We present a detailed calculation of the contributions from supersymmetric diagrams (involving gluino exchange) to flavor-changing decay modes of the Z boson. We find that for all processes such as Ztc» and Ztū, the supersymmetric contribution to the branching ratios is small compared to that from the standard model. Any experimental detection of such modes beyond the standard-model prediction will therefore point to the existence of new physics other than supersymmetry. © 1989 The American Physical Society.

B MUKHOPADHYAYA

A RAYCHAUDHURI

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Physical Review D

Many extensions of the Standard Model include SU(2) L × U(1) Y singlet higgs bosons, h 0 , and also vector-like fermions which couple to it. The production and detection possibilities of such singlet neutral scalars at hadron colliders are considered for different scenarios of vectorlike fermions. We find that for some values of masses and couplings, detection at the CERN large hadron collider (LHC) appears to be a distinct possibility, while at the Fermilab Tevatron upgrade the h 0 might be observed only in very favourable circumstances. © Springer-Verlag 1996.

Fulltext

Zeitschrift fur Physik C-Particles and Fields

Singlet-Higgs-Boson signals at hadron colliders

A gauge-invariant subset of minimal supersymmetry, driven by the quark-squark-gluino Lagrangian, is our concern in the context of precision measurements at the CERN e+e- collider LEP on Z decays. Shifts of the parameter R=hadll, a precisely measured top-quark-free observable at LEP, due to vertex corrections induced by the above interaction, have been evaluated for different regions of the supersymmetric parameter space. Owing mainly to the stringent bounds on the masses of the squarks and the gluino from the direct search at the Fermilab Tevatron, the effects are not too large to cast an observable impact at the present stage of LEP precision. © 1993 The American Physical Society.

Gluino-induced effects and precision measurements at the CERN e+e- collider LEP

We examine the possibility of an exotic vectorlike charge (-13) quark h mixing with the d-type quarks. The currently accepted Cabibbo-Kobayashi-Maskawa matrix elements, though consistent with unitarity, allow substantial mixing of such an exotic quark with the b quark. Concentrating on h-b mixing, we find several distinctive signaturesin top-quark production and decay, Zbb, and flavor-violating rare Z decays which may be experimentally testable in the near future. © 1989 The American Physical Society.

Is the b quark mixed with a vectorlike quark?

The lowest-order contributions to the decay mode Z tc have been studied here in a supersymmetric E6 model containing "exotic" SU(2)-singlet charge -13 quarks. It is shown that the presence of such quarks give an appreciable boost to the branching ratio through not only weak one-loop diagrams but also gluino-induced ones. © 1989 The American Physical Society.

Journal	Physical Review D
Publisher	-
ISSN	0556-2821