Introduction Detector Search for Gluonic Excitations in Hadrons with GlueX Hadron 2011 Igor Senderovich June 16, 2011 Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 1
Introduction Physics Motivation Detector Production Approach Outline Introduction Physics Motivation Production Approach Detector Detector Overview Trigger and Readout Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 2
Introduction Physics Motivation Detector Production Approach Physics Motivation Can we probe the gluonic field in hadrons directly? ◮ hybrid mesons (i.e. with gluonic excitation) Other physics: ◮ precision measurement of Γ( η → γγ ) via Primakoff effect † ◮ general light-quark spectroscopy, e.g. ◮ excited vector mesons poorly understood ◮ strange sector analogs of X, Y, Z mesons Figure: Lattice QCD mass ◮ understand the Ξ spectrum predictions as a function of pion mass. (J. Dudek et al., 2010) ◮ inverse DVCS ◮ production near charm threshold † approved ◮ hadronization in the nuclear medium Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 3
Introduction Physics Motivation Detector Production Approach Meson Quantum Numbers Consider the qq system and its J P C quantum numbers. Since: ◮ S = 0 , 1 and L = 0 , 1 , 2 , . . . = ⇒ J = L − 1 , L, L + 1 ◮ P = ( − 1) L +1 and C = ( − 1) L + S Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 4
Introduction Physics Motivation Detector Production Approach Meson Quantum Numbers Consider the qq system and its J P C quantum numbers. Since: ◮ S = 0 , 1 and L = 0 , 1 , 2 , . . . = ⇒ J = L − 1 , L, L + 1 ◮ P = ( − 1) L +1 and C = ( − 1) L + S ∴ qq quantum numbers: J ++ − + + − −− 0 ++ 0 − + 0 1 −− 1 ++ 1 + − 1 2 −− 2 ++ 2 − + 2 3 −− 3 ++ 3 + − 3 4 −− 4 ++ 4 − + 4 5 −− 5 ++ 5 + − 5 Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 4
Introduction Physics Motivation Detector Production Approach Meson Quantum Numbers Consider the qq system and its J P C quantum numbers. Since: ◮ S = 0 , 1 and L = 0 , 1 , 2 , . . . = ⇒ J = L − 1 , L, L + 1 ◮ P = ( − 1) L +1 and C = ( − 1) L + S ∴ qq quantum numbers: “exotic” quantum numbers: J ++ − + + − −− 0 −− 0 ++ 0 − + 0 + − 0 1 −− 1 ++ 1 − + 1 + − 1 2 −− 2 ++ 2 − + 2 + − 2 3 −− 3 ++ 3 − + 3 + − 3 4 −− 4 ++ 4 − + 4 + − 4 5 −− 5 ++ 5 − + 5 + − 5 ◮ Exotic states = ⇒ unambiguous signature of new degrees of freedom Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 4
Introduction Physics Motivation Detector Production Approach Exotic States: Experimental Evidence The following are some tentative observations of possible exotic states thus far: 1 State Mass (GeV) Width (GeV) Prod. Decays Experiments π − p , ¯ π − η , π 0 η π 1 (1400) 1 . 351 ± 0 . 03 0 . 313 ± 0 . 040 pn E852, CBAR π − p , ¯ η ′ π , b 1 π , π 1 (1600) 1 . 662 ± 0 . 015 0 . 234 ± 0 . 050 E852, CBAR, pp f 1 π , ρπ COMPASS, VES π − p π 1 (2015) 2 . 01 ± 0 . 03 0 . 28 ± 0 . 05 b 1 π , f 1 π E852 1 masses and widths from PDG Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 5
Introduction Physics Motivation Detector Production Approach Production Method Data so far: (mostly) π beam prod. ⇐ = exotic hybrid prod. suppressed? A possible argument: the spin flip needed for exotic q.n. is suppressed. Proposal: use S = 1 beam → photons! Lowest-lying hybrids (flux-tube model): γ X π X N N N N π beam ( S = 0 ) γ beam ( S = 1 ) 0 −− 0 ++ 0 − + 0 + − 1 −− 1 ++ 1 − + 1 + − 2 −− 2 ++ 2 − + 2 + − γ beam source: Coherent Bremsstrahlung in diamond ◮ 9 GeV , 40% polarization fraction ◮ 10 8 γ/s with ∼ 2 µ A beam current ◮ collimation 75 m downstream ◮ 8 MeV / counter tagging with high efficiency Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 6
Introduction Detector Overview Detector Trigger and Readout 12 GeV upgrade Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 7
Introduction Detector Overview Detector Trigger and Readout 12 GeV upgrade Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 7
Introduction Detector Overview Detector Trigger and Readout 12 GeV upgrade Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 7
Introduction Detector Overview Detector Trigger and Readout Hall Construction Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 8
Introduction Detector Overview Detector Trigger and Readout Hall Construction Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 8
Introduction Detector Overview Detector Trigger and Readout Detector Overview o 118.1 o 14.7 o 126.4 o 10.8 �� �� �� �� ��������������� ��������������� �� �� ��������������� ��������������� �� �� ��������������� ��������������� �� �� ��������������� ��������������� ������� ������� � � � � �� �� �� �� �� �� ������� ������� �� �� ������� ������� � � � � �� �� �� �� �� �� ◮ 2 . 2 T solenoid ������� ������� �� �� 185cm � � � � �� �� �� �� �� �� ������� ������� �� �� ������� ������� ◮ 30 cm L H 2 � � � � �� �� �� �� �� �� ������� ������� �� �� ������� ������� � � � � �� �� �� �� �� �� target ������� ������� �� �� ��������������� ��������������� �� �� ��������������� ��������������� �� �� ��������������� ��������������� �� �� �� �� 342cm 48cm solenoid tracking system 560cm calorimetry 30cm-Target time of flight C future PID L Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 9
Introduction Detector Overview Detector Trigger and Readout Barrel Calorimeter (BCAL) Sampling (10%) SpaCal Design based on KLOE Emcal: ◮ 40 MeV − 3 . 5 GeV range ◮ 11 ◦ < θ < 120 ◦ coverage ◮ 191 Sci/Pb layers → 15.5 X 0 √ ◮ σ E /E = 5 . 54 / E ⊕ 1 . 6% ◮ σ z = 5 mm √ ◮ σ ∆ t/ 2 = 70 ps / E ◮ +5 ◦ C -stabilized Hamamatsu SiPM readout Role: ◮ γ , π 0 , η reconstruction ◮ PID input through: energy, dE/dx, time of flight Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 10
Introduction Detector Overview Detector Trigger and Readout Barrel Calorimeter (BCAL) Sampling (10%) SpaCal Design based on KLOE Emcal: ◮ 40 MeV − 3 . 5 GeV range ◮ 11 ◦ < θ < 120 ◦ coverage TOF ◮ 191 Sci/Pb layers → 15.5 X 0 √ ◮ σ E /E = 5 . 54 / E ⊕ 1 . 6% ◮ σ z = 5 mm √ ◮ σ ∆ t/ 2 = 70 ps / E ◮ +5 ◦ C -stabilized Hamamatsu SiPM readout Role: ◮ γ , π 0 , η reconstruction ◮ PID input through: energy, dE/dx, time of flight Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 10
Introduction Detector Overview Detector Trigger and Readout Forward Calorimeter (FCAL) Lead Glass Calorimeter ◮ 2 ◦ < θ < 11 ◦ coverage ◮ 2800 F8-00 Pb-glass blocks: 4 × 4 × 45 cm ◮ FEU 84-3 PMT readout √ ◮ σ E /E = 5 . 7 / E ⊕ 1 . 6% ◮ σ r = 5 − 6 mm ◮ σ t < 150 ps using algorithms on FPGA Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 11
Introduction Detector Overview Detector Trigger and Readout Central Drift Chamber (CDC) Staw Tube Drift Chamber ◮ 3522 aluminized mylar straw tubes, 1 . 6 cm dia. ◮ 12 axial, 16 ( 6 ◦ ) stereo layers ◮ dE/dx for π , K , p < 450 MeV / c ◮ σ r = 150 µ m , σ z = 1 . 5 mm ◮ σ p /p = 1 . 5 − 3% ◮ 6 ◦ < θ < 165 ◦ coverage Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 12
Introduction Detector Overview Detector Trigger and Readout Forward Drift Chamber Cathode Strip Design: ◮ 4 packages × 6 planes/package × 96 wires/plane = 2304 wires ◮ 4 packages × 12 planes/package × 216 strips/plane= 10368 strips ◮ 1 cm sense wire pitch ◮ 0 . 5 cm cathode plane pitch ◮ σ x,y = 200 µ m ◮ 1 ◦ < θ < 30 ◦ coverage Figure: Cathode readout, redundancy and angular shifts to reduce ghosting. Next layer offset by 60 ◦ Igor Senderovich Search for Gluonic Excitations in Hadrons with GlueX 13
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