Changes between Initial Version and Version 1 of ExampleEEWW

Timestamp:

May 20, 2010, 5:46:35 PM (15 years ago)

Author:

Juergen Reuter

Comment:

--

ExampleEEWW

@@ +1 @@
+Define and compile the process
+
+{{{
+model = SM
+process eeww = "e+", "e-" => "W+", "W-"
+compile
+}}}
+
+Define the beams and event count (for simulation)
+
+{{{
+sqrts = 200 GeV
+beams = "e+", "e-"
+n_events = 100000
+}}}
+
+Tell WHIZARD to retain the W polarization in the generated events
+
+{{{
+polarized "W+", "W-"
+}}}
+
+Loop over e+ / e- helicity (explanations as comments inside the code)
+
+{{{
+scan int hel_ep = (-1, 1) {
+  scan int hel_em = (-1, 1) {
+    # Apply the helicity setup
+    beam_polarization = diagonal_density (hel_ep:1), diagonal_density (hel_em:1)
+
+    # (Re)calculate the integral for each initial state polarization
+    integrate (eeww)
+
+    # Define histograms for all different final state helicies. We
+    # have to automatically generate tags from the initial state
+    # helicites
+    string $hist_mm = sprintf "cta%i_%i_-1_-1" (hel_ep, hel_em)
+    histogram $hist_mm (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i -1 -1" (hel_ep, hel_em)
+    }
+    string $hist_ml = sprintf "cta%i_%i_-1_0" (hel_ep, hel_em)
+    histogram $hist_ml (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i -1  0" (hel_ep, hel_em)
+    }
+    string $hist_mp = sprintf "cta%i_%i_-1_1" (hel_ep, hel_em)
+    histogram $hist_mp (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i -1  1" (hel_ep, hel_em)
+    }
+    string $hist_lm = sprintf "cta%i_%i_0_-1" (hel_ep, hel_em)
+    histogram $hist_lm (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i  0 -1" (hel_ep, hel_em)
+    }
+    string $hist_ll = sprintf "cta%i_%i_0_0" (hel_ep, hel_em)
+    histogram $hist_ll (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i  0  0" (hel_ep, hel_em)
+    }
+    string $hist_lp = sprintf "cta%i_%i_0_1" (hel_ep, hel_em)
+    histogram $hist_lp (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i  0  1" (hel_ep, hel_em)
+    }
+    string $hist_pm = sprintf "cta%i_%i_1_-1" (hel_ep, hel_em)
+    histogram $hist_pm (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i  1 -1" (hel_ep, hel_em)
+    }
+    string $hist_pl = sprintf "cta%i_%i_1_0" (hel_ep, hel_em)
+    histogram $hist_pl (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i  1  0" (hel_ep, hel_em)
+    }
+    string $hist_pp = sprintf "cta%i_%i_1_1" (hel_ep, hel_em)
+    histogram $hist_pp (-1, 1, 0.1) {
+      $title = sprintf "polarization: %i %i  1  1" (hel_ep, hel_em)
+    }
+    # The analysis setup fills the different histograms
+    analysis =
+      if (all Hel == -1 ["W+"] and all Hel == -1 ["W-"] ) then 
+        record $hist_mm (eval cos (Theta) ["W+"])
+      endif; if (all Hel == -1 ["W+"] and all Hel ==  0 ["W-"] ) then
+        record $hist_ml (eval cos (Theta) ["W+"])
+      endif; if (all Hel == -1 ["W+"] and all Hel ==  1 ["W-"] ) then
+        record $hist_mp (eval cos (Theta) ["W+"])
+      endif; if (all Hel ==  0 ["W+"] and all Hel == -1 ["W-"] ) then
+        record $hist_lm (eval cos (Theta) ["W+"])
+      endif; if (all Hel ==  0 ["W+"] and all Hel ==  0 ["W-"] ) then
+        record $hist_ll (eval cos (Theta) ["W+"])
+      endif; if (all Hel ==  0 ["W+"] and all Hel ==  1 ["W-"] ) then
+        record $hist_lp (eval cos (Theta) ["W+"])
+      endif; if (all Hel ==  1 ["W+"] and all Hel == -1 ["W-"] ) then
+        record $hist_pm (eval cos (Theta) ["W+"])
+      endif; if (all Hel ==  1 ["W+"] and all Hel ==  0 ["W-"] ) then
+        record $hist_pl (eval cos (Theta) ["W+"])
+      endif; if (all Hel ==  1 ["W+"] and all Hel ==  1 ["W-"] ) then
+        record $hist_pp (eval cos (Theta) ["W+"])
+      endif
+
+    # Generate events (keep the helicity information). As this takes
+    # some time, we request status information.
+    simulate (eeww) {
+      ?polarized_events = true
+      checkpoint = 10000
+    }
+  }
+}
+
+}}}
+
+Write out the generated histograms in eeww_polarized.ps / eeww_polarized.pdf
+
+{{{
+$analysis_filename = "eeww_polarized"
+write_analysis
+}}}