# Presentation: 932683

## Electrons/photons: from detector to Ntuple 

- M. Jaffré
- LAL Orsay

- Outline :
- L1 and L2 EM objects
- L3 electron/photon tools
- Electron/photons in D0Reco

## L1 & L2 major challenges

- Input Rate to L1 ~ 7.6MHz at 1032cm-2s-1
- <pT> e- for J/ee-                                               <pT> e- for W,Z,top decays
-  ~ 2.7 GeV/c central                                   ~ 30-40GeV/c
- ~ 3.1 GeV/c forward                                    Although threshold high
- Low threshold in CAL high QCD rate            S/B ~ 1/50,000

*Mrinmoy Bhattacharjee*

## Definition of EM object (e-/)

***e************ = CFT trk + CPS cluster + CCEM Trigger Tower***
********* ******= No Trk + CPS cluster + CCEM Trigger Tower***

_**Forward Region**_

_**Central Region**_

***e************ = MIP + FPS cluster + ECEM Trigger Tower***
********* ******= No MIP + FPS cluster + ECEM Trigger Tower***

## L1 electron algorithm (high pT)

_**Central (**__****__**1.6)**_
**1 CPS cluster ******** high matched to 1 track **
**   ********5GeV/c in 4.5****0****   **
**1 Calo EM tower ******** 7-10GeV (********1.6)**
** ****matched to CPS cluster by quadrant**
_**Forward (1.6**__****__**2.6)**_
**1 FPS cluster ******** high + MIP confirmation   **
**1 Calo EM tower ******** 7-10GeV (1.6********2.6)**
**  ****matched to FPS cluster by quadrant**
**Track/MIP matching to PS optional;**
** ****perform only if rates high**

-  1.0
- Cal EM>7GeV

## L1 EM trigger rates (high pT)

**  ****Rates at L=2********10****32****cm****2****/s**
**Cluster/Track & CCAL Quadrant match**
**Cluster & ECAL Quadrant match**
**CEM(1,10,C)****	****	****	****200     W mass, QCD ******** **
**CEM(1,7,C)CEQ(1)TNQ(1)****	**** 62        QCD ******
**CEM(1,10,C)TEL(1,5)****	****	****   3     W mass, WZ ******** **
**CEM(1,10,N/S)****	****	****	****690     EC W mass**
**CEM(1,10,N/S)FQN(1)****	****	****400       FWD EM**
**CEM(1,10,N/S)FPQ(1)****	****	****200     EC W mass**
**Rates highly dependent on thresholds in CAL**** **
**Quadrant matching give ********2-4 in rates rejection**

******1.0**

## L2 EM triggers

_**	**_**Advantages at L2 are:**
**	****	****(1) Large decision time 100********sec**
**	****	****(2) Finer detector information available**
**             ****-- clustering in PS**
**             ****-- clustering in CAL**
**	****	****(3) Due to more time finer matching can be **
**             ****performed**
**	****	**
**	****	****     ****-- L1 CAL/PS matching in quadrant**
**	****	****     ****-- L2 CAL/PS match within 0.2********0.2 **
**                 ****in ******** **_**	**_

## L2 CAL Preprocessor

_**	**_**L1 EM Trigger based on following reference set**
- 		**2.5, 5, 7 & 10 GeV E****T**
**	****(1) L2 uses TT’s above low threshold ref. set**
**	****(2) Find 2nd. Maximum in 3********3 around seed**
**   ****(3)  E****T****EM  = ****E****T****EMseed ****+ E****T****2nd ****> Thr**
**   ****(4)  EMF = E****T****EM****/(E****T****EM****+E****T****HAD****) **
**   ****(5)  T****ISO  ****= ******** E****T****(EM+Had)/E****T****EM  ****( 3********3 ******** - seed )**
**	****	****       ****= E****T****EM****/********ET(EM+HAD) ****(3********3 ******** includes seed)**

**TISO < 0.4**

**EMF>0.85**

_**P**__**T**__** =20GeV**_

*Marc Buehler*

## L2 CAL Efficiency, Rates & Timing

**(In 1.6********2.6)**
_**L1 seed tower **__****__**7GeV / **__****__**10GeV**_
**           ****ETEM ******** 10GeV / 12GeV**
**      ****EMF   ******** 0.85  +  T****ISO    ******** 0.4**
**	****  ****p****T                ****15Gev/c     20GeV/c   32.5GeV/c**
**    ****L2/L1         93.3%       99.5%      100.0% **
**	****   “            ****86.0%       100.0%     100.0%****     **
_**Dijet Rates**_
**                 ****L1(1,7GeV)   L2(1,10GeV)   L2(1,12GeV)**
**    ****@2E32       900Hz        145Hz         90Hz**
_**L2 CAL Timing**_** ****(available 50********sec)**** **
**	****L2 Seed cut   0.5GeV  1.0GeV  1.5GeV  2.0GeV **
**   ****# of seeds      77        19       10         7**
**   ****Time ********s         179       46       25        18**

## L2 electron algorithm (high pT)

- _Central (____1.6) _(L2 Global 50sec)
-    1 CAL tower 7GeV_	_
-    1 CPS Axial cluster  5MIPs + CFT Track tag
-      CPS 3D match of X,U,V  , 
- 		(1) Axial ,U, V = 5MIPs
- 		(2) Axial = 5MIPs & U,V = 3MIPs
- _	_ Different detector info combined at L2 Global
-             CPS-CAL match within 0.250.25 in 
-        (1) efficiency loss for ET <40GeV
-             (Z  ee, 93.7%)
-           (W+Jets, 84.0%)
- 	 (2) regains lost electrons at low ET
-           (Z  ee, 99.0%)
-             (W+Jets, 95.4%)

## L2 electron algorithm (high pT)

_**Forward (1.6**__****__**2.6) **_**(L2 Global 50********sec)**
**    ****CAL Cluster (E****T****EM****)> 10GeV,**
**CAL EMF ********0.85 +  CAL Isolation ******** 0.4**
**FPS 3D match of U,V ******** ********, ******
**	****	****(1) U, V = high****	****	**
**	****	****(2) U = high & V = low OR vice versa **
** **
**Different detector info combined at L2 Global**
**   ****FPS, CAL matching within 0.25********0.25 in ******
**  ****Z ******** ee 94.3% - 97.5% (HH / HL.OR.LH)**

**80Hz**

**145Hz**

**900H****z**

**@ 2********10****32****cm****2****/s**

## B Physics: di-electron trigger

_**L1 & L2 Trigger Performance:**_
- Central Region (CAL EM>2.5GeV, CPS>3MIPs)
-   eff (pT>1.5GeV) = 10%, Rates = 50Hz
- Forward region (CAL EM>2.5GeV, FPS>5MIPs)
-   L1 eff (pT>1.5GeV) = 10%, Rates = 1.0-1.5KHz
-   L2 eff (pT>1.5GeV) = 4-5%, Rates = 50Hz

## L1 & L2 summary

-  _L1 Trigger_
- 	electron (pT>5GeV) efficiency    > 95%          (7-10GeV CAL)
- 	background rates                      1.5 Hz            (7GeV CAL thr)
-                                                     200 - 500 Hz  (10GeV CAL Thr)
- 	di-e (pT>1.5GeV) efficiency     ~ 20%(cen),  10%(fwd)
- 	background rates                     1-2kHz (cen+fwd)
- 	PS/CAL Quadrant matching 2-3 in rates
- 	_L2 Trigger_
- 	electron (pT>5GeV) efficiency        > 95% (10GeV ETEM)
- 	background rates                          50-100 Hz (10GeV ETEM)
- 	di-e (pT>1.5GeV) efficiency           ~ 10%(cen),5%(fwd)
- 	background rates                           100Hz (cen+fwd)
-     CAL EMF, Isolation, Invariant mass helps
-     PS/CAL 0.250.25 in  match = 2-3 in rates

## L3 Components

**Cal.Unpacker**
- Charles Leggett

**Cal. Cluster**
- Volker Buescher

**L3TEle, L3TPhoton**
- Volker Buescher Juan Estrada Vishnu Zutshi

**CPS.Unpacker**
- Andre Turcot

**L3TCps **
- Andre Turcot

**FPS  Unpack**
- U.Michigan

**L3TFps**
- U.Michigan

**L3track framework**
**Daniel Whiteson**

**L3TPrVtx**
- G. Lima

*Juan Estrada*

## L3 Preshower Clustering

- CPS ( A. Turcot )
- a review of algorithm performed last summer
- Algorithm :  - contiguous strips above threshold (2 MIPs) clustered in
-                             each layer ( Single Layer Cluster )
-                          - 3D matching of SLC with some energy correlation
- Localized clustering in  or - implemented to be used by L3 electron tool
- CPS resolution for single e-
-        (r) = 0.54 mm, (z) = 1.9 mm

## CPS strip energy

**2 MeV**

## L3TEle(L3TPhoton)

- List of calorimeter clusters from the l3fcalcluster.
- Possibilities:
- EMFR cut.
- Calorimeter cluster shape.
- Longitudinal and transverse variables from CPS
- Isolation
- Track matching
- Implemented
- EMFR cut.
- 4x4 Hmatrix (EM1,EM2,EM3,EM4)

## Some plots from L3Tele

- log 2

**Single 20 GeV electrons and pions**

**Track-Cluster matching in W events**

- EM fraction

## L3 status

- Functional tool exists to do L3 EM trigger.
- Access to calcluster, CPScluster and tracks is now possible at L3.
- Studies on the best way to use this variables are going on now.

**Efficiency of L3Ele:  98% for 50GeV electrons with a EMFR cut. Factor of 50 rejection for 50GeV pions. (Not realistic, waiting for   L2 Ele simulation).**
**Timing: **
**L3TEle: does not do anything that takes time just a few multiplications and a 1D cut**
**  ****CalCluster: 2msec for a top event****	**
** ****Unpackers: studies pending  (NTsystem)**

## EMRECO algorithm

- Cluster « finding » algorithms
- 3 Clustering coded based on Towers : *simple cone, cone and NN*
- Default now is simplecone R=0.4   (fast)
- 4th algorithm based on cells CellNN  almost ready interfaced to EMReco
- Selection of calorimeter clusters
- Ptmin > 1.5 GeV ;   e.m. fraction > 90%
- Isolation : (Etotal(cone 0.4) - Eem(cone0.2))/ Eem(cone0.2) < 0.2
- EMCluster definition            (EM1,EM2,EM3,EM4,FH1)
- CC  :  all channels in a (3x3) window
- EC  : all channels in a cone of 10 cm radius in EM3 around hottest channel in EM3
- RCP parameters
- rather independent of clustering algorithm for isolated electrons

*Serban Protopopescu*
*M.J.*

## EC electrons

- 99%

- 12.5cm

- 10cm

-  Results from  D00Kee Cho (Rochester)

## EC electrons 

-  Results from  D00Kee Cho (Rochester)

## Slide 22

## EMRECO (cont ’d)

- EMcluster position corrections (DooKee Cho)
-  CAL cell is given a weight : *w=w**0** + log(E**cell**/E**layer**)*
-      *w**0* varies for each layer
- Additional corrections depending on z and Pt   (CC),
-                                                            on  r (EC)
- EMcluster energy corrections (Serban)
- CPS :   *15.0 x E**CPS** + 0.18 GeV*
- FPS :    *15.3 x E**FPS*
- Overall correction :
*E=E/(1.3 –SQRT(0.08+0.4418/E))*

- CPS energy fraction

- DE/E uncorr

## Cluster position resolutions

- DooKee Cho

## EMRECO (cont ’d)

- Preshower matching
- input : PS 3D clusters from cal_reco and fps_reco
- select the most energetic cluster within a window :
-     x = 0.05x0.05 CPS     x = 0.1x0.1 FPS
- Track matching
- input : ChargedParticleChunk
-  P>1.5 GeV/c; x window = 0.05x0.05
- Window sizes can be reduced without loss of efficiency
- Emparticle direction and ID
- 1 - track (if it exists )direction at the vertex     electron   12
- 2 - vertex - CPS cluster direction                     photon      10
- 3 - vertex - cluster position in EM3                  photon      10

## HMRECO status

- (cvs) Package used by emreco to
- - build different flavours of H-matrices
- - calculate the covariance parameter 2 as a measure of the compatibility of the EMCluster object with an electron shower
- The choice between 1 and 2 is done by a RCP parameter in emreco
-   Emreco provides the same cluster preselection
- It uses the package hmatrix to store/read H-matrix files

*F.Touze, A. Abdesselam,M.J*.

## Available H-matrices in preco04

- Run I H matrix (41 parameters)
- Energy fractions in floors [EM1, EM2,EM4]
- Energy fractions in floor EM3 (6x6) channels
- log(Etot),Zvertex/28.
- H matrix (9 parameters)
- Energy fractions in floors [EPS,EM1, EM2, EM3,EM4]
- DETA, DRPHI in floor EM3
- log(Etot), Zvertex/28.
- Exists for 2 energy ranges : < > 30 GeV(RCP parameter)
-   2 2 values attached to each EM candidate

## Latest results with Hmatrices

- H09

- H41

- L09

- L41

- 30GeV

## Electron Likelihood

*ISNGrenoble (S.Crepé,..... )*

## E/p electron distributions

## EM ID using Neural network

*Dhiman Chakraborty*
*Supriya Jain*
*Vishnu Zutshi*

## NN vs H-matrix

## Generation of EM fake samples

- Principle is to select at the generator level jets which have a high probability to give a e/ fake at the RECO level without biasing the fake samples
*Nirmalya Parua* *(ISNG)*  : electron fakes
- ISAJET QCD events  with  em fraction > 0.65
-                                              high PT track > 1 GeV/c within
-                                              0.1 in (,) and PTjet / PTtrack  < 5
- Production at CCIN2P3(Lyon) has started
*Alex Menilchouk* *(Brown)* : electron/photon fakes
-        Pythia QCD events with a leading 0 or  (or 2 ) and
-      (Etotal(0.4)-EEM(0.2))/EEM(0.2) < 2
-      ETEM(0.2) > 6. GeV
- Alex Melnitchouk (Brown) photon fakes

## Efficiencies : mb1.1av

- CC+CC events :PYTHIA

**100%**

_**0) MC events**_

_**1**__**) after EM selection**_

_**WITHOUT EDGES**_

_**2) after EM sel.**_
_**    **__**& PS matching**_

_**3) after EM sel. **_
_**  **__**& PS match.**_
_** **__**& TRK match.**_

_**1. < |Detect. **__****__**|**_

- 99% (.992)

- 97% (.982)

- 84% (.922)

*F.Fleuret*

## Efficiencies : mb1.1av

_**2) after EM sel. **_
_**& PS matching**_

_**3) after EM sel.**_
_** **__**& PS match.**_
_** **__**& TRK match.**_

- EC+EC events : PYTHIA

**100%**

_**0) MC events**_

_**1) after EM selection**_

_**1.9 < |Detect. **__****__**| < 2.5**_

- 27%(.522)

- 75%(.872)

- 91%(.952)

*F.Fleuret*

## Slide 36

## Slide 37

## Conclusions

*D0 can trigger on electrons at high P**T** as well as on di-electrons of low P**T*
*Using calorimeter, PS and tracker electrons will be identified, and measured with high efficiency*
*Vertical Review Committee recognized that :*
*         “**The EM ID group has done a lot of very good work so far”*
*BUT still a lot of work to do .....*
* **!!!!!!!!** ** physics groups should not weaken the effort in the object ID groups** *