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Related papers: Measuring spin and CP from semi-hadronic ZZ decays…

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Many new physics models, e.g., leptoquarks, extra dimensions, extended Higgs sectors, supersymmetric theories, and dark sector extensions, are expected to manifest themselves in the final states with hadronic jets. Novel experimental…

High Energy Physics - Experiment · Physics 2024-01-19 Emmanouil Vourliotis

We study the four-top final state at the LHC as a probe for New Physics (NP) effects due to new particles that couple predominantly to the top quark and whose masses are below the top-quark-pair production threshold. We consider simple NP…

High Energy Physics - Phenomenology · Physics 2020-01-29 Ezequiel Alvarez , Aurelio Juste , Rosa María Sandá Seoane

Heavy quark decays provide a very advantageous investigation to test the Standard Model (SM). Recently, promising experiments with \textit{b} quark, as well as the analysis of the huge data sets produced at the B factories, have led to an…

High Energy Physics - Phenomenology · Physics 2015-05-14 Wanwei Wu

The CP nature of the Higgs coupling to top quarks is addressed in this paper, in single charged lepton final states of $t\bar{t}h$ events produced in proton-proton collisions at the LHC. Pure scalar ($h=H$) and pseudo-scalar ($h=A$) Higgs…

High Energy Physics - Phenomenology · Physics 2018-08-29 D. Azevedo , A. Onofre , F. Filthaut , R. Gonçalo

A search has been made for massive resonances decaying into a quark and a vector boson, qW or qZ, or a pair of vector bosons, WW, WZ, or ZZ, where each vector boson decays to hadronic final states. This search is based on a data sample…

High Energy Physics - Experiment · Physics 2013-06-21 CMS Collaboration

Semi-visible jets arise from a hypothetical, strongly interacting ``dark sector'' -- a dark counterpart of quantum chromodynamics whose partial decays back to Standard Model particles introduce new types of collider BSM signature. CMS and…

High Energy Physics - Phenomenology · Physics 2025-02-18 Andy Buckley , Jon Butterworth , Louie Corpe , Caterina Doglioni , Deepak Kar , Clarisse Prat , Sukanya Sinha , Danielle Wilson-Edwards

Top-antitop pairs produced at hadron colliders are largely unpolarized, but their spins are highly correlated. The structure of these correlations varies significantly over top production phase space, allowing very detailed tests of the…

High Energy Physics - Phenomenology · Physics 2015-06-12 Matthew Baumgart , Brock Tweedie

The degree of top polarization and strength of $t\bar{t}$ correlation are dependent on production dynamics, decay mechanism, and choice of the observables. At the LHC, measurement of the top polarization and spin correlations in $t\bar{t}$…

High Energy Physics - Experiment · Physics 2017-09-26 Ajeeta Khatiwada

Experimental falsification or validation of the Standard Model of Particle Physics involves the measurement of the CP quantum number and couplings of the Higgs boson. Both ATLAS and CMS have reported an SM Higgs-like excess around m_H=125…

High Energy Physics - Phenomenology · Physics 2015-06-04 Christoph Englert , Michael Spannowsky , Michihisa Takeuchi

Most sparticle decay cascades envisaged at the Large Hadron Collider (LHC) involve hadronic decays of intermediate particles. We use state-of-the art techniques based on the \kt jet algorithm to reconstruct the resulting hadronic final…

High Energy Physics - Phenomenology · Physics 2009-11-13 J. M. Butterworth , J. R. Ellis , A. R. Raklev

We consider the combined measurements of CP-averaged decay rates and direct CP asymmetries of $B^\pm\to K^\pm \ell^+ \ell^-$ and $B^\pm\to \pi^\pm \ell^+ \ell^-$ to probe (non-local) four-quark operator matrix element contributions to rare…

High Energy Physics - Phenomenology · Physics 2024-03-21 Jernej F. Kamenik , Nejc Košnik , Martín Novoa-Brunet

Measurement of $CP$-violating observables in semileptonic decays is a sensitive null-test of the Standard Model: any $CP$ violation would be an unambiguous sign of New Physics effects. The model-independent technique to measure parity and…

High Energy Physics - Phenomenology · Physics 2023-07-12 Vlad Dedu , Anton Poluektov

New heavy resonances with sizeable couplings to top quarks can be probed through searches for beyond-the-Standard-Model effects in four-top production at the LHC. In this work, we present the first next-to-leading-order QCD predictions for…

High Energy Physics - Phenomenology · Physics 2025-11-19 Luc Darmé , Benjamin Fuks , Hao-Lin Li , Matteo Maltoni , Julien Touchèque

This Letter proposes a new signature for confining dark sectors at the LHC. Under the assumption of a QCD-like hidden sector, hadronic jets containing stable dark bound states originating from hidden strong dynamics, known as semi-visible…

High Energy Physics - Phenomenology · Physics 2024-07-12 Cesare Cazzaniga , Alessandro Russo , Emre Sitti , Annapaola de Cosa

We systematically study the possibility of determining the spin of new particles after their discovery at the LHC. We concentrate on angular correlations in cascade decays. Motivated by constraints of electroweak precision tests and the…

High Energy Physics - Phenomenology · Physics 2010-10-27 Lian-Tao Wang , Itay Yavin

Quantum entanglement is a fundamental property of quantum mechanics. Recently, studies have explored entanglement in the $t\bar{t}$ system at the Large Hadron Collider (LHC) when both the top quark and anti-top quark decay leptonically.…

High Energy Physics - Phenomenology · Physics 2023-10-30 Tao Han , Matthew Low , Tong Arthur Wu

The recently observed excess in diphoton events at around 750\,GeV can be satisfactorily described in terms of a new spin-0 real singlet with effective interactions to the gauge bosons. In this letter we first review the current constraints…

High Energy Physics - Phenomenology · Physics 2016-07-22 M. Chala , C. Grojean , M. Riembau , T. Vantalon

Top quarks produced in multi-TeV processes will have large Lorentz boosts, and their decay products will be highly collimated. In semileptonic decay modes, this often leads to the merging of the b-jet and the hard lepton according to…

High Energy Physics - Phenomenology · Physics 2011-04-04 Keith Rehermann , Brock Tweedie

In the attempt to fully profile a $Z'$ boson accessible at the Large Hadron Collider (LHC), we study the sensitivity of di-lepton (for the electron, muon and tauon cases) and di-quark (for the case of the heavy flavours, $t$ and, possibly,…

High Energy Physics - Phenomenology · Physics 2015-06-05 L. Basso , K. Mimasu , S. Moretti

We investigate the sensitivity of top pair production to the properties of different Beyond the Standard Model theories embedding a new neutral boson. We include six-fermion decay, and account for the full tree-level Standard Model ttbar…

High Energy Physics - Phenomenology · Physics 2016-12-12 Lucio Cerrito , Declan Millar , Stefano Moretti , Francesco Spanò