# Presentation: 474171

## E05-115: Third Generation Hypernuclear Experiment 

- E05-115: Third Generation Hypernuclear Experiment

- Hall C User Meeting
- January 18th, 2008 (Fri)
- Yu Fujii
- Tohoku Univ.

- E05-115 : Spectroscopic investigation of  hypernuclei in
-                  the wide mass region using the (e,e’K+) reaction

## JLab E05–115 collaborators in proposal

**	****	****~ 87 researchers from 19 institiutes**

**Dept. of Phys. Tohoku Univ.**
**Y. Fujii, O. Hashimoto, H. Kanda, M. Kaneta, D. Kawama, K. Maeda, **
**N. Maruyama, A. Matsumura, S.N. Nakamura, K. Nonaka, Y. Okayasu,**
** ****M. Sumihama, H. Tamura, K. Tsukada, Y. Miyagi**
**Dept. of Phys. Hampton Univ.**
**O.K. Baker, L. Cole, M. Christy, P. Gueye, C. Jayalath, C. Keppel, **
**S. Malace, E.K. Segbefia, L. Tang, V. Tvaskis, L. Yuan**
**Dept. of Phys. Florida International Univ.**
**A.Acha, W. Boeglin, L. Kramer, P. Markowitz, N. Perez, B. Raue,**
**J. Reinhold, R. Rivera**
**Dept. of Phys. Yamagata Univ.**
**S. Kato**
**Institute of Particle and Nuclear Physics (KEK)**
**H. Noumi, Y. Sato, T. Takahashi**
**Laboratory of Phys, Osaka Electro-Comm. Univ.**
**T. Motoba**
**Dept. of Phys. Univ. of Houston**
**Ed. V. Hungerford, K.J. Lan, Y. Li, N. Elhayari, S. Randeniya, N. Klantrains**
**Thomas Jefferson National Accelerator Facility**
**P. Bosted, R. Carlini, V. Dharmawardane, R. Ent, H. Fenker, D. Gaskell,**
**M. Jones, D. Mack, J. Roche, G. Smith, W. Vulcan, S. Wood, C. Yan**

**Yerevan Physics Institute**
**R. Asaturyan, H. Mkrtchyan, A. Margaryan, S. Stepanyan, V. Tadevosyan**
**Nuclear Physics InstituteLanzhou Univ.**** **
**X. Chen, B. Hu, S. Hu, Y. Song, W. Luo, B. Wang**
**Dept. of Physics / Applied Phys. Univ. of Zagreb**
**D. Androic, M. Furic, T. Petkovic, M. Planinic, T. Seva**
**Dept. of Phys. North Carolina A&T State Univ.**
**A. Ahmidouch, S. Danagoulian, A. Gasparian**
**Dept. of Phys. Louisiana Tech Univ.**** **
**N. Simicevic, S. Wells**
**Dept. of Phys. James Madison Univ.**
**G. Niculescu, M.-I. Niculescu**
**Dept. of Phys. Univ. of North Carolina at Wilmington**
**L. Gan**
**Dept. of Phys. Duke Univ****.**
**M.W. Ahmed**
**Dept. of Phys. Univ. of Maryland**
**F. Benmokhtar, T. Horn**
**Dept. of Phys. Southern Univ. at New Orleans**
**M. Elaasar**
**Phys. and Astro. Dept. California State Univ. **
**Ed F. Gibson**

## Introduction

- p-shell nuclei : **6,7****Li, ****10,11****B, ****12****C, (H****2****O for calibration)**
- 		~ Fine structure ; core excited states etc.
- 		   Baryon-baryon interaction in SU(3),
- 		   charge symmetry breaking,
- 		    coupling in large isospin hypernuclei
- 		   cluster structure etc.
- fp-shell nuclei    :  **40****Ca(PR08-002), ****51****V, ****52****Cr**
- Beyond fp-shell :  **89****Y**
**	****	**~** **Single-particle potential
- 	  	   Distinguishability of a  hyperon
-          U0(r), m*(r), ..

_**E05-115 : Λ Hypernuclear Spectroscopy**_
_**in the wide mass region**__** **_

## Layout of HKS-HES system in Hall-C

- HKS

- HES

## Setup of the 3rd generation experiment

- Setup of the 3rd generation experiment

|  | HES (e’ arm) | HKS (K arm) |
| --- | --- | --- |
| Magnet Configuration | Q-Q-D | Q-Q-D |
| Central Momentum | 0.55~1.0 GeV/c | 1.2 GeV/c |
| Momentum Acceptance | ±0.1 GeV/c | ±0.15 GeV/c |
| Solid Angle | 10 msr | 8 msr |
| Resolution (FWHM) | 2.0×10-4 | 2.0×10-4 |

**Newly constructed**

**          **

## Comparison of available beam energy between

**E****top****1****pass**
**(GeV)**

**E****top****2pass**
**(GeV)**

**1**

**0.4**

**0.3**

**0.6**

**0.8**

**E****e’ ****(GeV)**

**2.5**

**1.8**

**1.9**

**E****e ****at Hall-C**
** ****(GeV)**

**Acceptable **
**Central Energy**
**(GeV)**

**HES**

**ENGE**

**2.0**

**2.2**

**2.4**

**4.4**

**4.55**

**5.0**

**6.0**

**9.45**

**10.3**

**10.8**

**12.0**

**2.1**

**Comparison of available beam energy between**
**HKS+ENGE**** and**** ****HKS+HES**

- (2nd gen.)

- (3rd gen.)

## How to avoid background electrons ~Tilt Method~

**e’ from Bremss.**

**Moeller ring**

**e’ associates**
**With virtual photon**

- Background

- Signal

- e’

|  | Beam (1.8GeV) | Target | e’-arm rate |
| --- | --- | --- | --- |
| 1st Exp. (w/o tilt) | 0.67 A | 12C, 22 mg/cm2 | 200 MHz |
| 2nd Exp. (w/ tilt) | 30 A | 12C, 100 mg/cm2 | 1 MHz |

- How to avoid background electrons ~Tilt Method~

- Backgrounds on e’ arm :
-    e’ from Bremss. & Moeller
- 	→Tilt Method

**x’**

**y’**

- 2.5GeV Electron Beam Energy

## Acceptance of HES

**Virtual Photon Energy**** ****1.5 GeV**

**Brems**

**Moller**

- Enge acceptance

**x’**

**y’**

- 2nd gen. (E01-011)
- Enge 0.3 GeV/*c*
- Beam Energy 1.8 GeV

- 3rd gen. (E05-115)
- HES 1.0 GeV/*c*
- Beam Energy 2.5 GeV

**×10**

- 10 times virtual photon tagging efficiency

**x’**

**y’**

## HES detectors

**e’**

- ED

**EDC1**

**EHODO1,2**

| Detector Specifications |  |
| --- | --- |
| EDC1 (used in the 2nd Exp.) |  |
| Effective area | 100W[cm] *12H[cm] *32T[cm] |
| Layers | 10 (xx’, uu’, xx’, vv’, xx’) |
| Layer distance  | 7.5[cm] |
| Cell Size | 0.5cm |
| EDC2 (same type as HKS DC) ; Hampton Univ. |  |
| Effective area | 105W[cm] *30H[cm] *3.5T[cm] |
| Layers | 6 (xx’, uu’, vv’) |
| Drift Distance | 6.35mm |
| EHODO1 ; Tohoku U. | 29 segments plastic scinti. |
| EHODO2 ; Tohoku U. | 29 segments plastic scinti. |

- Position Detectors	EDC1(Honeycomb type) + EDC2(Planer type)
- Trigger Counters	EHODO1 + EHODO2

**EDC2**

## Upgrade of HKS Detector package

- Renew boxes of Water Cherenkov (Tohoku U.)
- Improved light collection efficiency
- Add Lucite Cherenkov (Hampton U.)
- Additional information on PID and TOF measurements
- Add bucking coil for Aerogel Cherenkov (Florida Int’l U.)
- Cancel stray field of HKS dipole (~ 5 gauss) to recover gain of PMT

**LC**

**Renew**

**Bucking Coil**

- Q-Q-D

**Add**

## Yield Estimation

| Target
(100mg/cm2) | Yield for 100nb/sr [/hour] |  |
| --- | --- | --- |
|  | E01-011(1.8GeV, 24 A) | E05-115(2.5GeV, 30 A) |
| 7Li ( 15A ) | 9 | 48 |
| 10B | 10 | 67 |
| 12C | 10 | 56 |
| 40Ca | ― | 17 |
| 51V | ― | 13 |
| 89Y | ― | 7.5 |

- about 5 times

##  Simulated spectrum of 51V(e,e’K+)51Ti

-  _**Simulated spectrum of **__**51**__**V(e,e’K**__**+**__**)**__**51**_****_**Ti**_

**HKS (8msr ) + HES**
**⊿****E = 300 keV [FWHM]**
**Beam I = 30 [μA]**
**V 100 [mg/cm****2****]**** **
**S/N=5**

**Expected Counts /100KeV/144h**

**- B****Λ**** ( MeV )**

## Pictures @ TOKIN (Sendai, Japan)

**CEBAF 2.5GeV **
**Electron Beam**

- Splitter

*1.0GeV/c e**’*

*1.2GeV/c K**+*

- HES

- HKS

## Splitter Magnet

**1.72 m**

## Q-Q-D Magnet

**EQ1**

**EQ2**

**ED**

**EQ1**

**EQ2**

**1.25 m**

## Q-Q-D Magnet

- 		Tilt Version

## Schedule

- Dec 2007	HES departed from Japan
- Feb 2008	HES arrives at Norfolk
- Mar 2008	Test experiment of detectors 			              at Tohoku Univ. (LNS)
- Apr 2008	 	Tohoku group begins stay at JLab

**By the end of 2008**
**                    ****Ready to install HES in Hall C**

## Summary

-  HES magnets are on the way to JLab
-  HES detectors are under construction
-  Part of HKS detectors, WC and AC will be upgraded and LC will be added
-  Yield is 5 times larger than the 2nd generation exp.
-  Will be ready to install HES by the end of 2008

## Various targets

- E01-011 First Generation

- E94-107 Hall A Experiment

- E01-011 Second Generation

- E05-115 Third Generation

- PR08-002 Third Generation

## HES-HKS momentum acceptance

**51********Ti g.s**

****

****

**HKS**

**HES**

## E01-011 Set Up