Session D9: Higgs Searches III

Measurement of Standard Model ZZ production at ATLAS

The status of the first measurement by ATLAS of Standard Model ZZ production decaying to two leptons and two neutrinos will be presented. Using LHC data at $\sqrt{s}$ = 7 TeV taken during 2011, the expected significance of this signal is nearly 5$\sigma$. The intent is to measure the cross section of this process and to put limits on anomalous triple gauge couplings. This channel is an important background to Higgs searches with a heavy Higgs boson decaying to two Z bosons. It is also an irreducible background to associated production of a Higgs boson with a Z boson where the Higgs decays to invisible particles.   

Measurement of the ZZ diboson cross section using the leptonic decay mode with the ATLAS detector

A measurement of the $Z^{0}Z^{0}$ diboson cross section is presented using a data sample corresponding to up to $5 \* fb^{-1}$ of integrated luminosity collected at $\sqrt{s} = 7$ TeV by the ATLAS detector at the LHC in 2011. In this dataset two Z bosons decaying leptonically to electrons and/or muons are observed. Results on the triple gauge couplings will also be presented.   

Search for NMSSM Higgs production with the CMS detector

Light bosons weakly coupling to the Standard Model may appear in the context of Next-to-Minimal Supersymmetric Standard Model (NMSSM), which could resolve the tension between direct and indirect measurements of the Higgs mass. We present a search for the lightest CP-even Higgs boson (h1) decaying into two lightest CP-odd Higgs bosons (a1), followed by their decays into two pairs of collimated muons in the NMSSM. The search covers the lightest CP-odd Higgs boson (a1) mass from 0.25 to 3.5 GeV/c2 and sets upper limit on NMSSM Higgs boson production (sigma*B). It was performed using pp collisions data recorded by the CMS experiment at the LHC, at center-of-mass energy of 7 TeV, and corresponding to an integrated luminosity of 4.9 fb$^{-1}$.   

Search for di-muon decays of a light CP-odd Higgs boson produced in radiative decays of the $\Upsilon(1S)$ at BABAR

We search for di-muon decays of a light CP-odd Higgs boson ($A^0$) in the radiative decays of $\Upsilon(1S)$ mesons. The $A^0$ appears in the next-to-minimal supersymmetric extension of the Standard Model. The data sample contains $(92.8 \pm 0.8)$ million $\Upsilon(2S)$ and $(116.8 \pm 1.0)$ million $\Upsilon(3S)$ events collected by the BaBar detector at the PEP-II asymmetric $B$ Factory at the SLAC National Accelerator Laboratory. An $\Upsilon(1S)$ sample is selected by tagging the pion pair in the $\Upsilon(2S, 3S) \rightarrow \pi^+\pi^-\Upsilon(1S)$ transitions.   

Lepton Identification and Triggering for Standard Model Higgs Searches in the $\ell\nu jj$ final state at D0

We search for the standard model Higgs boson with the D0 detector at the Fermilab Tevatron collider with 9.7~fb$^{-1}$ of integrated luminosity in $p\bar{p}$ collisions at $\sqrt{s}=1.96$~TeV. In this analysis we consider lepton plus jets final states consistent with the decay process $H \to WW$, as well as $W$-associated Higgs production. Events are selected with a lepton ($e$ or $\mu$), missing $E_{T}$, and two or three reconstructed jets in the final state. To maximize sensitivity to Higgs production we update the electron identification criteria and use an inclusive trigger strategy to increase signal acceptance. This talk discusses the inclusive trigger as well as lepton ID requirements in these search channels.   

QCD and EW corrections in exclusive events at the LHC

The Higgs boson production is investigated in proton-proton collisions at next-to-leading-order accuracy in central exclusive diffractive processes at the LHC. The production process by the double Pomeron exchange is analyzed in the diffractive factorization through the Ingelman-Schlein approach, taking into account the parton content of the Pomeron by the diffractive partonic distribution function provided by the H1 Collaboration. Hence, we estimate the production cross section of the Higgs boson as well as its rapidity distribution for distinct energies of the LHC. Also, we include the gap survival probability in our calculation, which is studied in recent works and expected to lie in the range between 1{\%} and 5{\%} for the energy regime of 14 TeV. As a result, we found a production cross section of about 0.3--0.8 (1.2--3.7) fb at 7 (14) TeV, being of the same order as predicted by the two-photon and the Balitsky-Fadin-Kuraev-Lipatov Pomeron mechanisms. Therefore, assuming the selection rules of spin-parity properties, the exclusive production is a promising channel for the Higgs boson detection in the LHC.   

Missing Mass Calculator: Improvements and Application to Higgs to Ditau Searches at CMS

Reconstructing events which decay into two $\tau $'s is difficult due to the missing energy attributed to multiple neutrinos in the $\tau $ decays. Missing Mass Calculator (MMC) is a new, probabilistic mass reconstruction technique which has been shown to achieve significant improvement over previously used methods for reconstructing ditau events. The technique was first implemented and proven effective for the CDF experiment at Tevatron and later for the ATLAS experiment at the LHC. We discuss improvements to the existing MMC algorithm aimed at increasing the speed, and efficiency, as well as reconstruction accuracy and resolution, with the intention of utilizing the technique to improve the Higgs to ditau searches being conducted at the CMS experiment and achieve the sensitivity necessary to perform effective searches for Higgs in the $\tau \tau $ channel there.   

Measurement of the W boson mass at CDF

We describe a measurement of the $W$ boson mass using $\approx$ 2.2 fb$^{-1}$ of $\sqrt{s}$ = 1.96 TeV $p\bar{p}$ collision data collected by the CDF Run II detector at Fermilab. With 470,126 $W\rightarrow e\nu$ candidates and 624,708 $W\rightarrow\mu\nu$ candidates, we measure $m_W = 80387 \pm 19$ MeV/$c^{2}$. This is the most precise measurement of the $W$ boson mass to date.