An Introduction to Quarks and Partons. By F.E. Close. Pp.481. (Academic: London, New York and San Francisco, 1979.) £26.40; $54.50.

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Elementary particle theory

Abstract A search for an exotic decay of the Higgs boson to a pair of light pseudoscalar bosons is performed for the first time in the final state with two b quarks and two τ leptons. The search is motivated in the context of models of physics beyond the standard model (SM), such as two Higgs doublet models extended with a complex scalar singlet (2HDM + S), which include the next-to-minimal supersymmetric SM (NMSSM). The results are based on a data set of proton–proton collisions corresponding to an integrated luminosity of 35.9 fb − 1 , accumulated by the CMS experiment at the LHC in 2016 at a center-of-mass energy of 13 TeV . Masses of the pseudoscalar boson between 15 and 60 GeV are probed, and no excess of events above the SM expectation is observed. Upper limits between 3 and 12% are set on the branching fraction B ( h → a a → 2 τ 2 b ) assuming the SM production of the Higgs boson. Upper limits are also set on the branching fraction of the Higgs boson to two light pseudoscalar bosons in different 2HDM + S scenarios. Assuming the SM production cross section for the Higgs boson, the upper limit on this quantity is as low as 20% for a mass of the pseudoscalar of 40 GeV in the NMSSM.

Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state with two b quarks and two τ leptons in proton–proton collisions at √s = 13 TeV

A search for a light charged Higgs boson (H+) decaying to a W boson and a CP-odd Higgs boson (A) in final states with eμμ or μμμ is performed using data from pp collisions at s=13  TeV, recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 35.9  fb-1. In this search, it is assumed that the H+ boson is produced in decays of top quarks, and the A boson decays to two oppositely charged muons. The presence of signals for H+ boson masses between 100 and 160 GeV and A boson masses between 15 and 75 GeV is investigated. No evidence for the production of the H+ boson is found. Upper limits at 95% confidence level are obtained on the combined branching fraction for the decay chain, t→bH+→bW+A→bW+μ+μ-, of 1.9×10-6 to 8.6×10-6, depending on the masses of the H+ and A bosons. These are the first limits for these decay modes of the H+ and A bosons.

https://biblio.ugent.be/publication/8657711/file/8657954.pdf

Search for a Light Charged Higgs Boson Decaying to a W Boson and a CP -Odd Higgs Boson in Final States with eμμ or μμμ in Proton-Proton Collisions at s =13 TeV

We study the τ+τ− decay mode of a light CP-odd Higgs boson of the NMSSM, a1, produced in bottom-gluon fusion at the LHC. It is shown that for high luminosity of the LHC, there exist regions of the ...

Light CP-odd Higgs boson production of the NMSSM in bottom-gluon fusion at the LHC

We analyze the Next-to-minimal supersymmetric Standard Model with Grand unification boundary conditions under current theoretical and experimental constraints. We compute the mass spectrum of the m...

Impact of LHC Higgs couplings measurements on bosonic decays of the neutral Higgs sector in the scNMSSM

In this paper we examine the LHC discovery potential of the lightest CP-odd Higgs boson, a 1 , of the NMSSM produced in gluon fusion channel gg → a 1 . We evaluate the inclusive signal rates of the a 1 for a variety of decay channels and discuss its possible discovery. It is observed that the overall production and decay rates at inclusive level are quite sizable and should help extracting the a 1 signal over some regions of the NMSSM parameter space.

Discovery potential of the NMSSM CP-odd Higgs at the LHC

In this paper, we present the branching ratios of the two lightest CP-even Higgses, h 1 and h 2 , and the lightest CP-odd Higgs, a 1 , in the context of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). We find that for some regions of the parameter space, the branching fractions of a 1 into the lightest charginos ( a 1 → χ 1 + χ 1 - ) and neutralinos ( a 1 → χ 1 0 χ 1 0 ) are larger than 50 % , and can reach a 100 % level in the latter case. Furthermore, the branching ratio of the h 2 → a 1 a 1 can be equal to unity for all h 2 masses when it is a pure singlet. The above unusual channels are hallmarks of the existence of the NMSSM.

Prospects of Neutral Higgs boson decays in the NMSSM

The production of a light pseudoscalar Higgs boson in the NMSSM context at the LHC via bottom-quark fusion, b b ¯ → a 1 , followed by the a 1 → τ + τ - decay mode is discussed. We show that there exist some regions of parameter space of the NMSSM in which a low-mass CP-odd Higgs boson can be detected at the high-luminosity LHC via this production mode, provided that tan β is large enough. Since this production mode has not been studied in the context of the NMSSM so far, we present results for several benchmark points that can be probed by the LHC for extracting the a 1 signal. The production of a 1 via bottom-quark fusion in the τ + τ - final state can be exploited to measure both the bottom quark and tau lepton Yukawa couplings at the LHC.

Detection prospects of a low-mass pseudoscalar Higgs in bottom-quark fusion in the NMSSM at the LHC

In this paper, we present the branching ratios of the two lightest CP-even Higgses, $h_1$ and $h_2$, and of the lightest CP-odd Higgs, $a_1$, in the context of the Non-Minimal Supersymmetric Standard Model (NMSSM). We find that for some regions of the parameter space, the branching fractions of $a_1$ into the lightest charginos ($a_1\to \chi^+_1\chi^-_1)$ and neutralinos ($a_1\to \chi^0_1\chi^0_1)$ are larger than $50\%$, and can reach a $100 \%$ level in the latter case. Furthermore, the branching ratio of the $h_2\to a_1a_1$ can be equal to unity for all masses of $h_2$ when it is a pure singlet. The above unusual channels are hallmarks of the existence of the NMSSM.

In this paper we examine the LHC discovery potential of the lightest CP-odd Higgs boson, a1, of the NMSSM produced in gluon fusion channel gg->a1. We evaluate the inclusive signal rates of the a1 for a variety of decay channels and discuss its possible discovery. It is observed that the overall production and decay rates at inclusive level are quite sizable and should help extracting the a1 signal over some regions of the NMSSM parameter space.

M.M. Almarashi

Papers

Discovery potential of the NMSSM CP-odd Higgs at the LHC

Prospects of Neutral Higgs boson decays in the NMSSM

Detection prospects of a low-mass pseudoscalar Higgs in bottom-quark fusion in the NMSSM at the LHC

Prospects of Neutral Higgs boson decays in the NMSSM

Discovery potential of the NMSSM CP-odd Higgs at the LHC