K(892)*resonance production in Au+Au andp+pcollisions at

J. R. Adams¹,

M. M. Aggarwal²,

Z. Ahammed³

et al.

Abstract

The short-lived K(892)* resonance provides an efficient tool to probe properties of the hot and dense medium produced in relativistic heavy-ion collisions. We report measurements of K * in √ s NN = 200 GeV Au+Au and p + p collisions reconstructed via its hadronic decay channels K(892) * 0 → Kπ and K(892)using the STAR detector at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The K * 0 mass has been studied as a function of p T in minimum bias p + p and central Au+Au collisions. The K * p T spectra for minimum bias p + p interactions and for Au+Au collisions in different centralities are presented. The K * /K yield ratios for all centralities in Au+Au collisions are found to be significantly lower than the ratio in minimum bias p + p collisions, indicating the importance of hadronic interactions between chemical and kinetic freeze-outs. A significant nonzero K * 0 elliptic flow (v 2 ) is observed in Au+Au collisions and is compared to the K 0 S and v 2 . The nuclear modification factor of K * at intermediate p T is similar to that of K 0 S but different from . This establishes a baryon-meson effect over a mass effect in the particle production at intermediate p T

Influence of the hadronic phase on observables in ultrarelativistic heavy ion collisions

“…The resulting ratios for central collisions of Au+Au at a beam energy of √ s NN = 200 GeV, are depicted in figure 9. Here we also compare the results with experimental data from the STAR experiment [29][30][31]. We observe a very good agreement of our results with the experimental data in the case of the full model.…”

K*0production in Cu+Cu and Au+Au collisions atAggarwal1, Ahammed2, Alakhverdyants3 et al. 2011Phys. Rev. CSelf Cite705150View full textAdd to dashboardCite

“…This makes the K * meson sensitive to the properties of the dense matter and strangeness production from an early partonic phase [8,9]. Since the lifetime of the K * is ∼4 fm/c, less than the lifetime of the system formed in heavy-ion collisions [10], the K * is expected to decay, rescatter, and regenerate all the way to the kinetic freeze-out (vanishing elastic collisions).…”

Measurement ofKS0andK*0inp+p,dAdare1, Afanasiev2, Aidala3 et al. 2014Phys. Rev. CSelf Cite32070View full textAdd to dashboardCite

“…The estimated contributions are then normalized by the number of events analyzed for K * 0 meson and subtracted from the measured K * 0 invariant mass distributions. Apart from these contributions, a residual background owing to other correlated sources [39] remains in the subtracted spectra. The residual background is different depending on the collision systems, analysis techniques, and the pair p T .…”

“…The K * 0 meson spectra are measured in the p T range from 1.1 up to 8-8.5 GeV/c, depending on the collision system. The measurements extend the momentum coverage of the previously published results by the STAR Collaboration [39][40][41]. The nuclear modification factors are obtained for both particles in d + Au and Cu + Cu collisions at different centralities and are compared with those of the φ and π 0 mesons.…”

“…The solid blue line is the Tsallis function fit to the combined data points. The star symbols are the K * 0 meson measurements from the STAR Collaboration[39]. (b) Ratio of the yields obtained with the three analysis techniques to the fit function.…”