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QCD factorization for heavy quarkonium production and fragmentation functions

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dc.contributor.advisor Qiu, Jian-Wei en_US
dc.contributor.author Zhang, Hong en_US
dc.contributor.other Department of Physics. en_US
dc.date.accessioned 2017-09-20T16:51:06Z
dc.date.available 2017-09-20T16:51:06Z
dc.date.issued 2014-12-01 en_US
dc.identifier.uri http://hdl.handle.net/11401/76745 en_US
dc.description 181 pg. en_US
dc.description.abstract From the Tevatron and the LHC data, it is clear that current models for the heavy quarkonium production are not able to explain the polarization of produced heavy quarkonia at large transverse momentum p<sub>T</sub>. A new approach to evaluate the heavy quarkonium production, by expanding the cross section in powers of 1/p<sub>T</sub> before the expansion in powers of &alpha<sub>s</sub>, was proposed recently. In terms of the QCD factorization, it is proved that both the leading and next-to-leading power terms in 1/p<sub>T</sub> for the cross sections can be systematically factorized to all orders in powers of &alpha<sub>s</sub>. The predictive power of this new QCD factorization formalism depends on several unknown but universal fragmentation functions (FFs) at an input scale of the order of heavy quarkonium mass m<sub>Q</sub>. These FFs should be extracted from the data in principle. However, fitting so many unknown multi-variable functions from the data is formidable practically. The lack of knowledge of the input FFs impedes the application of the QCD factorization. In this dissertation, inspired by the fact that these input FFs depend on m<sub>Q</sub> >> Lambda<sub>QCD<\sub>, we apply the NRQCD factorization formalism to further separate the perturbative and non-perturbative interactions. With our calculations, all the input unpolarized FFs are expressed as complicated functions with a few unknown NRQCD long-distance matrix elements (LDMEs). In addition, by general symmetry arguments, we successfully generalize the polarized NRQCD four-fermion operators to <italic>d</italic> dimensions and calculate the polarized FFs with conventional dimensional regularization. In the first application of the QCD factorization to unpolarized J/psi production, we find those NRQCD channels, which are expected to be important in the J/psi polarization, are actually dominated by the next-to-leading-power term in the p<sub>T</sub> expansion at current collider energies. Therefore the QCD factorization is very promising to solve the long standing heavy quarkonium polarization puzzle. en_US
dc.description.sponsorship This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. en_US
dc.format Monograph en_US
dc.format.medium Electronic Resource en_US
dc.language.iso en_US en_US
dc.publisher The Graduate School, Stony Brook University: Stony Brook, NY. en_US
dc.subject.lcsh Nuclear physics en_US
dc.subject.other factorization, fragmentation, Heavy quarkonium, QCD en_US
dc.title QCD factorization for heavy quarkonium production and fragmentation functions en_US
dc.type Dissertation en_US
dc.mimetype Application/PDF en_US
dc.contributor.committeemember Sterman, George en_US
dc.contributor.committeemember Deshpande, Abhay en_US
dc.contributor.committeemember Weinacht, Thomas en_US
dc.contributor.committeemember Morrison, David. en_US


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