Photoproduction of p , K 0 + , and p using p p + 0 Data - PowerPoint PPT Presentation

Introduction Experimental Results Summary and Outlook Photoproduction of p η , K 0 Σ + , and p ω using γ p → p π + π − π 0 Data CLAS-g12 � Volker Credé Florida State University, Tallahassee, FL ∗ CLAS Collaboration Meeting Jefferson Lab ∗ 11/15/2019 V. Credé Cross Section Measurements from CLAS-g12

Introduction Experimental Results Summary and Outlook Outline Introduction 1 Spectroscopy of Nucleon Resonances Experimental Results 2 The CLAS-g12 Experiment The γ p → K 0 Σ + → p π + π − π 0 Channel The γ p → p η → p π + π − π 0 Channel The γ p → p ω → p π + π − π 0 Channel Summary and Outlook 3 V. Credé Cross Section Measurements from CLAS-g12

Introduction Experimental Results Spectroscopy of Nucleon Resonances Summary and Outlook Outline Introduction 1 Spectroscopy of Nucleon Resonances Experimental Results 2 The CLAS-g12 Experiment The γ p → K 0 Σ + → p π + π − π 0 Channel The γ p → p η → p π + π − π 0 Channel The γ p → p ω → p π + π − π 0 Channel Summary and Outlook 3 V. Credé Cross Section Measurements from CLAS-g12

Introduction Experimental Results Spectroscopy of Nucleon Resonances Summary and Outlook CLAS (6 GeV) at JLab 1998 - 2012 D A C B Double-Polarization Experiments Photo-/electroproduction experiments in search for N ∗ states and measurement of the transition amplitudes. ➜ CLAS FROST V. Credé Cross Section Measurements from CLAS-g12

Introduction Experimental Results Spectroscopy of Nucleon Resonances Summary and Outlook Table representing CLAS@JLab measurements σ Σ T P E F G H T x ′ T z ′ L x ′ L z ′ O x ′ O z ′ C x ′ C z ′ Proton targets p π 0 � � � ( � ) � � � � n π + published � � � ( � ) � � � � � p η � � � ( � ) � � � � � acquired or under analysis p η ′ � � � ( � ) � � � � Tensor polarization, SDMEs p ω ( φ ) � � � ( � ) � � � � K + Λ � � � � � � � � � � � � � � � � K + Σ 0 � � � � � � � � � � � � � � � � K 0 Σ + � � � � � � � � � � � � � � � � Neutron (deuteron) targets p π − � � � � K + Σ − � � � � � � � K 0 Λ � ∗ � � � � � � � � � � � � � � � K 0 Σ 0 � ∗ � � � � � � � � � � � � � � � ∗ published Complete Experiments? “Uncertainty is an uncomfortable position. But Certainty is an absurd one.” Voltaire V. Credé Cross Section Measurements from CLAS-g12

Introduction Experimental Results Spectroscopy of Nucleon Resonances Summary and Outlook Table representing CLAS@JLab measurements σ Σ T P E F G H T x ′ T z ′ L x ′ L z ′ O x ′ O z ′ C x ′ C z ′ � �� Proton targets p π 0 � � ( � ) � � � n π + published � � � ( � ) � � � � p η � � � ( � ) � � � � � acquired or under analysis p η ′ � � � ( � ) � � � � Tensor polarization, SDMEs p ω ( φ ) � � � ( � ) � � � � K + Λ � � � � � � � � � � � � � � � � K + Σ 0 � � � � � � � � � � � � � � � � K 0 Σ + � � � � � � � � � � � � � � � � Neutron (deuteron) targets � p π − � � � � � K + Σ − � � � � � K 0 Λ � ∗ � � � � � � � � � � � � � � � K 0 Σ 0 � ∗ � � � � � � � � � � � � � � � ∗ published Complete Experiments? “Uncertainty is an uncomfortable position. But Certainty is an absurd one.” Voltaire V. Credé Cross Section Measurements from CLAS-g12

Introduction Experimental Results Spectroscopy of Nucleon Resonances Summary and Outlook Table representing CLAS@JLab measurements σ Σ T P E F G H T x ′ T z ′ L x ′ L z ′ O x ′ O z ′ C x ′ C z ′ Proton targets p π 0 � � � ( � ) � � � � n π + published � � � ( � ) � � � � � p η � � � ( � ) � � � � � acquired or under analysis p η ′ � � � ( � ) � � � � Tensor polarization, SDMEs p ω ( φ ) � � � ( � ) � � � � K + Λ � � � � � � � � � � � � � � � � K + Σ 0 � � � � � � � � � � � � � � � � K 0 Σ + � � � � � � � � � � � � � � � � Neutron (deuteron) targets p π − � � � � K + Σ − � � � � � � � K 0 Λ � ∗ � � � � � � � � � � � � � � � K 0 Σ 0 � ∗ � � � � � � � � � � � � � � � ∗ published In addition, two-meson reactions are being analyzed: γ p → ( p ρ ) → p π + π − (CLAS), γ p → p π 0 π 0 , p π 0 η , p π 0 ω (ELSA, MAMI, etc.) V. Credé Cross Section Measurements from CLAS-g12

The CLAS-g12 Experiment Introduction The γ p → K 0 Σ + → p π + π − π 0 Channel Experimental Results The γ p → p η → p π + π − π 0 Channel Summary and Outlook The γ p → p ω → p π + π − π 0 Channel Outline Introduction 1 Spectroscopy of Nucleon Resonances Experimental Results 2 The CLAS-g12 Experiment The γ p → K 0 Σ + → p π + π − π 0 Channel The γ p → p η → p π + π − π 0 Channel The γ p → p ω → p π + π − π 0 Channel Summary and Outlook 3 V. Credé Cross Section Measurements from CLAS-g12

The CLAS-g12 Experiment Introduction The γ p → K 0 Σ + → p π + π − π 0 Channel Experimental Results The γ p → p η → p π + π − π 0 Channel Summary and Outlook The γ p → p ω → p π + π − π 0 Channel Spectrum of N ∗ Resonances 3000 ** *** 2500 **** **** ** **** Mass [MeV] * * ** 2000 ** ** S 1. Excitation Band: ** S S ( 70 , 1 − 1 ) ✓ **** *** *** **** **** **** 1500 2. Excitation Band: **** **** **** ( 56 , 0 + 2 ) , ( 56 , 2 + 2 ) ✓ ( 70 , 0 + 2 ) , ( 70 , 2 + 2 ) ( ✓ ) Theory ( 20 , 1 + 2 ) ? Experiment 1000 **** J � 1/2+ 3/2+ 5/2+ 7/2+ 9/2+ 11/2+ 13/2+ 1/2- 3/2- 5/2- 7/2- 9/2- 11/2- 13/2- V. C. & W. Roberts, Rep. Prog. Phys. 76 (2013) V. Credé Cross Section Measurements from CLAS-g12

The CLAS-g12 Experiment Introduction The γ p → K 0 Σ + → p π + π − π 0 Channel Experimental Results The γ p → p η → p π + π − π 0 Channel Summary and Outlook The γ p → p ω → p π + π − π 0 Channel γ p → K + � Polarization Transfer in � Λ : C x & C z without N ( 1900 ) P 13 with N ( 1900 ) P 13 ∗ ∗ N ( 1900 ) P 13 , N ( 2000 ) F 15 , N ( 1990 ) F 17 Quartet of ( 70 , 2 + 2 ) with S = 3 2 ➜ No (point-like) quark-diquark oscillations! R. Bradford et al. [CLAS Collaboration], PRC 75 , 035205 (2007) Fits: BoGa-Model, V. A. Nikonov et al. , Phys. Lett. B 662 , 245 (2008) V. Credé Cross Section Measurements from CLAS-g12

The CLAS-g12 Experiment Introduction The γ p → K 0 Σ + → p π + π − π 0 Channel Experimental Results The γ p → p η → p π + π − π 0 Channel Summary and Outlook The γ p → p ω → p π + π − π 0 Channel γ p → K + Λ (g8b) Polarization Observables in � C. A. Paterson et al. , Phys. Rev. C 93 , 065201 (2016) + needed + , N ∗ 5 θ θ θ θ ➜ Additional N ∗ 3 -0.75 < cos < -0.55 -0.55 < cos < -0.35 -0.35 < cos < -0.15 -0.15 < cos < 0.05 K K K K 1 1 1 1 Beam Asymmetry, Σ 2 2 0.5 0.5 0.5 0.5 in BnGa refit. Σ 0 0 0 0 Beam Asymmetry, − 0.5 0.5 0.5 0.5 − 1 1 1 1 1.7 1.8 1.9 θ 2 2.1 2.2 1.7 1.8 1.9 θ 2 2.1 2.2 1.7 1.8 1.9 θ 2 2.1 2.2 1.7 1.8 1.9 θ 2 2.1 2.2 comparison of kinematic coverage 0.05 < cos < 0.25 0.25 < cos < 0.45 0.45 < cos < 0.65 0.65 < cos < 0.85 K K K K 1 1 1 1 0.5 0.5 0.5 0.5 2.3 CLAS 0 0 0 0 − 0.5 0.5 0.5 0.5 2.2 − 1 − 1 − 1 1 1.7 1.8 1.9 2 2.1 2.2 1.7 1.8 1.9 2 2.1 2.2 1.7 1.8 1.9 2 2.1 2.2 1.7 1.8 1.9 2 2.1 2.2 LEPS W (GeV) 2.1 θ θ θ θ -0.75 < cos < -0.55 -0.55 < cos < -0.35 -0.35 < cos < -0.15 -0.15 < cos < 0.05 K K K K 1 1 1 1 W [ GeV ] Target Asymmetry, T W (GeV) 2 xxx 0.5 0.5 0.5 0.5 0 0 0 0 1.9 − 0.5 0.5 0.5 0.5 Target, T − 1 1 1 1 1.7 1.8 1.9 θ 2 2.1 2.2 1.7 1.8 1.9 θ 2 2.1 2.2 1.7 1.8 1.9 θ 2 2.1 2.2 1.7 1.8 1.9 θ 2 2.1 2.2 1.8 0.05 < cos < 0.25 0.25 < cos < 0.45 0.45 < cos < 0.65 0.65 < cos < 0.85 K K K K 1 1 1 1 GRAAL 0.5 0.5 0.5 0.5 1.7 0 0 0 0 − 0.5 0.5 0.5 0.5 1.6 − − − 1 1 1 1 1.7 1.8 1.9 2 2.1 2.2 1.7 1.8 1.9 2 2.1 2.2 1.7 1.8 1.9 2 2.1 2.2 1.7 1.8 1.9 2 2.1 2.2 − − 1 0.5 0 0.5 1 θ W [ GeV ] cos W (GeV) cos θ K K — ANL-Osaka — BnGa ’14 — BnGa ’14 refit V. Credé Cross Section Measurements from CLAS-g12