Glueball spectrum from Nf=2 lattice QCD study on anisotropic lattices

  • The lowest-lying glueballs are investigated in lattice QCD using Nf=2 clover Wilson fermions on anisotropic lattices. We simulate at two different and relatively heavy quark masses, corresponding to physical pion masses of mπ~938 MeV and 650 MeV. The quark mass dependence of the glueball masses has not been investigated in the present study. Only the gluonic operators built from Wilson loops are utilized in calculating the corresponding correlation functions. In the tensor channel, we obtain the ground state mass to be 2.363(39) GeV and 2.384(67) GeV at mπ~938 MeV and 650 MeV, respectively. In the pseudoscalar channel, when using the gluonic operator whose continuum limit has the form of εijkTrBiDjBk, we obtain the ground state mass to be 2.573(55) GeV and 2.585(65) GeV at the two pion masses. These results are compatible with the corresponding results in the quenched approximation. In contrast, if we use the topological charge density as field operators for the pseudoscalar, the masses of the lowest state are much lighter (around 1 GeV) and compatible with the expected masses of the flavor singlet qq meson. This indicates that the operator εijkTrBiDjBk and the topological charge density couple rather differently to the glueball states and qq mesons. The observation of the light flavor singlet pseudoscalar meson can be viewed as the manifestation of effects of dynamical quarks. In the scalar channel, the ground state masses extracted from the correlation functions of gluonic operators are determined to be around 1.4-1.5 GeV, which is close to the ground state masses from the correlation functions of the quark bilinear operators. In all cases, the mixing between glueballs and conventional mesons remains to be further clarified in the future.
  • [1] R. Jaffe and K. Johnson, Physics Letters B, 60:201 (1976)
    [2] J. Cornwall and A. Soni, Physics Letters B, 120:431 (1983)
    [3] W.-S. Hou and A. Soni, Phys. Rev. D, 29:101 (1984)
    [4] R. C. Brower, S. D. Mathur, and C.-I. Tan, Nucl. Phys. B, 587:249 (2000), hep-th/0003115
    [5] A. P. Szczepaniak and E. S. Swanson, Phys. Lett. B, 577:61 (2003), hep-ph/0308268
    [6] S. Narison, Phys. Rev. D, 73:114024 (2006), hep-ph/0512256
    [7] H. Sanchis-Alepuz, C. S. Fischer, C. Kellermann, and L. von Smekal, Phys. Rev. D, 92:034001 (2015), arXiv:1503.06051[hep-ex]
    [8] E. Klempt and A. Zaitsev, Phys. Rept., 454:1 (2007),arXiv:0708.4016[hep-ex]
    [9] V. Mathieu, N. Kochelev, and V. Vento, Int. J. Mod. Phys. E, 18:1 (2009), arXiv:0810.4453[hep-ex]
    [10] V. Crede and C. A. Meyer, Prog. Part. Nucl. Phys., 63:74 (2009), arXiv:0812.0600[hep-ex]
    [11] W. Ochs, J. Phys. G, 40:043001 (2013), arXiv:1301.5183[hep-ex]
    [12] C. J. Morningstar and M. Peardon, Phys. Rev. D, 56:4043 (1997)
    [13] C. J. Morningstar and M. J. Peardon, Phys. Rev. D, 60:034509 (1999), hep-lat/9901004
    [14] Y. Chen, A. Alexandru, S. J. Dong, T. Draper, I. Horvth, F. X. Lee, K. F. Liu, N. Mathur, C. Morningstar, M. Peardon, et al., Phys. Rev. D, 73:014516 (2006), hep-lat/0510074
    [15] L.-C. Gui, Y. Chen, G. Li, C. Liu, Y.-B. Liu, J.-P. Ma, Y.-B. Yang, and J.-B. Zhang (CLQCD Collaboration), Phys. Rev. Lett., 110:021601 (2013), arXiv:1206.0125[hep-ex]
    [16] Y.-B. Yang, L.-C. Gui, Y. Chen, C. Liu, Y.-B. Liu, J.-P. Ma, and J.-B. Zhang (CLQCD Collaboration), Phys. Rev. Lett., 111:091601 (2013), arXiv:1304.3807[hep-ex]
    [17] M. Ablikim et al. (BESⅢ), Phys. Rev. D, 87:092009 (2013),[Erratum:Phys. Rev. D, 87(11):119901 (2013)], arXiv:1301.0053[hep-ex]
    [18] M. Ablikim et al. (BESⅢ), Phys. Rev. D, 93:112011 (2016), arXiv:1602.01523[hep-ex]
    [19] G. S. Bali, B. Bolder, N. Eicker, T. Lippert, B. Orth, P. Ueberholz, K. Schilling, and T. Struckmann (SESAM and TL Collaborations), Phys. Rev. D, 62:054503 (2000), hep-lat/0003012
    [20] A. Hart and M. Teper (UKQCD Collaboration), Phys. Rev. D, 65:034502 (2002), hep-lat/0108022
    [21] C. M. Richards, A. C. Irving, E. B. Gregory, and C. McNeile (UKQCD Collaboration), Phys. Rev. D, 82:034501 (2010), arXiv:1005.2473[hep-ex]
    [22] E. Gregory, A. Irving, B. Lucini, C. McNeile, A. Rago, C. Richards, and E. Rinaldi, JHEP, 10:170 (2012), arXiv:1208.1858[hep-ex]
    [23] H. Fukaya, S. Aoki, G. Cossu, S. Hashimoto, T. Kaneko, and J. Noaki (JLQCD Collaboration), Phys. Rev. D, 92:111501 (2015), arXiv:1509.00944[hep-ex]
    [24] A. Chowdhury, A. Harindranath, and J. Maiti, Phys. Rev. D, 91:074507 (2015), arXiv:1409.6459[hep-ex]
    [25] S.-q. Su, L.-m. Liu, X. Li, and C. Liu, Int. J. Mod. Phys. A, 21:1015 (2006), hep-lat/0412034
    [26] G. P. Lepage and P. B. Mackenzie, Phys. Rev. D, 48:2250 (1993)
    [27] T. Umeda, S. Aoki, M. Fukugita, K.-I. Ishikawa, N. Ishizuka, Y. Iwasaki, K. Kanaya, Y. Kuramashi, V. I. Lesk, Y. Namekawa, et al. (CP-PACS Collaboration), Phys. Rev. D, 68:034503 (2003), hep-lat/0302024
    [28] T. R. Klassen, Nucl. Phys. B, 533:557 (1998), hep-lat/9803010
    [29] R. G. Edwards, B. Joo, and H.-W. Lin, Phys. Rev. D, 78:054501 (2008), arXiv:0803.3960[hep-ex]
    [30] E. V. Shuryak and J. J. M. Verbaarschot, Phys. Rev. D, 52:295 (1995)
    [31] P. J. Moran and D. B. Leinweber, Phys. Rev. D, 78:054506 (2008), arXiv:0801.2016[hep-ex]
    [32] M. Lscher, JHEP, 08:071 (2010),[Erratum:JHEP, 03:092 (2014)], arXiv:1006.4518[hep-ex]
    [33] S. Borsanyi et al, JHEP, 09:010 (2012), arXiv:1203.4469[hep-ex]
    [34] E. Witten, Nucl. Phys. B, 156:269 (1979)
    [35] G. Veneziano, Nuclear Physics B, 159:213 (1979), ISSN 0550-3213
    [36] Yu. A. Simonov, Sov. J. Nucl. Phys., 50:134 (1989); Yad. Fiz., 50:213 (1989)
    [37] C. Helmes, B. Knippschild, B. Kostrzewa, L. Liu, C. Jost, K. Ottnad, C. Urbach, U. Wenger, and M. Werner (ETM) (2017), arXiv:1710.03698[hep-ex]
    [38] N. H. Christ, C. Dawson, T. Izubuchi, C. Jung, Q. Liu, R. D. Mawhinney, C. T. Sachrajda, A. Soni, and R. Zhou, Phys. Rev. Lett., 105:241601 (2010), arXiv:1002.2999[hep-ex]
    [39] C. Michael, K. Ottnad, and C. Urbach (ETM), Phys. Rev. Lett., 111:181602 (2013), arXiv:1310.1207[hep-ex]
  • [1] R. Jaffe and K. Johnson, Physics Letters B, 60:201 (1976)
    [2] J. Cornwall and A. Soni, Physics Letters B, 120:431 (1983)
    [3] W.-S. Hou and A. Soni, Phys. Rev. D, 29:101 (1984)
    [4] R. C. Brower, S. D. Mathur, and C.-I. Tan, Nucl. Phys. B, 587:249 (2000), hep-th/0003115
    [5] A. P. Szczepaniak and E. S. Swanson, Phys. Lett. B, 577:61 (2003), hep-ph/0308268
    [6] S. Narison, Phys. Rev. D, 73:114024 (2006), hep-ph/0512256
    [7] H. Sanchis-Alepuz, C. S. Fischer, C. Kellermann, and L. von Smekal, Phys. Rev. D, 92:034001 (2015), arXiv:1503.06051[hep-ex]
    [8] E. Klempt and A. Zaitsev, Phys. Rept., 454:1 (2007),arXiv:0708.4016[hep-ex]
    [9] V. Mathieu, N. Kochelev, and V. Vento, Int. J. Mod. Phys. E, 18:1 (2009), arXiv:0810.4453[hep-ex]
    [10] V. Crede and C. A. Meyer, Prog. Part. Nucl. Phys., 63:74 (2009), arXiv:0812.0600[hep-ex]
    [11] W. Ochs, J. Phys. G, 40:043001 (2013), arXiv:1301.5183[hep-ex]
    [12] C. J. Morningstar and M. Peardon, Phys. Rev. D, 56:4043 (1997)
    [13] C. J. Morningstar and M. J. Peardon, Phys. Rev. D, 60:034509 (1999), hep-lat/9901004
    [14] Y. Chen, A. Alexandru, S. J. Dong, T. Draper, I. Horvth, F. X. Lee, K. F. Liu, N. Mathur, C. Morningstar, M. Peardon, et al., Phys. Rev. D, 73:014516 (2006), hep-lat/0510074
    [15] L.-C. Gui, Y. Chen, G. Li, C. Liu, Y.-B. Liu, J.-P. Ma, Y.-B. Yang, and J.-B. Zhang (CLQCD Collaboration), Phys. Rev. Lett., 110:021601 (2013), arXiv:1206.0125[hep-ex]
    [16] Y.-B. Yang, L.-C. Gui, Y. Chen, C. Liu, Y.-B. Liu, J.-P. Ma, and J.-B. Zhang (CLQCD Collaboration), Phys. Rev. Lett., 111:091601 (2013), arXiv:1304.3807[hep-ex]
    [17] M. Ablikim et al. (BESⅢ), Phys. Rev. D, 87:092009 (2013),[Erratum:Phys. Rev. D, 87(11):119901 (2013)], arXiv:1301.0053[hep-ex]
    [18] M. Ablikim et al. (BESⅢ), Phys. Rev. D, 93:112011 (2016), arXiv:1602.01523[hep-ex]
    [19] G. S. Bali, B. Bolder, N. Eicker, T. Lippert, B. Orth, P. Ueberholz, K. Schilling, and T. Struckmann (SESAM and TL Collaborations), Phys. Rev. D, 62:054503 (2000), hep-lat/0003012
    [20] A. Hart and M. Teper (UKQCD Collaboration), Phys. Rev. D, 65:034502 (2002), hep-lat/0108022
    [21] C. M. Richards, A. C. Irving, E. B. Gregory, and C. McNeile (UKQCD Collaboration), Phys. Rev. D, 82:034501 (2010), arXiv:1005.2473[hep-ex]
    [22] E. Gregory, A. Irving, B. Lucini, C. McNeile, A. Rago, C. Richards, and E. Rinaldi, JHEP, 10:170 (2012), arXiv:1208.1858[hep-ex]
    [23] H. Fukaya, S. Aoki, G. Cossu, S. Hashimoto, T. Kaneko, and J. Noaki (JLQCD Collaboration), Phys. Rev. D, 92:111501 (2015), arXiv:1509.00944[hep-ex]
    [24] A. Chowdhury, A. Harindranath, and J. Maiti, Phys. Rev. D, 91:074507 (2015), arXiv:1409.6459[hep-ex]
    [25] S.-q. Su, L.-m. Liu, X. Li, and C. Liu, Int. J. Mod. Phys. A, 21:1015 (2006), hep-lat/0412034
    [26] G. P. Lepage and P. B. Mackenzie, Phys. Rev. D, 48:2250 (1993)
    [27] T. Umeda, S. Aoki, M. Fukugita, K.-I. Ishikawa, N. Ishizuka, Y. Iwasaki, K. Kanaya, Y. Kuramashi, V. I. Lesk, Y. Namekawa, et al. (CP-PACS Collaboration), Phys. Rev. D, 68:034503 (2003), hep-lat/0302024
    [28] T. R. Klassen, Nucl. Phys. B, 533:557 (1998), hep-lat/9803010
    [29] R. G. Edwards, B. Joo, and H.-W. Lin, Phys. Rev. D, 78:054501 (2008), arXiv:0803.3960[hep-ex]
    [30] E. V. Shuryak and J. J. M. Verbaarschot, Phys. Rev. D, 52:295 (1995)
    [31] P. J. Moran and D. B. Leinweber, Phys. Rev. D, 78:054506 (2008), arXiv:0801.2016[hep-ex]
    [32] M. Lscher, JHEP, 08:071 (2010),[Erratum:JHEP, 03:092 (2014)], arXiv:1006.4518[hep-ex]
    [33] S. Borsanyi et al, JHEP, 09:010 (2012), arXiv:1203.4469[hep-ex]
    [34] E. Witten, Nucl. Phys. B, 156:269 (1979)
    [35] G. Veneziano, Nuclear Physics B, 159:213 (1979), ISSN 0550-3213
    [36] Yu. A. Simonov, Sov. J. Nucl. Phys., 50:134 (1989); Yad. Fiz., 50:213 (1989)
    [37] C. Helmes, B. Knippschild, B. Kostrzewa, L. Liu, C. Jost, K. Ottnad, C. Urbach, U. Wenger, and M. Werner (ETM) (2017), arXiv:1710.03698[hep-ex]
    [38] N. H. Christ, C. Dawson, T. Izubuchi, C. Jung, Q. Liu, R. D. Mawhinney, C. T. Sachrajda, A. Soni, and R. Zhou, Phys. Rev. Lett., 105:241601 (2010), arXiv:1002.2999[hep-ex]
    [39] C. Michael, K. Ottnad, and C. Urbach (ETM), Phys. Rev. Lett., 111:181602 (2013), arXiv:1310.1207[hep-ex]
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Wei Sun, Long-Cheng Gui, Ying Chen, Ming Gong, Chuan Liu, Yu-Bin Liu, Zhaofeng Liu, Jian-Ping Ma and Jian-Bo Zhang. Glueball spectrum from Nf=2 lattice QCD study on anisotropic lattices[J]. Chinese Physics C, 2018, 42(9): 093103. doi: 10.1088/1674-1137/42/9/093103
Wei Sun, Long-Cheng Gui, Ying Chen, Ming Gong, Chuan Liu, Yu-Bin Liu, Zhaofeng Liu, Jian-Ping Ma and Jian-Bo Zhang. Glueball spectrum from Nf=2 lattice QCD study on anisotropic lattices[J]. Chinese Physics C, 2018, 42(9): 093103.  doi: 10.1088/1674-1137/42/9/093103 shu
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Glueball spectrum from Nf=2 lattice QCD study on anisotropic lattices

    Corresponding author: Wei Sun,
    Corresponding author: Ying Chen,
  • 1. Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
  • 2. School of Physics, University of Chinese Academy of Sciences, Beijing 100049, China
  • 3. Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha 410081, China
  • 4. Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Changsha 410081, China
  • 5. School of Physics and Center for High Energy Physics, Peking University, Beijing 100871, China
  • 6. Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China
  • 7.  School of Physics, Nankai University, Tianjin 300071, China
  • 8.  Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100080, China
  • 9.  Department of Physics, Zhejiang University, Hangzhou, Zhejiang 310027, China

Abstract: The lowest-lying glueballs are investigated in lattice QCD using Nf=2 clover Wilson fermions on anisotropic lattices. We simulate at two different and relatively heavy quark masses, corresponding to physical pion masses of mπ~938 MeV and 650 MeV. The quark mass dependence of the glueball masses has not been investigated in the present study. Only the gluonic operators built from Wilson loops are utilized in calculating the corresponding correlation functions. In the tensor channel, we obtain the ground state mass to be 2.363(39) GeV and 2.384(67) GeV at mπ~938 MeV and 650 MeV, respectively. In the pseudoscalar channel, when using the gluonic operator whose continuum limit has the form of εijkTrBiDjBk, we obtain the ground state mass to be 2.573(55) GeV and 2.585(65) GeV at the two pion masses. These results are compatible with the corresponding results in the quenched approximation. In contrast, if we use the topological charge density as field operators for the pseudoscalar, the masses of the lowest state are much lighter (around 1 GeV) and compatible with the expected masses of the flavor singlet qq meson. This indicates that the operator εijkTrBiDjBk and the topological charge density couple rather differently to the glueball states and qq mesons. The observation of the light flavor singlet pseudoscalar meson can be viewed as the manifestation of effects of dynamical quarks. In the scalar channel, the ground state masses extracted from the correlation functions of gluonic operators are determined to be around 1.4-1.5 GeV, which is close to the ground state masses from the correlation functions of the quark bilinear operators. In all cases, the mixing between glueballs and conventional mesons remains to be further clarified in the future.

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