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
Input in GeV, such as 14000.0
- #4 PDF file name.
-
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.
Choose from {MH, MT}.
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:
Renormalization : | mu_R=chiR*muScale. |
Factorization : | mu_F=chiF*muScale. |
- #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.