THE EXPERIMENT Curtis A. Meyer Carnegie Mellon 2 June - PowerPoint PPT Presentation

THE EXPERIMENT Curtis A. Meyer Carnegie Mellon

2 June 4, 2016 Meson 2016 - C.A. Meyer The GlueX Collaboration Arizona State, Athens, Carnegie Mellon, Catholic University, Univ. of Connecticut, Florida International, Florida State, George Washington, Glasgow, GSI, Indiana University, ITEP, Jefferson Lab, U. Mass Amherst, MIT, MePhi, Norfolk State, North Carolina A&T, Univ. North Carolina Wilmington, Northwestern, Santa Maria, University of Regina, Tomsk and Yerevan Physics Institute. Over 120 collaborators from 24 institutions with others joining and more are welcome.

3 June 4, 2016 Meson 2016 - C.A. Meyer Outline • The GlueX physics program. • The GlueX experiment and its performance during commissioning. • Expected initial physics from GlueX. • Future plans and other physics. • Summary. 12-GeV beam, Dec.2015

4 June 4, 2016 Meson 2016 - C.A. Meyer Quantum Chromo Dynamics QCD describes the interactions of quarks and gluons and should predict the spectrum of bound- state baryons ( ) and mesons ( ). qqq qq There should also be mesons in which the gluonic field contributes directly to the J PC quantum numbers of the states --- hybrid mesons. Some are expected to have ``exotic’’ quantum numbers. Lattice QCD calculation of exotics s ¯ the light-quark meson s 2.5Gev spectrum. u ¯ u u ¯ d ``Constituent gluon’’: J PC = 1 +- 2.0GeV mass of 1-1.5 GeV. The lightest hybrid nonets 0 +- 1 -+ 2 +- 1 -- , (0 -+ ,1 -+ , 2 -+ )

5 June 4, 2016 Meson 2016 - C.A. Meyer Light-quark Mesons (u,d,s) Lattice QCD negative parity positive parity exotics 2.5 2.0 1.5 1.0 isoscalar isovector 0.5 YM glueball 1 1 � � � � uu − dd uu + dd ( ss ) √ √ 2 2 PRD83, 111502 & PRD88, 094505

6 June 4, 2016 Meson 2016 - C.A. Meyer Light-quark Mesons (u,d,s) Lattice QCD negative parity positive parity exotics 2.5 2.0 2 -+ 1 -+ 1.5 States with non-trivial 1.0 gluonic fields. Supermultiplet isoscalar F j,µ ν F µ ν j isovector 1 -- 1 -- , 0 -+ , 1 -+ , 2 -+ 0.5 YM glueball 0 -+ 1 1 � � � � uu − dd uu + dd ( ss ) √ √ 2 2 PRD83, 111502 & PRD88, 094505

7 June 4, 2016 Meson 2016 - C.A. Meyer QCD Exotics exotics s ¯ s 2.5Gev La#ce QCD suggests 5 nonets of u ¯ u mesons with exo7c quantum u ¯ d η 1 number: 2.0GeV π 1 1 nonet of 0 +- exo7c mesons 2 nonets of 1 -+ exo7c mesons 0 +- 1 -+ 2 +- 2 nonets of 2 +- exo7c mesons Experimental evidence exists for π 1 states. π 1 I G (J PC )=1 - (1 -+ ) K 1 I G (J PC )= ½ (1 - ) ``Constituent gluon’’ behaves η ’ 1 I G (J PC )=0 + (1 -+ ) like J PC = 1 +- with a mass of η 1 I G (J PC )=0 + (1 -+ ) 1-1.5 GeV The lightest hybrid nonets: Kaon states do not have exotic QNs 1 -- , (0 -+ ,1 -+ , 2 -+ ) PRD84, 074023

8 June 4, 2016 Meson 2016 - C.A. Meyer Photoproduction Mechanisms γ ρ , ω , φ Simple quantum number counting for X production: (I G )J PC up to L=2 π , η , ρ , ω , P,... P = Pomeron exchange p N ρπ is charge-exchange only ρπ , ρω π 1 ωω , ρρ η 1 Can couple to all the lightest exotic ωω , ρρ , φω η ’ 1 ρ P b 0 hybrid nonets through photo- ω P h 0 production and VMD. ω P, φ P h’ 0 ωπ , ρη , ρ P b 2 Linear polarization is a filter on the ρπ , ωη , ω P h 2 naturality of the exchanged particle. ρπ , ωη , φ P h’ 2

9 June 4, 2016 Meson 2016 - C.A. Meyer Decay Modes of Exotic Hybrids π 1 → πρ πρ , π b 1 , π f 1 , πη ’ , η a 1 η 1 → η f 2 ,a 2 π , η f 1 , ηη ηη ’ , π (1300) π , a 1 π , η 1 ’ → K * Κ , Κ 1 (1270) Κ , Κ 1 (1410) Κ , ηη ηη ’ b 2 → ωπ ωπ , a 2 π , ρη ρη , f 1 ρ , a 1 π , h 1 π , b 1 η h 2 → ρπ ρπ , b 1 π , ωη , f 1 ω h’ 2 → Κ 1 (1270) Κ , Κ 1 (1410) Κ , K 2 * Κ , φη , f 1 φ b 0 → π (1300) π , h 1 π , f 1 ρ , b 1 η h 0 → b 1 π , h 1 η h’ 0 → K 1 (1270) Κ , Κ (1460) Κ , h 1 η Models suggest narrower states Early Reach With Statistics Hard are in the spin-1 and spin-2 nonets, Hybrid kaons do not have exotic QN’s while the spin-0 nonets are broad.

10 June 4, 2016 Meson 2016 - C.A. Meyer The GlueX Experiment BaBar DIRC Bars G lue X forward calorimeter barrel time-of calorimeter -flight target Photo Production of Hybrids, Light-quark Mesons and Strangeonium States photon beam diamond forward drift wafer chambers central drift chamber electron superconducting tagger magnet beam electron magnet tagger to detector distance beam is not to scale Initial Physics in 2016

11 June 4, 2016 Meson 2016 - C.A. Meyer The GlueX Experiment Photon Tagger Pair Spectrometer Polarimeter North LINAC 75 m Photon Beam Dump Collimator Diamond Radiator Electron GlueX East ARC Beam Dump select � < 25 � r Spectrometer ​"↑ − " % → &​"↑ − % polarized photons Tagger Area Hall-D • 12 GeV e - beam up to 2.2 µA. Goniometer with diamonds • Linearly polarized photons (P ɣ ≈ 40%) from coherent bremsstrahlung on thin diamond radiator. • Polarization parallel and perpendicular to floor. • Design intensity of 10 8 ɣ /s in coherent peak (E ɣ = 8.4-9 GeV)

12 June 4, 2016 Meson 2016 - C.A. Meyer The GlueX Experiment Photon Tagger Pair Spectrometer Polarimeter North LINAC 75 m Photon Beam Dump Collimator Diamond Radiator Electron GlueX East ARC Beam Dump select � < 25 � r Spectrometer ​"↑ − " % → &​"↑ − % polarized photons Tagger Area Hall-D

13 June 4, 2016 Meson 2016 - C.A. Meyer GlueX Commissioning Spring 2016 run with 12-GeV electrons on thin diamond radiators. Linear polarization, both perpendicular and parallel to the earth, collected. Generated: April 25, 2016 30 Number of Events Collected / 10 9 ⊥ Polarization 20 || Polarization Unpolarized Total 10 0 0 5 10 15 Integrated Beam Time [Days]

14 June 4, 2016 Meson 2016 - C.A. Meyer GlueX Calorimeter Performance Forward Lead Glass Calorimeter Barrel Lead-Scintillating Fiber Calorimeter Candidates / 2 MeV/ c 2 Candidates / 2 MeV/ c 2 250 300 250 200 200 150 Design Goal Design Goal 150 100 100 50 50 0 0 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.00 0.05 0.10 0.15 0.20 0.25 0.30 M γγ [GeV/ c 2 ] M γγ [GeV/ c 2 ]

15 June 4, 2016 Meson 2016 - C.A. Meyer GlueX Tracking Performance Central Drift Chamber (CDC) Forward Drift Chamber (FDC) 1000 260 Wire Position Resolution [µm] Position Resolution [µm] 240 800 Achieved Cathode 220 Resolution: 150 µm 600 200 Design Resolution for Cathodes and Wires: 200 µm 180 400 160 200 Design Resolution: 150 µm 140 0 0 1 2 3 4 0 1 2 3 4 5 6 7 8 9 10 Track to Wire Distance [mm] Track to Wire Distance ( d ) [mm] 1.0 Straw E ffj ciency 0.98 3D Reconstruction E ffj ciency 0.8 0.94 0.6 d 0.90 Colors Index Chambers in the Third Package 0.4 0.86 0.2 8 mm 0.82 0.0 0 1 2 3 4 5 6 7 8 -400 -200 0 200 400 Track to Wire Distance ( d ) [mm] x Coordinate [mm]

16 June 4, 2016 Meson 2016 - C.A. Meyer GlueX Particle Identification Negatively Charged Particles Positively Charged Particles β from Time of Flight β from Time of Flight e 1.0 1.0 e π π K K 10 2 0.8 0.8 10 2 p Incorrect RF Bunch 0.6 0.6 10 10 0.4 0.4 0.2 0.2 1 1 0.0 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Track Momentum [GeV/ c ] Track Momentum [GeV/ c ] Positively Charged Particles 2.5 450 CDC d E /d x [keV/cm] FCAL Energy / Track Momentum 14 10 4 400 12 2.0 350 10 3 10 300 1.5 e + / e - 250 8 p 10 2 200 6 1.0 150 4 10 100 0.5 hadrons 2 π /K/e 50 0 1 0.0 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0 2 4 6 8 10 12 Track Momentum [GeV/ c ] Track Polar Angle [degrees]

17 June 4, 2016 Meson 2016 - C.A. Meyer Start of Physics in GlueX • Initial reactions will be polarization transfer and beam asymmetry measurements. γ p → ( ρ 0 , ω , φ ) p γ p → ( π 0 , η , η 0 ) p • Spin-density matrix elements to understand production mechanisms. • Opportunistic results from data exploration. • Cross section measurements. • Identify known mesons in PWA. • Move on to the search for exotic hybrids.

18 June 4, 2016 Meson 2016 - C.A. Meyer Early Physics in GlueX • Initial reactions will be polarization transfer and beam asymmetry measurements. γ p → ( ρ 0 , ω , φ ) p γ p → ( π 0 , η , η 0 ) p • Spin-density matrix elements to understand production mechanisms. • Opportunistic results from data exploration. • Cross section measurements. • Identify known mesons in PWA. • Move on to the search for exotic hybrids.