Studies of the Deuteron at High Studies of the Deuteron at High QQ22

Hassan IbrahimHassan Ibrahim

Old Dominion UniversityOld Dominion University

(for the E01-020 Collaboration*)(for the E01-020 Collaboration*)

Hall A Collaboration MeetingHall A Collaboration MeetingJune 22, 2006June 22, 2006

* Spokespersons: * Spokespersons: W. Boeglin, M. Jones, A. Klein, P. Ulmer and E. Voutier Graduate Students: Graduate Students: L. Coman and H. Ibrahim

(E01-020 Update)(E01-020 Update)

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 2

Electron SpectrometerElectron Spectrometer Proton SpectrometerProton Spectrometer

ElectronElectron

BeamBeam

Target (LDTarget (LD22))

22HH((ee,,ee''pp))nn

ServiceServicePositionsPositions

QQQQ QQ QQ

QQQQ

DDDD

BeamBeam

DumpDump

Hall A at Jefferson Lab

E01-020

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 3

Reaction Kinematics

)(2

MeV 2.225,

)(),(

2

)cos1(2

)(),(

22

2

2

mass invariant

momentum-4 missing

transfer momentum-4

QMMW

pppqp

TEMTE

pEp

M

Qx

eeqqQ

kkq

ee

qq

pp

rnm

nmmpm

mmm

pB

e

ee

e'e'

qq

pp

nn

nq

Rea

ctio

n Pl

ane

Rea

ctio

n Pl

ane

Scattering Plane

Scattering Plane

e

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Plane Wave Impulse Approximation and Beyond

dd

pp nn

ee

e'e'

qqp'p'

dd

PWIAPWIAnnpp

n'n'p'p'

dd

p''p''

FSIFSI

ee

e'e'

qq

MECMEC

ee

e'e'pp nn

qqp'p'

ICIC

ee

e'e'

qqp'p'

dd

nnpp

n'n'n'n'

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 5

Reaction Cross Section

LTLT

LTTTTL

LTTTTL

LTLTTTTTTTLL

5

of Separation )]180()0([1

functions. response are and , ,

and factors leptonic are , and , ,

Section, CrossMott is

factor, recoil a is

factor, lkinematica a is

)cos2cos(

RKf

R

RRRR

f

K

RRRRKfddd

d

Mott

Mott

Mottpe

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 6

RLT and Relativity

The longitudinal component of the relativistic electromagnetic The longitudinal component of the relativistic electromagnetic

nuclear current contains nuclear current contains additional spin-orbit termadditional spin-orbit term..

This additional term can interfere with the This additional term can interfere with the spin-flip spin-flip

magnetization termmagnetization term in the transverse current component. in the transverse current component.

But, non-relativistically, there is no such additional term since But, non-relativistically, there is no such additional term since L L

reflects charge only and can not interfere with the spin-flip part reflects charge only and can not interfere with the spin-flip part

of of T.T.

Therefore, we can test relativistic models by separating Therefore, we can test relativistic models by separating RRLTLT..

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 7

Run Summary

Neutron Direction

Q2

(GeV/c)2

Pm

(MeV/c)xB FSI MEC / IC Motivation

Parallel

(pm || q)2.12.1

100, 200, 100, 200, 300, 400 and 300, 400 and

500500< 1< 1 MinimumMinimum MaximumMaximum

Emphasize

MEC / IC

Anti-Parallel

(pm || - q)2.12.1

100, 200, 100, 200, 300, 400 and 300, 400 and

500500> 1> 1 MinimumMinimum MinimumMinimum

Study Deuteron

Short-range Structure

Perpendic-ular

(pm q)

0.80.8

2.12.1

3.53.5

0, 100, 200, 0, 100, 200, 300, 400 and 300, 400 and

50050011 VariableVariable MinimumMinimum

Test Relativistic Models (RLT)

Neutron Angular

Distribution

0.80.8

2.12.1

3.53.5

0, 100, 200, 0, 100, 200, 300, 400 and 300, 400 and

500500VariableVariable VariableVariable VariableVariable Study FSI

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 8

Mean versus Most Probable Energy Loss (ELoss)

EEmissmiss (MeV) (MeV) EEmissmiss (MeV) (MeV)

DataData SimulationSimulation

Mean Mean EELossLoss : :

M. P. M. P. EELossLoss : :

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 9

ARC versus Tiefenbach Beam Energy

Run # ARC Emiss (MeV)Tief. EBeam

(MeV)Tief. Emiss (MeV)

Emiss (MeV)

(ARC - Tief.)

1242 3.5 2843.5 3.5 0.0

1243 3.6 2843.5 3.6 0.0

1252 4.0 2843.1 3.7 0.3

1254 3.9 2843.1 3.5 0.4

The dependence of Emiss on the beam energy for 2H is calculated for the shown runs from the same kinematics. The nominal ARC EBeam = 2843.6 MeV.

This table shows that the variations in the Tief. beam energy are adequate to calculate the actual beam energy for each run.

TiefTief

ARCBeam E

E

EE

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 10

Coincidence Time

No Cuts:No Cuts: EEmissmiss Cut: Cut:Q3D f20lQ3D f20l

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 11

Scintillator Calibration

No Cuts:No Cuts: EEmissmiss Cut: Cut:

Q3D f20lQ3D f20lQ3D f20rQ3D f20r

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Beam Current

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Beam Position

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Kinematics Calibration Use different hydrogen elastic kinematics at the same EBeam.

Minimize the W, Em, pmx, pmy and pmz offsets (yj, j=1,…,5) between the data and the simulation (W Mp, Em 0, pm 0).

Fit for the relative momentum deviations, e= e'/e' and p = p/p, the in-plane angular offsets, e and p and the out-of-plane angular offsets, e and p (xi, i=1,…,6) to minimize yj.

ii

i

jj

kins jji

i i

jj

ii i

jj

x

y

xx

yy

xx

yy

2

2

2

2

2

2 )( /

)(

Square-Chi

Offsets Variable

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 15

Original Variable Offsets A new code was written to fit for the kinematics offsets by minimizing the

variable offsets in this table.

Run #EBeam

(MeV)k’

(MeV)p

(MeV)θe

(mr)θp

(mr)δW

(MeV)δEm

(MeV)δpmx

(MeV)δpmy

(MeV)δpmz

(MeV)

2594 5008.4 2918.5 2877.3 30.474 -30.483 9.966 2.239 3.221 0.847 0.863

2596 5008.4 3159.3 2617.4 26.981 -33.301 10.858 2.347 4.008 0.841 1.001

2599 5008.4 3425.2 2338.9 23.979 -36.579 10.771 2.563 4.214 -0.394 1.358

2600 5008.4 3695.4 2044.6 20.980 -40.398 8.799 1.835 3.944 -0.978 0.696

2632 5008.4 3140.3 2648.0 27.265 -32.917 9.836 2.323 3.599 0.606 1.290

2672 5008.5 3140.3 2648.0 27.265 -32.917 9.902 2.059 3.830 0.347 0.964

2792 5008.5 3140.2 2648.0 27.264 -32.927 11.061 2.525 4.096 0.554 1.300

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 16

Minimized Variable Offsets The minimized variable offsets after the kinematics calibration are shown in

this table.

Run #δW

(MeV)δEm

(MeV)δpmx

(MeV)δpmy

(MeV)δpmz

(MeV)

2594 -0.526 -0.168 -0.359 -0.220 -0.239

2596 +0.652 +0.027 +0.216 +0.401 -0.064

2599 +0.818 +0.335 +0.188 -0.152 +0.353

2600 -0.732 -0.292 -0.326 -0.028 -0.265

2632 -0.402 -0.011 -0.182 +0.102 +0.218

2672 -0.336 -0.275 +0.049 -0.157 -0.109

2792 +0.824 +0.192 +0.315 +0.050 +0.228

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 17

Kinematics Offsets

-2

0

2

4

6

8

10

12

0 1 2 3 4 5 6 7 8

Kinematics

W O

ffse

t (M

eV)

Before After

e (x10-3) p (x10-3) e (mr) p (mr) e (mr) p (mr)

Offsets -0.287 -0.574 -1.146 -0.448 +1.054 -1.440

Uncert. ±0.173 ±0. 232 ±0.117 ±0.132 ±0.230 ±0.291

-0.5

0

0.5

1

1.5

2

2.5

3

0 1 2 3 4 5 6 7 8

Kinematics

Em

iss

Off

set

(MeV

)

Before After

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Missing Energy (Emiss)

Data (MeV/c2) Simulation (MeV/c2)

Kinematics Left Right Left Right

Q3D f00 2.3531 2.51

Q3D f10 2.10 2.71 2.55 2.55

Q3D f20 2.42 3.10 2.64 2.45

Q3D f30 2.51 3.15 2.79 2.45

Q3D f40 2.25 3.05 2.80 2.57

Q3D f50 - 2.95 - 2.62

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 19

Relative Momentum Deviation (δp)

Simulation :Simulation : Data :Data :

Q3D f20l Q3D f20r

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 20

PID (Čerenkov Detector)

ECSUM

ECSUM > 150

99% Efficiency

No Cuts:No Cuts:ECSUM Cut:ECSUM Cut:

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 21

PID (Pion Rejector)

99% Efficiency

PRSUM Cut

No Cuts:No Cuts:PRSUM Cut:PRSUM Cut:

6/22/2006 Studies of the Deuteron at High Four-Momentum Transfer, Hassan Ibrahim, HAll A Meeting 22

Theoretical Calculations

We have now Laget’s PWIA calculations fully integrated with the recent official MCEEP version.

We hope that the full Laget’s calculations will be available soon to us (This will include all the different mechanisms such as FSI, MEC and IC.

We also expect to use Sargsian’s calculations once they are made available to us.

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Summary The experiment ran in 2002 for 2 months and collected about

2 TB of data for more than 120 different kinematics. All the optimizations and calibrations of the two spectrometers

have been completed or are finishing up. Extensive software improvements and additions have been

made in ESPACE and MCEEP. Many new standalone codes were written to display and

optimize the different aspects of the data. Several passes through the data were done to correct for the

beam position and to extract the stable current time periods. Laget’s PWIA grid interpolation was implemented in MCEEP. The highest Q2 final results are expected by the end of 2006.