From: J.H. Lee (jhlee@sgs1.hirg.bnl.gov)
Date: Thu Sep 25 2003 - 16:58:40 EDT
Hi, Zhangbao, I have some suggestions on your abstract. It seems to me that you might have some difficulty delivering the physics point you promise in the motivation by comparing two different species at two different rapidities. (high-pt proton at y=0 and high-pt pi- at y=2.2) I'm wondering if you can look at high-pt pbar spectra at y~2. At high-pt, they might have comparable statistics as pi-. I would then focus on identified high-pt spectra/ratios/comparisons of pions and baryons (pi- and pbar) at y~2. Of course you can also compare the pbar spectra with the y=0 results if you want to make the story more exciting. JH ----- Original Message ----- From: <yin.zhongbao@fi.uib.no> To: "BRAHMS List" <brahms-l@bnl.gov> Sent: Thursday, September 25, 2003 2:51 PM Subject: RE: Updated QM abstracts from Bergen. > Dear Michael, > > First thank you for your comments. > > To understand the species dependence of high pt suppression, one has > to think out where and how those high pt particles produced. If one > assumes that high pt particles are produced by hard parton fragmentation > then it is quite difficult to understand why there is so much different > suppression from meson to baryon. That's why it is so interesting for > theory to understand the hadronization mechanism (certainly it is not > clear at all till now even though there are some phenomenological theory e.g. > string theory). Now heavy ion collisions provide people a few environment > to try to understand how particles are hadronized. Certainly if we trust > hydro-dynamic description of the space-time evolution of relativistic > heavy ion collision, hadronization is also an important issue need > to be understand. It is relate to how to understand the phase transition > from QGP to hadron gas. That might be the reason why it is so interesting > for theorist to understand the different suppression between meson and > baryon. There are quite a lot papers released to address such issue, for > detail refer to references in [2]. Well, for us, we only show what our > data look like... > > Best regards, > Zhongbao > > > WHAT WE WANT HERE IS NOT TO UNDERSTAND HADRONIZATION ITSELF BUT RATHER > > HOW ENERGY LOSS MIGHT DEPEND ON THE NATURE OF THE HIGH PT PARTICLE. > > FOR EXAMPLE WHAT DOES THEORY SAY ABOUT THE ENERGY LOSS FOR PARTICLES THAT > > BECOME MESONS VERSUS THOSE THAT BECOME HADRONS. > > There have been recent attempts to describe the different behaviour of > > baryons and mesons through different hadronization mechanisms [2] (e.g. > > gluon junction, recombination or parton coalescence). > > > > The BRAHMS spectrometers have the unique ability to identify hadrons > > over a broad range of rapidity and transverse momenta. This allows us > > to study the high $p_{\rm T}$ hadron production mechanism through > > rapidity dependence of hadron spectra and particle composition. > > > > In this talk the BRAHMS collaboration presents new measurements for > > identified > > high $p_{\rm T}$ charged hadron production in Au+Au and d+Au collisions at > > different rapidities and centralities. (Anti)-Proton spectra at midrapidity > > were measured up to $p_{\rm T} = 3.5$ GeV/c, $\pi^-$ spectra at forward > > rapidity cover $p_{\rm T}$ range up to 4.0 GeV/c. First results show %MJM > > a clear suppression of $\pi^-$ at forward rapidity ($y = 2.2$). > > Particle composition will further be discussed > > in terms of $p/h^+$ and $\bar{p}/h^-$ at > > midrapidity and of $\pi^-/h^-$ at forward rapidity. \\ > > > > > > \par > > [1] K. Adcox et al., Phys. Rev. Lett. 88 (2002) 242301;\ \ > > C. Adler et al., Phys. Rev. Lett. 86 (2001) 4778;\ \ > > S. S. Adler et.al., nucl-ex/0307022 .\\ > > AND BRAHMS > > > > [2] Z. W. Lin and C. M. Ko, Phys. Rev. Lett. 89 (2002) 202302; \ \ > > S. A. Voloshin, Nucl. Phys. A715 (2003) 379c; \ \ > > D. Molnar and S. A. Voloshin, nucl-th/0302014; \ \ > > Z. W. Lin and D. Molnar, nucl-th/0304045.\\ > > > > \end{document} > > > > > > > > > > > > > > > > > > > > > > -----Original Message----- > > From: Jens Ivar Jordre [mailto:jensivar.jordre@fi.uib.no] > > Sent: Thu 9/25/2003 10:24 AM > > To: BRAHMS List > > Cc: > > Subject: Updated QM abstracts from Bergen. > > > > Dear collaborators. > > > > Here are updated abstracts from Bergen. Please read and comment. > > > > Best wishes from > > Zhongbao and Jens Ivar > > > > > > -- > ----------------------------------------------------- > Zhongbao YIN Phone: +47-55-582792 (O) > Address: +47-55-276803 (H) > Fantoftveien 14G 466 E-mail: > 5075 Bergen Yin.Zhongbao@fi.uib.no > ------------------------------------------------------ >
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