Correlating <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>A</mml:mi> <mml:mo stretchy="false">→</mml:mo> <mml:mi>γ</mml:mi> <mml:mi>γ</mml:mi> </mml:math> with electric dipole moments in the two Higgs doublet model in light of the diphoton excesses at 95 GeV and 152 GeV

Abstract

We examine the correlations between new scalar boson decays to photons and electric dipole moments (EDMs) in the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mi>C</a:mi> <a:mi>P</a:mi> </a:mrow> </a:math> -violating flavor-aligned two-Higgs-doublet model (2HDM). It is convenient to work in the Higgs basis <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mo stretchy="false">{</c:mo> <c:msub> <c:mi mathvariant="script">H</c:mi> <c:mn>1</c:mn> </c:msub> <c:mo>,</c:mo> <c:msub> <c:mi mathvariant="script">H</c:mi> <c:mn>2</c:mn> </c:msub> <c:mo stretchy="false">}</c:mo> </c:math> where only the first Higgs doublet field <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"> <i:msub> <i:mi mathvariant="script">H</i:mi> <i:mn>1</i:mn> </i:msub> </i:math> acquires a vacuum expectation value. In light of the LHC Higgs data, which agree well with Standard Model (SM) predictions, it follows that the parameters of the 2HDM are consistent with the Higgs alignment limit. In this parameter regime, the observed SM-like Higgs boson resides almost entirely in <l:math xmlns:l="http://www.w3.org/1998/Math/MathML" display="inline"> <l:msub> <l:mi mathvariant="script">H</l:mi> <l:mn>1</l:mn> </l:msub> </l:math> , and the other two physical neutral scalars, which reside almost entirely in <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"> <o:msub> <o:mi mathvariant="script">H</o:mi> <o:mn>2</o:mn> </o:msub> </o:math> , are approximate eigenstates of <r:math xmlns:r="http://www.w3.org/1998/Math/MathML" display="inline"> <r:mi>C</r:mi> <r:mi>P</r:mi> </r:math> (denoted by the <t:math xmlns:t="http://www.w3.org/1998/Math/MathML" display="inline"> <t:mi>C</t:mi> <t:mi>P</t:mi> </t:math> -even <v:math xmlns:v="http://www.w3.org/1998/Math/MathML" display="inline"> <v:mi>H</v:mi> </v:math> and the <x:math xmlns:x="http://www.w3.org/1998/Math/MathML" display="inline"> <x:mi>C</x:mi> <x:mi>P</x:mi> </x:math> -odd <z:math xmlns:z="http://www.w3.org/1998/Math/MathML" display="inline"> <z:mi>A</z:mi> </z:math> ). In the Higgs basis, the scalar potential term <bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" display="inline"> <bb:msub> <bb:mover accent="true"> <bb:mi>Z</bb:mi> <bb:mo stretchy="false">¯</bb:mo> </bb:mover> <bb:mn>7</bb:mn> </bb:msub> <bb:msubsup> <bb:mi mathvariant="script">H</bb:mi> <bb:mn>1</bb:mn> <bb:mi>†</bb:mi> </bb:msubsup> <bb:msub> <bb:mi mathvariant="script">H</bb:mi> <bb:mn>2</bb:mn> </bb:msub> <bb:msubsup> <bb:mi mathvariant="script">H</bb:mi> <bb:mn>2</bb:mn> <bb:mi>†</bb:mi> </bb:msubsup> <bb:msub> <bb:mi mathvariant="script">H</bb:mi> <bb:mn>2</bb:mn> </bb:msub> <bb:mo>+</bb:mo> <bb:mi mathvariant="normal">H</bb:mi> <bb:mo>.</bb:mo> <bb:mi mathvariant="normal">c</bb:mi> <bb:mo>.</bb:mo> </bb:math> governs the charged-Higgs loop contributions to the decay of <lb:math xmlns:lb="http://www.w3.org/1998/Math/MathML" display="inline"> <lb:mi>H</lb:mi> </lb:math> and <nb:math xmlns:nb="http://www.w3.org/1998/Math/MathML" display="inline"> <nb:mi>A</nb:mi> </nb:math> to photons. If <pb:math xmlns:pb="http://www.w3.org/1998/Math/MathML" display="inline"> <pb:mi>Re</pb:mi> <pb:msub> <pb:mover accent="true"> <pb:mi>Z</pb:mi> <pb:mo stretchy="false">¯</pb:mo> </pb:mover> <pb:mn>7</pb:mn> </pb:msub> <pb:mi>Im</pb:mi> <pb:msub> <pb:mover accent="true"> <pb:mi>Z</pb:mi> <pb:mo stretchy="false">¯</pb:mo> </pb:mover> <pb:mn>7</pb:mn> </pb:msub> <pb:mo>≠</pb:mo> <pb:mn>0</pb:mn> </pb:math> , then <vb:math xmlns:vb="http://www.w3.org/1998/Math/MathML" display="inline"> <vb:mi>C</vb:mi> <vb:mi>P</vb:mi> </vb:math> -violating effects are present and allow for an <xb:math xmlns:xb="http://www.w3.org/1998/Math/MathML" display="inline"> <xb:msup> <xb:mi>H</xb:mi> <xb:mo>+</xb:mo> </xb:msup> <xb:msup> <xb:mi>H</xb:mi> <xb:mo>−</xb:mo> </xb:msup> <xb:mi>A</xb:mi> </xb:math> coupling, which can yield a sizable branching ratio for <zb:math xmlns:zb="http://www.w3.org/1998/Math/MathML" display="inline"> <zb:mi>A</zb:mi> <zb:mo stretchy="false">→</zb:mo> <zb:mi>γ</zb:mi> <zb:mi>γ</zb:mi> </zb:math> . These <cc:math xmlns:cc="http://www.w3.org/1998/Math/MathML" display="inline"> <cc:mi>C</cc:mi> <cc:mi>P</cc:mi> </cc:math> -violating effects also generate nonzero EDMs for the electron, the neutron and the proton. We examine these correlations for the cases of <ec:math xmlns:ec="http://www.w3.org/1998/Math/MathML" display="inline"> <ec:msub> <ec:mi>m</ec:mi> <ec:mi>A</ec:mi> </ec:msub> <ec:mo>=</ec:mo> <ec:mn>95</ec:mn> <ec:mtext> </ec:mtext> <ec:mtext> </ec:mtext> <ec:mi>GeV</ec:mi> </ec:math> and <gc:math xmlns:gc="http://www.w3.org/1998/Math/MathML" display="inline"> <gc:msub> <gc:mi>m</gc:mi> <gc:mi>A</gc:mi> </gc:msub> <gc:mo>=</gc:mo> <gc:mn>152</gc:mn> <gc:mtext> </gc:mtext> <gc:mtext> </gc:mtext> <gc:mi>GeV</gc:mi> </gc:math> where interesting excesses in the diphoton spectrum have been observed at the LHC. These excesses can be explained via the decay of <ic:math xmlns:ic="http://www.w3.org/1998/Math/MathML" display="inline"> <ic:mi>A</ic:mi> </ic:math> while being consistent with the experimental bound for the electron EDM in regions of parameter space that can be tested with future neutron and proton EDM measurements. This allows for the interesting possibility where the 95 GeV diphoton excess can be identified with <kc:math xmlns:kc="http://www.w3.org/1998/Math/MathML" display="inline"> <kc:mi>A</kc:mi> </kc:math> , while <mc:math xmlns:mc="http://www.w3.org/1998/Math/MathML" display="inline"> <mc:msub> <mc:mi>m</mc:mi> <mc:mi>H</mc:mi> </mc:msub> <mc:mo>≃</mc:mo> <mc:mn>98</mc:mn> <mc:mtext> </mc:mtext

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