with a hadron molecule interpretation. Phys. Rev. Lett. 103, 162001 (2009). arXiv:0906.0882

    Article  ADS  Google Scholar 

  13. 13.

    P. Artoisenet, E. Braaten, Production of the X(3872) at the Tevatron and the LHC. Phys. Rev. D 81, 114018 (2010). arXiv:0911.2016

    Article  ADS  Google Scholar 

  14. 14.

    A.A. Alves Jr et al. (LHCb collaboration), The LHCb detector at the LHC. J. Instrum. 3, S08005 (2008)

    Article  Google Scholar 

  15. 15.

    R. Aaij et al. (LHCb collaboration), Measurement of b-hadron masses. Phys. Lett. B 708, 241 (2012). arXiv:1112.4896

    Article  ADS  Google Scholar 

  16. 16.

    T. Sjöstrand, S. Mrenna, P. Skands, PYTHIA 6.4 physics and manual. J. High Energy Phys. 05, 026 (2006). arXiv:hep-ph/0603175

    Article  ADS  Google Scholar 

  17. 17.

    I. Belyaev et al., Handling of the generation of primary events in GAUSS, the LHCb simulation framework, in Nuclear Science Symposium Conference Record (NSS/MIC) (IEEE Press, New York, 2010), p. 1155

    Google Scholar 

  18. 18.

    D.J. Lange, The EvtGen particle decay simulation package. Nucl. Instrum. Methods, Sect. A 462, 152 (2001)

    Article  ADS  Google Scholar 

  19. 19.

    E. Barberio, Z. Wa̧s, PHOTOS—a universal Monte Carlo for QED radiative corrections: version 2.0. Comput. Phys. Commun. 79, 291 (1994)

    Article  ADS  Google Scholar 

  20. 20.

    S. Agostinelli et al. (GEANT4 collaboration), GEANT4—a simulation toolkit. Nucl. Instrum. Methods, Sect. A 506, 250 (2003)

    Article  ADS  Google Scholar 

  21. 21.

    S. Kullback, R.A. Leibler, On information and sufficiency. Ann. Math. Stat. 22, 79 (1951)

    MathSciNet  MATH  Article  Google Scholar 

  22. 22.

    S. Kullback, Letter to editor: the Kullback–Leibler distance. Am. Stat. 41, 340 (1987)

    Google Scholar 

  23. 23.

    M. Needham, Clone track identification using the Kullback–Leibler distance, LHCb-2008-002 (The use of the Kullback–Leibler distance is described)

  24. 24.

    W.D. Hulsbergen, Decay chain fitting with a Kalman filter. Nucl. Instrum. Methods, Sect. A 552, 566 (2005). arXiv:physics/0503191

    Article  ADS  Google Scholar 

  25. 25.

    K. Nakamura et al. (Particle Data Group), Review of particle physics. J. Phys. G 37, 075021 (2010)

    Article  ADS  Google Scholar 

  26. 26.

    R. Aaij et al. (LHCb collaboration), Measurement of the \(B^{0}_{s} - \bar{B}^{0}_{s}\) oscillation frequency Δm s in \(B^{0}_{s} \to D_{s}^{-}(3)\pi\) decays. Phys. Lett. B 709, 177 (2012). arXiv:1112.4311

    Article  ADS  Google Scholar 

  27. 27.

    R. Aaij et al. (LHCb collaboration), Prompt \(K^{0}_{\mathrm{S}}\) production in pp collisions at \(\sqrt{s}=0.9\mbox{~TeV}\). Phys. Lett. B 693, 69 (2010). arXiv:1008.3105

    Article  ADS  Google Scholar 

  28. 28.

    R. Aaij et al. (LHCb collaboration), Absolute luminosity measurements with the LHCb detector at the LHC. J. Instrum. 7, P01010 (2012). arXiv:1110.2866

    Article  Google Scholar 

  29. 29.

    S. van der Meer, Calibration of the effective beam height in the ISR. CERN-ISR-PO-68-31

  30. 30.

    M. Ferro-Luzzi, Proposal for an absolute luminosity determination in colliding beam experiments using vertex detection of beam-gas interactions. Nucl. Instrum. Methods, Sect. A 553, 388 (2005). CERN-PH-EP-2005-023

    Article  ADS  Google Scholar 

  31. 31.

    M. Pivk, F.R. Le Diberder, sPlot: a statistical tool to unfold data distributions. Nucl. Instrum. Methods, Sect. A 555, 356 (2005). arXiv:physics/0402083

    Article  ADS  Google Scholar 

  32. 32.

    R. Aaij et al. (LHCb collaboration), Measurement of J/ψ production in pp collisions at \(\sqrt{s}=7\mbox{~TeV}\). Eur. Phys. J. C 71, 1645 (2011). arXiv:1103.0423

    Article  ADS  Google Scholar 

  33. 33.

    N. Brambilla et al., Heavy quarkonium: progress, puzzles, and opportunities. Eur. Phys. J. C 71, 1534 (2011). arXiv:1010.5827

    Article  ADS  Google Scholar 

Download references

Author information

Affiliations

Authors