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LHCb/FAQ Web>BenderFAQ (2009-12-10, VanyaBelyaev) (raw view)

---+!! Bender  F.A.Q.

This page will be populated with Frequently Asked Questions concerning [[http://web.cern.ch/LHCb-release-area/DOC/bender/][Bender]] project.

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---++ Add your own Question

Did you not find the answer you were looking for? If not please submit your question here.

%COMMENT{target="UserFAQ"}%

Current user-submitted FAQ's can be found [[UserFAQ][here]]

---++ Can Bender be used for analysis of REAL data ?

Yes! From the version [[http://cern.ch/LHCb-release-area/DOC/bender/releases/v12r5/][v12r5]] Bender really can be used for analysis of real data!

---+++ Beam-Gas events versus pp-Collisions 


The script [[%ATTACHURLPATH%/FirstRealData.py.txt][FirstRealData.py]] demonstrates that the summed transverse energy in Ecal allows to discriminate beam-gas events with respect to events with pp-collision.
E.g. the plot shows "zPoca" distributions for Collision/BeamGas events (similar to the original plots by Wouter & Juan):

%IMAGE{"%ATTACHURLPATH%/no-cuts.gif" size ="500" align="center"}%

The same distribution for events with  <latex>\Sigma_{i}  E^T \ge 3~GeV</latex>: one clearly sees the reduction of 'beam-gas' component:

%IMAGE{"%ATTACHURLPATH%/etEcal_gt_3.gif" size ="500" align="center"}%


The same distribution for events with  <latex>\Sigma_{i}  E^T \le 1~GeV</latex>: one clearly sees the reduction of 'collision' component:

%IMAGE{"%ATTACHURLPATH%/etEcal_lt_1.gif" size ="500" align="center"}%

---+++ Real <latex>\pi^0\to\gamma\gamma</latex>

Using the attched Bender script [[%ATTACHURLPATH%/RealPi0.py.txt][RealPi0.py]]
one can easily produce the plot for "the first real  <latex>\pi^0</latex>":
 
%IMAGE{"%ATTACHURLPATH%/new_pi0.gif" size ="500" align="center"}%

Add a cut on the transverse momentum: 

%IMAGE{"%ATTACHURLPATH%/pi0_PT_gt_400.gif" size ="500" align="center"}%

Use Spd/Prs infomration  (no Spd hits, and require some energy Prs):

%IMAGE{"%ATTACHURLPATH%/new_pi0_spdprs.gif" size ="500" align="center"}%



---+++ Real mip peak 

Using the attched Bender script [[%ATTACHURLPATH%/RealMip.py.txt][RealMip.py]]
one can easily produce the plot for "mip signal in Ecal" :
 
%IMAGE{"%ATTACHURLPATH%/Mip.gif" size ="500" align="center"}%

Changing the scale and adding comparison with Monte Carlo for 450 GeV pp-collisions (BLUE histogram)  one gets the following  plot, where data correspond to RED histogram: 

%IMAGE{"%ATTACHURLPATH%/mip2.gif" size ="500" align="center"}%


---+++ E/P in Ecal

The same Bender script [[%ATTACHURLPATH%/RealMip.py.txt][RealMip.py]]
can be used to produce E/P-ratio for tracks (thanks to Victor Egorychev):  


%IMAGE{"%ATTACHURLPATH%/EoverP.jpg" size ="500" align="center"}%

The "bump" sits at ~ 0.71, but if one re-uses the scaling coefficient from  the previous plot ( the ratio of mip-peaks in DATA/MC) one gets following "energy  corrected" plot:, where the bump sits at ~0.94:


 %IMAGE{"%ATTACHURLPATH%/EoverP_corr.jpg" size ="500" align="center"}%




-- [[Main.VanyaBelyaev][Vanya Belyaev]] - 26-Nov-2009

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who
jpg	EoverP.jpg	r1	manage	160.3 K	2009-12-10 - 09:21	VanyaBelyaev
jpg	EoverP_corr.jpg	r1	manage	154.6 K	2009-12-10 - 09:23	VanyaBelyaev
txt	FirstRealData.py.txt	r1	manage	11.7 K	2009-12-10 - 09:39	VanyaBelyaev
gif	Mip.gif	r1	manage	9.2 K	2009-12-10 - 09:08	VanyaBelyaev
txt	RealMip.py.txt	r1	manage	12.2 K	2009-12-10 - 09:08	VanyaBelyaev
txt	RealPi0.py.txt	r1	manage	7.9 K	2009-12-09 - 21:42	VanyaBelyaev
gif	etEcal_gt_3.gif	r1	manage	9.9 K	2009-12-10 - 09:31	VanyaBelyaev
gif	etEcal_lt_1.gif	r1	manage	13.4 K	2009-12-10 - 09:32	VanyaBelyaev
gif	mip2.gif	r1	manage	9.8 K	2009-12-10 - 09:07	VanyaBelyaev
gif	new_pi0.gif	r1	manage	9.8 K	2009-12-09 - 21:41	VanyaBelyaev
gif	new_pi0_spdprs.gif	r1	manage	12.6 K	2009-12-09 - 21:41	VanyaBelyaev
gif	no-cuts.gif	r1	manage	9.9 K	2009-12-10 - 09:32	VanyaBelyaev
gif	pi0_PT_gt_400.gif	r1	manage	9.6 K	2009-12-09 - 21:41	VanyaBelyaev

Topic revision: r6 - 2009-12-10 - VanyaBelyaev

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