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تسجيل مستخدم جديدEnergy dependence of directed flow over a wide range of pseudorapidity in Au+Au collisions at RHIC
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We report on measurements of directed flow as a function of pseudorapidity in Au+Au collisions at energies of $sqrt{s_{_{NN}}} =$ 19.6, 62.4, 130 and 200 GeV as measured by the PHOBOS detector at the Relativistic Heavy Ion Collider (RHIC). These results are particularly valuable because of the extensive, continuous pseudorapidity coverage of the PHOBOS detector. There is no significant indication of structure near midrapidity and the data surprisingly exhibit extended longitudinal scaling similar to that seen for elliptic flow and charged particle pseudorapidity density.
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We present a measurement of the first-order azimuthal anisotropy, $v_1(y)$, of deuterons from Au+Au collisions at $sqrt{s_{NN}}$ = 7.7, 11.5, 14.5, 19.6, 27, and 39 GeV recorded with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC).
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ll described by the thermal model. The collision energy, centrality, and transverse momentum dependence of the coalescence parameter $B_2$ are discussed. We find that the values of $B_2$ for anti-deuterons are systematically lower than those for deuterons, indicating that the correlation volume of anti-baryons is larger than that of baryons at $sqrt{s_text{NN}}$ from 19.6 to 39 GeV. In addition, values of $B_2$ are found to vary with collision energy and show a broad minimum around $sqrt{s_text{NN}}= $20 to 40 GeV, which might imply a change of the equation of state of the medium in these collisions.
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Rapidity-odd directed flow($v_1$) measurements for charged pions, protons and antiprotons near mid-rapidity ($y=0$) are reported in $sqrt{s_{NN}} =$ 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV Au + Au collisions as recorded by the STAR detector at the
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