Changes between Version 2 and Version 3 of ExampleCascadeDecays

Timestamp:

Apr 12, 2010, 10:16:11 AM (15 years ago)

Author:

ohl

Comment:

--

ExampleCascadeDecays

@@ +1 @@
+Select the minimal supersymmetric standard model
 {{{
 model = MSSM
 }}}
+and consider a decay cascade of up-squarks into neutralinos and selectrons
 {{{
 process dec_su_q        = su1 => u, neu2
 process dec_neu_sl2     = neu2 => SE12, e1
 }}}
+where the up-squark pairs are generated from up quarks
 {{{
 process susybg = u,U => SU1, su1
+}}}
+We will compare the results with the full process including all irreducible backgrounds
+{{{
 process full = u, U => SU1, u, e1, SE12
 }}}
+Call O'Mega and compile the matrix elements
 {{{
 compile
 }}}
+We use the SLHA convention to choose the SPS1a parameter point
 {{{
 ?slha_read_decays = true
 read_slha("sps1ap_decays.slha")
 }}}
+Obtain the total widths (simple integration, no singularities, not too many points required)
 {{{
 integrate (dec_su_q, dec_neu_sl2) { iterations = 1:1000 }
 }}}
+We're at the full energy LHC
 {{{
 sqrts = 14000
 beams = p, p => lhapdf
 }}}
+Obtain the up-squark production cross section and the cross section for full process
 {{{
 integrate (susybg) { iterations = 5:10000, 2:10000 }
 integrate (full)
 }}}
+Simulate 10K events
 {{{
 n_events = 10000
 }}}
+Allocate histograms
 {{{
 $title = "Full process"
@@ -53 +66 @@
 histogram inv_mass1_iso (0,600,20)
 }}}
+Simulate the full process
 {{{
 simulate (full) {
@@ -60 +74 @@
 }
 }}}
+Simulate the cascade decay, including all off-diagonal spin correlations
 {{{
 unstable neu2 (dec_neu_sl2)
@@ -70 +85 @@
 }
 }}}
+Simulate the cascade decay, keeing only the classical (diagonal) spin correlations
 {{{
 ?diagonal_decay = true
@@ -80 +96 @@
 }
 }}}
+Simulate the cascade decay, dropping all spin correlations (i.e. assume isotropic decays)
 {{{
 ?isotropic_decay = true
@@ -90 +107 @@
 }
 }}}
+Write the results to file
 {{{
-write_analysis
 $analysis_filename = "casc_dec"
 write_analysis