Limitations and opportunities of off-shell coupling measurements

Englert, C. and Spannowsky, M. (2014) Limitations and opportunities of off-shell coupling measurements. Physical Review D, 90(5), 053003. (doi: 10.1103/PhysRevD.90.053003)

Abstract

Indirect constraints on the total Higgs width Γh from correlating Higgs signal strengths with cross-section measurements in the off-shell region for p(g)p(g)→4ℓ production have received considerable attention recently, and the CMS Collaboration have published a first measurement. We revisit this analysis from a new physics and unitarity constraints perspective and conclude that limits on Γh obtained in this fashion are not reliable unless we make model-specific assumptions, which cannot be justified at the current stage of the LHC program. Relaxing the Γh interpretation, we discuss the merits of high invariant mass cross-section measurements in the context of Higgs CP analyses, higher-dimensional operator testing, and resolved new physics in the light of electroweak precision constraints beyond effective theory limitations. Furthermore, we show that a rather model-independent LHC constraint can be obtained from adapting the gg→4ℓ analysis to the weak boson fusion channels at lower statistical yield.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Englert, Professor Christoph
• Authors: Englert, C., and Spannowsky, M.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review D
• Publisher: American Physical Society
• ISSN: 1550-7998
• ISSN (Online): 1550-2368