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2\section{Input\label{INPUT}}
3
4\subsection{Input Format}
5
6 ISAJET is controlled by commands read from the specified input
7file by subroutine READIN. (In the interactive version, this file is
8first created by subroutine DIALOG.) Syntax errors will generate a
9message and stop execution. Based on these commands, subroutine LOGIC
10will setup limits for all variables and check for inconsistencies.
11Several runs with different parameters can be combined into one job.
12The required input format is:
13\begin{verbatim}
14Title
15Ecm,Nevent,Nprint,Njump/
16Reaction
17(Optional parameters)
18END
19(Optional additional runs)
20STOP
21\end{verbatim}
22with all lines starting in column 1 and typed in {\it upper} case. These
23lines are explained below.
24
25 Title line: Up to 80 characters long. If the first four letters
26are STOP, control is returned to main program. If the first four letters
27are SAME, the parameters from previous run are used excepting those
28which are explicitly changed.
29
30 Ecm line: This line must always be given even if the title is
31SAME. It must give the center of mass energy (Ecm) and the number of
32events (Nevent) to be generated. One may also specify the number of
33events to be printed (Nprint) and the increment (Njump) for printing.
34The first event is always printed if Nprint $>$ 0. For example:
35\begin{verbatim}
36800.,1000,10,100/
37\end{verbatim}
38generates 1000 events at $E_{\rm cm} = 800\,\GeV$ and prints 10
39events. The events printed are: 1,100,200,\dots. Note that an event
40typically takes several pages of output. This line is read with a list
41directed format (READ*).
42
43 After Nprint events have been printed, a single line containing the
44run number, the event number, and the random number seed is printed
45every Njump events (if Njump is nonzero). This seed can be used to start
46a new job with the given event if in the new run NSIGMA is set equal to
47zero:
48\begin{verbatim}
49SEED
50value/
51NSIGMA
520/
53\end{verbatim}
54In general the same events will only be generated on the same type of
55computer.
56
57 Reaction line: This line must be given unless title is SAME, when
58it must be omitted. It selects the type of events to be generated. The
59present version can generate TWOJET, E+E-, DRELLYAN, MINBIAS, WPAIR,
60SUPERSYM, HIGGS, PHOTON, TCOLOR, or WHIGGS events. This line is read
61with an A8 format.
62
63\subsection{Optional Parameters}
64
65 Each optional parameter requires two lines.
66The first line is a keyword specifying the parameter and the second
67line gives the values for the parameter. The parameters can be given in
68any order. Numerical values are read with a list directed format
69(READ*), jet and particle types are read with a character format and
70must be enclosed in quotes, and logical flags with an L1 format. All
71momenta are in GeV and all angles are in radians.
72
73 The parameters can be classified in several groups:
74\begin{center}
75\begin{tabular}{lllll}
76\hline\hline
77Jet Limits: & W/H Limits: & Decays: & Constants: & Other: \\
78\hline
79JETTYPE1 & HTYPE & FORCE & AMSB & BEAMS \\
80JETTYPE2 & PHIW & FORCE1 & CUTJET & EPOL \\
81JETTYPE3 & QMH & NODECAY & CUTOFF & EEBEAM \\
82MIJLIM & QMW & NOETA & EXTRAD & EEBREM \\
83MTOT & QTW & NOEVOLVE & FRAGMENT & NPOMERON \\
84P & THW & NOFRGMNT & GAUGINO & NSIGMA \\
85PHI & WTYPE & NOGRAV & GMSB & NTRIES \\
86PT & XW & NOPI0 & GMSB2 & PDFLIB \\
87TH & YW & & HMASS & SEED \\
88X & & & HMASSES & STRUC \\
89Y & & & LAMBDA & WFUDGE \\
90WMODE1 & & & MGVTNO & WMMODE \\
91WMODE2 & & & MSSMA & WPMODE \\
92 & & & MSSMB & Z0MODE \\
93 & & & MSSMC & \\
94 & & & MSSMD & \\
95 & & & MSSME & \\
96 & & & NUSUG1 & \\
97 & & & NUSUG2 & \\
98 & & & NUSUG3 & \\
99 & & & NUSUG4 & \\
100 & & & NUSUG5 & \\
101 & & & SIGQT & \\
102 & & & SIN2W & \\
103 & & & SLEPTON & \\
104 & & & SQUARK & \\
105 & & & SSBCSC & \\
106 & & & SUGRA & \\
107 & & & SUGRHN & \\
108 & & & TCMASS & \\
109 & & & TMASS & \\
110 & & & WMASS & \\
111\hline\hline
112\end{tabular}
113\end{center}
114
115 It may be helpful to know that the TWOJET, WPAIR, PHOTON,
116SUPERSYM, and WHIGGS processes use the same controlling routines and
117so share many of the same variables. In particular, PT limits should
118normally be set for these processes, and JETTYPE1 and JETTYPE2 are
119used to select the reactions. Similarly, the DRELLYAN, HIGGS, and
120TCOLOR processes use the same controlling routines since they all
121generate s-channel resonances. The mass limits for these processes are
122set by QMW. Normally the QMW limits will surround the $W^\pm$, $Z^0$,
123or Higgs mass, but this is not required. (QMH acts like QMW for the
124Higgs process.) For historical reasons, JETTYPE1 and JETTYPE2 are used
125to select the W decay modes in DRELLYAN, while WMODE1 and WMODE2 select
126the W decay modes for WPAIR, HIGGS, and WHIGGS. Also, QTW can be used
127to generate DRELLYAN events with non-zero transverse momentum, whereas
128HIGGS automatically fixes QTW to be zero. (Of course, non-zero
129transverse momentum will be generated by gluon radiation.)
130
131 For example the lines
132\begin{verbatim}
133P
13440.,50.,10.,100./
135\end{verbatim}
136would set limits for the momentum of jet 1 between 40 and 50 GeV, and
137for jet 2 between 10 and 100 GeV. As another example the lines
138\begin{verbatim}
139WTYPE
140'W+'/
141\end{verbatim}
142would specify that for DRELLYAN events only W+ events will be generated.
143If for a kinematic variable only the lower limit is specified then that
144parameter is fixed to the given value. Thus the lines
145\begin{verbatim}
146P
14740.,,10./
148\end{verbatim}
149will fix the momentum for jet 1 to be 40 GeV and for jet 2 to be 10
150GeV. If only the upper limit is specified then the default value is used
151for the lower limit. Jet 1 or jet 2 parameters for DRELLYAN events refer
152to the W decay products and cannot be fixed. If QTW is fixed to 0, then
153standard Drell-Yan events are generated.
154
155 A complete list of keywords and their default values follows.
156
157\newpage
158\begin{center}
159\begin{tabular}{lll}
160\hline\hline
161Keyword & & Explanation \\
162Values & Default values & \\
163\hline
164AMSB & & Anomaly-mediated SUSY breaking \\
165$m_0$,$m_{3/2}$,$\tan\beta$,$\sgn\mu$ & none & scalar mass, gravitino mass, \\
166 & & VEV ratio, sign \\
167 & & \\
168BEAMS & & Initial beams. Allowed are \\
169type$_1$,type$_2$ & 'P','P' & 'P','AP','N','AN'. \\
170 & & \\
171CUTJET & & Cutoff mass for QCD jet \\
172$\mu_c$ & 6. & evolution. \\
173 & & \\
174CUTOFF & & Cutoff $qt^2=\mu^2Q^\nu$ for \\
175$\mu^2$, $\nu$ & .200,1.0 & DRELLYAN events. \\
176 & & \\
177EEBEAM & & impose brem/beamstrahlung \\
178$\sqrt{\hat{s}}_{min}$, $\sqrt{\hat{s}}_{max}$, $\Upsilon$, $\sigma_z$ &
179none & min and max subprocess energy, \\
180 & & beamstrahlung parameter $\Upsilon$ \\
181 & & longitudinal beam size $\sigma_z$ in mm \\
182 & & \\
183EEBREM & & impose bremsstrahlung for $e^+e^-$ \\
184$\sqrt{\hat{s}}_{min}$, $\sqrt{\hat{s}}_{max}$ & none & min and max subprocess
185energy \\
186 & & \\
187EPOL & & Polarization of $e^-$ ($e^+$) beam, \\
188$P_L(e^-),P_L(e^+)$ & 0,0 & $P_L(e)=(n_L-n_R)/(n_L-n_R)$, \\
189 & & so that $-1 \le P_L \le 1$ \\
190 & & \\
191EXTRAD & & Parameters for EXTRADIM process\\
192$\delta$,$M_D$,UVCUT & None & UVCUT is logical flag \\
193 & & \\
194FORCE & & Force decay of particles, \\
195$i,i_1,...,i_5$/ & None & $\pm i \to \pm(i1+...+i5)$. \\
196 & & Can call 20 times. \\
197 & & See note for $i$ = quark. \\
198 & & \\
199FORCE1 & & Force decay $i \to i1+...+i5$. \\
200$i,i_1,...,i_5$/ & None & Can call 40 times. \\
201 & & See note for $i$ = quark. \\
202 & & \\
203FRAGMENT & & Fragmentation parameters. \\
204$P_{ud}$,\dots & .4,\dots & See also SIGQT, etc. \\
205 & & \\
206GAUGINO & & Masses for $\tilde g$,
207$\tilde\gamma$, \\
208$m_1$,$m_2$,$m_3,m_4$ & 50,0,100,100 & $\tilde W^+$, and $\tilde Z^0$ \\
209\hline\hline
210\end{tabular}
211\end{center}
212
213\newpage
214\begin{center}
215\begin{tabular}{lll}
216\hline\hline
217GMSB & & GMSB messenger SUSY breaking, \\
218$\Lambda_m$,$M_m$,$N_5$ & none & mass, number of $5+\bar5$, VEV \\
219$\tan\beta$,$\sgn\mu$,$C_{\rm gr}$ & & ratio, sign, gravitino scale \\
220 & & \\
221GMSB2 & & non-minimal GMSB parameters \\
222$\slashchar{R}$,$\delta M_{H_d}^2$,$\delta M_{H_u}^2$,$D_Y(M)$ & 1,0,0,0 &
223gaugino mass multiplier \\
224$N_{5_1}$,$N_{5_2}$,$N_{5_3}$ & $N_5$ & Higgs mass shifts, D-term mass$^2$\\
225 & & indep. gauge group messengers \\
226 & & \\
227HMASS & 0 & Mass for standard Higgs. \\
228$m$ & & \\
229 & & \\
230HMASSES & & Higgs meson masses for \\
231$m_1$,\dots,$m_9$ & 0,...,0 & charges 0,0,0,0,0,1,1,2,2. \\
232HTYPE & & One MSSM Higgs type ('HL0', \\
233'HL0'/ or... & none & 'HH0', or 'HA0') \\
234 & & \\
235JETTYPE1 & & )Select types for jets: \\
236'GL','UP',... & 'ALL' & )'ALL'; 'GL'; 'QUARKS'='UP', \\
237 & & )'UB','DN','DB','ST','SB', \\
238JETTYPE2 & & )'CH','CB','BT','BB','TP', \\
239'GL','UP',... & 'ALL' & )'TB','X','XB','Y','YB'; \\
240 & & )'LEPTONS'='E-','E+','MU-', \\
241JETTYPE3 & & )'MU+','TAU-','TAU+'; 'NUS'; \\
242'GL','UP',... & 'ALL' & )'GM','W+','W-','Z0' \\
243 & & ) See note for SUSY types. \\
244 & & \\
245LAMBDA & & QCD scale \\
246$\Lambda$ & .2 & \\
247 & & \\
248MGVTNO & & Gravitino mass -- ignored for \\
249$M_{\rm gravitino}$ & $10^{20}$~GeV & GMSB model \\
250 & & \\
251MIJLIM & & Multimet mass limits \\
252$i$,$j$,$M_{\rm min}$,$M_{\rm max}$ & 0,0,$1\,\GeV$,$1\,\GeV$ & \\
253 & & \\
254MSSMA & & MSSM parameters -- \\
255$m(\tilde g)$,$\mu$, & Required & Gluino mass, $\mu$, $A$ mass, \\
256$m(A)$,$\tan\beta$ & & $\tan\beta$ \\
257 & & \\
258MSSMB & & MSSM 1st generation -- \\
259$m(q_1)$,$m(d_r)$,$m(u_r)$, & Required & Left and right soft squark and \\
260$m(l_1)$,$m(e_r)$ & & slepton masses \\
261\hline\hline
262\end{tabular}
263\end{center}
264
265\newpage
266\begin{center}
267\begin{tabular}{lll}
268\hline\hline
269MSSMC & & MSSM 3rd generation -- \\
270$m(q_3)$,$m(b_r)$,$m(t_r)$, & Required & Soft squark masses, slepton \\
271$m(l_3)$,$m(\tau_r)$, & & masses, and squark and slepton \\
272$A_t$,$A_b$,$A_\tau$ & & mixings \\
273 & & \\
274MSSMD & & MSSM 2nd generation -- \\
275$m(q_2)$,$m(s_r)$,$m(c_r)$, & from MSSMB & Left and right soft squark and \\
276$m(l_2)$,$m(mu_r)$ & & slepton masses \\
277 & & \\
278MSSME & & MSSM gaugino masses -- \\
279$M_1$,$M_2$ & MSSMA + GUT & Default is to scale from gluino\\
280 & & \\
281MTOT & & Mass range for multiparton \\
282$M_{\rm min}$,$M_{\rm max}$ & None & processes \\
283 & & \\
284NODECAY & & Suppress all decays. \\
285TRUE or FALSE & FALSE & \\
286 & & \\
287NOETA & & Suppress eta decays. \\
288TRUE or FALSE & FALSE & \\
289
290NOEVOLVE & & Suppress QCD evolution and \\
291TRUE or FALSE & FALSE & hadronization. \\
292 & & \\
293NOGRAV & & Suppress gravitino decays in \\
294TRUE or FALSE & FALSE & GMSB model \\
295 & & \\
296NOHADRON & & Suppress hadronization of \\
297TRUE or FALSE & FALSE & jets and beam jets. \\
298 & & \\
299NONUNU & & Suppress $Z^0$ neutrino decays.\\
300TRUE or FALSE & FALSE & \\
301 & & \\
302NOPI0 & &Suppress $\pi^0$ decays. \\
303TRUE or FALSE & FALSE & \\
304 & & \\
305NPOMERON & & Allow $n_1<n<n_2$ cut pomerons.\\
306$n_1$,$n_2$ & 1,20 & Controls beam jet mult. \\
307 & & \\
308NSIGMA & & Generate n unevolved events \\
309$n$ & 20 & for SIGF calculation. \\
310 & & \\
311NTRIES & & Stop if after n tries \\
312$n$ & 1000 & cannot find a good event. \\
313\hline\hline
314\end{tabular}
315\end{center}
316
317\newpage
318\begin{center}
319\begin{tabular}{lll}
320\hline\hline
321NUSUG1 & & Optional non-universal SUGRA \\
322$M_1$,$M_2$,$M_3$ & none & gaugino masses \\
323 & & \\
324NUSUG2 & & Optional non-universal SUGRA \\
325$A_t$,$A_b$,$A_\tau$ & none & $A$ terms \\
326 & & \\
327NUSUG3 & & Optional non-universal SUGRA \\
328$M_{H_d}$,$M_{H_u}$ & none & Higgs masses \\
329 & & \\
330NUSUG4 & & Optional non-universal SUGRA \\
331$M_{u_L}$,$M_{d_R}$,$M_{u_R}$, & none & 1st/2nd generation masses \\
332$M_{e_L}$,$M_{e_R}$ & & \\
333 & & \\
334NUSUG5 & & Optional non-universal SUGRA \\
335$M_{t_L}$,$M_{b_R}$,$M_{t_R}$, & none & 3rd generation masses \\
336$M_{\tau_L}$,$M_{\tau_R}$ & & \\
337 & & \\
338P & & Momentum limits for jets. \\
339$p_{\rm min}(1)$,\dots,$p_{\rm max}(3)$ &
3401.,$0.5E_{\rm cm}$ & \\
341 & & \\
342PDFLIB & & CERN PDFLIB parton distribution\\
343'name$_1$',val$_1$,\dots & None & parameters. See PDFLIB manual. \\
344 & & \\
345PHI & & Phi limits for jets. \\
346$\phi_{\rm min}(1)$,\dots,$\phi_{\rm max}(3)$ & 0,$2\pi$ & \\
347 & & \\
348PHIW & & Phi limits for W. \\
349$\phi_{\rm min}$,$\phi_{\rm max}$ &
3500,$2\pi$ & \\
351 & & \\
352PT or PPERP & & $p_t$ limits for jets. \\
353$p_{t,{\rm min}}(1)$,\dots,$p_{t,{\rm max}}(3)$ &
354$.05E_{\rm cm}$,$.2E_{\rm cm}$ & Default for TWOJET only. \\
355 & & \\
356QMH & & Mass limits for Higgs. \\
357$q_{\rm min}$,$q_{\rm max}$ &
358$.05E_{\rm cm}$,$.2E_{\rm cm}$ & Equivalent to QMW. \\
359 & & \\
360QMW & & Mass limits for $W$. \\
361$q_{\rm min}$,$q_{\rm max}$ &
362$.05E_{\rm cm}$,$.2E_{\rm cm}$ & \\
363 & & \\
364QTW & & $q_t$ limits for $W$. Fix
365$q_t=0$ \\
366$q_{t,{\rm min}}$,$q_{t,{\rm max}}$ &
367.1,$.025E_{\rm cm}$ & for standard Drell-Yan. \\
368 & & \\
369SEED & & Random number seed (double \\
370real & 0 & precision if 32 bit). \\
371\hline\hline
372\end{tabular}
373\end{center}
374
375\newpage
376\begin{center}
377\begin{tabular}{lll}
378\hline\hline
379SIGQT & & Internal $k_t$ parameter for \\
380$\sigma$ & .35 & jet fragmentation. \\
381 & & \\
382SIN2W & & Weinberg angle. See WMASS. \\
383$\sin^2(\theta_W)$ & .232 & \\
384 & & \\
385SLEPTON & & Masses for $\tilde \nu_e$,
386$\tilde e$, $\tilde\nu_\mu$, $\tilde\mu$, $\tilde\nu_\tau$, $\tilde\tau$ \\
387$m_1$,\dots,$m_6$ & 100,\dots,101.8 & \\
388 & & \\
389SQUARK & & Masses for $\tilde u$,
390$\tilde d$, $\tilde s$, $\tilde c$, $\tilde b$, $\tilde t$ \\
391$m_1$,\dots,$m_6$ & 100.3,...,240. & \\
392 & & \\
393SSBCSC & & Alternate mass scale for RGE \\
394$M$ & $M_{GUT}$ & boundary conditions. \\
395 & & \\
396STRUC & & Structure functions. CTEQ3L, \\
397name & 'CTEQ3L' & CTEQ2L, EHLQ, OR DO \\
398 & & \\
399SUGRA & & Minimal supergravity parameters\\
400$m_0$,$m_{1/2}$,$A_0$, & none & scalar M, gaugino M, trilinear \\
401$\tan\beta$,$\sgn\mu$ & & breaking term, vev ratio, +-1 \\
402TH or THETA & & Theta limits for jets. Do not \\
403$\theta_{\rm min}(1)$,\dots,$\theta_{\rm max}(3)$ & 0,$\pi$ & also set Y. \\
404 & & \\
405SUGRHN & & SUGRA see-saw $\nu$-effect \\
406$m_{\nu_\tau}$,$M_N$,$A_n$,$m_{\tilde\nu_R}$ & $0,1E20,0,0$ & nu-mass,
407int. scale, \\
408 & & GUT scale nu SSB terms \\
409 & & \\
410THW & & Theta limits for W. Do not \\
411$\theta_{\rm min}$,$\theta_{\rm max}$ & 0,$\pi$ & also set YW. \\
412 & & \\
413TCMASS & & Technicolor mass and width. \\
414$m$,$\Gamma$ & 1000,100 & \\
415 & & \\
416TMASS & & t, y, and x quark masses. \\
417$m_t$,$m_y$,$m_x$ & 180.,-1.,-1. & \\
418 & & \\
419WFUDGE & & Fudge factor for DRELLYAN \\
420factor & 1.85 & evolution scale. \\
421 & & \\
422WMASS & & W and Z masses. See SIN2W. \\
423$M_W$,$M_Z$ & 80.2, 91.19 & \\
424\hline\hline
425\end{tabular}
426\end{center}
427
428\newpage
429\begin{center}
430\begin{tabular}{lll}
431\hline\hline
432WMMODE & & Decay modes for $W^-$ in parton\\
433'UP',\dots,'TAU+' & 'ALL' & cascade. See JETTYPE. \\
434 & & \\
435WMODE1 & & ) \\
436'UP','UB',\dots & 'ALL' & )Decay modes for WPAIR. \\
437 & & )Same code for quarks and \\
438WMODE2 & & )leptons as JETTYPE. \\
439'UP','UB',\dots & 'ALL' & ) \\
440 & & \\
441WPMODE & & Decay modes for $W^+$ in parton\\
442'UP',\dots,'TAU+' & 'ALL' & cascade. See JETTYPE. \\
443 & & \\
444WTYPE & & Select W type: W+,W-,GM,Z0. \\
445type$_1$,type$_2$ & 'GM','Z0' & Do not mix W+,W- and GM,Z0. \\
446 & & \\
447X & & Feynman x limits for jets. \\
448$x_{\rm min}(1)$,\dots,$x_{\rm max}(3)$ &
449$-1$,1 & \\
450 & & \\
451XGEN & & Jet fragmentation, Peterson \\
452a(1),\dots,a(8) & .96,3,0,.8,.5,... & with $\epsilon=a(n)/m^2$,
453$n=4$-8. \\
454 & & \\
455XGENSS & & Fragmentation of GLSS, UPSS, \\
456a(1),\dots,a(7) & .5,.5,... & etc. with $\epsilon=a(n)/m**2$ \\
457 & & \\
458XW & & Feynman x limits for W. \\
459$x_{\rm min}$,$x_{\rm max}$ &
460$-1$,1 & \\
461 & & \\
462Y & & Y limits for each jet. \\
463$y_{\rm min}(1)$,\dots,$y_{\rm max}(3)$ & from PT & Do not also set TH. \\
464 & & \\
465YW & & Y limits for W. \\
466$y_{\rm min}$,$y_{\rm max}$ & from QTW,QMW & Do not set both YW and THW. \\
467 & & \\
468Z0MODE & & Decay modes for $Z^0$ in parton\\
469'UP',\dots,'TAU+' & 'ALL' & cascade. See JETTYPE. \\
470\hline\hline
471\end{tabular}
472\end{center}
473
474\newpage
475\subsection{Kinematic and Parton-type Parameters}
476
477 While the TWOJET PT limits and the DRELLYAN QMW limits are
478formally optional parameters, they are set by default to be fractions of
479$\sqrt{s}$. Thus, for example, the parameter file
480\begin{verbatim}
481DEFAULT TWOJET JOB
48214000,100,1,100/
483TWOJET
484END
485STOP
486\end{verbatim}
487will execute, but it will generate jets between 5\% and 20\% of
488$\sqrt{s}$, which is probably not what is wanted. Similarly, the
489parameter file
490\begin{verbatim}
491DEFAULT DRELLYAN JOB
49214000,100,1,100/
493DRELLYAN
494END
495STOP
496\end{verbatim}
497will generate $\gamma + Z$ events with masses between 5\% and 20\% of
498$\sqrt{s}$, not masses around the $Z$ mass, and transverse momenta
499between $1\,{\rm GeV}$ and 2.5\% of $\sqrt{s}$.
500
501 Normally the user should set PT limits for TWOJET, PHOTON, WPAIR,
502SUPERSYM, and WHIGGS events and QMW and QTW limits for DRELLYAN,
503HIGGS, and TCOLOR events. If these limits are not set, they will be
504selected as fractions of $E_{\rm cm}$. This can give nonsense. For
505TWOJET the $p_t$ range should usually be less than about a factor of
506two except for $b$ and $t$ jets at low $p_t$ to produce uniform
507statistics. For $W^+$, $W^-$, or $Z^0$ events or for Higgs events the
508QMW (QMH) range should usually include the mass. But one can select
509different limits to study, e.g., virtual $W$ production or the effect
510of a lighter or heavier Higgs on WW scattering. If only $t$ decays are
511selected, then the lower QMW limit must be above the $t$ threshold.
512For standard Drell-Yan events QTW should be fixed to zero,
513\begin{verbatim}
514QTW
5150/
516\end{verbatim}
517Transverse momenta will then be generated by initial state gluon
518radiation. A range of QTW can also be given. For SUPERSYM either the
519masses and decay modes should be specified, or the MSSM, SUGRA, GMSB, or
520AMSB parameters should be given. For fourth generation quarks it is
521necessary to specify the quark masses.
522
523 Note that if the limits given cover too large a kinematic range,
524the program can become very inefficient, since it makes a fit to the
525cross section over the specified range. NTRIES has to be increased if
526narrow limits are set for X, XW or for jet 1 and jet 2 parameters in
527DRELLYAN events. For larger ranges several runs can be combined together
528using the integrated cross section per event SIGF/NEVENT as the weight.
529This cross section is calculated for each run by Monte Carlo integration
530over the specified kinematic limits and is printed at the end of the
531run. It is corrected for JETTYPEi, WTYPE, and WMODEi selections; it
532cannot be corrected for branching ratios of forced decays or for WPMODE,
533WMMODE, or Z0MODE selections, since these can affect an arbitrary number
534of particles.
535
536 To generate events over a large range, it is much more efficient
537to combine several runs. This is facilitated by using the special job
538title SAME as described above. Note that SAME cannot be used to combine
539standard DRELLYAN events (QTW fixed equal to 0) and DRELLYAN events with
540nonzero QTW.
541
542 The cross sections for multiparton final states in general have
543infrared and collinear singularities. To obtain sensible results, it
544is in general essential to set limits both on the $p_T$ of each final
545parton using PT and on the mass of each pair of partons using MIJLIM.
546The default lower limits are all $1\,{\rm GeV}$. Using these default
547limits without thought will likely give absurd results.
548
549 For TWOJET, DRELLYAN, and most other processes, the JETTYPEi and
550WTYPEi keywords should be used to select the subprocesses to be
551included. For $e^+ e^- \to W^+ W^-$, $Z^0 Z^0$, use FORCE and FORCE1
552instead of WMODEi to select the $W$ decay modes. Note that these {\it
553do not} change the calculated cross section. (In the E+E- process, the
554$W$ and $Z$ decays are currently treated as particle decays, whereas in
555the WPAIR and HIGGS processes they are treated as $2 \to 4$ parton
556processes.)
557
558 For HIGGS with $W^+W^-$ or $Z^0Z^0$ decays allowed it is
559generally necessary to set PT limits for the W's, e.g.
560\begin{verbatim}
561PT
56250,20000,50,20000/
563\end{verbatim}
564If this is not done, then the default lower limit of 1 GeV is used,
565and the $t$-channel exchanges will dominate, as they should in the
566effective $W$ approximation. Depending on the other parameters, the
567program may fail to generate an event in NTRIES tries.
568
569\subsection{SUSY Parameters}
570
571 SUPERSYM (SUSY) by default generates just gluinos and squarks in
572pairs. There are no default masses or decay modes. Masses can be set
573using GAUGINO, SQUARK, SLEPTON, and HMASSES. Decay modes can be
574specified with FORCE or by modifying the decay table. Left and right
575squarks are distinguished but assumed to be degenerate, except for
576stops. Since version 7.11, types must be selected with JETTYPEi using
577the supersymmetric names, e.g.
578\begin{verbatim}
579JETTYPE1
580'GLSS','UPSSL','UPSSR'/
581\end{verbatim}
582Use of the corresponding standard model names, e.g.
583\begin{verbatim}
584JETTYPE1
585'GL','UP'/
586\end{verbatim}
587and generation of pure photinos, winos, and zinos are no longer
588supported.
589
590 If MSSMA, MSSMB and MSSMC are given, then the specified parameters
591are used to calculate all the masses and decay modes with the ISASUSY
592package assuming the minimal supersymmetric extension of the standard
593model (MSSM). There are no default values, so you must specify values
594for each MSSMi, i=A-C. MSSMD can optionally be used to set the second
595generation squark and slepton parameters; if it is omitted, then the
596first generation ones are used. MSSME can optionally be used to set the
597U(1) and SU(2) gaugino masses; if it is omitted, then the grand
598unification values are used. The parameters and the use of the MSSM is
599preserved if the title is SAME. FORCE can be used to override the
600calculated branching ratios.
601
602 The MSSM option also generates charginos and neutralinos with
603cross sections based on the MSSM mixing angles in addition to squarks
604and sleptons. These can be selected with JETTYPEi; the complete list of
605supersymmetric options is:
606\begin{verbatim}
607'GLSS',
608'UPSSL','UBSSL','DNSSL','DBSSL','STSSL','SBSSL','CHSSL','CBSSL',
609'BTSS1','BBSS1','TPSS1','TBSS1',
610'UPSSR','UBSSR','DNSSR','DBSSR','STSSR','SBSSR','CHSSR','CBSSR',
611'BTSS2','BBSS2','TPSS2','TBSS2',
612'W1SS+','W1SS-','W2SS+','W2SS-','Z1SS','Z2SS','Z3SS','Z4SS',
613'NUEL','ANUEL','EL-','EL+','NUML','ANUML',MUL-','MUL+','NUTL',
614'ANUTL','TAU1-','TAU1+','ER-','ER+','MUR-','MUR+','TAU2-','TAU2+',
615'Z0','HL0','HH0','HA0','H+','H-',
616'SQUARKS','GAUGINOS','SLEPTONS','ALL'.
617\end{verbatim}
618Note that mixing between $L$ and $R$ stop states results in 1 (light)
619and 2 (heavy) stop, sbottom and stau eigenstates, which depend on the
620input parameters of left- and right- scalar masses, plus $A$ terms,
621$\mu$ and $\tan\beta$. The last four JETTYPE's generate respectively
622all allowed combinations of squarks and antisquarks, all combinations
623of charginos and neutralinos, all combinations of sleptons and
624sneutrinos, and all SUSY particles.
625
626 For SUSY Higgs pair production or associated production in E+E-,
627select the appropriate JETTYPE's, e.g.
628\begin{verbatim}
629JETTYPE1
630'Z0'/
631JETTYPE2
632'HL0'/
633\end{verbatim}
634
635As usual, this gives only half the cross section. For single production
636of neutral SUSY Higgs in $pp$ and $\bar pp$ reactions, use the HIGGS
637process together with the MSSMi, SUGRA, GMSB, or AMSB keywords. You must
638specify one and only one Higgs type using
639\begin{verbatim}
640HTYPE
641'HL0' or 'HH0' or 'HA0'/ <<<<< One only!
642\end{verbatim}
643If no QMH range is given, one is calculated using $M \pm 5 \Gamma$ for
644the selected Higgs. Decays into quarks, leptons, gauge bosons, lighter
645Higgs bosons, and SUSY particles are generated using the on-shell
646branching ratios from ISASUSY. You can use JETTYPEi to select the
647allowed Higgs modes and WMODEi to select the allowed decays of W and Z
648bosons. Since heavy SUSY Higgs bosons couple weakly to W pairs, WW
649fusion and WW scattering are not included.
650
651 SUGRA can be used instead of MSSMi to generate MSSM decays with
652parameters determined from $m_0$, $m_{1/2}$, $A_0$, $\tan\beta$, and
653$\sgn\mu=\pm1$ in the minimal supergravity framework. The NUSUGi
654keywords can optionally be used to specify additional parameters for
655non-universal SUGRA models, while SUGRHN is used to specify the
656parameterf of an optional right-handed neutrino. Similarly, the GMSB
657keyword is used to specify the $\Lambda$, $M_m$, $N_5$, $\tan\beta$,
658$\sgn\mu=\pm1$, and $C_{\rm grav}$ parameters of the minimal Gauge
659Mediated SUSY Breaking model. GMSB2 can optionally be used to specify
660additional parameters of non-minimal GMSB models. The AMSB keyword is
661used to specify $m_0$, $m_{3/2}$, $\tan\beta$, and $\sgn\mu$ for the
662minimal Anomaly Mediated SUSY Breaking model. Note that $m_{3/2}$ is
663much larger than the weak scale, typically 50~TeV.
664
665 WHIGGS is used to generate $W$ plus neutral Higgs events. For the
666Standard Model the JETTYPE is \verb|HIGGS|. If any of the SUSY models
667is specified, then the appropriate SUSY Higgs type should be used,
668most likely \verb|HL0|. In either case WMODEi is used to specify the
669$W$ decay modes. The Higgs is treated as a particle; its decay modes
670can be set using FORCE.
671
672\subsection{Forced Decay Modes}
673
674 The FORCE keyword requires special care. Its list must contain the
675numerical particle IDENT codes, e.g.
676\begin{verbatim}
677FORCE
678140,130,-120/
679\end{verbatim}
680The charge-conjugate mode is also forced for its antiparticle. Thus the
681above example forces both $\bar D^0 \to K^+ \pi^-$ and $D^0 \to K^-
682\pi^+$. If only a specific decay is wanted one should use the FORCE1
683command; e.g.
684\begin{verbatim}
685FORCE1
686140,130,-120/
687\end{verbatim}
688only forces $\bar D^0 \to K^+ \pi^-$.
689
690 To force a heavy quark decay one must generally separately force
691each hadron containing it. If the decay is into three leptons or quarks,
692then the real or virtual W propagator is inserted automatically. Since
693Version 7.30, top and fourth generation quarks are treated as
694particles and decayed directly rather than first being made into
695hadrons. Thus for example
696\begin{verbatim}
697FORCE1
6986,-12,11,5/
699\end{verbatim}
700forces all top quarks to decay into an positron, neutrino and a
701b-quark (which will be hadronized). For the physical top mass, the
702positron and neutrino will come from a real W. Note that forcing $t
703\to W^+ b$ and $W^+ \to e^+ \nu_e$ does {\it not} give the same
704result; the first uses the correct $V-A$ matrix element, while the
705second decays the $W$ according to phase space.
706
707 Forced modes included in the decay table or generated by ISASUSY
708will automatically be put into the correct order and will use the
709correct matrix element. Modes not listed in the decay table are
710allowed, but caution is advised because a wrong decay mode can cause
711an infinite loop or other unexpected effects.
712
713 FORCE (FORCE1) can be called at most 20 (40) times in any run plus
714all subsequent 'SAME' runs. If it is called more than once for a given
715parent, all calls are listed, and the last call is used. Note that FORCE
716applies to particles only, but that for gamma, W+, W-, Z0 and
717supersymmetric particles the same IDENT codes are used both as jet types
718and as particles.
719
720\subsection{Parton Distributions}
721
722 The default parton distributions are fit CTEQ3L from the CTEQ
723Collaboration using lowest order QCD. The CTEQ and the older EHLQ and
724Duke-Owens distributions can be selected using the STRUC keyword.
725
726 If PDFLIB support is enabled (see Section 4), then any of the
727distributions in the PDFLIB compilation by H. Plothow-Besch can be
728selected using the PDFLIB keyword and giving the proper parameters,
729which are identical to those described in the PDFLIB manual and are
730simply passed to the routine PDFSET. For example, to select fit 29
731(CTEQ3L) by the CTEQ group, leaving all other parameters with their
732default values, use
733\begin{verbatim}
734PDFLIB
735'CTEQ',29D0/
736\end{verbatim}
737Note that the fit-number and the other parameters are of type DOUBLE
738PRECISION (REAL on 64-bit machines). There is no internal passing of
739parameters except for those which control the printing of messages.
740
741\subsection{Multiparton Processes}
742
743 For multiparton final states one should in general set limits
744on the total mass \verb|MTOT| of the final state, on the minimum
745\verb|PT| of each light parton, and on the minimum mass \verb|MIMLIM|
746of each pair of light partons. Limits for \verb|PT| are set in the
747ususal way. Limits for the mass $M_{ij}$ of partons $i,j$ are set using
748\begin{verbatim}
749MIJLIM
750i,j,Mmin,Mmax
751\end{verbatim}
752If $i=j=0$, the limit is applied to all jet pairs. For example the
753following parameter file generates \verb|ZJJ| events at the LHC with a
754mimimum $p_T$ of $20\,\GeV$ and a minimum mass of $20\,\GeV$ for all
755jet pairs:
756\begin{verbatim}
757GENERATE ZJJ with PTMIN = 20 GEV AND MMIN = 20 GEV
75814000,100,1,100/
759ZJJ
760PT
76120,7000,20,7000,20,7000/
762MIJLIM
7630,0,20,7000/
764MTOT
765100,500/
766NSIGMA
767200/
768NTRIES
76910000/
770END
771STOP
772\end{verbatim}
773The default lower limits for \verb|PT| and \verb|MIJLIM| are
774$1\,\GeV$. While these limits are sufficient to make the cross
775sections finite, they will in general not give physically sensible
776results. Thus, {\it the user must think carefully about what limits
777should be set.}