Future Spectroscopy Studies at Jefferson Lab
E.Chudakov1
1JLab, Hall D
Presented at Workshop COMPASS beyond 2020 CERN, 21-22 Mar 2016
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 1 / 32 Outline
1 JLab at 12 GeV 2 Physics motivation for JLab spectroscopy program 3 Experiments at JLab: GlueX in Hall D and CLAS12 in Hall B Apparatus Performance of GlueX during commissioning 4 Experimental schedule
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 2 / 32 Google Maps https://www.google.com/maps/@37.3745642,-76....
Jefferson Lab
JLab •
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 3 / 32
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Jefferson Lab
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E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 3 / 32
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E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 3 / 32 Jefferson Lab
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 3 / 32 Jefferson Lab History
Continuous Electron Beam Accelerator (CEBAF)
Up to 5 passes through 2 superconducting linacs ( 1500 MHz at 2◦K) ∼ Injector: 3 independent 500 MHz beams Parallel delivery of 1-5 passes beams to 3 Halls Electron beam polarization
History: 1995 4 GeV CEBAF and Hall C started 1997 4 GeV 3 hall operations started 1999-2012 6 GeV operations 2007-2017 12 GeV Upgrade (includes a new Hall D) 2016 12 GeV operations started for Hall D and Hall A
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 4 / 32 CEBAF Upgrade to 12 GeV
D
CHL
Accelerator: 2.2 GeV/pass • Halls A,B,C: e− 1-5 passes 11 GeV • ≤ Hall D: e− 5.5 passes 12 GeV γ-beam • Beam separation to 4 Halls at 250⇒ MHz A B C • Upgrade Status 12 GeV started in Feb 2016 • Halls A,D: running; B,C: start in 2017 • E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 5 / 32 Hall D: photoproduction by tagged real photons Hall B: photoproduction by tagged virtual photons at low Q2
JLab Experimental Halls
Hall D Hall B Hall C Hall A forward calorimeter barrel time-of calorimeter -flight GlueX target
photon beam diamond forward drift wafer chambers central drift chamber electron superconducting tagger magnet beam electron magnet beam tagger to detector distance large custom is not to scale hermeticity high resolution acceptance installations 12 GeV e− γ e 2.2–11 GeV ⇒ − γ linear polariz. e− longitudinal polarization 35 2 1 38 2 1 <100 MHz/GeV 10 cm− s− 10 cm− s− σ(p)/p 1 3% σ(p)/p 0.5% σ(p)/p 0.1% σ(p)/p 0.02% ∼ − ∼ ∼ ∼ spectroscopy program
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 6 / 32 JLab Experimental Halls
Hall D Hall B Hall C Hall A forward calorimeter barrel time-of calorimeter -flight GlueX target
photon beam diamond forward drift wafer chambers central drift chamber electron superconducting tagger magnet beam electron magnet beam tagger to detector distance large custom is not to scale hermeticity high resolution acceptance installations 12 GeV e− γ e 2.2–11 GeV ⇒ − γ linear polariz. e− longitudinal polarization 35 2 1 38 2 1 <100 MHz/GeV 10 cm− s− 10 cm− s− σ(p)/p 1 3% σ(p)/p 0.5% σ(p)/p 0.1% σ(p)/p 0.02% ∼ − ∼ ∼ ∼ spectroscopy program
Hall D: photoproduction by tagged real photons Hall B: photoproduction by tagged virtual photons at low Q2
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 6 / 32 The focus of the spectroscopy program at JLab for 2016-2022 Complimentary to the current COMPASS research - a different beam will be used
Spectroscopy of Hadrons - Highlights
Important Historic Role Structure - the Quark Model was motivated by hadron spectroscopy Forces - QCD forces were derived from the spectra of charmonium
Present Highlights Observation of the predicted states and identification of the observed non-exotic states Are there multi-quark states? Interpretation of the observed X,Y,Z stated: are they multi-quark states, or threshold effects, or something else? Is there a glueball? Are there hybrid states made of quarks and “constituent” gluons?
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 7 / 32 Complimentary to the current COMPASS research - a different beam will be used
Spectroscopy of Hadrons - Highlights
Important Historic Role Structure - the Quark Model was motivated by hadron spectroscopy Forces - QCD forces were derived from the spectra of charmonium
Present Highlights Observation of the predicted states and identification of the observed non-exotic states Are there multi-quark states? Interpretation of the observed X,Y,Z stated: are they multi-quark states, or threshold effects, or something else? Is there a glueball? Are there hybrid states made of quarks and “constituent” gluons? The focus of the spectroscopy program at JLab for 2016-2022
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 7 / 32 Spectroscopy of Hadrons - Highlights
Important Historic Role Structure - the Quark Model was motivated by hadron spectroscopy Forces - QCD forces were derived from the spectra of charmonium
Present Highlights Observation of the predicted states and identification of the observed non-exotic states Are there multi-quark states? Interpretation of the observed X,Y,Z stated: are they multi-quark states, or threshold effects, or something else? Is there a glueball? Are there hybrid states made of quarks and “constituent” gluons? The focus of the spectroscopy program at JLab for 2016-2022 Complimentary to the current COMPASS research - a different beam will be used E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 7 / 32 Gluons in QCD
Asymptotic Freedom Confinement High Energy Small Distance Low Energy Large Distance Gluons self-interaction⇐⇒ is weak Gluons self-interaction⇐⇒ is strong
Perturbative QCD - calculable Lattice QCD calculations ChP theory Gluon Jets observed The field makes most of the hadron’s mass 3-jet event, JADE 1980 No explicit manifestation of gluons has been observed so far
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 8 / 32 Flux Tube Notions Supported by LQCD Gluonic field in a qq pair Q Q 2.0 cc spectra suggested a QCD potential: B = 6.0 1.5 B = 6.2 fit Flux Tube Notions Supported bya LQCD Flux Tube Notions SupportedV (r) +byκr LQCD 1.0 ∝ − r ) (GeV) r ( Linear term confinement 0 0.5 ⇒ V Q Q 0 Q Q 2.0 2.0 B =LQCD 6.0 calculation -0.5 = 6.2 1.5 B 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 fit B = 6.0 FROM "ALI QUENCHED HEAVY QUARKS r (fm) 1.5 B = 6.2 fit 1.0 Quenched LQCD, heavy quarks
• Flux tubes lead to a linear, confining potential. ) (GeV)
r 1.0 (
0 0.5 V ) (GeV)
r Flux tube model (Nambu 1970) ( 0 0.50 • V Lattice QCD Calculations GlueX - A. Dzierba - 11/10/2006 5 -0.50 • The models and the LQCD predict 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 FROM "ALI QUENCHED HEAVY QUARKS -0.5 r (fm) gluonic excitations which may be observable in the mass spectra LQCD quenched0.2 0.4 and0.6 unquenched0.8 1.0 1.2 1.4 1.6 FROM "ALI QUENCHED HEAVY QUARKS reproduce the shape ofr (fm) the potential “Constituent gluon”: + 2 • Flux tubes lead to a linear, confining potential. LQCD:1 −, mass 1.3 GeV/c E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 9 / 32
• Flux tubes lead to a linear, confining potential.
GlueX - A. Dzierba - 11/10/2006 5
GlueX - A. Dzierba - 11/10/2006 5 Meson spectroscopy
Naive quark model: Mesons are qq, constituent quarks are S = 1/2 fermions No gluonic degrees of freedom Restrictions on the quantum numbers: JPC: P = ( 1)L+1, C = ( 1)L+S − − J ++ + + −− − − Glue and spectroscopy 0 0++ 0−+ −− ++ +− Gluonic excitations hybrid mesons 1 1 1 1 ⇒ 2 2−− 2++ 2−+ Exotic QN: an excellent signature 3 3−− 3++ 3+− of a new degree of freedom qq QN “exotic” QN no mixing with the regular qq states
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 10 / 32 Meson spectroscopy
Naive quark model: Mesons are qq, constituent quarks are S = 1/2 fermions No gluonic degrees of freedom Restrictions on the quantum numbers: JPC: P = ( 1)L+1, C = ( 1)L+S − − J ++ + + −− − − Glue and spectroscopy 0 0++ 0−+ −− ++ +− Gluonic excitations hybrid mesons 1 1 1 1 ⇒ 2 2−− 2++ 2−+ Exotic QN: an excellent signature 3 3−− 3++ 3+− of a new degree of freedom qq QN “exotic” QN no mixing with the regular qq states
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 10 / 32 Meson spectroscopy
Naive quark model: Mesons are qq, constituent quarks are S = 1/2 fermions No gluonic degrees of freedom Restrictions on the quantum numbers: JPC: P = ( 1)L+1, C = ( 1)L+S − − J ++ + + −− − − Glue and spectroscopy 0 0−− 0++ 0−+ 0+− −− ++ −+ +− Gluonic excitations hybrid mesons 1 1 1 1 1 ⇒ 2 2−− 2++ 2−+ 2+− Exotic QN: an excellent signature 3 3−− 3++ 3−+ 3+− of a new degree of freedom qq QN “exotic” QN no mixing with the regular qq states
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 10 / 32 Meson spectroscopy
Naive quark model: Mesons are qq, constituent quarks are S = 1/2 fermions No gluonic degrees of freedom Restrictions on the quantum numbers: JPC: P = ( 1)L+1, C = ( 1)L+S − − J ++ + + −− − − Glue and spectroscopy 0 0−− 0++ 0−+ 0+− −− ++ −+ +− Gluonic excitations hybrid mesons 1 1 1 1 1 ⇒ 2 2−− 2++ 2−+ 2+− Exotic QN: an excellent signature 3 3−− 3++ 3−+ 3+− of a new degree of freedom qq QN “exotic” QN no mixing with the regular qq states
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 10 / 32 Lattice QCD - the Meson Spectra
J.Dudek et al PRD 83 (2011); PRD 84 (2011), PRD 88 (2013)
HybridsTOWARD THE identified: EXCITED ISOSCALAR States MESON with SPECTRUM non-trivial... gluonicPHYSICAL fields REVIEW D 88, 094505 (2013)
3000 + J− regular QN J regular QN Exotic QN
2500
2000
+ + + 1− 0 − 2 − 1500 Nonets: 2 1 2
1000 Lowest-lying hybrid supermultiplet + + + 1−−, 0− , 1− . 2− 500 exotic
3 FIG. 11 (color online). Isoscalar (green and black) and isovector (blue) meson spectrum on the m ¼ 391 MeV, 24 128 lattice. CalculationsThe vertical height of each for boxm indicatesπ 400 the statisticalMeV uncertainty on the mass determination. States outlined in orange are the lowest- lying states having dominant overlap∼ with operators featuring a chromomagnetic construction—their interpretation as the lightest Orangehybrid meson frames supermultiplet - will lightest be discussed hybrids later.
3 E.ChudakovC. SUð3ÞF point, m COMPASS ¼ 702 MeV> 2020,, ð16; Mar20Þ 2016 128 Spectroscopymight be at the JLab complex resonance pole11 position, / 32 but we do In this case we take all three quark flavors to be mass not obtain this in our simple calculations using only single- hadron operators. degenerate, with the mass we have tuned to correspond to þ the physical strange quark. Here, because there is an exact We discuss the specific case of the 0 and 1 systems in the next subsections. SUð3Þ flavor symmetry, we characterize mesons in terms of their SUð3Þ representation, octet (8) or singlet (1), and F E. The low-lying pseudoscalars: , , 0 compute correlation matrices using the basis in Eq. (5). The octet correlators feature only connected diagrams In lattice calculations of the type performed in this while the singlets receive an additional contribution from paper, where isospin is exact and electromagnetism does a disconnected diagram. Since the strange quarks are now not feature, the and mesons are exactly stable and 0 no heavier than the ‘‘light’’ quarks, any splitting between is rendered stable since its isospin conserving states in the octet and singlet spectra is purely due to the decay mode is kinematically closed. Because of this, disconnected diagrams and thus to ‘‘annihilation dynam- many of the caveats presented in Sec. III B do not apply. ics.’’ In Fig. 13 we present the spectra extracted on two Figure 17 shows the quality of the principal correlators lattice volumes. from which we extract the meson masses, in the form of an effective mass, 1 ðtÞ D. Quark mass and volume dependence m ¼ log ; (16) eff t ðt þ tÞ Figures 14–16 show the quark mass and volume depen- dence of the extracted isoscalar and isovector spectra. for the lightest quark mass and largest volume consid- In general, the extracted spectrum is fairly consistent ered. The effective masses clearly plateau and can be across quark masses. There are some cases, such as the described at later times by a constant fit which gives a second level in 3þ , that are not cleanly extracted at the mass in agreement with the two exponential fits to the lowest pion mass. principal correlator that we typically use. We refrain from performing extrapolations of the masses Figure 18 indicates the detailed quark mass and volume to the limit of the physical quark masses, since, as we have dependence of the and 0 mesons. We have already already pointed out, we expect most excited states to be commented on the unexplained sensitivity of the 0 mass unstable resonances. A suitable quantity for extrapolation to the spatial volume at m ¼ 391 MeV, and we note that
094505-11 Lattice QCD - the Meson Spectra
J.Dudek et al PRD 83 (2011); PRD 84 (2011), PRD 88 (2013)
HybridsTOWARD THE identified: EXCITED ISOSCALAR States MESON with SPECTRUM non-trivial... gluonicPHYSICAL fields REVIEW D 88, 094505 (2013)
3000 + J− regular QN J regular QN Exotic QN
2500
2000
+ + + 1− 0 − 2 − 1500 Nonets: 2 1 2
1000 Lowest-lying hybrid supermultiplet + + + 1−−, 0− , 1− . 2− 500 exotic
3 FIG. 11 (color online). Isoscalar (green and black) and isovector (blue) meson spectrum on the m ¼ 391 MeV, 24 128 lattice. CalculationsThe vertical height of each for boxm indicatesπ 400 the statisticalMeV uncertainty on the mass determination. States outlined in orange are the lowest- lying states having dominant overlap∼ with operators featuring a chromomagnetic construction—their interpretation as the lightest Orangehybrid meson frames supermultiplet - will lightest be discussed hybrids later.
3 E.ChudakovC. SUð3ÞF point, m COMPASS ¼ 702 MeV> 2020,, ð16; Mar20Þ 2016 128 Spectroscopymight be at the JLab complex resonance pole11 position, / 32 but we do In this case we take all three quark flavors to be mass not obtain this in our simple calculations using only single- hadron operators. degenerate, with the mass we have tuned to correspond to þ the physical strange quark. Here, because there is an exact We discuss the specific case of the 0 and 1 systems in the next subsections. SUð3Þ flavor symmetry, we characterize mesons in terms of their SUð3Þ representation, octet (8) or singlet (1), and F E. The low-lying pseudoscalars: , , 0 compute correlation matrices using the basis in Eq. (5). The octet correlators feature only connected diagrams In lattice calculations of the type performed in this while the singlets receive an additional contribution from paper, where isospin is exact and electromagnetism does a disconnected diagram. Since the strange quarks are now not feature, the and mesons are exactly stable and 0 no heavier than the ‘‘light’’ quarks, any splitting between is rendered stable since its isospin conserving states in the octet and singlet spectra is purely due to the decay mode is kinematically closed. Because of this, disconnected diagrams and thus to ‘‘annihilation dynam- many of the caveats presented in Sec. III B do not apply. ics.’’ In Fig. 13 we present the spectra extracted on two Figure 17 shows the quality of the principal correlators lattice volumes. from which we extract the meson masses, in the form of an effective mass, 1 ðtÞ D. Quark mass and volume dependence m ¼ log ; (16) eff t ðt þ tÞ Figures 14–16 show the quark mass and volume depen- dence of the extracted isoscalar and isovector spectra. for the lightest quark mass and largest volume consid- In general, the extracted spectrum is fairly consistent ered. The effective masses clearly plateau and can be across quark masses. There are some cases, such as the described at later times by a constant fit which gives a second level in 3þ , that are not cleanly extracted at the mass in agreement with the two exponential fits to the lowest pion mass. principal correlator that we typically use. We refrain from performing extrapolations of the masses Figure 18 indicates the detailed quark mass and volume to the limit of the physical quark masses, since, as we have dependence of the and 0 mesons. We have already already pointed out, we expect most excited states to be commented on the unexplained sensitivity of the 0 mass unstable resonances. A suitable quantity for extrapolation to the spatial volume at m ¼ 391 MeV, and we note that
094505-11 Lattice QCD - the Meson Spectra
J.Dudek et al PRD 83 (2011); PRD 84 (2011), PRD 88 (2013)
HybridsTOWARD THE identified: EXCITED ISOSCALAR States MESON with SPECTRUM non-trivial... gluonicPHYSICAL fields REVIEW D 88, 094505 (2013)
3000 + J− regular QN J regular QN Exotic QN
2500
2000
+ + + 1− 0 − 2 − 1500 Nonets: 2 1 2
1000 Lowest-lying hybrid supermultiplet + + + 1−−, 0− , 1− . 2− 500 exotic
3 FIG. 11 (color online). Isoscalar (green and black) and isovector (blue) meson spectrum on the m ¼ 391 MeV, 24 128 lattice. CalculationsThe vertical height of each for boxm indicatesπ 400 the statisticalMeV uncertainty on the mass determination. States outlined in orange are the lowest- lying states having dominant overlap∼ with operators featuring a chromomagnetic construction—their interpretation as the lightest Orangehybrid meson frames supermultiplet - will lightest be discussed hybrids later.
3 E.ChudakovC. SUð3ÞF point, m COMPASS ¼ 702 MeV> 2020,, ð16; Mar20Þ 2016 128 Spectroscopymight be at the JLab complex resonance pole11 position, / 32 but we do In this case we take all three quark flavors to be mass not obtain this in our simple calculations using only single- hadron operators. degenerate, with the mass we have tuned to correspond to þ the physical strange quark. Here, because there is an exact We discuss the specific case of the 0 and 1 systems in the next subsections. SUð3Þ flavor symmetry, we characterize mesons in terms of their SUð3Þ representation, octet (8) or singlet (1), and F E. The low-lying pseudoscalars: , , 0 compute correlation matrices using the basis in Eq. (5). The octet correlators feature only connected diagrams In lattice calculations of the type performed in this while the singlets receive an additional contribution from paper, where isospin is exact and electromagnetism does a disconnected diagram. Since the strange quarks are now not feature, the and mesons are exactly stable and 0 no heavier than the ‘‘light’’ quarks, any splitting between is rendered stable since its isospin conserving states in the octet and singlet spectra is purely due to the decay mode is kinematically closed. Because of this, disconnected diagrams and thus to ‘‘annihilation dynam- many of the caveats presented in Sec. III B do not apply. ics.’’ In Fig. 13 we present the spectra extracted on two Figure 17 shows the quality of the principal correlators lattice volumes. from which we extract the meson masses, in the form of an effective mass, 1 ðtÞ D. Quark mass and volume dependence m ¼ log ; (16) eff t ðt þ tÞ Figures 14–16 show the quark mass and volume depen- dence of the extracted isoscalar and isovector spectra. for the lightest quark mass and largest volume consid- In general, the extracted spectrum is fairly consistent ered. The effective masses clearly plateau and can be across quark masses. There are some cases, such as the described at later times by a constant fit which gives a second level in 3þ , that are not cleanly extracted at the mass in agreement with the two exponential fits to the lowest pion mass. principal correlator that we typically use. We refrain from performing extrapolations of the masses Figure 18 indicates the detailed quark mass and volume to the limit of the physical quark masses, since, as we have dependence of the and 0 mesons. We have already already pointed out, we expect most excited states to be commented on the unexplained sensitivity of the 0 mass unstable resonances. A suitable quantity for extrapolation to the spatial volume at m ¼ 391 MeV, and we note that
094505-11 Lower-lying exotic hybrids: masses, widths, decays
LQCD: masses Models: widths and decays + 2 2 1− 2.0 – 2.4 GeV/c Γ 0.1-0.5 GeV/c , + ∼ 2 ∼ + + + 0 − 2.3 – 2.5 GeV/c Γ(1− ) Γ(2 −) < Γ(0 −) + ∼ 2 ∼ 2 − 2.4 – 2.6 GeV/c ∼
easy ⇒ statistics ⇒ hard reach needed π1 ρπ, b1π, f1π, η0π, a1η + → 1− η1 f2η, a2π, f1η, η0η, π(1300)π, a1π → η01 K ∗K , K (1270)K , K (1410)K , η0η, → Final states: b2 ωπ, a2π, ρη, f1ρ, a1π, h1π, b1η (p, n)+3π, 4π, 3πη, 4πη... + → 2 − h2 ρπ, b1π, ωη, f1ω 70% 1π◦ → ≥ h02 K1(1270)K , K (1410)K , K2K , φη, f1φ 50% 2π◦ → ≥
b π(1300)π, h1π, f1ρ, b1η + ◦ → 0 − h b1π, h1η ◦ → h0 K1(1270)K , K (1410)K , h1η ◦→
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 12 / 32 Effect of Beam Linear Polarization Filter on the naturality MC simulation γp 3πp: ++ →+ 2 2−
Linear Polarization t ±1 ± γ ∝ iφ X Y! (θ, φ) P!(cos θ)e X → a + b a γ s e θ e quantization axis
m determined by polarization of photon
p p b t r Only linearly polarized photons Photoproduction Mechanismsprovide azimuthal angle dependence.
γ Allowed Processes ρ◦, ω, φ X Exotic Production: Takes placevector via unnatural meson (U) + exchange parity exchange particle Diffractive Production: N: JP = 0+, 1–, 2+, ... Exchange Final , π, η, ρ, ω,...e Through natural parity (N) exchange P U: JP = 0–, 1+, 2–, ... particle states ++ + + 0 2 −, 0 − b◦, h, h0 Only linearlyP polarized0 + photons2+ b h h p p π◦ − − 2◦, 2, 20 t r can distinguish between+ U and+ N. π± 0− 1− π1± + ω 1−− 1− π1, η1, η10 GlueX PAC30 Presentation - AleCanx Dzierba couple - 8/21/2006 to all19 the lightest exotic hybrid nonets through photoproduction and VMD
Photon Polarization at JLab Coherent Bremsstrahlung at • Ee = 12 GeV provides 40% at Eγ 9 GeV P ∼ ∼
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 13 / 32 Linear Polarization t ±1 ± γ ∝ iφ X Y! (θ, φ) P!(cos θ)e X → a + b a γ s e θ e quantization axis
m determined by polarization of photon
p p b t r Only linearly polarized photons Photoproduction Mechanismsprovide azimuthal angle dependence.
γ Allowed Processes ρ◦, ω, φ X Exotic Production: Takes placevector via unnatural meson (U) + exchange parity exchange particle Diffractive Production: N: JP = 0+, 1–, 2+, ... Exchange Final , π, η, ρ, ω,...e Through natural parity (N) exchange P U: JP = 0–, 1+, 2–, ... particle states ++ + + 0 2 −, 0 − b◦, h, h0 Only linearlyP polarized0 + photons2+ b h h p p π◦ − − 2◦, 2, 20 t r can distinguish between+ U and+ N. π± 0− 1− π1± + ω 1−− 1− π1, η1, η10 Effect of Beam LinearGlueX Polarization PAC30 Presentation - Alex Dzierba - 8/21/2006 19 Can couple to all the lightest exotic Filter on the naturality hybrid nonets through photoproduction MC simulation γp 3πp: ++ →+ and VMD 2 2−
Photon Polarization at JLab Coherent Bremsstrahlung at • Ee = 12 GeV provides 40% at Eγ 9 GeV P ∼ ∼
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 13 / 32 + Experimental Evidence for Exotic Hybrids 1− mass reaction experiment mass width
1400 π−p ηπ◦n GAMS, 100 GeV 1988 1406 20 180 20 → ± ± π−p ηπ−p BKEI, 6 GeV 1993 1320 5 140 10 → ± ± π−p ηπ−p MPS, 18 GeV 1997 1370 60 380 100 → ± ± π−p ηπ◦n E-852, 18 GeV 2007 1260 40 350 60 → ± ± pp ηπ◦π◦ CBAR, 0 GeV 1999 1360 25 360 80 → ± ± pn ηπ◦π− CBAR, 0 GeV 1998 1400 30 220 90 → + ± ± 1600 π−A π π−π−A VES, 37 GeV 2000 1610 20 290 30 → VES, 37 GeV 2005 none± ± COMPASS, 190 GeV 2009 1660 60 270 60 + ± ± π−p π π−π−p E-852, 18 GeV 2002 1590 40 170 60 → E-852, 18 GeV 2006 none± ± COMPASS, 190 GeV 2015 in progress + + γp π π π−n CLAS, 5. GeV 2008 none → π−p π−π◦π◦p E-852, 18 GeV 2006 none → COMPASS, 190 GeV 2015 in progress π−p η0π−p E-852, 18 GeV 2001 1600 40 340 50 → COMPASS, 190 GeV 2015 ±in progress± π−A η0π−A VES, 37 GeV 2005 1600 300 → GAMS, 100 GeV 2005 1600 300 + π−p ηπ π−π−p E-852, 18 GeV 2004 1710 60 400 90 → ± ± π−p ωπ−π◦p E-852, 18 GeV 2005 1660 10 190 30 → ± ± π−A ωπ−π◦A VES, 18 GeV 2005 1600 300 → 2000 π−p b1π, f1π E-852, 18 GeV 2005 2010 25 230 80 → ± ± E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 14 / 32 + Experimental Evidence for Exotic Hybrids 1− mass reaction experiment mass width
1400 π−p ηπ◦n GAMS, 100 GeV 1988 1406 20 180 20 → ± ± π−p ηπ−p BKEI, 6 GeV 1993 1320 5 140 10 → ± ± π−p ηπ−p MPS, 18 GeV 1997 1370 60 380 100 → Signal: solid, seen by several± experiments± π−p ηπ◦n E-852, 18 GeV 2007 1260 40 350 60 → Interpretation: unclear, but not a hybrid:± ± pp ηπ◦π◦ CBAR, 0 GeV 1999 1360 25 360 80 → 1400 dynamic origin; 4-quark± state ± pn ηπ◦π− CBAR, 0 GeV 1998 1400 30 220 90 → + ± ± 1600 π−A π π−π−A VES, 37 GeV 2000 1610 20 290 30 → VES, 37 GeV 2005 none± ± COMPASS, 190 GeV 2009 1660 60 270 60 + ± ± π−p π π−π−p E-852, 18 GeV 2002 1590 40 170 60 → E-852, 18 GeV 2006 none± ± COMPASS, 190 GeV 2015 in progress + + γp π π π−n CLAS, 5. GeV 2008 none → π−p π−π◦π◦p E-852, 18 GeV 2006 none → COMPASS, 190 GeV 2015 in progress π−p η0π−p E-852, 18 GeV 2001 1600 40 340 50 → COMPASS, 190 GeV 2015 ±in progress± π−A η0π−A VES, 37 GeV 2005 1600 300 → GAMS, 100 GeV 2005 1600 300 + π−p ηπ π−π−p E-852, 18 GeV 2004 1710 60 400 90 → ± ± π−p ωπ−π◦p E-852, 18 GeV 2005 1660 10 190 30 → ± ± π−A ωπ−π◦A VES, 18 GeV 2005 1600 300 → 2000 π−p b1π, f1π E-852, 18 GeV 2005 2010 25 230 80 → ± ± E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 14 / 32 + Experimental Evidence for Exotic Hybrids 1− mass reaction experiment mass width
1400 π−p ηπ◦n GAMS, 100 GeV 1988 1406 20 180 20 → ± ± π−p ηπ−p BKEI, 6 GeV 1993 1320 5 140 10 → ± ± π−p ηπ−p MPS, 18 GeV 1997 1370 60 380 100 → Signal: solid, seen by several± experiments± π−p ηπ◦n E-852, 18 GeV 2007 1260 40 350 60 → Interpretation: unclear, but not a hybrid:± ± pp ηπ◦π◦ CBAR, 0 GeV 1999 1360 25 360 80 → 1400 dynamic origin; 4-quark± state ± pn ηπ◦π− CBAR, 0 GeV 1998 1400 30 220 90 → + ± ± 1600 π−A π π−π−A VES, 37 GeV 2000 1610 20 290 30 → VES, 37 GeV 2005 none± ± COMPASS, 190 GeV 2009 1660 60 270 60 + ± ± π−p π π−π−p E-852, 18 GeV 2002 1590 40 170 60 + → Signal: 3π - controversial -± leakage from± 2− E-852, 18COMPASS: GeV 2006 confirmationnone in π A COMPASS, 190 GeV 2015 in progress− + + COMPASS: in progress π−p γp π π π−n CLAS, 5. GeV 2008 none → η0π− - promising π−p π−π◦π◦p E-852, 18 GeV 2006 none → Interpretation: may be a hybrid 1600COMPASS, 190needs GeV 2015 more analysisin and progress data π−p η0π−p E-852, 18 GeV 2001 1600 40 340 50 → COMPASS, 190 GeV 2015 ±in progress± π−A η0π−A VES, 37 GeV 2005 1600 300 → GAMS, 100 GeV 2005 1600 300 + π−p ηπ π−π−p E-852, 18 GeV 2004 1710 60 400 90 → ± ± π−p ωπ−π◦p E-852, 18 GeV 2005 1660 10 190 30 → ± ± π−A ωπ−π◦A VES, 18 GeV 2005 1600 300 → 2000 π−p b1π, f1π E-852, 18 GeV 2005 2010 25 230 80 → ± ± E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 14 / 32 + Experimental Evidence for Exotic Hybrids 1− mass reaction experiment mass width
1400 π−p ηπ◦n GAMS, 100 GeV 1988 1406 20 180 20 → ± ± π−p ηπ−p BKEI, 6 GeV 1993 1320 5 140 10 → ± ± π−p ηπ−p MPS, 18 GeV 1997 1370 60 380 100 → Signal: solid, seen by several± experiments± π−p ηπ◦n E-852, 18 GeV 2007 1260 40 350 60 → Interpretation: unclear, but not a hybrid:± ± pp ηπ◦π◦ CBAR, 0 GeV 1999 1360 25 360 80 → 1400 dynamic origin; 4-quark± state ± pn ηπ◦π− CBAR, 0 GeV 1998 1400 30 220 90 → + ± ± 1600 π−A π π−π−A VES, 37 GeV 2000 1610 20 290 30 → VES, 37 GeV 2005 none± ± COMPASS, 190 GeV 2009 1660 60 270 60 + ± ± π−p π π−π−p E-852, 18 GeV 2002 1590 40 170 60 + → Signal: 3π - controversial -± leakage from± 2− E-852, 18COMPASS: GeV 2006 confirmationnone in π A COMPASS, 190 GeV 2015 in progress− + + COMPASS: in progress π−p γp π π π−n CLAS, 5. GeV 2008 none → η0π− - promising π−p π−π◦π◦p E-852, 18 GeV 2006 none → Interpretation: may be a hybrid 1600COMPASS, 190needs GeV 2015 more analysisin and progress data π−p η0π−p E-852, 18 GeV 2001 1600 40 340 50 → COMPASS, 190 GeV 2015 ±in progress± π−A η0π−A VES, 37 GeV 2005 1600 300 → GAMS, 100 GeV 2005 1600 300 + π−p ηπ π−π−p Signal:E-852, 18weak GeV - 2004 one experiment1710 60 only400 90 → ± ± π−p ωπ−π◦p Interpretation:E-852, 18may GeV be 2005 a hybrid1660 10 190 30 → ± ± π−A ωπ−π◦A VES, 18expected GeV 2005 decay1600 modes 300 → 2000 π−p b1π, f1π 2000 E-852, 18needs GeV 2005 more data2010 25 230 80 → ± ± E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 14 / 32 JLab approved program for spectroscopy
Program CLAS12 GlueX Hall B Hall D 1 Search for hybrid mesons yes yes Search for hybrid baryons: regular QN, identi- 2 yes – fication through electrocouplings 3 Measure missing QN for excited hyperons yes yes
Features: Beam: linearly polarized photons Acceptance: uniform and hermetic High statistics Partial Wave Analysis (PWA): a strong organized support from the JLab theory group and a broader community
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 15 / 32 JLab approved program for spectroscopy
Program CLAS12 GlueX Λ(1405): 1 − Hall B Hall2 D from CLAS 1 Search for hybrid mesons yes yes PRL 112 (2014) Search for hybrid baryons: regular QN, identi- 2 yes – fication through electrocouplings 3 Measure missing QN for excited hyperons yes yes
Features: Beam: linearly polarized photons Acceptance: uniform and hermetic High statistics Partial Wave Analysis (PWA): a strong organized support from the JLab theory group and a broader community
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 15 / 32 JLab approved program for spectroscopy
Program CLAS12 GlueX Hall B Hall D 1 Search for hybrid mesons yes yes Search for hybrid baryons: regular QN, identi- 2 yes – fication through electrocouplings 3 Measure missing QN for excited hyperons yes yes
Features: Beam: linearly polarized photons Acceptance: uniform and hermetic High statistics Partial Wave Analysis (PWA): a strong organized support from the JLab theory group and a broader community
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 15 / 32 Hall D/GlueX Beamline
Tagger Magnet
Hodoscope (TAGH), µ-scope (TAHM) γ-polarimeter
12 GeV e− beam0 .05 2.2 µA • − 20 µm diamond: coherent <25 µrad • Collimation r <1.8 mm at 80 m 8.4-9.0 GeV 100 MHz • ∼ ∼ Coherent peak8 .4 9.0 GeV 40% tagged 40% • 2.2 µA 100 MHz−γ P ∼ P ∼ Energy/polarization⇒ measured: collimated • Tagger spectrometer σE /E 0.1% • Pair spectrometer: spectrum∼ σ / 5% • ⇒ P P ∼ Eγ GeV E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 16 / 32 Hall D/GlueX Spectrometer and DAQ
forward calorimeter barrel time-of calorimeter -flight target Detectors GlueX 30 cm LH 2 Resolutions start counter I CDC, FDC h±: σp/p 1 3% ∼ − I BCAL, FCAL γ: σE /E 6%/√E 2% ∼ ⊕ TOF, ST Acceptance 1◦ < θ < 120◦ I photon beam Plans to add diamond forward drift wafer chambers I 2017 L3 central drift chamber I 2018 electron superconducting tagger magnet beam Cherenkov electron magnet beam tagger to detector distance is not to scale B = 2.0 T
Photoproduction γp 15 kHz for a 100 MHz beam Beam 10 MHz/GeV: inclusive trigger 20 kHz DAQ tape Beam 100 MHz/GeV: inclusive trigger 200 kHz ⇒ DAQ ⇒ L3 farm tape ⇒ ⇒ ⇒
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 17 / 32 Experimental set up: Hall B/CLAS12CLAS12 Forward Forward Tagger tagger(FT)
Calorimeter Ee’: 0.5-6.0GeV o o qe’: 2.5 -4.5 Tracker Eg: 5.0-10.5GeV Pg: 10-85% Q2: 0.01-0.3GeV2 HTCC Moller cup
Scintillation Moller Hodoscope Shield
GEMC implementation CLAS12 acceptance5 ◦ < θ FT:35 not CLAS122 1 baseline equipment. CLAS12 max e−p –luminosity 10 cm− s− Tagged photon rate 50 MHz Under construction Advantage for very thin targets 11 2 1 Linear polarization (1 + ν /2EE 0)− ∼ E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 18 / 32 Hall D
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 19 / 32 Spectrometer, Detectors and Dimensions
Future Particle ID CDC Central Drift Chamber FDC 118.1 o Forward Drift Chambers 126.4 o o Solenoid 14.7
10.8 o
185 cm photon beam BCAL FCAL Barrel Calorimeter 390 cm long inner radius: 65 cm outer radius: 90 cm
Forward 342 cm Calorimeter 48 cm 240 cm diameter 45 cm thick 560 cm 30-cm target C L GlueX Detector
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 20 / 32 Spectrometer, Detectors and Dimensions
Future Central Drift Chamber Particle ID CDC CDC Central Drift Chamber FDC 118.1 o Forward Drift Chambers 126.4 o o Solenoid 14.7
10.8 o 3500 straws 28 layers Aluminized Mylar, r=8 mm 185 cm Wire 20 µm; Ar/CO2 50/50 photon beam BCAL FCAL Barrel Calorimeter 390 cm long inner radius: 65 cm outer radius: 90 cm
Forward 342 cm Calorimeter 48 cm 240 cm diameter 45 cm thick 560 cm Readout FADC 30-cm target ⇒ C L GlueX Detector
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 20 / 32 Spectrometer, Detectors and Dimensions
Future Forward Drift Chambers Particle ID CDC FDC Central Drift Chamber FDC 118.1 o Forward Drift Chambers 126.4 o o Solenoid 14.7
10.8 o 4 6 planes, Ar/CO2 50/50 2300× wires, 10 mm pitch 10400 cathode strips 185 cm 5 mm pitch photon beam BCAL FCAL Barrel Calorimeter 390 cm long inner radius: 65 cm outer radius: 90 cm
Forward 342 cm Calorimeter 48 cm 240 cm diameter 45 cm thick 560 cm Readout: strips FADC 30-cm target Readout: wires ⇒ TDC C L GlueX Detector ⇒
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 20 / 32 Spectrometer, Detectors and Dimensions
Future Barrel Calorimeter Particle ID CDC BCAL Central Drift Chamber FDC 118.1 o Forward Drift Chambers 126.4 o o Solenoid 14.7
10.8 o
Lead-scintill.fibers 185 cm 3840 light guides SiPMs photon ⇒ beam BCAL FCAL Barrel Calorimeter 390 cm long inner radius: 65 cm outer radius: 90 cm
Forward 342 cm Calorimeter 48 cm 240 cm diameter 45 cm thick 560 cm Readout: 1536 FADC 30-cm target ⇒ 1152 TDC C L GlueX Detector ⇒
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 20 / 32 Spectrometer, Detectors and Dimensions
Future Forward Calorimeter Particle ID FCAL CDC Central Drift Chamber FDC 118.1 o Forward Drift Chambers 126.4 o o Solenoid 14.7
10.8 o
Lead glass 4 4 45185 cm cm3 photon × × beam BCAL FCAL Barrel Calorimeter 390 cm long inner radius: 65 cm outer radius: 90 cm
Forward 342 cm Calorimeter 48 cm 240 cm diameter 45 cm thick 560 cm Readout: 280030-cm targ FADCet C ⇒ L GlueX Detector
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 20 / 32 Spectrometer, Detectors and Dimensions
Future Start Counter, TOF Particle ID Scintil. ST CDC Central Drift Chamber FDC 118.1 o Forward Drift Chambers 126.4 o o Solenoid 14.7
10.8 o 30 counters
185 cm photon beam BCAL FCAL Scintil. TOF Barrel Calorimeter 390 cm long inner radius: 65 cm outer radius: 90 cm
Forward 342 cm Calorimeter 48 cm 240 cm diameter 45 cm thick 560 cm 160 counters 30-cm target C L GlueX Detector
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 20 / 32 Hall D/GlueX Commissioning Status
Runs with beam: Fall 2014 10.0 GeV beam: beam commissioning and detector checkout Unpolarized beam and nuclear target 120 TB of data collected, 0.9 G events Spring 2015 5.5 GeV beam: 1 week of beam - commissioning Commissioning of the linearly polarized beam Commissioning of the Liquid Hydrogen target 70 TB of data collected, 1.3 G events Spring 2016 12 GeV beam (started Feb 10, ongoing) Finish the commissioning of all the systems Data for early physics results 8 G events recorded up to now ∼
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 21 / 32 Hall D/GlueX Beam: Coherent Bremsstrahlung Coherent Bremsstrahlung Shape Analysis (CBSA)
20-50 µm thick diamond Run 10492: 50 μm diamond Run 10782: 20 μm diamond • radiators 6 3.5 Rate 5 3 Precision alignment using a crystal/amorphous • 2.5 goniometer 4 2 3 1.5 2 1
1 0.5 Enhancement: Diamond/Amorph 0 Enhancement: Diamond/Amorph 0 0 2000 4000 6000 8000 10000 12000 0 2000 4000 6000 8000 10000 12000 Energy (MeV) Energy (MeV)
1 1 0.9 0.9 0.8 0.8 0.7 0.7 Polarization measurements 0.6 0.6 0.5 P 40% 0.5 Derived from the spectrum 0.4 ≈ 0.4 Degree of Polarization • Degree of Polarization Triple polarimeter 0.3 0.3 0.2 0.2 • + γe− e e−e− 0.1 0.1 → 0 0 0 2000 4000 6000 8000 10000 12000 0 2000 4000 6000 8000 10000 12000 Processes like γp ρ◦p • → Energy (MeV) Energy (MeV) E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 22 / 32 Work ongoing to better understand accidental subtraction, especially at high rates
Could be causing reduced enhancements at high rate with 20 μm diamond
3.16.16 Justin Stevens, 4 Physics With Linearly Polarized Beam ρ asymmetry: 50 μm diamond (J1A50) from 2016 data
300 2 1000 Runs 10491-10498: ~38K ρ events in 8.4 < Eɣ < 9 GeV 250 coherent bremsstrahlung 2015 data 38k γp ρ◦p Events peak has high degree of 800 • → linear polarization in8 .4 < Eγ < 9.0 GeV 200 Fit asymmetry in bins of Eɣ 600 150 2 crystal orientations at 90◦ 14000 N N • N N Events / 20 MeV/ c 0 90 k ? 400 12000 − = PΣ cos= P 2⌃ψ cos2 100 Diamond N0+N90N + N · 10000 • k ? 8000 Amorphous 200800 Yield / 100 MeV 800 50 0.4 6000 700 700 0 0 4000 0.3 0 1 2 3 4 5 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 + − 2000 2 Energy of Beam Photon [GeV] 600 π π Invariant Mass600 [GeV/c ] 0.2 0 0 2 4 6 8 10 12 Integrated over 500 500 Eγ (GeV) 0.1 + 8.4 < Eɣ < 9 GeV: π 1 dσ Σ 400 (1 + P cos 2ψ) 400 0 100 P dψ 0.8 Events Diamond 300 300 -0.1 PΣ = 0.341 ± 0.007 80 Amorphous 0.6 200 200 -0.2 − ρ Decay Plane 0.4 π -0.3 60 100 100 ψ 0.2 Photon Beam -0.4 40 0 Polarization Plane 0 -150 -100 -50 0 50 100 150 0 -150 -100 -50 0 50 100 150 -150 -100 -50 0 50 100 150 + 0 2 4 6 8 10 +12 + 20 ρ π ψ E (GeV) π ψ π ψ Polarization P γ is preserved γ 3.16.16 p Justin Stevens, 7 0 in ρ production. PΣ= 0.341 0.007% -150 -100 -50 0 50 100 150 ± Angle Between Polarization and Decay Planes ψ [deg.] p
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 23 / 32 PID
Positively Charged Particles Negatively Charged Particles 1.0 e 1.0 e π π K K 2 0.8 2 0.8 10 p 10 0.6 0.6 Incorrect RF Bunch 10 β from Time of Flight β from Time of Flight 0.4 10 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 14 104 400 12 2.0 350 3 10 10 300 1.5 8 e+/e- 250 p 102 200 6 1.0 CDC d E /d x [keV/cm] 150 4 10 0.5 hadrons 100 2 π/K/e 50 0 1 Momentum Track / FCAL Energy 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] E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 24 / 32 7 Event ReconstructionFive photons and Signals Observed
2015 data from 2016 data ×103
2 22 2 500 γp 2π◦ γ p 5γ p 20 → → 18 600 400 2 16 500 14 Missing400 300 12 GeV/c
,
300 ) Events / 6 MeV/ c 10from Events / 10 MeV/ c 200 γ b (1235) 8 200 ◦ 1 π
6 100 2 4 100 ( 2 0.3 0.4 0.5 0.6 0.7 0.8 M 0 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0.0 0.5 1.0 1.5 2.0 2.5 γγ Invariant Mass [GeV/c2] π+π−π0 Invariant Mass [GeV/c2] ×103
2 22 2 500 20 18 600 400 2 16 500 M(π◦γ), GeV/c 14 400 300 12 300 Events / 6 MeV/ c 10 Events / 10 MeV/ c 200 8 200 6 100 4 100 2 0.3 0.4 0.5 0.6 0.7 0.8 0 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0.0 0.5 1.0 1.5 2.0 2.5 γγ Invariant Mass [GeV/c2] π+π−π0 Invariant Mass [GeV/c2]
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 25 / 32 Using DIRC Detector in GlueX
Yi Qiang 2/19/13
The synthetic fused Silica bars (n = 1.473) used in BARBAR DIRC detector can potentially be used in GlueX spectrometer of Hall-D to provide additional charged particle identification in the forward region with a momentum coverage between 1.5 to 4 GeV where either the existing Time-of-Flight detector or a threshold gas Cherenkov detector will have difficulties to cover. The geometry of existing BARBAR DIRC bars is 17.25 mm × 35.00 mm × 4.9 m. Each of them consists of four 1.225 m long bars glued end- to-end. BARBAR DIRC used 144 bars in total to cover the whole azimuthal acceptance. At normal incidence, the DIRC will introduce a total of about 17% radiation length thickness including supports.
In GlueX spectrometer, the DIRC bars will be placed right in front of the TOF wall to reduce the impact on photon reconstruction due to its thickness. 68 DIRC bars will be reconfigured into two flat panels to Forward Kaon Identification provide an angular coverage up to 11 degrees with a 10 cm gap in between for beam exit as Figure 1. One side of bars will be covered by mirrors and Cherenkov lights will be collected on the other side. Present PID: TOF, dE/dx, Kinematics
Upgrade
4 of the BaBar DIRC bar boxes New readout system
Allows to study: Figure 1 Configuration of DIRC for GlueX The Focusing DIRC readout currently being developed by SLAC will provide better performance than the Strangeonium and hybrids original one used in BARBAR. The new design uses focusing mirrors to remove the smearing due to finite thickness of the bars. In addition, the use of Multi-anode PMTs will allow a much more compact Hyperons design of the readout assembly (25 times smaller) and the faster timing resolution (~150 ps) can be used to correct chromatic dispersion. As a result, the new design will improve the angular resolution of single Cherenkov photon from 9.6 mrad to less than 7 mrad, thus boost the upper limit of π/K separation with 3 Installation planned for 2018 standard deviations from 3.8 GeV to 4.3 GeV. For GlueX, 276 2” MaPMTs will be needed to readout all 68 bars and the cost for them alone will be about $1.4 M.
Furthermore, the recent development carried out by the large-area picoseconds photo-detector (LAPPD) collaboration since 2009 may provide a very attractive alternative readout solution than MaPMT. Their approach is to apply micro-channel plate (MCP) technology to produce large-area photo-detectors with excellent space and time resolution. These MCP-PMTs can provide much better timing resolution (<10 ps), similar spatial resolution compared to MaMPT at a much lower cost: $140 k for GlueX DIRC (photo- detector alone, another $110 k for DAQ). As the development of individual components is going very well, small size (5 cm × 5 cm) samples will be available by the end of 2013.
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 26 / 32 Hall D Preliminary Running Schedule
2016-2018 GlueX at “low” intensity of 10 MHz in the peak 2018 PRIMEX (Primakoff) experiment 2018 DIRC installation 2019-2022 GlueX at “high” intensity5 10 MHz in the peak focus on hidden strangeness and hyperon× resonances
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 27 / 32 Summary
Spectroscopy is big part of the JLab program for 2016-2022 the main focus is on the search for hybrid mesons GlueX (Hall D) and CLAS12 (Hall B) are of comparable capabilities, but have different acceptances, tagging methods etc. GlueX is finishing the commissioning phase By the Fall 2016 GlueX is planning to be ready to start the main program - the search for exotic mesons
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 28 / 32 APPENDIX
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 29 / 32 Hall D Physics Program
Proposal/ Sta- Title Beam PAC experiment tus days # E12-06-102 A Mapping the Spectrum of Light Quark 120 30 Mesons and Gluonic Excitations with Lin- early Polarized Photons E12-10-011 A- A Precision Measurement of the η Radia- 79 35 tive Decay Width via the Primakoff Effect E12-13-003 A An initial study of hadron decays to 200 40 strange final states with GlueX in Hall D E12-13-008 A- Measuring the Charged Pion Polarizabil- 25 40 ity in the γγ → π+π− Reaction E12-12-002 A A study of meson and baryon decays to 220 42 strange final states with GlueX in Hall D C12-14-004 C2 Eta Decays with Emphasis on Rare Neu- (130) 42 tral Modes: The JLab Eta Factory Exper- iment (JEF) partly concurrent with GlueX (η → 3π) ◦ LOI12-15-001 Physics with secondary KL beam 43 LOI12-15-006 ω-production on nuclei 43
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 30 / 32 The GlueX Collaboration
Arizona State, Athens, Carnegie Mellon, Catholic University, Univ. of Connecticut, Florida International, Florida State, George Washington, Glasgow, 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, and Yerevan Physics Institute.
Over 100 collaborators from 22 institutions. Others are planning to join and more are welcome.
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 31 / 32 Regular and hybrid multiplets
JPC The lowest excitation L = 1: P = ( 1)L+1, C = ( 1)L+S JPC : 1+− or 1−+ − − Conventional mesons Lower hybrid mesons Regular quantum numbers: Regular quantum numbers: 0−+ S = 0, L = 0 π, η, K 1−− ... 1−− S = 1, L = 0 ρ, ω, φ, K ∗ 1++ ... +− 1 S = 0, L = 1 b1, h1, K1.. Exotic quantum numbers: ++ ∗ −+ 0 S = 1, L = 1 a◦, f◦, K◦ 1 π1, η1... ++ ∗ +− 1 S = 1, L = 1 a1, f1, K1A 2 b2, h2... ++ ∗ +− 2 S = 1, L = 1 a2, f2, K2 0 b◦, h◦... etc. etc.
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 32 / 32 Regular and hybrid multiplets
JPC The lowest excitation L = 1: P = ( 1)L+1, C = ( 1)L+S JPC : 1+− or 1−+ Flux tube − − Conventional mesons Lower hybrid mesons Regular quantum numbers: Regular quantum numbers: 0−+ S = 0, L = 0 π, η, K 1−− ... 1−− S = 1, L = 0 ρ, ω, φ, K ∗ 1++ ... +− 1 S = 0, L = 1 b1, h1, K1.. Exotic quantum numbers: ++ ∗ −+ 0 S = 1, L = 1 a◦, f◦, K◦ 1 π1, η1... ++ ∗ +− 1 S = 1, L = 1 a1, f1, K1A 2 b2, h2... ++ ∗ +− 2 S = 1, L = 1 a2, f2, K2 0 b◦, h◦... etc. etc.
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 32 / 32 Regular and hybrid multiplets
JPC The lowest excitation L = 1: P = ( 1)L+1, C = ( 1)L+S JPC : 1+− or 1−+ LQCD − − Conventional mesons Lower hybrid mesons Regular quantum numbers: Regular quantum numbers: 0−+ S = 0, L = 0 π, η, K 1−− ... 1−− S = 1, L = 0 ρ, ω, φ, K ∗ 1++ ... +− 1 S = 0, L = 1 b1, h1, K1.. Exotic quantum numbers: ++ ∗ −+ 0 S = 1, L = 1 a◦, f◦, K◦ 1 π1, η1... ++ ∗ +− 1 S = 1, L = 1 a1, f1, K1A 2 b2, h2... ++ ∗ +− 2 S = 1, L = 1 a2, f2, K2 0 b◦, h◦... etc. etc.
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 32 / 32 Event Display
2 positive tracks • 1 negative track • Hits in FDC, CDC, BCAL, FCAL. • TOF
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 33 / 32 Track Reconstruction in Drift Chambers
Alignment, calibration: in progress FDC: Resolution Empty target reconstruction 7 Field-off alignment Resolution Distance between entrance and exit windows of targetm = 29.9 cmwires: (C. Keith)160 µm Window thickness = 0.0127 cm, material=Kapton σ, µ cathode:∼ 200 µm FDC - tracks from the target ∼ “•Empty” target contains H gas at 33 psia and 30 K in progress CDC - cosmics 2 Positions• of chambers in XML set according to survey results
Empty LH2 Target: thin windows Require doca < 1 cm, r<2 mm σZ 4 mm ∼ Measured distance between windows = 29.28±0.01 cm Distance to wire, mm Run 2931 Per-straw EfficiencyCDC efficiency Target center: H2 gas vacuum Survey: z=63.816 cm Measured: z=63.17 cm Z, cm Efficiency 0.95% ∼
Efficiency Resolution 200 µm ∼
Distance to wire, cm
E.Chudakov COMPASS > 2020, Mar 2016 Spectroscopy at JLab 34 / 32
7