314 research outputs found
Nonlinear Parameterization in Bi-Criteria Sample Balancing
Sample balancing is widely used in applied research to adjust a sample data to achieve better correspondence to Census statistics. The classic Deming-Stephan iterative proportional approach finds the weights of observations by fitting the cross-tables of sample counts to known margins. This work considers a bi-criteria objective for finding weights with maximum possible effective base size. This approach is presented as a ridge regression with the exponential nonlinear parameterization that produces nonnegative weights for sample balancing
Reduction of Vector and Axial--Vector Fields in a Bosonized Nambu--Jona--Lasinio Model
We derive the effective action for pseudoscalar mesons by integrating out
vector and axial--vector collective fields in the generating functional of the
bosonized NJL--model. The corresponding modifications of the nonlinear
effective Lagrangian and the bosonized currents, arising at , are
discussed.Comment: 30p. 1 fig. on reques
The Goldstini Variations
We study the 'goldstini' scenario of Cheung, Nomura, and Thaler, in which
multiple independent supersymmetry (SUSY) breaking sectors lead to multiple
would-be goldstinos, changing collider and cosmological phenomenology. In
supergravity, potentially large corrections to the previous prediction of twice
the gravitino mass for goldstini masses can arise when their scalar partners
are stabilized far from the origin. Considerations arising from the complexity
of realistic string compactifications indicate that many of the independent
SUSY-breaking sectors should be conformally sequestered or situated in warped
Randall-Sundrum-like throats, further changing the predicted goldstini masses.
If the sequestered hidden sector is a metastable SUSY-breaking sector of the
Intriligator-Seiberg-Shih (ISS) type then multiple goldstini can originate from
within a single sector, along with many supplementary 'modulini', all with
masses of order twice the gravitino mass. These fields can couple to the
Supersymmetric Standard Model (SSM) via the 'Goldstino Portal'. Collider
signatures involving SSM sparticle decays can provide strong evidence for
warped-or-conformally-sequestered sectors, and of the ISS mechanism of SUSY
breaking. Along with axions and photini, the Goldstino Portal gives another
potential window to the hidden sectors of string theory.Comment: 30 pages, 3 figures; v2 minor changes, references adde
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