Higgs boson discovery potential of LHC in the channel pp→γγ+jet

Abstract

We discuss the SM Higgs discovery potential of LHC in the reaction pp → H + jet → γγ + jet when the jet is observed at sufficiently high E t to be reliably identified. We conclude that this channel gives promising discovery possibilities for the Higgs boson mass range 100-140 GeV, during LHC operation at a low luminosity. With 30 fb −1 of accumulated data and for M H = 120 GeV about 100 signal events could be observed with the number of background events larger by a factor of 2 only, showing a signal significance S/ √ B ∼ 7. We use the difference of distributions in the partonic subprocess energy √ŝ for the signal and background for a better separation of the signal.

Diphoton background to Higgs boson production at the LHC with soft gluon effects

“…5;1 (1,2,3,4,5) + A [1/2] 5;1 (1,2,4,3,5) + A [1/2] 5;1 (1,4,2,3,5) + A [1/2] 5;1 (4, 1, 2, 3, 5) + A [1/2] 5;1 (3,1,2,4,5) + A [1/2] 5;1 (3,1,4,2,5) + A [1/2] 5;1 (3,4,1,2,5) + A [1/2] 5;1 (4, 3, 1, 2, 5) + A [1/2] 5;1 (2,3,1,4,5) + A [1/2] 5;1 (2,3,4,1,5) + A [1/2] 5;1 (2,4,3,1,5) + A [1/2] 5;1 (4,...…”

“…(2) The partial amplitudes A [1/2] 5;1 (1,2,3,4,5) for the various helicities of the external gluons and photons are given in Ref. [11].…”

“…Meanwhile, recent electroweak global fits [2], and the measurements of the W ± boson and top quark masses [3] suggest that the SM Higgs mass is lower than about 260 GeV. If m H is less than twice the Z 0 boson mass, as the electroweak fits hint, then at the CERN Large Hadron Collider (LHC) the most promising detection modes of the SM Higgs boson will be pp → HX → γγX [4] and the associated production pp → H jet X → γγ jet X [5]. According to earlier studies, a statistical significance on the order of 5-10 can be reached for both of these signals, actual values depending on luminosity and background estimates.…”

“…In Ref. [5] it was also found that in order to optimize the significance it is necessary to impose a 30 GeV cut on the transverse momentum of the jet, or equivalently (at NLO precision), on the Q T of the photon pair. With this cut in place extraction of the signal in the Higgs plus jet mode requires the precise knowledge of both the signal and background distributions in the mid-to high-Q T region.…”

Threshold resummation for high-transverse-momentum Higgs production at the LHC

“…A possible way to improve the signal significance for Higgs discovery in the considered mass range is to study the less inclusive γ +γ + jet(s) final states 1 , which offer several advantages [7]. In this case the photons are more energetic than for the inclusive channel, and the reconstruction of the jet in the calorimeter allows a more precise determination of the interaction vertex, improving the efficiency and mass resolution.…”