Top quark polarization as a probe of charged Higgs bosons

Abstract

We study the production and decay of a heavy charged Higgs boson in the bg → tH − and H − → bt processes at the Large Hadron Collider (LHC). We show that the chiral structure of the H − tb vertex entering both stages is sensitive to the underlying Higgs mechanism of Electro-Weak Symmetry Breaking (EWSB) and we specifically demonstrate that one could distinguish between two popular realizations of a 2-Higgs Double Model (2HDM) embedding a new H ± state, i.e., those with Type-I and -Y Yukawa couplings. The chiral structure of such a vertex, which is different in the two cases, in turn triggers a particular spin state of the top quark which is then transmitted to its decay products. Hence, both inclusive rates and exclusive observables can be used to extract the presence of such a charged Higgs boson state in LHC data.

Precise predictions for single-top production: the impact of EW corrections and QCD shower on the t-channel signature

“…The positron angular distribution cos(θ t e + j l ) carries the higher spin-analysing power (degree of correlation) with the top-quark spin. Thanks to the dependence on the top-quark spin and polarisation these distributions are sensitive to new physics [10][11][12][13]16].…”

“…Within the SM the interest in single-top production is mainly motivated by the possibility of directly extracting the value of |V tb | in the CKM matrix element [1][2][3][4][5]. Moreover, in numerous BSM scenarios, single-top production provides a sensitive probe to New Physics effects [6][7][8][9][10][11][12][13][14][15][16], possibly parametrised through dimension-6 operators [14][15][16][17][18]. Indeed, involving the heaviest of the SM particles and EW interactions, this class of processes is of paramount interest for physics beyond-the-SM (BSM).…”

Two-Higgs-Doublet Model with Soft CP-violation Confronting Electric Dipole Moments and Colliders

“…In addition to the aforementioned observables, we also study the sensitivity of the following angle [21] which applies to all the spin quantization axses used here. It was also found that the energy distributions of the top quark decay products carry some information on the polarization state of the top (anti)quark [148][149][150][151][152][153][154][155][156]. We follow the same definitions used by [150,152] and study the ratios of the different energies.…”

Searching for heavy charged Higgs bosons through top quark polarization

“…For details about the model and the constraints used in this study, we refer the interested reader to [14]. It is customary to study H ± production in association with a top quark (bg → tH − + c.c.)…”