2026/05/02 by Siddharth P. Maharathy, Srimoy Bhattacharya, Andreas Crivellin +6
Physics and Astronomy · #Particle physics theoretical and experimental studies #Neutrino Physics Research #Particle Detector Development and Performance
paper · pdf · doi:10.1140/epjc/s10052-026-16082-4
Abstract Excesses in di-photon, Zγ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Z</mml:mi> <mml:mi>γ</mml:mi> </mml:mrow> </mml:math> , and WW spectra indicate the existence of a new Higgs boson with mass 152± 1 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>152</mml:mn> <mml:mo>±</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> GeV. However, no excess is observed in the ZZ channel. This pattern aligns with a Real Higgs Triplet model with hypercharge Y = 0 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Y</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0</mml:mn> </mml:mrow> </mml:math> ( \varDelta \hbox SM <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Δ</mml:mi> <mml:mtext>SM</mml:mtext> </mml:mrow> </mml:math> ). A prediction of this model is the Drell–Yan production of scalars at the LHC, which dominantly decay to electroweak bosons, thus enhancing the cross sections of triboson channels such as WWZ , WZZ , and WWW . Interestingly, both ATLAS and CMS have reported higher-than-expected significances for such processes: 6.4σ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>6.4</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> </mml:math> (observed) vs 4.7σ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>4.7</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> </mml:math> (expected) in the VVZ (where V = W <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>V</mml:mi> <mml:mo>=</mml:mo> <mml:mi>W</mml:mi> </mml:mrow> </mml:math> or Z ) channel and 4.4σ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>4.4</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> </mml:math> vs 3.6σ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>3.6</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> </mml:math> in WWZ , suggesting the possibility that these signals may be the manifestations of an extended Higgs sector. We investigate whether the \varDelta <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Δ</mml:mi> </mml:math> SM can account for these triboson excesses through electroweak production and decay of triplet scalars. We find that while current data prefers a non-zero new physics signal ( 2.6σ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>2.6</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> </mml:math> ), the \varDelta <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Δ</mml:mi> </mml:math> SM predicts more events than observed, such that it is consistent with data but not preferred over the SM. However, this tension could be clarified with Run 3 and HL-LHC data.