Alice Workshop in Seoul Hideyuki Obayashi

内容 日程・場所 FCal の紹介 Di-baryon の検出可能性について まとめ

日程 11/4 広島空港 9:40 → 仁川空港 11:20 11/7 仁川空港 19:20 → 広島空港 21:00 ( 飛行機の遅れのため ) 場所 延世大学 ( 韓国 )

講演内容の紹介

FCAL (Forward CALorimeter) PMD Z~360 FCAL

Forward Physics in ALICE 1.Physics at high gluon density - C olor G lass C ondensate Gluon distribution functions in proton and nuclei 2.Tests of pQCD predictions: pp Forward particle production:  0 cross-section 3. Many interesting physics: Jets, Jet quenching Cronin effect, Shadowing  -tagging of the jets Limiting Fragmentation Diffractive physics Centrality selection, Event plane determination Exotic events ….. （以下、 Tapan Nayak さんのスライドよ り）

Gluon Distribution : Proton Low-x gluon density is large and continues to increase as x  0 It cannot grow forever Fundamental question - Where does saturation set in ? Deep inelastic scattering 

LHC: extending the low-x Reach RHIC has opened the low-x frontier finding indications for new physics (CGC ?) LHC will lower the x- frontier by another factor 30 Can reach x = 3 * in pp, < in PbPb Photon measurements will remain unaffected by final state nuclear distributions and hence will measure true nuclear PDFs.

Hadronization through coalescence : c / D ratio ud d u d u u s d s c c d u d u u s d s c d u d u c ud  c production through 3-body coalescence  c production through 2-body coalescence c c c c u c u D meson production through 2-body coalescence D meson production through 2-body coalescence of diquark and c  suppressed c

T cc /D > 0.34 x RHIC > 0.8 x LHC H c /D > 0.8 x H c /D s > 0.25 x Production ratios for predicted Multiquarks  c /D > 0.74 x  c /D s > 0.23 x   c production at RHIC and LHC  H c production at RHIC and LHC  T cc production

まとめ ALICE 検出器の Up Grade について学んで きた。 英語の勉強が必要だと感じた。

Buck up

Lattice calculation (Nakamura, Saito 05) Phenomenological fit to hadron spectrum quark-antiquark vs diquark  One gluon exchange  confining part  Spin part u d d u

When does scalar diquarks survive SHL, S. Yasui: EPJ C64, 283 (09) Based on 3x C B = C M = 635 m u 2 ud d u x 3 =

 Tetraquark : T cc (S=1), T bb (S=1), T cb (S=1), T cb (S=0)  Previous works on T cc Z. Zouzou, B. Silverstre-Brac, C. Gilgnooux, J Richard (86), D. Janc, M. Rosina (04), Y. Cui, S. L. Zhu (07) QCD sum rules: F Navarra, M.Nielsen, SHLee, PLB 649, 166 (2007) simple diquark: SHL, S. Yasui, W.Liu, C Ko EPJ C54, 259 (2008), SHL, S. Yasui: EPJ C (09) in press Tetraquark with two heavy antiquarks [ qq (cc)]  Tcc(S=1), Tbb(S=1), Tcb(S=1), Tcb(S=0)  Stable configuration d u c c c d qc (qc) states vs qq (cc)

Di-bayron (Conf 1) – (qq) (qq) (qq) u d  0+0+ s d H di-baryon  marginal s u u d s u d s H di-baryon CFLPhase of color superconductivity ? 2SC Phase  Stability: competition between (us) (ds) diquarks and (ud) diquark

Di-baryon (Conf 2) – (qq) (qq) (qQ) u d  0+0+ u s H c di-baryon  Stable  New prediction u c u d u c H c di-baryon P cc  Stability: must be stable as (uc) has to break u s

Mass diffM  –M N M  -M  M  c -M  c M  b -M  b Formula290 MeV77 MeV154 MeV180 MeV Experiment290 MeV75 MeV170 MeV192 MeV Mass diffM  –M  M K* -M K M D* -M D M B* -M B Formula635 MeV381 MeV127 MeV41 MeV Experiment635 MeV397 MeV137 MeV46 MeV u d ud s s Example

(Ex) PHENIX FoCAL Detector assembly “brick” 85 cm 17 cm 6cm Super tower 24

FCAL の案 FCAL Design Parameters Distance from the vertex~ 370 cm (see note in previous page) Eta Coverage2.3 – 4.5 Radial Coverage8cm to 73cm AbsorberTungsten (W) Depth23-25 Rad. Length (~17cm) Weight~ 4Tons SENSORS / READOUT: Scintillator tilesAPD readout Silicon Pads / Pixels

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