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.

B MUKHOPADHYAYA

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

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.

Can flavor-changing Z decay provide a test for supersymmetry?

At low energies, superstring models lead to an effective E6 theory containing exotic charge -(1/3 quarks, denoted h. Here we work out the consequences of the mixing of h with the b quark, on CP violation, and heavy-neutral-meson systems. This mixing is found to remove the lower bound on mt from and significantly reduces the prediction for. While B0-B» 0 mixing remains unaltered, there is a considerable enchancement of D0-D» 0 mixing from supersymmetric contributions. © 1988 The American Physical Society.

Exotic quarks in superstring models: Implications on CP violation and heavy-meson mixing

Exotic charge - 1 3 colour triplet (h) quarks are contained in E6 models. We examine the effects on CP violation resulting from h-b mixing and find that the lower bound on mt is removed, ε{lunate}' ε{lunate} is reduced and BoBo mixing remains unchanged. © 1987.

Fulltext

Physics Letters B

CP-violation in a superstring inspired model with oxotic quarks

In E6 models emerging at low energies from the superstring there are exotic charge- 1 3 h-quarks. When h-b mixing is taken into account, SUSY contribution to D0-D0mixing is enhanced several orders beyond that in the standard model and is close to the experimental upper limit. © 1987.

Journal	Physical Review D
Publisher	-
ISSN	0556-2821