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A<sc>bstract</sc> A search for Higgs boson pair (HH) production in association with a vector boson V (W or Z boson) is presented. The search is based on proton-proton collision data at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 138 fb−1. Both hadronic and leptonic decays of V bosons are used. The leptons considered are electrons, muons, and neutrinos. The HH production is searched for in the$$ \textrm{b}\overline{\textrm{b}}\textrm{b}\overline{\textrm{b}} $$ decay channel. An observed (expected) upper limit at 95% confidence level of VHH production cross section is set at 294 (124) times the standard model prediction. Constraints are also set on the modifiers of the Higgs boson trilinear self-coupling,kλ, assumingk2V= 1, and vice versa on the coupling of two Higgs bosons with two vector bosons,k2V. The observed (expected) 95% confidence intervals of these coupling modifiers are−37.7 <kλ< 37.2 (−30.1 <kλ< 28.9) and−12.2 <k2V< 13.5 (−7.2 <k2V< 8.9), respectively.
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This content will become publicly available on May 1, 2026
Measuring the polarization of boosted, hadronic W bosons with jet substructure observables
A<sc>bstract</sc> In this work, we present a new technique to measure the longitudinal and transverse polarization fractions of hadronic decays of boostedWbosons. We introduce a new jet substructure observable denoted aspθ, which is a proxy constructed purely out of subjet energies for the parton level decay polar angle of theWboson in its rest-frame. The distribution of this observable is sensitive to the polarization ofWbosons and can therefore be used to reconstruct theWpolarization in a way that is independent of the production process — assuming Standard Model (SM) rules governing decays. We argue that this proxy variable has lower reconstruction errors as compared to the other proxies that have been used by the experimental collaborations, especially for large boosts of theW-boson. As a test case, we study the efficacy of our technique on vector boson scattering (VBS) processes at the high luminosity Large Hadron Collider. We find that with only SM production channels, measuring the longitudinal polarization fraction is likely to be challenging even with 10 ab−1of data. We suggest further strategies and scenarios that may improve the prospects of measurement of the hadronicWpolarization fraction.
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- Award ID(s):
- 2412995
- PAR ID:
- 10629732
- Publisher / Repository:
- JHEP
- Date Published:
- Journal Name:
- Journal of High Energy Physics
- Volume:
- 2025
- Issue:
- 5
- ISSN:
- 1029-8479
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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