Report on the triple coincidence analysis Eli Piasetzky for Igor Korover Collaboration meeting Jlab 17June 2013 triple /double ratios: Triple coincidence ratios: MM distributions Pcm distributions

Isospin 1 states Isospin 0 states Explanation lies in the dominance of the tensor part in the NN interaction M.S, Abrahamyan, Frankfurt,Strikman PRC,2005 Adapted from Sargasian talk Jlab., June 2013

In plan angle ±4°Out of plan angle ±14° Nominal acceptance cuts 750 MeV/c

In plan angle ±4°Out of plan angle ±14° Nominal acceptance cuts 625 MeV/c

In plan angle ±4°Out of plan angle ±14° Nominal acceptance cuts 500 MeV/c

Report on the triple coincidence analysis triple /double ratios:

Triple / double coincidence ratios The main challenge is to correct for the finite angular and momentum acceptances of the recoil detectors: BigBite for the protons, HAND for the neutrons. The method (Following Ran’s analysis): # Assume that the shape of the CM momentum distribution is known and fit the triple coincidence data to get the best parameters (and estimate of their uncertainty). # simulate the recoil nucleon for each (e,e’p) event assuming 2N_SRC and the known CM motion. # check what fraction of the recoil nucleons are being detected.

p e e’ p Pmiss P recoil p/n We assumed : PCM (x direction) dist G(σ x,0) PCM (y direction) dist G(σ y,0) PCM (z direction) dist G(σ z,z 0 ) Ran assumed: -92,-97 0

“C.M. Momentum Distribution” X Y z 4 He(e,e’pn) 750 MeV/c Notice that Pcm* is not the cm momentum of the pair: FSI, not relevant for the extrapolation. Finite acceptance – need to be corrected by simulation In plan angle ±4° Out of plan angle ±14° TOF ns (~ MeV/c) Nominal acceptance cuts

“C.M. Momentum Distribution” 4 He(e,e’pn) 750 MeV/c No TOF cut In plan angle ±4° Out of plan angle ±14° TOF ns (~ MeV/c) Nominal acceptance cuts

“C.M. Momentum Distribution” 4 He(e,e’pn) 750 MeV/c No TOF cut In plan angle ±4° Out of plan angle ±14° TOF ns (~ MeV/c) Nominal acceptance cuts

“C.M. Momentum Distribution” 4 He(e,e’pn) 500 MeV/c XY z 4 He(e,e’pn) 625MeV/c X Y z

“C.M. Momentum Distribution” 750 MeV/c 625 MeV/c 500 MeV/c

“C.M. Momentum Distribution” 750 MeV/c 500 MeV/c 625 MeV/c

“C.M. Momentum Distribution” 750 MeV/c 500 MeV/c 625 MeV/c

“C.M. Momentum Distribution” 4 He(e,e’pn) For acceptance correction to the 4 He data we assumed: To be compared with 136±20 MeV/C for 12 C Pmiss= MeV/c, Ran analysis MeV/c Or analysis, hall B data summary X XX

How well this assumption described the data ? 750 MeV/c 625MeV/c 500 MeV/c

How well this assumption described the data ? 750 MeV/c 80 MeV/c 100 MeV/c 120 MeV/c We plan to do Х 2 analysis

How well this assumption described the data ? 625MeV/c 80 MeV/c 100 MeV/c 120 MeV/c We plan to do Х 2 analysis

Acceptance correction factor? 500 MeV/c 625MeV/c 750 MeV/c MeV/c 625 MeV/c500 MeV/c These are for ω<0.97 Analysis was done for ω<0.95

Event selection (e,e’p) 500 MeV/c X>1.05 M=0.94 X>1.05 ω<0.95 X>1.05 M+m π Peter analysis ω<0.95 X>1.05

Event selection (e,e’p) 625 MeV/c Peter analysis M=0.94 X>1.05 ω<0.95 M+m π X>1.05 ω<0.95 X>1.05

Event selection (e,e’p) 750 MeV/c Peter analysis M=0.94 X>1.05 ω<0.95 M+m π X>1.05 ω<0.95 X>1.05

Event selection (e,e’p) Need to add cut sensitivity analysis

(e,e’pn) / (e,e’p) In plan angle ±4° Out of plan angle ±14° TOF ns (~ MeV/c) Nominal acceptance cuts 96 ± 23 % 500 MeV/c 625MeV/c 750 MeV/c Statistical uncertainties only (Max) total uncertainties 20% overall normalization uncertainty

(e,e’pp) / (e,e’p) In plan angle ±4° Out of plan angle ±14° TOF ns (~ MeV/c) Nominal acceptance cuts 9.5 ± 2 % Statistical uncertainties only 625MeV/c 750 MeV/c total uncertainty

[(e,e’pn) +(e,e’pp)] / (e,e’p) In plan angle ±4° Out of plan angle ±14° TOF ns (~ MeV/c) Nominal acceptance cuts 500 MeV/c 625MeV/c 750 MeV/c Assuming 10% (e,e’pp) Statistical uncertainties only

(e,e’pn), (e,e’pp), and (e,e’p) In plan angle ±4° Out of plan angle ±14° TOF ns (~ MeV/c) Nominal acceptance cuts Statistical uncertainties only

Preliminary R. Subedi et al., Science 320 (2008) ± 2 % Missing momentum [MeV/c] BNL Experiment measurment was 92 % ± 23 % Yield Ratio [%] R. Shneor et al., PRL 99, (2007) EXP / Jlab (e,e’p) (e,e’pp)

Isospin 1 states Isospin 0 states Explanation lies in the dominance of the tensor part in the NN interaction M.S, Abrahamyan, Frankfurt,Strikman PRC,2005 Adapted from Sargasian talk Jlab., June 2013

Adapted from Sargasian’s talk, Jlab., June 2013: For MeV/c New Data For MeV/c When Pmiss increases we loose the extra np -SRC pairs due to the tensor force

Hall B Or analysis No class acceptance correction to the recoil proton

Report on the triple coincidence analysis Triple coincidence ratios:

(e,e’pn) /(e,e’pp) In plan angle ±4° Out of plan angle ±14° Nominal acceptance cuts no SRC correction Need x2 for the np/pp ratio

The global picture no SRC correction to the new data R. Subedi et al., Science 320, 1476 (2008) and the new data

BNL / EVA 12 C(e,e’pn) / 12 C(e,e’p) [ 12 C(e,e’pp) / 12 C(e,e’p)] / 2 [ 12 C(e,e’pn) / 12 C(e,e’pp)] / 2 R. Subedi et al., Science 320, 1476 (2008).

Report on the triple coincidence analysis MM distributions

Missing mass 750 MeV/c (e,e’pn) (e,e’pp) M p +m π

Missing mass 625 MeV/c (e,e’pn) (e,e’pp) M p +m π

Missing mass 500 MeV/c (e,e’pn) M p +m π

Report on the triple coincidence analysis Pcm distributions

“C.M. Momentum Distribution” 4 He(e,e’pn) For acceptance correction to the 4 He data we assumed: To be compared with 136±20 MeV/C for 12 C Pmiss= MeV/c, Ran analysis MeV/c Or analysis, hall B data summary X XX ?

Sensitivity to angular and momentum cuts No angular cuts In ±5° Out ±15° In ±4° Out ±14° In ±6° Out ±16° 625 MeV/c

Sensitivity to angular and momentum cuts In ±5° Out ±15° In ±4° Out ±14° 750 MeV/c No angular cuts In ±6° Out ±16° In ±5° Out ±15° In ±4° Out ±14°

Sensitivity to angular and momentum cuts No angular cuts In ±5° Out ±15° In ±4° Out ±14° In ±6° Out ±16° 625 MeV/c

Sensitivity to angular cuts 625 MeV/c No angular cuts No MWDC In ±4° Out ±14° In ±6° Out ±16° In ±5° Out ±15°

750 MeV/c 625 MeV/c 500 MeV/c