BCVEGPY2.0: An upgraded version of the generator BCVEGPY with the addition of hadroproduction of the P-wave image states Original Research Article

The generator BCVEGPY is upgraded by improving some of its features and by adding the hadroproduction of the P-wave excited image states (denoted by image or by image and image). In order to make the generator more efficient, we manipulate the amplitude as compact as possible with special effort. The correctness of the program is tested by various checks. We denote it as BCVEGPY2.0. As for the added part of the P-wave production, only the dominant gluon–gluon fusion mechanism (image) is taken into account. Moreover, in the program, not only the ability to compute the contributions from the color-singlet components image to the P-wave production but also the ability to compute the contributions from the color-octet components image are available. With BCVEGPY2.0 the contributions from the two ‘color components’ to the production of each of the P-wave states may be computed separately by an option, furthermore, besides individually the event samples of the S-wave and P-wave (image)-heavy-quarkonium in various correct (realistic) mixtures can be generated by relevant options too.