The Glue X Experiment Curtis A Meyer CH

The Glue. X Experiment Curtis A. Meyer CH L-2 9/16/2020 CIPANP 2006 1

JLab Upgrade magnets and power supplies CHL-2 9/16/2020 CIPANP 2006 2

What’s New: The CEBAF Upgrade will take advantage of recent advances in computing power, combined with a doubling of the existing energy of the electron beam, to create a 12 giga-volt electron beam capable of providing much more precise. Project data on the structure of. CD-1 protons and neutrons. Specifically, February 2006: Receives the upgrade will enable scientists to address one of the great mysteries of Secretary of Energy Approval Funding for together. New modern physics. Announces – the mechanism that and “confines” quarks supercomputing studies indicate that force fields Lab called “flux-tubes” may be Facilities Upgrade at the Thomas Jefferson National and responsible, and that exciting these should lead to the creation of neverbefore. Highlights Lab’s Successful Education Programs seen particles. 12 Ge. V Upgrade CD-0 Signing at Jefferson Lab April 19, 2004 November 2003 9/16/2020 CIPANP 2006 Deputy Energy Secretary Kyle Mc. Slarrow 3

The Glue. X Collaboration 9/16/2020 CIPANP 2006 4

quark-antiquark pairs u d J=L+S P=(-1) L+1 C=(-1) G=C (-1) L+S I 9/16/2020 d s (2 S+1) 1 S L J -+ = 0 0 3 S = 1 -1 Normal Mesons Non-quark-antiquark 0 -- 0+- 1 -+ 2+- 3 -+ … orbital 3, 3, 3, K 3 2, 2, 2, K 2 L=2 , , , K 1 1 2, 2, ’ 2, K 2 3 -2 -1 -2 -+ a 2, f’ 2, K 2 a 1, f’ 1, K 1 L=1 a , f’ , K 0 0 b 1, h’ 1, K 1 2++ 1++ 0++ 1+- , K* L=0 ’, K 1 -0 -+ CIPANP 2006 radial 5

Flux Tubes 9/16/2020 CIPANP 2006 6

Hybrid Mesons built on quark-model mesons excited flux-tube m=1 ground-state flux-tube m=0 1 -+ or 1+ , normal mesons CP={(-1)L+S}{(-1)L+1} ={(-1)S+1} Flux-tube Model m=0 CP=(-1) S+1 m=1 CP=(-1) S 9/16/2020 S=0, L=0, m=1 S=1, L=0, m=1 J=1 CP=+ J=1 CP=JPC=0 -+, 0+- JPC=1++, 1 -(not exotic) CIPANP 2006 1 -+, 1+-+, 2+2 exotic 7

Hybrid Predictions Flux-tube model: 8 degenerate nonets 1++, 1 -- 0 -+, 0+-, 1 -+, 1+-, 2 -+, 2+- ~1. 9 Ge. V/c 2 S=0 S=1 Lattice calculations --- 1 -+ nonet is the lightest UKQCD (97) 1. 87 0. 20 ~2. 0 Ge. V/c 2 MILC (97) 1. 97 0. 30 -+ 1 MILC (99) 2. 11 0. 10 Splitting 0. 20 + 0. 50 0 Lacock(99) 1. 90 0. 20 +2 Mei(02) 2. 01 0. 10 In the charmonium sector: 1 -+ 4. 39 0. 08 Splitting = 0. 20 +0 4. 61 0. 11 9/16/2020 CIPANP 2006 8

-p! n + - E 852 (BNL): Exotic reported at a mass of 1. 6 Ge. V JPC = 1 -+ A new analysis with 10 times the statistics shows no exotic signal in . 9/16/2020 CIPANP 2006 E 852 9

Exotic Signals 1(1400) Width ~ 0. 3 Ge. V, Decays: only weak signal in p production (scattering? ? ) strong signal in antiproton-deuterium. 1(1600) Width ~ 0. 16 to 0. 3 Ge. V, Decays , ’ , (b 1 ) Only seen in p production, (E 852 + VES) In a nonet, there should only be one 1 state. 1 IG(JPC)=1 -(1 -+) K 1 IG(JPC)= ½ (1 -) 1 IG(JPC)=0+(1 -+) ’ 1 IG(JPC)=0+(1 -+) Both of these are lighter than expectations, and The [ ’] decay modes are not what are expected. 9/16/2020 CIPANP 2006 10

Hybrid Decays The angular momentum in the flux tube stays in one of the daughter mesons (L=1) and (L=0) meson. L flux Lflux Exotic Quantum Number Hybrids 1 b 1 , f 1 , , a 1 1 (1300) , a 1 1: . 25: . 20 b 2 a 1 , h 1 , a 2 h 2 b 1 , Mass and model dependent predictions b 0 (1300) , h 1 h 0 b 1 , h 1 9/16/2020 CIPANP 2006 11

Photoproduction More likely to find exotic hybrid mesons using beams of photons 9/16/2020 CIPANP 2006 12

Exotics and QCD In order to establish the existence of gluonic excitations, We need to establish the nonet nature of the 1 -+ state. We need to establish other exotic QN nonets – the 0+- and 2+-. In the scalar glueball sector, the decay patterns have provided the most sensitive information. I expect the same will be true in the hybrid sector as well. DECAY PATTERNS ARE CRUCIAL 9/16/2020 CIPANP 2006 13

The Glue. X Experiment 9/16/2020 CIPANP 2006 14

Optimized for PWA Nearly 4 acceptance for neutral and charged particles. Linearly polarized photons with energy optimized for hybrid searches. Uniform acceptance in the variables appropriate for Partial Wave Analysis. PWA Leakage studies have been performed using Monte Carlo. 9/16/2020 CIPANP 2006 15

Acceptance Gottfried-Jackson frame: In the rest frame of X the decay angles are theta, phi p! + + -n 9/16/2020 CIPANP 2006 Mass [X] = 1. 4 Ge. V Mass [X] = 1. 7 Ge. V Mass [X] = 2. 0 Ge. V 16

Partial Wave Analysis g p Double blind studies of 3 final states Glue. X Monte Carlo X +n! + + -n p ! 1 n a 2 + 0 0 n ! Polarization 2 h=+1 f. GJ h=-1 h=+1 9/16/2020 m 3 [Ge. V/c 2] CIPANP 2006 17

Leakage If your acceptance is not well understood, The PWA can “leak” one wave into another. Break the Glue. X detector in Monte Carlo: distort B-field degrade resolution change hole sizes distort beam energy Largest leakage is ~ 1/2% of a strong signal. a 1(1++) $ 1(1 -+) 9/16/2020 CIPANP 2006 neutral charged 18

Partial Wave Analysis Have been able to pull out signals that are ~1% of a strong signal using PWA. It is extremely difficult to produce leakage that is as large as 1%. Assuming a good theoretical understanding, if hybrids are present at ~1% of normal mesons strength, this detector will be able to find them. Studies are currently being redone with detector software. 9/16/2020 CIPANP 2006 19

Detector R&D Work Drift Chambers 9/16/2020 CIPANP 2006 20

Solenoid Refurbishment LASS Solenoid Superconducting 2. 5 T Used in Los Alamos MEGA Experiment. Moved to IUCF for refurbishing. 9/16/2020 CIPANP 2006 21

Calorimeters Existing Pb-Glass for Forward Barrel Calorimeter Pb-Sci. Fib Beam tests fall 2006 9/16/2020 CIPANP 2006 Backwards Veto 22

Electronics Flash ADC System The F 1 TDC 9/16/2020 CIPANP 2006 23

Detector Reviews July 2003: Held a 2 -day review of Glue. X Electronics October 2004: Held a 2 -day review of the Glue. X Detector. November 2004: Solenoid Assessment January 2006: Tagger Review 9/16/2020 CIPANP 2006 24

Analysis Preparation From the very start, the Glue. X Collaboration has had an active theory group. It is well recognized that theorists need to be closely integrated into the analysis from the start. The theoretical underpinnings of Partial Wave Analysis need to Be looked at closely now that large data sets are becoming available. What exactly are the model assumptions and how do they affect The results. The scale of data from Glue. X will be comparable to LHC experiments. However, the needs are different – GRID technologies will be crucial. Also, the tools to parallelize the analysis of 100, 000 event data sets are being developed. 9/16/2020 CIPANP 2006 25

Summary The Glue. X Collaboration is moving forward! The DOE 20 -year plan and CD 0 have opened the door to a great deal of interest by new groups in Glue. X. The Collaboration is pressing forward with detector R&D coupled with external reviews of what we are doing. The Collaboration is working hard to make sure that analysis issues due to the large data sets are in hand. We are paying close attention to theoretical underpinnings of PWA to make sure that what comes out of Glue. X is a clear answer. 9/16/2020 CIPANP 2006 26

Gluonic Excitations Workshop at JLab May 14 -16, 2003. 9/16/2020 CIPANP 2006 27

Theoretical Underpinnings PWA Workshop Three Day Workshop on partial wave analysis held at Carnegie Mellon University last week. 35 Participants from Europe and North America, about 50% theorists and 50% Experimentalists. About equal numbers of “Baryon” and “Meson” people. 9/16/2020 CIPANP 2006 28