-- AlexanderFedotov - 26-Jan-2010

γ+jet: introductory info

Cross section

PTDRV2, p.572 (sec.E.5.4) Table E.6

To be compared to "di-jets":

CMS-NOTE-2006-042 "Jet Calibration using gamma+jet Events in the CMS Detector "

http://cdsweb.cern.ch/record/934069/files/NOTE2006_042.pdf , dom2

V.Konoplyanikov: Oct 2010 and later on

22.10.10: talk "Gamma + jet: Photon and parton PT imbalance"

The talk as given at the Forward Calibration meeting

An explanation of HCAL calibration method ("30aug06.pdf")

According to Viktor, the document is based on slides shown in a talk in Dubna given on 30aug06. Explained here is the calibration method used for 2007 calibration results shown by Victor at the Forward Calibration Meeting 22.10.10.

CMS NOTE 1999/038 E. Doroshkevich, V. Gavrilov, "Calibration of HF based on minimisation of missing Et"


mail AF -> NA,JD,VK: The discussion between VK,AF

Date: Thu, 28 Oct 2010 02:04:14 +0200 (CEST)
From: Alexander Fedotov <fedotov@mail.cern.ch>
To: "Akchurin, Nural" <nural.akchurin@ttu.edu>
Cc: Viktor Konoplianikov <kon@mail.cern.ch>, Jordan Damgov <jdamgov@fnal.gov>
Subject: The discussion between VK,AF (Re: lost connection)

On Wed, 27 Oct 2010, Akchurin, Nural wrote:

> I hope you continued the discussions. If so, can someone summarize it

Hi all,

I think I can summarize Viktor's comments on the "30aug06.pdf" document
is now a new 8-page version without some "insignificant" pages contained earlier).

Pages 4,7: presented are calibration results with a strong ET(gamma) dependence (two sets differ by selections); they are similar to the plot shown on Friday.

Page 6 (a formula above the plot to be ignored): shows the average values of ET (zero responses included) contained in an (HCAL?) eta ring (tower) for events used in a calibration. The energies are quite small. Sorry, I already forgot Viktor's comments on that.

Page 8 : the calibration is done for ET=~60 selecting only events with the jet in HE. This can be compared with the "all events" case on p.7. There is a big difference in the HB region: the corrections become few times smaller on p.8 where jets are absent and calibration is done in the HB region based on some soft stuff in the calo.

This has to demonstrate that the method may lead to an underestimation of the corrections due to inclusion of quasi-empty areas of the calo into the fit. According to Viktor, this was one of the reasons to abandon the method, and to start thinking of compact jets balancing the photon.

Now my own first toughts of this strange effect.

The question arises why does the method try to suppress the areas of soft response.
The HCAL is unlinear: the softer a probe is, the more undermeasured its energy is. Then why the method does not try to compensate for that with bigger corrections, and goes in the opposite direction?
Is it a noise response that the method suppresses?
Or, may be, it is a real soft signal, most of which is just lost under the cell threshold (of order of 1 GeV?), and only the cases where it strongly fluctuates to bigger values above the threshold, get (over)measured?

BTW, such effects may be important for any method...
I hope the answers are already known to somebody...

Cheers, Sasha

02.11.10 "HF calibration with gamma + jet" -- a doc for discussion ("kon2nov10.pdf")

02.11.10 VK -> NA,AF,JD,VG

Date: Tue, 2 Nov 2010 17:36:56 +0100
From: Viktor Konoplianikov <kon@mail.cern.ch>
To: nural.akchurin@ttuNOSPAMPLEASE.edu, fedotov@mailNOSPAMPLEASE.cern.ch, jdamgov@fnalNOSPAMPLEASE.gov,gavrilov@mail.cern.ch
Subject: gamma+jet and HF

Dear colleagues,

I suggest to look at the report of Semenov 2006:

and my new plots for diskussion: Plots are received with events of 2006.

I can count coefficients C_i on new productions or under the real data. I badly know CMSSW. I without problems will calculate C_i if to me someone makes calculation for approximately 100 000 events according slide 4 ("2th method"):
E_x^ECAL, ETAjet, E^x_1, ... E_x_41
E_y^ECAL, ETAjet, E^y_1, ... E_y_41 for |ETA_index|=1,... 41
on a format:


AF: local copies of Viktor's files:

S.Semenov, A.Ulyanov 15.09.06 "HCAL calibration using gamma+jets events"

Talk at the 11th Annual RDMS CMS Collaboration Conference : pdf , ppt

05.11.10: talk "Gamma+Jet Update: HF calibration using gamma + jet"

The talk at Forward Calibration meeting

14.11.10: a note "Calibration of the CMS forward calorimeters by physical events ("hf-cal.pdf")

17.11.10: First draft of CMS IN "HF calibration using physical processes"

The first draft was prepared for the Forw.Calibr.Meeting

"QCD Photon Status..." at QCD Meeting 26.01.10

The meeting: http://indico.cern.ch/conferenceDisplay.py?confId=76815
The report: http://indico.cern.ch/getFile.py/access?contribId=6&resId=0&materialId=slides&confId=76815
The reporter: Ted Ritchie Kolberg, ND (U.of Notre Dame)
The title: "QCD photons:status and plot proposal"

QCD Photons Meetings

see in the list of "QCD physics" meetings:

Konoplyanikov: dissertation (in russian)

Title: Использование канала "прямой фотон + струя" для установления абсолютной шкалы энергии струи на установке CMS

Original location: http://cmsdoc.cern.ch/~kon/old/dis09okt08/

Local copies:
dissertation: attachment , dom2
autoreferat: attachment , dom2



Tune Z1: R.D.Field's report to CMS 18.08.10: 1 , 2


"JETPHOX is a program to calculate the reactions h h -> gamma/hadron + jet + X. By integrating over the jet, one can get the inclusive photon/hadron cross section at NLO."

Home page:

Steering file template: jetphox_1.0/working/parameter.indat

JETPHOX based papers

EGM-10-006 Isolated Photon Reconstruction and Identification at sqrt{s}=7 TeV

The posting:

> Analysis to be presented for preapproval: EGM-10-006 Isolated Photon reconstruction and Identification at sqrt{s}=7 TeV

> Forum: Physics Announcements
> Date: Oct 22, 09:43
> From: Marco Pieri

Dear Colleagues,

The physics analysis `Isolated Photon Reconstruction and Identification at sqrt{s}=7 TeV` (CADI entry EGM-10-006) is seeking pre-approval by the EGM physics group.

The pre-approval presentation will take place on Thu, Oct 28, 2010, during the regular EGM Working meeting at 4 pm.

The corresponding documentation can be found on CADI at

For the analysis notes, due to technical reasons, it is not currently possible to link all of them from CADI, they are:

  • AN-10-268
  • AN-10-292
  • AN-10-295
  • AN-10-289

Please take them directly from iCMS page.

Best regards,
The EGM conveners: Paolo Meridiani, Marco Pieri

Topic attachments
I Attachment History Action Size Date Who Comment
PDFpdf Konoplyanikov_VF.autoreferat.pdf r1 manage 1874.5 K 2010-03-05 - 16:52 AlexanderFedotov  
PDFpdf Konoplyanikov_VF.dissertation.pdf r1 manage 6798.7 K 2010-03-05 - 16:45 AlexanderFedotov  
PDFpdf Semenov_Ulyanov.060915.HCAL_calibr_gammaJets.pdf r1 manage 1238.4 K 2010-11-02 - 22:45 AlexanderFedotov  
PowerPointppt Semenov_Ulyanov.060915.HCAL_calibr_gammaJets.ppt r1 manage 1069.0 K 2010-11-02 - 22:49 AlexanderFedotov  
PDFpdf V.Konoplianikov.30aug06.On_hcal_calibration.pdf r1 manage 208.8 K 2010-10-26 - 03:21 AlexanderFedotov  
PDFpdf V.Konoplianikov.30aug06.On_hcal_calibration.snapshot101027.pdf r1 manage 108.5 K 2010-10-27 - 23:36 AlexanderFedotov  
PDFpdf VKonoplyanikov.101102.kon2nov10.pdf r1 manage 219.0 K 2010-11-02 - 22:51 AlexanderFedotov  
Texttxt VKonoplyanikov.101102.x.dat.txt r1 manage 3.4 K 2010-11-02 - 22:55 AlexanderFedotov  
Texttxt VKonoplyanikov.101102.y.dat.txt r1 manage 3.4 K 2010-11-02 - 22:56 AlexanderFedotov  
PDFpdf VKonoplyanikov.101103_1240.kon2nov10.pdf r1 manage 252.3 K 2010-11-03 - 17:32 AlexanderFedotov  
PDFpdf VKonoplyanikov.101104_1823.kon2nov10.pdf r1 manage 285.1 K 2010-11-05 - 04:35 AlexanderFedotov  
PDFpdf VKonoplyanikov.internal_note_draft.101121_1249.in-hf.pdf r1 manage 193.8 K 2010-12-02 - 09:34 AlexanderFedotov  
PDFpdf VKonoplyanikov.note.hf-cal.101114_0855.pdf r1 manage 429.8 K 2010-11-14 - 13:08 AlexanderFedotov  
PDFpdf VKonoplyanikov.note.hf-cal.101115_1436.pdf r1 manage 240.4 K 2010-11-16 - 19:51 AlexanderFedotov  
Unknown file formatindat jetphox_1.0.parameter.indat r1 manage 17.0 K 2010-06-01 - 16:36 AlexanderFedotov  
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