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Release on unidentified hadrons Aug. 2011
In the following, the information needed by a newcomer to start the analysis are given.
If you think that something is missing, please feel free to add more information.
The first starting point is the
Release note
, in which a good detailed description is given.
More details and clarifications wrt release note, raisen during xchecks, are given in the following.
- Cuts: the description of the cuts is on pag 9-10
Some clarifications:
1.muon beam selection:
In CORAL, beam particles with no BMS momentum are put artificially at 160 GeV, and their error to some very big value. To remove these tracks, it was suggested to make the cut on the error and not on the momentum, so to avoid to reject tracks that by chance have momentum equal to 160 GeV. So it can be done like this:
mu0_errbeam = pow(fabs(ParamMu0.qP()),2)*sqrt(ParamMu0(5,5));
if(mu0_errbeam>4) return;
Details about this cut are here
2.scattered beam selection:
the Phast function is used in the following way: PaVertex::iMuPrim(false,true,true,false);
Details on the four switches are in Phast documentation and, e.g., in here
On top of this selection, there are the cuts x/X0<30 and χ²/ndf<10 .
3. The number of degree of freedom of the χ² of the tracks are evluated as PaTrack::NDF(), not as "NHits -5"
4. For all the tracks (hadrons, muons), the variables (momentum, χ²/ndf , etc ) are taken from the PaTPar of the track associated to the vertex.
- Bad spills/runs list used for the release : list

Note that for the release, slot 1 was used for all the periods, apart for period w27, in which slot 2 was used.
Not also that the mDST of run 86525, W31, is missing at the time of writing: use the chunks, if the mDST is still not there.
Further rejection are some triggers in week w29:
if((run>=run_start_10w29a) && (run<=run_end_10w29b))
{
if(!(((TrgMsk&8)!=0)||((TrgMsk&4)!=0)||((TrgMsk&256)!=0)) ) return 0;//select iMT OT LT
}
- Final statistics of one run of W33 (86784) : In the following, the number of events (first part ) and the number of hadrons (second part: there are 3 columns referring to all hadrons, positive hadrons, negative hadrons), after all the cuts described in the note are applied. Bad spill list applied also. The Phast version used was the 106. Please note that using the same UserEvent in different Phast version can bring different results, due to lack of backward compatibility.
Events:
|
Events |
% |
number of events |
3.6615e+07 |
1 |
BestPrimaryVertex |
3.64598e+07 |
0.995762 |
Nprim>2 && Mu beam selection |
1.07228e+07 |
0.292853 |
Cross Cell |
1.02649e+07 |
0.280346 |
In Target |
8.43779e+06 |
0.230446 |
mu prime selection |
2.14526e+06 |
0.0585895 |
Z>350 |
1.79656e+06 |
|
Q^2>1 |
208080 |
0.00568292 |
W |
168906 |
0.00461303 |
0.1<y<0.9 |
157441 |
0.0042999 |
Xbj Cut 0.003<Xbj<0.7 |
157418 |
0.00429928 |
Hadrons statistics
|
total |
h+ |
h- |
Total |
511039 |
272236 |
238803 |
Chi2 > 10 |
504066 |
268470 |
235596 |
nX0 > 10 |
502263 |
268064 |
234199 |
Zlast and Zfirst |
474031 |
253330 |
220701 |
pt > 0.1 |
410537 |
221118 |
189419 |
z < 1 |
410333 |
220997 |
189336 |
z >0.2 |
101902 |
57118 |
44784 |
- total statistics in period W33:
| h+ | h- |
W33 | 3854452 | 3036795 |
For a complete table with the statistics for each period, see pag 17 of the release note
- Asymmetries values: In these files (1D, UL ) there are the asymmetries for the W33 period, extracted with "quadrupole ratio" 1D method and with the Unbinned Likelihood method. The results for all the 2010 periods, for the 1D "double" and "quadrupole" ratio are in this tar archive. The results using a newer version of the UL wrt used in the release are in this archive
. The UL is described in details at this address
.
The numbers in the files are the variable mean value
(x, z, pt or W respectively), the asymmetries and their errors.
The Sivers asymmetries are indicated by label
names containing "sivR" (raw asymmetries)
or "siv" (final asymmetries).
Same for Collins.
The numbers of bins are the following:
const Int_t Nx = 9;
const Int_t Npt = 9;
const Int_t Nz = 8;
const Int_t Nw = 8;
The limits for the bins are as follow:
x_bin[Nx+1] = {0.003, 0.008, 0.013,0.020, 0.032, 0.050,0.080, 0.130, 0.210, 0.7};
z_bin[Nz+1] = { 0.2, 0.25, 0.3, 0.35, 0.4, 0.5, 0.65, 0.8, 1};
pt_bin[Npt+1]={0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.75, 0.9, 1.3, 1000};
w_bin[Nw+1]={5, 5.7, 7, 7.7, 8.5, 9.5, 10.5, 12, 18};
The bins used for all the samples used in the analysis, namely the samples with some kinematical cut, or for the identified hadrons, are contained in
this file.
- Final asymmetries: the final asymmetries are obtained doing the weigthed mean of the UL asymmetries from all the periods. The results can be found in Hepdata as well as in this tar archive:
Release on pions and kaons Aug. 2012
Read the release note for details and for the identification cuts used (same as for 2007 analysis).
- Rejection of runs due to RICH stability:
On top of the bad runs/spills used for the unidentified hadron analysis, also the following runs are excluded : list
--
FedericaSozzi - 2013-01-24