EMC : PHOTON STUDIES
An examination by David Hopkins of the energy resolution of the calorimeter as a photon detector using
μ^{+} μ^{} γ events.
Talks to EMC group at Wednesday meetings on:
Neutrals meeting talks:
Collaboration meeting talks:
Talk given at EMC workshop (December '04)
(pdf)
A basic overview given at the RAL Summer School, September 2004
(pdf)
Plots showing FWHMs and peak positions:
Plots showing fits from minimizing χ^{2} using method outlined in talk of 22nd June '05:
(Key: MC E_{&gamma}^{meas}/E_{&gamma}^{true},
MC/data E_{&gamma}^{meas}/E_{&gamma}^{fit},
function from minimizing χ^{2}).
Plots showing E_{&gamma}^{meas}/E_{&gamma}^{fit}, with crystal ball fits used to derive values in the parameter plots above:
Plots showing E_{&gamma}^{meas}/E_{&gamma}^{true}, with associated crystal ball fit
(ps).
Plots of response matrices used in unfolding method (ps).
Plots of E_{&gamma}^{fit}/E_{&gamma}^{true} (ps).
Some old plots comparing photon energy response:
 backwards barrel (Runs 14) (ps)
 forwards barrel (Runs 14) (ps)
 endcap (Runs 14) (ps)
 backwards barrel (Run 1) (ps)
 forwards barrel (Run 1) (ps)
 endcap (Run 1) (ps)
 backwards barrel (Run 2) (ps)
 forwards barrel (Run 2) (ps)
 endcap (Run 2) (ps)
 backwards barrel (Run 3) (ps)
 forwards barrel (Run 3) (ps)
 endcap (Run 3) (ps)
 backwards barrel (Run 4) (ps)
 forwards barrel (Run 4) (ps)
 endcap (Run 4) (ps)
(Key: Data E_{&gamma}^{meas}/E_{&gamma}^{fit},
MC E_{&gamma}^{meas}/E_{&gamma}^{fit},
MC E_{&gamma}^{meas}/E_{&gamma}^{true}.)
Note that the above plots were all produced using a cut on the photon's C of M energy at 3.0 GeV.
ROOT files containing E_{&gamma}^{meas}/E_{&gamma}^{fit} distributions and unfolded resolution functions for MC and data.
ROOT files containing (amongst other things) response matrices and E_{&gamma}^{fit}/E_{&gamma}^{true} for MC and data. Note that these latter two files were produced for use in my own macros, and as such I have stored a number of 1D histograms as part of a 2D histogram, which can be projected out using the function ProjectionX(). Contact me with any questions about using these.
Text files with output of the mean and fwhm values from this study: MC and data.
Useful note by Glen Cowan on unfolding the energy resolution (ps)
Questions or comments? Email:
dhopkins@slac.stanford.edu
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