Electro- and photo-production �of muon pairs with μCLAS12: �Double Deeply Virtual Compton Scattering, Timelike Compton Scattering, �and J/ψ production
Spokesperson: N. Baltzell, M. Bondi, P. Chatagnon, R. De Vita, M. Hoballah, V. Kubarovsky, R. Paremuzyan, S. Stepanyan (contact)
A proposal to PAC 53
July 2024
PAC 53 – Electro- and photo-production of muon pairs with μCLAS12 – July 2025
Outline
I Physics Motivation
- Probing the structure of the nucleon via the experimental extraction of GPDs using
Double Deeply Virual Compton Scattering
Timelike Compton Scattering
- Probing the gluon content of the proton using the exclusive photoproduction of J/Psi
- Constraining the exclusive Pentaquark production
II Detector Configuration
- The muCLAS12 detector, beamline and target
- Background studies, trigger rates, luminosity limits and DAQ
- Muon identification, Event reconstruction
III Proposed measurements and projected results
- DDVCS ALU, and impact on shadow GPD models
- TCS Photon polarization and Forward-Backward assymetries
- J/Psi photoproduction cross-section, impact on mass radius measurements
- Expected number of Pentaquarks
Motivations ●●●● ●● Detector Configuration ●●● ●●● ●●●●●● Proposed Measurements ●● ● ●● ●●
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Physics motivations
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Generalized Parton Distributions
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Double Deeply Virtual Compton Scattering
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Timelike Compton Scattering
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J/ψ photoproduction near threshold
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Current experimental state of the proposed program
JPsi results
TCS results
DDVCS Proposals
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μCLAS12 detector configuration
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μCLAS12 General concept
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μCLAS12 sub-detectors and cost estimate
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Backgrounds, luminosity limits and trigger rates
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Event reconstruction and resolution
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Physics backgrounds
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Proposed measurement and expected results
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DDVCS measurements (1)
Analysis strategy
Kinematic coverage
Observable of interest
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DDVCS measurements (2)
ALU from Spacelike to Timelike region
ALU as a function of t
Impact on shadow GPDs
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DDVCS measurements : Systematics
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TCS measurments (1)
Analysis strategy
Kinematic coverage
ALU as a function of t
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TCS measurments (2)
AFB as a function of t
Systematics
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J/ψ photoproduction near-threshold (1)
Analysis strategy
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J/ψ photoproduction near-threshold (2)
Total cross-section
Differential cross-section
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Potential measurement of pentaquarks
Analysis strategy
Expected number of Pentaquarks
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Conclusion and beam time request
Motivations ●●● Data, MC & analysis tools ● ●● ●●●●● Results & interpretation ●● ● ●●● ●● ●●●●●
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Back-up
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Back-up 1
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