Renormalization corrections in heavy colored scalar effective field theory
<p>Recently, QCD processes involving a heavy quark at energ1es much smaller than its mass have been examined in an effective field theory approach. In this 'heavy quark theory', the mass of the quark is taken to infinity while its four velocity is held fixed. The effective theory...
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| Format: | Others |
| Language: | en |
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1993
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| Online Access: | https://thesis.library.caltech.edu/7380/1/Sharma_m_1993.pdf Sharma, Murali (1993) Renormalization corrections in heavy colored scalar effective field theory. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/k333-2a97. https://resolver.caltech.edu/CaltechTHESIS:01082013-134838904 <https://resolver.caltech.edu/CaltechTHESIS:01082013-134838904> |
| Summary: | <p>Recently, QCD processes involving a heavy quark at energ1es much
smaller than its mass have been examined in an effective field theory approach. In this
'heavy quark theory', the mass of the quark is taken to infinity while its four velocity is
held fixed. The effective theory has a large set of symmetries because of the decoupling of
the flavor (when the kinematic dependence on masses is removed) and spin of the heavy
quark from its interactions with the light degrees of freedom . As a consequence, several
matrix elements of the theory are determined in terms of a single function, the Isgur-Wise
function. Being nonperturbative in character, this function is not fully calculable. However,
it has a calculable logarithmic dependence on the masses of the heavy particles, arising
from QCD effects in the full theory. </p>
<p>Some extensions of the standard model contain heavy color triplet scalars.
It is instructive therefore to consider the analogous effective field theory for scalars. In
processes where pair production does not occur, the statistics of the heavy particles are
irrelevant, and their interactions are identical with those of quarks. Thus there is a 'superflavor
symmetry' that interchanges quarks and scalars, and a flavor symmetry between
scalars. Again, these symmetries determine several matrix elements involving scalars up
to the same Isgur-Wise function. In this thesis, the logarithmic mass dependence of the
operators ϕ_2^†ϕ_1, ϕ_2^† (ὶð^µ ϕ_1), and (ὶð^µ ϕ_2) ^† ϕ_1 is calculated. The latter two operators
mix under renormalization. </p>
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