Skip to main content
Log in

Annihilation mechanisms of e+e and μ+μ production in relativistic nuclear collisions

Acta Physica Hungarica Series A, Heavy Ion Physics

Abstract

We revise the μ+μ and \(q\bar q\) annihilation mechanisms of dilepton production during relativistic nuclear collisions. We focus on the modifications caused by the specific features of in-medium pion and quark states rather than by medium modification of the ρ-meson spectral density. The main ingreditent emerging in our approach is a form-factor of the multi-pion (multi-quark) system. Replacing the usual delta-function the form-factor plays the role of distribution which, in some sense, “connects” the total 4-momenta of the annihilating and outgoing particles. The difference between the c.m.s. velocities attributed to annihilating and outgoing particles is a particular consequence of this replacement and results in the appearance of a new factor in the formula for the lepton pair production rate. We obtained that the form-factor of the multi-pion (multi-quark) system causes broadening of the rate which is most pronounced for small invariant masses, in particular, we obtain a growth of the rate for the invariant masses below two masses of the annihilating particles.

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.

Institutional subscriptions

Similar content being viewed by others

References

  1. G. Agakichiev et al., Phys. Rev. Lett. 75 (1995) 1272.

    Article  ADS  Google Scholar 

  2. G. Agakichiev et al., Phys. Lett. B422 (1998) 405.

    Google Scholar 

  3. C. Gale and K.L. Haglin, hep-ph/0306098.

  4. W. Cassing and E.L. Bratkovskaya, Phys. Rept. 308 (1999) 65.

    Article  Google Scholar 

  5. R. Rapp and J. Wambach, Adv. Nucl. Phys. 25 (2000) 1.

    Article  Google Scholar 

  6. V. Koch and C. Song, Phys. Rev C 54 (1996) 1903.

    Article  ADS  Google Scholar 

  7. K. Haglin, Phys. Rev. C 53 (1996) R2606.

    Article  ADS  Google Scholar 

  8. G. Agakichiev et al., Eur. Phys. J. C 41 (2005) 475 [nucl-ex/0506002].

    Article  Google Scholar 

  9. D. Anchishkin, V. Khryapa and V. Ruuskanen, hep-ph/0210346.

  10. D. Anchishkin, V. Khryapa, R. Naryshkin and V. Ruuskanen, Ukrainian J. Phys. 49 (2004) 1039.

    Google Scholar 

  11. H. van Hees, J. Knoll, Nucl. Phys. A683 (2000) 369 [hep-ph/0007070].

    Google Scholar 

  12. D. Anchishkin and R. Naryshkin, Mod. Phys. Lett. A20 (2005) 2047 [nucl-th/0407042].

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Anchishkin, D. Annihilation mechanisms of e+e and μ+μ production in relativistic nuclear collisions. Acta Phys. Hung. A 27, 403–411 (2006). https://doi.org/10.1556/APH.27.2006.4.3

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1556/APH.27.2006.4.3

Keywords

PACS

Navigation