Explanation of the hints for a 95 GeV Higgs boson within a 2-Higgs Doublet Model
A. Belyaev, Rachid Benbrik, Mohammed Boukidi, Manimala Chakraborti, Stefano Moretti, Souad Semlali
Abstract
A bstract We suggest an explanation for and explore the consequences of the excess around 95 GeV in the di-photon and di-tau invariant mass distributions recently reported by the CMS collaboration at the Large Hadron Collider (LHC), together with the discrepancy that has long been observed at the Large Electron-Positron (LEP) collider in the $$ b\overline{b} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>b</mml:mi> <mml:mover> <mml:mi>b</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> invariant mass. Interestingly, the most recent findings announced by the ATLAS collaboration do not contradict, or even support, these intriguing observations. Their search in the di-photon final state similarly reveals an excess of events within the same mass range, albeit with a bit lower significance, thereby corroborating and somewhat reinforcing the observations made by CMS. We demonstrate that the lightest CP-even Higgs boson in the general 2-Higgs Doublet Model (2HDM) Type-III can explain simultaneously the observed excesses at approximately 1.3 σ C.L. while satisfying up-to-date theoretical and experimental constraints. Moreover, the 2HDM Type-III predicts an excess in the $$ pp\to t\overline{t}{H}_{\textrm{SM}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>pp</mml:mi> <mml:mo>→</mml:mo> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:msub> <mml:mi>H</mml:mi> <mml:mi>SM</mml:mi> </mml:msub> </mml:math> production channel of the 125 GeV Higgs boson, H SM . This effect is caused by a up to 12% enhancement of the H SM tt Yukawa coupling in comparison to that predicted by the Standard Model. Such an effect can be tested at the High Luminosity LHC (HL-LHC), which can either discover or exclude the scenario we suggest. This unique characteristic of the 2HDM Type-III makes this scenario with the 95 GeV resonance very attractive for further theoretical and experimental investigations at the (HL-)LHC and future colliders.