HiggsPt_R version 1.2 Program Manual

Program Manual and input-file guide for HiggsPt_R version 1.2

This manual describes how to use the program HiggsPt_R, which computes the Higgs boson Transverse Momentum distribution at NLO in the limit of large top quark mass, with input grid and output files for use with the resummation program RESBOS.
The code produces two output files. The "xxx_Pert.out" output file displays the order alpha_s^3 Pert_1 and order alpha_s^4 Pert_2 contributions to the perturbative cross sections and the K factor (K=(Pert_1+Pert_2)/Pert_1) as a function of the input grid variables. The "xxx_Y.out" output file displays the order alpha_s^3 Y_1 and order alpha_s^4 Y_2 contributions to Y=sigma(exact)-sigma(small-pt) and the associated K factor (K=(Y_1+Y_2)/Y_1) as a function of the input grid variables. The manual gives line-by-line instructions for the input file "HiggsPt_R.indat".

General Formatting Notes:

It should be fairly easy to use the input file, "HiggsPt_R.indat", just by modifying the example that came with the source distribution. However, there are a few general formatting requirements to be aware of.
The input file must have exactly 10 lines.
In the following explanations of the inputs, a list {a, b, c} indicates a choice of string inputs on a line, while an ordered list [x y z] indicates multiple numerical parameters input on a single line. Possible inputs are colored red.
If the input to a line is a string, then it MUST have trailing white spaces after the string (NOT TABS!). It is easiest to do this by keeping the explanatory comment after the input string (i.e, white spaces followed by #x Comment) from the example file.
Any input which is a string must be spelled exactly as given below, including capitalization and without quotation marks, or else the program will complain.
The program ignores anything in a line that comes after the expected input.

Line-by-line explanation of input file:

#1 Name of the output files.

Input a string, such as output/HiggsPt_R (without quotes) to name the output files. The program generates two output files by appending the strings "_Pert.out" and "_Y.out" to the input string. (In the example, the program would produce the files "output/HiggsPt_R_Pert.out" and "output/HiggsPt_R_Y.out". There is an empty directory "output/" in the same directory as the executable, which may be used for output files. Or you may organize as you desire.

#2 Type of collider.

Choose from {pp, ppbar}.

#3 Collider COM energy

#4 PDF file name.

14000.0 The file name (such as cteq6m.LHpdf) for the particular PDF distribution to be used. The LHAPDF script "lhapdf-config" determines the correct path to the file, so make sure that the script is in the system $PATH.

#5 PDF member set.

This is an integer, which specifies the specific member set for the given PDF distribution. The default of 0 gives the "best fit" for any distribution. For more info, read the LHAPDF manual at http://projects.hepforge.org/lhapdf/.

#6 Choice of Ren/Fact Scale Variable.

MHMT

MH :	muScale = M_H (Higgs Mass)
MT :	muScale = M_T = sqrt(M_H^2+p_T^2) (Higgs Transverse Mass)

#7 Input scale choices.

The input format is [chiR chiF]. For example, 1.0 1.0.
The scale factors are defined by:

#8 Name of the Q grid file.

Input a string, such as q_grid_h0.inp (without quotes) to identify the input grid file in the variable Q (the Higgs Boson Mass). This file should be organized with one Q value on each line and nothing else.

#9 Name of the y grid file.

Input a string, such as y_grid_h0.inp (without quotes) to identify the input grid file in the variable y (the Higgs Boson rapidity). This file should be organized with one y value on each line and nothing else.

#10 Name of the qt grid file.

Input a string, such as qt_grid_h0.inp (without quotes) to identify the input grid file in the variable qt (the Higgs Boson transverse momentum). This file should be organized with one qt value on each line and nothing else.

Renormalization :	mu_R=chiR*muScale.
Factorization :	mu_F=chiF*muScale.