May 22 – 28, 2011
Centre Bonlieu
Europe/Zurich timezone

Status of the Search for Hadronic Squeezed Correlations at RHIC Energies

Not scheduled
Théâtre National (Centre Bonlieu)

Théâtre National

Centre Bonlieu

Board: 108
Poster Correlations and fluctuations


Dr Sandra S. Padula (Instituto de Fisica Teorica (IFT)-Univ. Estadual Paulista, SP, Brazil)


The hot and dense medium formed in high energy heavy ion collisions may induce shifts of hadronic masses from their asymptotic values. In case this mass modification indeed occurs, it was demonstrated that squeezed correlations of particle-antiparticle pairs, also known as Back-to-Back Correlations (BBC), should appear. They are expected either in the bosonic (bBBC) or in the fermionic (fBBC) cases [1], in both being positive correlations of unlimited intensity, even for finite-size systems expanding with moderate flow [2]. Although they could nicely probe the mass shift with asymptotic particles, these hadronic squeezed correlations are very sensitive to the functional form of their time emission distribution. This strong sensitivity was demonstrated in [1], by comparing the sudden emission with a Lorentzian distribution, which reduced the intensity of the effect by orders of magnitude. We show here that the reduction of the signal is even more dramatic if this time emission is parameterized by a Levy-type of distribution [3], although it could still survive if the duration of the process is short and if we search for the effect with lighter mesons, such as kaons. To experimentally search for the BBC signal, we have suggested to look for the particle-antiparticle squeezed correlation function, plotted in terms of the average momentum of the pair, $\vec{K}_{12}=(\vec{k}_1+\vec{k}_2)/2$, for high values of their relative momentum, $\vec{q}_{12}=(\vec{k}_1-\vec{k}_2)$ [4]. The first experimental search for the squeezed particle-antiparticle correlations was shown for different hadron pairs in Ref. [5]. We compare here such preliminary results with predictions of our model for $K+ K-$ pairs, showing that the outcome of the experimental search may be still inconclusive, however it does not deny the existence of the squeezing effect on kaons produced at RHIC energies with in-medium modified masses. [1] M. Asakawa, T. Csorgo, M. Gyulassy, Phys. Rev. Lett. 83, 4013 (1999); P. K. Panda, T. Csorgo, Y. Hama, G. Krein, and Sandra S. Padula, Phys. Lett. B 512, 49 (2001). [2] Sandra S. Padula, G. Krein, T. Csorgo, Y. Hama, and P. K. Panda, Phys. Rev. C 73, 044906 (2006). [3] Danuce M. Dudek and Sandra S. Padula, Phys. Rev. C 82, 034905 (2010). [4] Sandra S. Padula, O. Socolowski Jr., T. Csorgo and M. I. Nagy, Proc. Quark Matter 2008, J. Phys. G: Nucl. Part. Phys. 35, 104141 (2008); Sandra S. Padula and Otavio Socolowski Jr., Phys. Rev. C 82, 034908 (2010). [5] Marton Nagy (for the RHIC/PHENIX Collaboration) ``Particle-antiparticle back-to-back correlation measurement in $\sqrt{s_{NN}}=200$ GeV Au+Au collisions'', WPCF 2009, .

Primary author

Dr Sandra S. Padula (Instituto de Fisica Teorica (IFT)-Univ. Estadual Paulista, SP, Brazil)


Ms Danuce M. Dudek (Instituto de Fisica Teorica (IFT)-Univ. Estadual Paulista, SP, Brazil) Dr Otavio Socolowski, Jr. (IMEF - Univ. Federal de Rio Grande, RS, Brazil)

Presentation materials