Hadron freeze-out conditions in high energy nuclear collisions

Systematic trend of the hadron freeze-out conditions from AGS/SPS to RHIC is discussed. The most interesting results from collisions at RHIC are that the system is indeed approaching net-baryon free and the transverse expansion is much stronger than that from collisions at AGS/SPS energies. In order to understand the trend of the collective velocity, an energy scan between $\sqrt{s_{NN}} = 20 - 200 GeV, is important. In addition, systematic studies on the anisotropy parameter$v_2$and the transverse momentum distributions of$\phi, \Omega,$and$J / \psi$ are necessary as they will help in determining whether the collectivity is developed at the partonic stage.Comment: Talk presented at the Quark Matter 2001 conference, 8 pages, 8 figures. To appear in Nucl. Phys.

Strangeness and heavy flavor at RHIC: Recent results from PHENIX

We report recent results of strangeness and heavy flavor measurements from PHENIX. The topics are: Elliptic flow of strangeness and heavy flavor electron production comparing to the other hadrons, $\phi$ meson production, and an exotic particle search.Comment: 8 pages, 6 figures, 1 table. Submitted to J. Phys. G (Proceedings of the 8th International Conference on Strangeness in Quark Matter, Cape Town, South Africa, September 15-20, 2004

Event anisotropy of identified π0\pi^{0}, photon and electron compared to charged π\pi, KK, pp and deuteron in sNN\sqrt{s_{NN}} = 200 GeV Au+Au at PHENIX

We report the recent results of event anisotropy analysis focused on $v_2$ in $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions at PHENIX.Comment: 4 pages, 3 figures, contribution to the proceedings of the 17th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter, Oakland, January 11-17, 2004). To appear in the proceedings (Journal of Physics G

Nov sistem za identifikaciju čestica u području 3 − 8 GeV/c

A threshold imaging Cherenkov (TIC) detector, in conjunction with a tracking device, has been developed to allow pion/kaon, proton identification in the 3–8 GeV/c range of momenta. The most important feature of the system is that it allows spatial identification of the photons of particles above the Cherenkov threshold and their correlation to a particular track. The TIC detector uses a MWPC detector with TMAE for photon conversion into electrons. The first results obtained in ultrarelativistic lead–lead collisions at the CERN SPS accelerator are presented. In a recent development use of a solid CsI cathode instead of TMAE has been successfully tested in proton–lead collisions at the CERN SPS.Razvijen je pozicioni detektor fotona Cerenkovljeva zračenja iznad praga emisije (TIC), koji omogućuje (u sklopu sistema za mjerenje tragova čestica) razlikovanje piona od kaona i protona u području između praga emisije za pione i za kaone t.j između 3 i 8 GeV/c. Najbitnija odlika sistema jest mogućnost dvodimenzijske lokalizacije emitiranih fotona i njihovo jednoznačno pridruživanje određenom tragu čestice koji je odreden drugim detektorima. Detektor TIC primjenjuje višezičane proporcionalne komore s TMAE dodanom brojačkom plinu za konverziju fotona u elektrone. Prikazuju se prvi rezultati dobiveni u ultrarelativističkim sudarima iona olova s metom olova u SPS akceleratoru u CERNu. Nedavno je upotreba čvrstih fotokatoda umjesto TMAE bila uspješno iskušana procesima sudara protona s olovom u SPS akceleratoru

Status Report of Neutral Kaon photo-production study using Neutral Kaon Spectrometer 2 (NKS2) at LNS-Tohoku(I. Nuclear Physics)

The approach described in this paper uses an array of Field Programmable Gate Array (FPGA) devices to implement a fault tolerant hardware system that can be compared to the running of fault tolerant software on a traditional processor. Fault tolerance is achieved is achieved by using FPGA with on the fly partial programmability feature. Major considerations while mapping to the FPGA includes the size of the area to be mapped and communication issues related to their communication. Area size selection is compared to the page size selection in Operating System Design. Communication issues between modules are compared to the software engineering paradigms dealing with module coupling, fan-in, fan-out and cohesiveness. Finally, the overhead associated with the downloading of the reconfiguration files is discussed

Focal dose escalation using FDG-PET-guided intensity-modulated radiation therapy boost for postoperative local recurrent rectal cancer: a planning study with comparison of DVH and NTCP

<p>Abstract</p> <p>Background</p> <p>To evaluate the safety of focal dose escalation to regions with standardized uptake value (SUV) >2.0 using intensity-modulated radiation therapy (IMRT) by comparison of radiotherapy plans using dose-volume histograms (DVHs) and normal tissue complication probability (NTCP) for postoperative local recurrent rectal cancer</p> <p>Methods</p> <p>First, we performed conventional radiotherapy with 40 Gy/20 fr. (CRT 40 Gy) for 12 patients with postoperative local recurrent rectal cancer, and then we performed FDG-PET/CT radiotherapy planning for those patients. We defined the regions with SUV > 2.0 as biological target volume (BTV) and made three boost plans for each patient: 1) CRT boost plan, 2) IMRT without dose-painting boost plan, and 3) IMRT with dose-painting boost plan. The total boost dose was 20 Gy. In IMRT with dose-painting boost plan, we increased the dose for BTV+5 mm by 30% of the prescribed dose. We added CRT boost plan to CRT 40 Gy (<it>summed plan 1</it>), IMRT without dose-painting boost plan to CRT 40 Gy (<it>summed plan 2</it>) and IMRT with dose-painting boost plan to CRT 40 Gy (<it>summed plan 3</it>), and we compared those plans using DVHs and NTCP.</p> <p>Results</p> <p>D_meanof PTV-PET and that of PTV-CT were 26.5 Gy and 21.3 Gy, respectively. V₅₀of small bowel PRV in <it>summed plan 1 </it>was significantly higher than those in other plans ((<it>summed plan 1 </it>vs. <it>summed plan 2 </it>vs. <it>summed plan 3</it>: 47.11 ± 45.33 cm³vs. 40.63 ± 39.13 cm³vs. 41.25 ± 39.96 cm³(p < 0.01, respectively)). There were no significant differences in V₃₀, V₄₀, V₆₀, D_meanor NTCP of small bowel PRV.</p> <p>Conclusions</p> <p>FDG-PET-guided IMRT can facilitate focal dose-escalation to regions with SUV above 2.0 for postoperative local recurrent rectal cancer.</p