ترغب بنشر مسار تعليمي؟ اضغط هنا

Directed Flow of $Lambda$-Hyperons in 2-6 AGeV Au+Au Collisions

207   0   0.0 ( 0 )
 نشر من قبل Roy A. Lacey
 تاريخ النشر 2001
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

Directed flow measurements for $Lambda$-hyperons are presented and compared to those for protons produced in the same Au+Au collisions (2, 4, and 6 AGeV; $b < 5 - 6$ fm). The measurements indicate that $Lambda$-hyperons flow consistently in the same direction and with smaller magnitudes than those of protons. Such a strong positive flow [for $Lambda$s] has been predicted in calculations which include the influence of the $Lambda$-nucleon potential. The experimental flow ratio $Lambda$/p is in qualitative agreement with expectations ($sim 2/3$) from the quark counting rule at 2 AGeV but is found to decrease with increasing beam energy.



قيم البحث

اقرأ أيضاً

We have measured the sideward flow of neutral strange ($K^0_s$) mesons in 6 AGeV Au + Au collisions. A prominent anti-flow signal is observed for an impact parameter range (b $lesssim 7$ fm) which spans central and mid-central events. Since the $K^0_ s$ scattering cross section is relatively small in nuclear matter, this observation suggests that the in-medium kaon vector potential plays an important role in high density nuclear matter.
Rapidity distributions of protons from central $^{197}$Au + $^{197}$Au collisions measured by the E895 Collaboration in the energy range from 2 to 8 AGeV at the Brookhaven AGS are presented. Longitudinal flow parameters derived using a thermal model including collective longitudinal expansion are extracted from these distributions. The results show an approximately linear increase in the longitudinal flow velocity, $<betagamma>_{L}$, as a function of the logarithm of beam energy.
Proton elliptic flow is studied as a function of impact-parameter $b$, for two transverse momentum cuts in 2 - 6 AGeV Au + Au collisions. The elliptic flow shows an essentially linear dependence on b (for $1.5 < b < 8$ fm) with a negative slope at 2 AGeV, a positive slope at 6 AGeV and a near zero slope at 4 AGeV. These dependencies serve as an important constraint for discriminating between various equations of state (EOS) for high density nuclear matter, and they provide important insights on the interplay between collision geometry and the expansion dynamics. Extensive comparisons of the measured and calculated differential flows provide further evidence for a softening of the EOS between 2 and 6 GeV/nucleon.
Source images are extracted from two-particle correlations constructed from strange and non-strange hadrons produced in 6 AGeV Au + Au collisions. Very different source images result from pp vs p$Lambda$ vs $pi^-pi^-$ correlations. These observations suggest important differences in the space-time emission histories for protons, pions and neutral strange baryons produced in the same events.
Directed flow of antiprotons is studied in Au+Au collisions at a beam momentum of 11.5A GeV/c. It is shown that antiproton directed flow is anti-correlated to proton flow. The measured transverse momentum dependence of the antiproton flow is compared with predictions of the RQMD event generator.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا