| High pt project |
| ShinIchi Esumi | |
| For High pt Upgrade Team | |
| http://utkhii.px.tsukuba.ac.jp/~highpt/ |
| Future Extention of PHENIX |
| Basic strategy of PHENIX | |||
| PHENIX as photon, hadron, electron and muon spectrometer | |||
| Rare event detection capability. | |||
| It is natural to extend the PID towards higher pt region. | |||
| Strong motivation given; | |||
| Never seen at SPS | |||
| Interesting behaviour at high pt | |||
| Jet Qunching!? | |||
| Jet quenching |
| Parton energy loss in dense matter | ||
| Analogous to EM energy loss of charged particles in matter | ||
| Dominated by gluon radiation in QCD | ||
| Hard processes/probes are from the earliest stage of the collision | ||
| Could be a good probe of QGP formation | ||
| Jet Quench via pt distribution |
| One straight way to see the effect | ||
| Extend the pt range helps! | ||
| May be difficult when the other effects involved | ||
| Jet Quench via Flavor Dependence |
| Gluons in QCD stronger interaction than quarks | |||
| Gluon density in nucleon larger in small x | |||
| @sgg > sqq | |||
| Larger energy loss of gluons than that of quarks | |||
| dEq/dx ~ 1 GeV/fm | |||
| dEg/dx ~ 2 GeV/fm | |||
| At high pt, some particles are fragmented more from gluon than quark jet. | |||
| Gluon jets fragment into same number of particles and anti-particles. | |||
| Gluon jets produce more particles ; softer distr. | |||
| Effect of jet qunching can be seen in particle ratios. | |||
| @p-/ p+ ratios |
| Low pt, same numbers of pions produced from gluons and quarks, while at high pt, only (u,d) quark jet contributes. | |||
| @pp; | |||
| Saturates at 0.5 (nd/nu of p) | |||
| Au+Au; | |||
| Saturates at 1.14 (nd/nu of Au nuclei) | |||
| Change due to the parton energy loss is small in pions because of smaller contributions from gluons. | |||
| @Antiproton/proton ratios |
| (u,d) quark jets likely produce a leading proton than antiproton. | ||
| Ratio decreases with pt. | ||
| Gluon jets produce the same number of proton and antiproton with softer distribution. | ||
| At high pt, most of antiproton from gluons, while proton from both valence quark and gluon fragmentation. | ||
| If gluon jets lose more energy, then ratio behavior modified. | ||
| Jet quench effect in v2 |
| Azimuthal asymmetry provides sensitive measure of initial density distribution. | |
| More sensitive than pt spectra!? |
| Charm |
| Deacy from D0 (open charm) contributes a lot to high pt kaons. | |
| May enhance the capability of open charm measurement. | |
| Need further study! |
| PID capability of PHENIX |
| Time-of Flight | ||
| TOF | ||
| PbSc | ||
| BBC | ||
| Cherenkov | ||
| RICH | ||
| EM calorimeter | ||
| PBGl | ||
| PbSc | ||
| PID by TOF |
| Overall timing resolution <100 ps achieved. | ||
| Pion/Kaon < 2.5 GeV/c | ||
| Kaon/Proton < 4.0 GeV/c | ||
| PID by RICH |
| RICH | |||
| CH4;1.00044 | |||
| CO2;1.00041 | |||
| gth= 34 | |||
| Pion ; 4.7 GeV/c | |||
| eID; 0.2 - 4 GeV/c | |||
| 10 - 15 p.e. achieved! | |||
| Additional Cherenkov |
| RICH | |||
| CH4;1.00044 | |||
| CO2;1.00041 | |||
| gth= 34 | |||
| Pion ; 4.7 GeV/c | |||
| Aerogel | |||
| Best match at 1.005 | |||
| Commercially available for 1.007 - 1.07 | |||
| Samples for test | |||
| 1.007 | |||
| 1.01 | |||
| 1.015 | |||
| Extended PID |
| Aerogel Cherenkov at KEK-B BELLE |
| Non-imaging Cherenkov | ||
| 960 modules at Barrel, 228 at Endcap. | ||
| Index n = 1.01 - 1.03 | ||
| 12 x 12 x 12 cm3 | ||
| 2 Fine-mesh PMT (1.5T) | ||
| R6683(3h) for n = 1.01 | ||
| R6682(2.5h) for n = 1.015 | ||
| R6681(2h) for n = 1.02 | ||
| ~ 10 - 20 p.e. | ||
| Segmentation of Aerogel |
| TOF | ||
| ~ 100 cm2 at 5 m | ||
| Sensitive to all > 150 MeV/c | ||
| Backgrounds (low energy e/gfs@ from yoke & EM cal) | ||
| Occupancy 10% in Au+Au | ||
| Aerogel of n = 1.01 | ||
| Sensitive to all g > 7.1 | ||
| Delta rays in Aerogel (~%) | ||
| Muon from decayed pion | ||
| Backgrounds | ||
| GEANT required! | ||
| Satoshi Takagi working on. | ||
| Plan Guestimate |
| Coverage of 4 TOF panel equivalent as a first stage | |||
| 150 modules | |||
| 300 PMTfs ; 12,000,000 yen | |||
| 400 liter; 20,000,000 yen | |||
| Total ; ~40,000,000 yen | |||
| Since no space on the East, we install on the West. | |||
| Remove 2 lower TOF panels from the East after successful pp measurements | |||
| 1 spare panel | |||
| 1 panel to be constructed | |||
| TOF 1 panel ; 13,000,000 yen | |||
| PMT selections |
| PMT Requirements | |||
| Photon counting | |||
| Gain; > 10**6 | |||
| Low dark current | |||
| Non-UV | |||
| Larger diameter | |||
| Cost | |||
| Hamamatsu recommended | |||
| 2h@ ;@ R6231 | |||
| 3h@ ;@ R6233 | |||
| Russian PMTfs will be also evaluated | |||
| Pulse height distr.of single p.e.fs |
| 2h R6231 | ||
| Clean single photoelectron peak seen. | ||
| Gain of 2x10**6 will be obtained. | ||
| Done by Hamamatsu | ||
| Will be tested at Tsukuba | ||
| Index of Aerogel |
| Commercially available | ||
| Matsushita-Denko | ||
| ~50k yen / litter | ||
| For the test experiments, n=1.007 -8, 1.015, 1.020 have been purchased for the tests. | ||
| Index measurements done. | ||
| Masahiro Konno | ||
| Measurement of Refractive Index |
| @Surface condition of the sample dominates the error. |
| Simulation for the design |
| MonteCalro Simulation | ||
| Cherenkov emission | ||
| Transmission | ||
| Absorption | ||
| Scattering | ||
| Parameterize measured transmission curve | ||
| Šabs | ||
| Šscat | ||
| Absorption and Scattering length |
| Transport length (L) is assumed to be from Scattering length(Lscat) and absorption length (Labs) | |
| Determined from transmittance curve assuming; |
| Measured Transmittance |
| Tested with the sample in hand | |||
| Better transmittance observed | |||
| Could depend on LOT and the index | |||
| Need tests with the real sample | |||
| Last points before PMT hits |
| Results depends strongly on Šabs and Šscat! |
| Other way to evaluate Šscat |
| Measure scattered photons off the Aerogel | |
| Could be better way to evaluate Šabs and Šscat |
| Scattered Photons (Exp) |
| Very preliminary | ||
| Consistent with scattering length of a few cm at 410 nm | ||
| 80 p.e. out of 300 p.e.? | ||
| No directionarity of light expected!? | ||
| Scattered Photons (MC) |
| Very preliminary | ||
| KEK parametrizations used | ||
| Šscat ; 3 cm @ 415 nm | ||
| Šabs ; 12 cm @ 415 nm | ||
| Note that transmittance of our sample is different. | ||
| Qualitative agreement | ||
| Plan |
| Kick start the GEANT activity. | |||
| Satoshi Takagi | |||
| Evaluate Šabs and Šscat | |||
| Transmission | |||
| Scattering lights | |||
| MC vs Exp | |||
| Evaluation of PMTfs | |||
| 3h vs 2h | |||
| Position dep. of photo cathode | |||
| Pulse height dist. of 1 p.e. | |||
| Bleeder evaluation | |||
| From 2-2-1-1-1 to 1-1-1-1-1 | |||
| Design of prototype | |||
| KEK test beam plan |
| KEK test beam in Dec. | ||
| Proposal will be submitted in September | ||
| Need names of participants | ||
| Prototypes to be built | ||
| Type-A; 12 x 12 w 3h@ (BELLE) | ||
| Type-B; 20 x 20@ w 3h | ||
| Type-C; 20 x 20 w mirror | ||
| Items to be tested | ||
| # of p.e. vs. mom.;@ 0.4 - 4 GeV/c | ||
| # of p.e. vs. thickness | ||
| Position of PMT | ||
| Air between Aerogel and PMT | ||
| Direction of stack | ||
| Call for issues/ideas! | ||