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Abstract

In this chapter, we discuss several applications which illustrate the usefulness of the functional analysis and optimization methods for improving the knowledge of the weak and electromagnetic hadronic form factors. We first present the method of “unitarity bounds”, proposed in the early 1970s by Meiman and Okubo for deriving model-independent bounds on the semileptonic form factors. The development of the method in the frame of the Standard Model is then reviewed, emphasizing the increased strength of the formalism when it is combined with additional theoretical information provided by heavy-quark symmetry, chiral perturbation theory or lattice QCD. Finally, we show how this approach leads to precise predictions for the pion electromagnetic form factor, in particular for the charge radius of the pion. We briefly describe also the way in which the rigorous bounds can be merged with statistical simulations.

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Notes

  1. 1.

    Other choices of invariant amplitudes which satisfy unsubtracted dispersion relations have been also investigated in the literature.

  2. 2.

    As shown in [37], the world average of R(D) and \(R(D^*)\) measured by BABAR, Belle and LHCb is in tension with the SM expectation at the \(4\sigma \) level.

  3. 3.

    For the form factors of interest, the thresholds occur at the minimum values of \(\sqrt{t}\) at which the relevant \(B^{(*)} D^{(*)}\) pairs can be produced, i.e. at \((m_B+m_D)\approx 7.15\,\text{ GeV }\), \((m_B+m_{D^*})\approx 7.29\,\text{ GeV }\), \((m_{B^*}+m_D)\approx 7.19\,\text{ GeV }\), or \((m_{B^*}+m_{D^*})\approx 7.33\,\text{ GeV }\).

  4. 4.

    A similar quantity, not observable but of theoretical interest for \(\chi \)PT, is the pion scalar form factor, defined from the matrix element between pion states of a suitable scalar operator. The pion scalar form factor was investigated in the Meiman-Okubo approach in [38, 39].

  5. 5.

    As discussed below (4.62), the minors of the determinant should be also nonnegative. Some of these conditions involve only input quantities, and are violated if the input values are not consistent.

References

  1. N.N. Meiman, Zh. Eksp. Teor. Fiz. 44, 1228 (1963) [Sov. Phys. JETP 17, 830 (1963)]

    Google Scholar 

  2. S. Okubo, Phys. Rev. D 3, 2807 (1971); Phys. Rev. D 4, 725 (1971)

    Article  ADS  Google Scholar 

  3. M. Micu, Nucl. Phys. B 44, 531 (1972); Phys. Rev. D 7, 2136 (1973)

    Google Scholar 

  4. G. Auberson, G. Mahoux, F.R.A. Simăo, Nucl. Phys. B 98, 204 (1975)

    Article  ADS  Google Scholar 

  5. C. Bourrely, B. Machet, E. de Rafael, Nucl. Phys. B 189, 157 (1981)

    Article  ADS  Google Scholar 

  6. E. de Rafael, J. Taron, Phys. Lett. B 282, 215 (1992)

    Article  ADS  Google Scholar 

  7. E. de Rafael, J. Taron, Phys. Rev. D 50, 373 (1994)

    Article  ADS  Google Scholar 

  8. I. Caprini, Z. Phys. C 61, 651 (1994)

    Google Scholar 

  9. I. Caprini, Phys. Lett. B 339, 187 (1994)

    Article  ADS  Google Scholar 

  10. C.G. Boyd, B. Grinstein, R.F. Lebed, Phys. Rev. Lett. 74, 4603 (1995)

    Article  ADS  Google Scholar 

  11. C.G. Boyd, B. Grinstein, R.F. Lebed, Phys. Lett. B 353, 306 (1995)

    Article  ADS  Google Scholar 

  12. C.G. Boyd, B. Grinstein, R.F. Lebed, Nucl. Phys. B 461, 493 (1996)

    Article  ADS  Google Scholar 

  13. L. Lellouch, Nucl. Phys. B 479, 353 (1996)

    Article  ADS  Google Scholar 

  14. C.G. Boyd, M.J. Savage, Phys. Rev. D 56, 303 (1997)

    Article  ADS  Google Scholar 

  15. C.G. Boyd, B. Grinstein, R.F. Lebed, Phys. Rev. D 56, 6895 (1997)

    Article  ADS  Google Scholar 

  16. I. Caprini, L. Lellouch, M. Neubert, Nucl. Phys. B 530, 153 (1998)

    Article  ADS  Google Scholar 

  17. C. Bourrely, I. Caprini, Nucl. Phys. B 722, 149 (2005)

    Article  ADS  Google Scholar 

  18. R.J. Hill, Phys. Rev. D 74, 096006 (2006)

    Article  ADS  Google Scholar 

  19. T. Becher, R.J. Hill, Phys. Lett. B 633, 61 (2006)

    Article  ADS  Google Scholar 

  20. M.C. Arnesen, J. Kundu, I.W. Stewart, Phys. Rev. Lett. 95, 071802 (2005)

    Article  ADS  Google Scholar 

  21. C. Bourrely, I. Caprini, L. Lellouch, Phys. Rev. D 79, 013008 (2009); Erratum: Phys. Rev. D 82, 099902 (2010)

    Google Scholar 

  22. G. Abbas, B. Ananthanarayan, I. Caprini, I.S. Imsong, S. Ramanan, Eur. Phys. J. A 45, 389 (2010)

    Article  ADS  Google Scholar 

  23. G. Abbas, B. Ananthanarayan, I. Caprini, I.S. Imsong, Phys. Rev. D 82, 094018 (2010)

    Article  ADS  Google Scholar 

  24. I. Caprini, E.M. Babalic, Rom. J. Phys. 55, 920 (2010)

    Google Scholar 

  25. B. Ananthanarayan, I. Caprini, I.S. Imsong, Eur. Phys. J. A 47, 147 (2011)

    Article  ADS  Google Scholar 

  26. B. Grinstein, R.F. Lebed, Phys. Rev. D 92, 116001 (2015)

    Article  ADS  Google Scholar 

  27. I. Caprini, B. Grinstein, R.F. Lebed, Phys. Rev. D 96, 036015 (2017)

    Article  ADS  Google Scholar 

  28. G. Duplancic et al., JHEP 04, 014 (2008)

    Article  ADS  Google Scholar 

  29. M. Okamoto et al., Nucl. Phys. Proc. Suppl. 140, 461 (2005)

    Article  ADS  Google Scholar 

  30. E. Dalgic et al., Phys. Rev. D 73, 074502 (2006)

    Article  Google Scholar 

  31. D. Bigi, P. Gambino, Phys. Rev. D 94, 094008 (2016)

    Article  ADS  Google Scholar 

  32. D. Bigi, P. Gambino, S. Schacht, Phys. Lett. B 769, 441 (2017)

    Article  ADS  Google Scholar 

  33. D. Bigi, P. Gambino, S. Schacht, JHEP 11, 061 (2017)

    Article  ADS  Google Scholar 

  34. B. Grinstein, A. Kobach, Phys. Lett. B 771, 359 (2017)

    Article  ADS  Google Scholar 

  35. F.U. Bernlochner, Z. Ligeti, M. Papucci, D.J. Robinson, Phys. Rev. D 96, 091503 (2017)

    Article  ADS  Google Scholar 

  36. F.U. Bernlochner, Z. Ligeti, M. Papucci, D.J. Robinson, Phys. Rev. D 95, 115008 (2017); Erratum: Phys. Rev. D 97, 059902 (2018)

    Google Scholar 

  37. Y. Amhis et al., HFLAV collaboration. Eur. Phys. J. C 77, 895 (2017)

    Article  ADS  Google Scholar 

  38. L. Lellouch, E. de Rafael, J. Taron, Phys. Lett. B 414, 195 (1997)

    Article  ADS  Google Scholar 

  39. I. Caprini, Phys. Rev. D 98, 056008 (2018)

    Article  ADS  Google Scholar 

  40. R.R. Akhmetshin et al., CMD-2 collaboration. Phys. Lett. B 648, 28 (2007)

    Article  ADS  Google Scholar 

  41. M.N. Achasov et al., J. Exp. Theor. Phys. 103, 380 (2006) [Zh. Eksp. Teor. Fiz. 130, 437 (2006)]

    Google Scholar 

  42. B. Aubert et al., BaBar collaboration. Phys. Rev. Lett. 103, 231801 (2009)

    Article  ADS  Google Scholar 

  43. J.P. Lees et al., BaBar collaboration. Phys. Rev. D 86, 032013 (2012)

    Article  ADS  Google Scholar 

  44. F. Ambrosino et al., KLOE collaboration. Phys. Lett. B 670, 285 (2009)

    Article  ADS  Google Scholar 

  45. F. Ambrosino et al., KLOE collaboration. Phys. Lett. B 700, 102 (2011)

    Article  ADS  Google Scholar 

  46. D. Babusci et al., KLOE collaboration. Phys. Lett. B 720, 336 (2013)

    Article  ADS  Google Scholar 

  47. M. Ablikim et al., BESIII collaboration. Phys. Lett. B 753, 629 (2016)

    Article  ADS  Google Scholar 

  48. H. Leutwyler, in Continuous Advances in QCD 2002, ed. by K.A. Olive, M.A. Shifman, M.B. Voloshin (2002), pp. 23–40, arXiv:hep-ph/0212324

  49. I. Caprini, Eur. Phys. J. C 13, 471 (2000)

    Article  ADS  Google Scholar 

  50. G.R. Farrar, D.R. Jackson, Phys. Rev. Lett. 43, 246 (1979)

    Article  ADS  Google Scholar 

  51. G.P. Lepage, S.J. Brodsky, Phys. Lett. B 87, 359 (1979)

    Article  ADS  Google Scholar 

  52. B. Ananthanarayan, I. Caprini, I. Sentitemsu Imsong, Phys. Rev. D 83, 096002 (2011)

    Google Scholar 

  53. B. Ananthanarayan, I. Caprini, I. Sentitemsu Imsong, Phys. Rev. D 85, 096006 (2012)

    Google Scholar 

  54. B. Ananthanarayan, I. Caprini, D. Das, I. Sentitemsu Imsong, Phys. Rev. D 89, 036007 (2014)

    Google Scholar 

  55. B. Ananthanarayan, I. Caprini, D. Das, I. Sentitemsu Imsong, Phys. Rev. D 93, 116007 (2016)

    Google Scholar 

  56. B. Ananthanarayan, I. Caprini, D. Das, Phys. Rev. Lett. 119, 132002 (2017)

    Article  ADS  Google Scholar 

  57. B. Ananthanarayan, I. Caprini, D. Das, Phys. Rev. D 98, 114015 (2018)

    Article  ADS  Google Scholar 

  58. T. Horn et al., Jefferson lab \(F_\pi \) collaboration. Phys. Rev. Lett. 97, 192001 (2006)

    Article  ADS  Google Scholar 

  59. G.M. Huber et al., Jefferson lab \(F_\pi \) collaboration. Phys. Rev. C 78, 045203 (2008)

    Article  ADS  Google Scholar 

  60. M. Schmelling, Phys. Scr. 51, 676 (1995)

    Article  ADS  Google Scholar 

  61. S.R. Amendolia et al., NA7 collaboration. Nucl. Phys. B 277, 168 (1986)

    Article  ADS  Google Scholar 

  62. C. Alexandrou et al., ETM collaboration. Phys. Rev. D 97, 014508 (2018)

    Article  ADS  Google Scholar 

  63. S.P. Schneider, B. Kubis, F. Niecknig, Phys. Rev. D 86, 054013 (2012)

    Article  ADS  Google Scholar 

  64. R.I. Dzhelyadin et al., Phys. Lett. B 102, 296 (1981); [JETP Lett. 33, 228 (1981)]

    Google Scholar 

  65. R. Arnaldi et al., NA60 collaboration. Phys. Lett. B 677, 260 (2009)

    Article  ADS  Google Scholar 

  66. G. Usai [NA60 collaboration], Nucl. Phys. A 855, 189 (2011)

    Google Scholar 

  67. B. Ananthanarayan, I. Caprini, B. Kubis, Eur. Phys. J. C 74, 3209 (2014)

    Article  Google Scholar 

  68. I. Caprini, Phys. Rev. D 92, 014014 (2015)

    Article  ADS  Google Scholar 

  69. R.R. Akhmetshin et al., CMD-2 collaboration. Phys. Lett. B 562, 173 (2003)

    Article  ADS  Google Scholar 

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Correspondence to Irinel Caprini .

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Caprini, I. (2019). Constraints on Hadronic Form Factors. In: Functional Analysis and Optimization Methods in Hadron Physics. SpringerBriefs in Physics. Springer, Cham. https://doi.org/10.1007/978-3-030-18948-8_5

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