Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2011-03-09
Eur.Phys.J.C71:1737,2011
Physics
High Energy Physics
High Energy Physics - Phenomenology
32 pages, 21 figures; corrected numerical errors; added analysis for LHC@7 TeV; version accepted for publication in the Eur. P
Scientific paper
10.1140/epjc/s10052-011-1737-8
We present an analysis with improved sensitivity to the light charged Higgs ($m_{H^+} < m_t-m_b$) searches in the top quark decays $t \to b H^+ \to b (\tau^+\nu_\tau) + ~{\rm c.c.}$ in the $t\bar{t}$ and single $t/\bar{t}$ production processes at the LHC. In the Minimal Supersymmetric Standard Model (MSSM), one anticipates the branching ratio ${\cal B} (H^+ \to \tau^+\nu_\tau)\simeq 1$ over almost the entire allowed $\tan \beta $ range. Noting that the $\tau^+$ arising from the decay $H^+ \to \tau^+\nu_\tau$ are predominantly right-polarized, as opposed to the $\tau^+$ from the dominant background $W^+ \to \tau^+\nu_\tau$, which are left-polarized, a number of $H^+/W^+ \to \tau^+\nu_\tau$ discriminators have been proposed and studied in the literature. We consider hadronic decays of the $\tau^\pm$, concentrating on the dominant one-prong decay channel $\tau^\pm \to \rho^\pm \nu_\tau$. The energy and $p_T$ of the charged prongs normalised to the corresponding quantities of the $\rho^\pm$ are convenient variables which serve as $\tau^\pm$ polariser. We use the distributions in these variables and several other kinematic quantities to train a boosted decision tree (BDT). Using the BDT classifier, and a variant of it called BDTD, which makes use of decorrelated variables, we have calculated the BDT(D)-response functions to estimate the signal efficiency vs. the rejection of the background. We argue that this chain of analysis has a high sensitivity to light charged Higgs searches up to a mass of 150 GeV in the decays $t \to b H^+$ (and charge conjugate) at the LHC. For the case of single top production, we also study the transverse mass of the system determined using Lagrange multipliers.
Ali Ahmed
Barreiro Fernando
Llorente Javier
No associations
LandOfFree
Improved sensitivity to charged Higgs searches in Top quark decays $t \to bH^+ \to b (τ^+ν_τ)$ at the LHC using $τ$ polarisation and multivariate tecnniques does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Improved sensitivity to charged Higgs searches in Top quark decays $t \to bH^+ \to b (τ^+ν_τ)$ at the LHC using $τ$ polarisation and multivariate tecnniques, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Improved sensitivity to charged Higgs searches in Top quark decays $t \to bH^+ \to b (τ^+ν_τ)$ at the LHC using $τ$ polarisation and multivariate tecnniques will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-644836