Skip to main content
Log in

Two-loop representations of low-energy pion form factors and ππ scattering phases in the presence of isospin breaking

  • Regular Article - Theoretical Physics
  • Published:
The European Physical Journal C Aims and scope Submit manuscript

Abstract

Dispersive representations of the ππ scattering amplitudes and pion form factors, valid at two-loop accuracy in the low-energy expansion, are constructed in the presence of isospin-breaking effects induced by the difference between the charged and neutral pion masses. Analytical expressions for the corresponding phases of the scalar and vector pion form factors are computed. It is shown that each of these phases consists of the sum of a “universal” part and a form-factor dependent contribution. The first one is entirely determined in terms of the ππ scattering amplitudes alone, and reduces to the phase satisfying Watson’s theorem in the isospin limit. The second one can be sizeable, although it vanishes in the same limit. The dependence of these isospin corrections with respect to the parameters of the subthreshold expansion of the ππ amplitude is studied, and an equivalent representation in terms of the S-wave scattering lengths is also briefly presented and discussed. In addition, partially analytical expressions for the two-loop form factors and ππ scattering amplitudes in the presence of isospin breaking are provided.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. S. Pislak et al. (BNL-E865 Collaboration), Phys. Rev. Lett. 87, 221801 (2001) [Erratum-ibid. 105, 019901 (2010)]. arXiv:hep-ex/0106071

    Article  ADS  Google Scholar 

  2. S. Pislak et al. (BNL-E865 Collaboration), Phys. Rev. D 67, 072004 (2003) [Erratum-ibid. D 81, 119903 (2010)]. arXiv:hep-ex/0301040

    Article  ADS  Google Scholar 

  3. J.R. Batley et al. (NA48/2 Collaboration), Eur. Phys. J. C 54, 411 (2008)

    Article  ADS  Google Scholar 

  4. J.R. Batley et al. (NA48/2 Collaboration), Eur. Phys. J. C 70, 635 (2010)

    Article  ADS  Google Scholar 

  5. J.R. Batley et al. (NA48/2 Collaboration), Phys. Lett. B 633, 173 (2006). arXiv:hep-ex/0511056

    Article  ADS  Google Scholar 

  6. J.R. Batley et al. (NA48/2 Collaboration), Eur. Phys. J. C 64, 589 (2009). arXiv:0912.2165 [hep-ex]

    Article  ADS  Google Scholar 

  7. N. Cabibbo, Phys. Rev. Lett. 93, 121801 (2004). arXiv:hep-ph/0405001

    Article  ADS  Google Scholar 

  8. N. Cabibbo, G. Isidori, J. High Energy Phys. 0503, 021 (2005). arXiv:hep-ph/0502130

    Article  ADS  Google Scholar 

  9. E. Gamiz, J. Prades, I. Scimemi, Eur. Phys. J. C 50, 405 (2007). arXiv:hep-ph/0602023

    Article  ADS  Google Scholar 

  10. J. Gasser, B. Kubis, A. Rusetsky, Nucl. Phys. B 850, 96 (2011). arXiv:1103.4273 [hep-ph]

    Article  ADS  MATH  Google Scholar 

  11. L. Masetti, in Proceedings of International Conference on Heavy Quarks and Leptons (HQL 06), Munich, Germany, 16–20 Oct. (2006), p. 008. arXiv:0704.1307 [hep-ex]

    Google Scholar 

  12. B. Bloch-Devaux, Presentation at the 46th Rencontres de Moriond QCD and High Energy Interactions, 20–27 March 2011. Available from the NA48/2 web page, under the URL. http://www.cern.ch/NA48/Welcome/images/talks/moriond2011/bloch_proc_QCD2011.pdf

  13. D. Madigozhin (NA48/2 Collaboration), PoS KAON09, 032 (2009)

    Google Scholar 

  14. V. Yazkov (DIRAC Collaboration), PoS CD09, 003 (2009)

    Google Scholar 

  15. B. Adeva et al. (DIRAC Collaboration), arXiv:1109.0569 [hep-ex]

  16. G. Colangelo, J. Gasser, H. Leutwyler, Nucl. Phys. B 603, 125 (2001). arXiv:hep-ph/0103088

    Article  ADS  Google Scholar 

  17. J. Gasser, H. Leutwyler, Phys. Lett. B 125, 321 (1983)

    Article  ADS  Google Scholar 

  18. J. Gasser, H. Leutwyler, Ann. Phys. 158, 142 (1984)

    Article  MathSciNet  ADS  Google Scholar 

  19. S. Descotes-Genon, N.H. Fuchs, L. Girlanda, J. Stern, Eur. Phys. J. C 24, 469 (2002). arXiv:hep-ph/0112088

    Article  Google Scholar 

  20. P. Budini, L. Fonda, Phys. Rev. Lett. 6, 419 (1961)

    Article  ADS  Google Scholar 

  21. J. Gasser, PoS KAON, 033 (2008). arXiv:0710.3048 [hep-ph]

    Google Scholar 

  22. G. Colangelo, PoS KAON, 038 (2008). arXiv:0710.3050 [hep-ph]

    Google Scholar 

  23. G. Colangelo, J. Gasser, A. Rusetsky, Eur. Phys. J. C 59, 777 (2009). arXiv:0811.0775 [hep-ph]

    Article  ADS  Google Scholar 

  24. V. Bernard, S. Descotes-Genon, M. Knecht, work in preparation

  25. J. Stern, H. Sazdjian, N.H. Fuchs, Phys. Rev. D 47, 3814 (1993). arXiv:hep-ph/9301244

    Article  ADS  Google Scholar 

  26. M. Knecht, B. Moussallam, J. Stern, N.H. Fuchs, Nucl. Phys. B 457, 513 (1995). arXiv:hep-ph/9507319

    Article  ADS  Google Scholar 

  27. J. Gasser, U.G. Meißner, Nucl. Phys. B 357, 90 (1991)

    Article  ADS  Google Scholar 

  28. G. Colangelo, M. Finkemeier, R. Urech, Phys. Rev. D 54, 4403 (1996). arXiv:hep-ph/9604279

    Article  ADS  Google Scholar 

  29. J. Bijnens, G. Colangelo, P. Talavera, J. High Energy Phys. 9805, 014 (1998). arXiv:hep-ph/9805389

    ADS  Google Scholar 

  30. J. Bijnens, G. Colangelo, G. Ecker, J. Gasser, M.E. Sainio, Phys. Lett. B 374, 210 (1996). arXiv:hep-ph/9511397

    Article  ADS  Google Scholar 

  31. J. Bijnens, G. Colangelo, G. Ecker, J. Gasser, M.E. Sainio, Nucl. Phys. B 508, 263 (1997) [Erratum-ibid. B 517, 639 (1998)]. arXiv:hep-ph/9707291

    ADS  Google Scholar 

  32. J. Novotný, M. Zdráhal, Phys. Rev. D 78, 116016 (2008). arXiv:0806.4529 [hep-ph]

    Article  Google Scholar 

  33. M. Zdrahal, K. Kampf, M. Knecht, J. Novotny, PoS CD09, 122 (2009). arXiv:0910.1721 [hep-ph]

    Google Scholar 

  34. M. Zdrahal, K. Kampf, M. Knecht, J. Novotny, PoS EFT09, 063 (2009). arXiv:0905.4868 [hep-ph]

    Google Scholar 

  35. K. Kampf, M. Knecht, J. Novotny, M. Zdrahal, Nucl. Phys. B, Proc. Suppl. 186, 334 (2009). arXiv:0810.1906 [hep-ph]

    Article  ADS  Google Scholar 

  36. K. Kampf, M. Knecht, J. Novotny, M. Zdrahal, Phys. Rev. D 84, 114015 (2011). arXiv:1103.0982 [hep-ph]

    Article  ADS  Google Scholar 

  37. J. Bijnens, P. Talavera, J. High Energy Phys. 0203, 046 (2002). arXiv:hep-ph/0203049

    Article  ADS  Google Scholar 

  38. J. Bijnens, P. Dhonte, J. High Energy Phys. 0310, 061 (2003). arXiv:hep-ph/0307044

    Article  ADS  Google Scholar 

  39. S. Weinberg, in A Festschrift for I. I. Raby, ed. by L. Motz (New York Academy of Sciences, New York, 1977), p. 185

    Google Scholar 

  40. J. Gasser, H. Leutwyler, Phys. Rep. 87, 77 (1982)

    Article  ADS  Google Scholar 

  41. S. Weinberg, Physica A 96, 327 (1979)

    Article  ADS  Google Scholar 

  42. R. Urech, Nucl. Phys. B 433, 234 (1995). arXiv:hep-ph/9405341

    Article  ADS  Google Scholar 

  43. H. Neufeld, H. Rupertsberger, Z. Phys. C 68, 91 (1995)

    Article  ADS  Google Scholar 

  44. H. Neufeld, H. Rupertsberger, Z. Phys. C 71, 131 (1996). arXiv:hep-ph/9506448

    Article  ADS  Google Scholar 

  45. M. Knecht, R. Urech, Nucl. Phys. B 519, 329 (1998). arXiv:hep-ph/9709348

    Article  ADS  Google Scholar 

  46. U.G. Meissner, G. Muller, S. Steininger, Phys. Lett. B 406, 154 (1997) [Erratum-ibid. B 407, 454 (1997)]. arXiv:hep-ph/9704377

    Article  ADS  Google Scholar 

  47. J. Schweizer, J. High Energy Phys. 0302, 007 (2003). arXiv:hep-ph/0212188

    Article  ADS  Google Scholar 

  48. M. Knecht, A. Nehme, Phys. Lett. B 532, 55 (2002)

    Article  ADS  Google Scholar 

  49. B. Kubis, U.G. Meissner, Nucl. Phys. A 671, 332 (2000) [Erratum-ibid. A 692, 647 (2001)]. arXiv:hep-ph/9908261

    Article  ADS  Google Scholar 

  50. J. Gasser, A. Zepeda, Nucl. Phys. B 174, 445 (1980)

    Article  ADS  Google Scholar 

  51. R.P. Feynman, Phys. Rev. 56, 340 (1939)

    Article  ADS  MATH  Google Scholar 

  52. H. Hellmann, Einführung in die Quantenchemie (Deuticke, Leipzig, 1937)

    Google Scholar 

  53. G. Ecker, J. Gasser, A. Pich, E. de Rafael, Nucl. Phys. B 321, 311 (1989)

    Article  ADS  Google Scholar 

  54. M. Knecht, Unpublished notes, 1997

  55. S.W. MacDowell, Phys. Rev. 116, 774 (1959)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  56. J. Kennedy, T.D. Spearman, Phys. Rev. 126, 1596 (1962)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  57. M. Blazek, Czechoslov. J. Phys. 19, 589 (1969)

    Article  MathSciNet  ADS  Google Scholar 

  58. J.L. Petersen, Nucl. Phys. B 13, 73 (1969)

    Article  ADS  Google Scholar 

  59. M. Knecht, B. Moussallam, J. Stern, N.H. Fuchs, Nucl. Phys. B 471, 445 (1996). arXiv:hep-ph/9512404

    Article  ADS  Google Scholar 

  60. A. Czarnecki, U. Kilian, D. Kreimer, Nucl. Phys. B 433, 259 (1995). arXiv:hep-ph/9405423

    Article  ADS  Google Scholar 

  61. A. Ghinculov, Y.-P. Yao, Nucl. Phys. B 516, 385 (1998). arXiv:hep-ph/9702266

    Article  ADS  MATH  Google Scholar 

  62. A. Ferroglia, M. Passera, G. Passarino, S. Uccirati, Nucl. Phys. B 680, 199 (2004). arXiv:hep-ph/0311186

    Article  MathSciNet  ADS  MATH  Google Scholar 

  63. S. Actis, G. Passarino, A. Ferroglia, M. Passera, S. Uccirati, Nucl. Phys. B 703, 3 (2004). arXiv:hep-ph/0402132

    Article  MathSciNet  ADS  MATH  Google Scholar 

  64. C. Haefeli, M.A. Ivanov, M. Schmid, Eur. Phys. J. C 53, 549 (2008). arXiv:0710.5432 [hep-ph]

    Article  ADS  Google Scholar 

  65. B. Ananthanarayan, B. Moussallam, J. High Energy Phys. 0406, 047 (2004). arXiv:hep-ph/0405206

    Article  MathSciNet  ADS  Google Scholar 

  66. B. Moussallam, Nucl. Phys. B 504, 381 (1997). arXiv:hep-ph/9701400

    Article  ADS  Google Scholar 

  67. G. ’t Hooft, Nucl. Phys. B 72, 461 (1974)

    Article  MathSciNet  ADS  Google Scholar 

  68. E. Witten, Nucl. Phys. B 160, 57 (1979)

    Article  MathSciNet  ADS  Google Scholar 

  69. J. Gasser, H. Leutwyler, Nucl. Phys. B 250, 465 (1985)

    Article  ADS  Google Scholar 

  70. G. Amoros, J. Bijnens, P. Talavera, Nucl. Phys. B 602, 87 (2001). arXiv:hep-ph/0101127

    Article  ADS  Google Scholar 

  71. S. Descotes-Genon, L. Girlanda, J. Stern, J. High Energy Phys. 0001, 041 (2000). arXiv:hep-ph/9910537

    Article  ADS  Google Scholar 

  72. S. Descotes-Genon, J. High Energy Phys. 0103, 002 (2001). arXiv:hep-ph/0012221

    Article  ADS  Google Scholar 

  73. S. Descotes-Genon, J. Stern, Phys. Lett. B 488, 274 (2000). arXiv:hep-ph/0007082

    Article  ADS  Google Scholar 

  74. S. Descotes-Genon, N.H. Fuchs, L. Girlanda, J. Stern, Eur. Phys. J. C 34, 201 (2004). arXiv:hep-ph/0311120

    Article  ADS  Google Scholar 

  75. S. Descotes-Genon, Eur. Phys. J. C 52, 141 (2007). arXiv:hep-ph/0703154 [hep-ph]

    Article  ADS  Google Scholar 

  76. V. Bernard, S. Descotes-Genon, G. Toucas, J. High Energy Phys. 1101, 107 (2011). arXiv:1009.5066 [hep-ph]

    Article  ADS  Google Scholar 

  77. J. Bijnens, I. Jemos, Nucl. Phys. B 854, 631 (2012). arXiv:1103.5945 [hep-ph]

    Article  ADS  MATH  Google Scholar 

  78. K. Nakamura et al., J. Phys. G 37, 075021 (2010)

    Article  ADS  Google Scholar 

  79. E. Remiddi, J.A.M. Vermaseren, Int. J. Mod. Phys. A 15, 725 (2000). arXiv:hep-ph/9905237

    Article  MathSciNet  ADS  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Marc Knecht.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Descotes-Genon, S., Knecht, M. Two-loop representations of low-energy pion form factors and ππ scattering phases in the presence of isospin breaking. Eur. Phys. J. C 72, 1962 (2012). https://doi.org/10.1140/epjc/s10052-012-1962-9

Download citation

  • Received:

  • Published:

  • DOI: https://doi.org/10.1140/epjc/s10052-012-1962-9

Keywords

Navigation