From: yin.zhongbao@fi.uib.no
Date: Fri Sep 26 2003 - 03:47:01 EDT
Hi J.H., I agree with you. Actually it is possible to get pi spectra up to 3.0 GeV/c at midrapidity if we use a little bit trick on TOFW pid, that is to say, use half of pi mass^2 band to count pi's for pt>2.0 GeV/c and then correct for it. Certainly there are a lot of works. For pbar spectra at forward rapidity I will certainly look into it soon. But when I wrote the abstract I am not sure if it is possible to deliver all of them. That's why I wrote like that. Anyway, I will go to Copenhagen in November and stay there for half a month, hopefully we can get all of them done. Best regards, Zhongbao On Thu, 25 Sep 2003, J.H. Lee wrote: > 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 > > ------------------------------------------------------ > > > > -- ----------------------------------------------------- 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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