90 research outputs found
The Supersymmetric Flavor Problem for Heavy First-Two Generation Scalars at Next-to-Leading Order
We analyze in detail the constraints on SUSY-model parameters obtained from
K-Kbar mixing in the hypothesis of a splitted SUSY spectrum. FCNC contributions
from gluino-squark-quark interactions are studied in the so-called mass
insertion approximation. We present boundaries on mass insertions and on SUSY
mass scales. We improve previous results by including the NLO-QCD corrections
to Delta S=2 effective Hamiltonian and the complete set of B-parameters for the
evaluation of hadronic matrix elements.
A full set of magic-numbers, that can be used for further analyses of these
models, is also given. We find that the inclusion of NLO-QCD corrections and
the B-parameters change the results obtained at LO and in the Vacuum Insertion
Approximation by an amount of about 25-35%.Comment: 22 Latex pages, 5 figures; Figs. 1,2 redrawn for K=0.22, section 4.1
revisited, references corrected. Submitted to European Journal of Physics
The T-Wilson Line
We argue that soft-collinear effective theory, as is currently formulated,
lacks an ingredient which is essential for obtaining a gauge invariant
definitions of certain non-perturbative matrix elements relevant for
semi-inclusive high-energy processes. Those processes and the companion
cross-sections are to be analyzed and measured at the Large Hadron Collider.
The missing feature is a gauge link constructed only from the transverse
component of the gluon field denoted by the "-Wilson line"'. It is neither
soft nor collinear. As such it is a new feature of the theory.Comment: 4 pages. To appear in the proceedings of "Quark Confinement and
Hadron Nuclei", Madrid 201
A short review on recent developments in TMD factorization and implementation
In the latest years the theoretical and phenomenological advances in the
factorization of several collider processes using the transverse momentum
dependent distributions (TMD)has greatly increased. I attempt here a short
resume of the newest developments discussing also the most recent perturbative
QCD calculations. The work is not strictly directed to experts in the field and
it wants to offer an overview of the tools and concepts which are behind the
TMD factorization and evolution. I consider both theoretical and
phenomenological aspects, some of which have still to be fully explored. It is
expected that actual colliders and the Electron Ion Collider (EIC) will provide
important information in this respect.Comment: Prepared for the Special Issue "Transverse Momentum Dependent
Observables from Low to High Energy: Factorization, Evolution, and Global
Analyses" which will be published in Advances in High Energy Physic
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