Antikaon flow in heavy-ion collisions: Effects of absorption and mean-field potential

Abstract

We study antikaon flow in heavy-ion collisions at SIS energies based on the relativistic transport model (RVUU 1.0). The production of antikaons from both baryon-baryon and pion-baryon collisions are included. Taking into account only elastic and inelastic collisions of the antikaon with nucleons and neglecting its mean-field potential as in the cascade model, a strong antiflow or anti-correlation of antikaons with respect to nucleons is seen as a result of the strong absorption of antikaons by nucleons. However, the antiflow of antikaons disappears after including also their propagation in the attractive mean-field potential. The experimental measurement of antikaon flow in heavy-ion collision will be very useful in shedding lights on the relative importance of antikaon absorption versus its mean-field potential.Typeset using REVT E X * Dedicated to Gerry Brown on the occasion of his 70th birthday.

Kaons in dense matter, kaon production in heavy-ion collisions, and kaon condensation in neutron stars

“…On the other hand, the ratio, K + /K − , and especially the shapes of its transverse mass spectra and rapidity distribution, is less sensitive to the elementary cross sections, and should be able to provide more definite information about kaon in-medium properties. Also, the collective flow signals of K + and K − [102][103][104] in heavy-ion collisions are very useful probes of kaon medium effects.…”

Production ofK+and ofK−mesons in heavy-ion collisions from 0.6<

“…Early transport-model calculations predicted that the K + yield in Au+Au collisions would be enhanced by a factor of about 2 if a soft rather than a hard nuclear equation of state is assumed [6,51]. Recent calculations take into account modifications of the kaon properties in the dense nuclear medium leading to a repulsive K + N potential which depends on the baryonic density [16] and which leads to a reduction of the calculated K + yields.…”

“…The maximum baryonic density reached in Au+Au reactions is about 2 -3 times normal nuclear matter density while the increase in density in C+C collisions is significantly less pronounced. Moreover, the maximum baryonic density reached in Au+Au reactions depends on the compression modulus of nuclear matter K N [51,52] whereas in C+C collisions this dependence is rather weak [8]. Hence, the ratio of the K + multiplicity per nucleon M/A in Au+Au to the one in C+C is expected to be sensitive to the compression modulus K N .…”

Radial flow of kaon mesons in heavy ion reactions

“…The techniques developed in studying the collective flow of nuclear matter have also been applied to secondary particles such as pions, kaons, hyperons etc. [14][15][16][17][18][19][20][21][22][23][24][25][26]. For secondary particles "squeeze-out" and "transverse flow" are defined in the same way as for nucleons by the azimuthal anisotropy and the rapidity dependence of the in-plane component of the particle momentum, respectively.…”