Combined explanation of LHC multilepton, diphoton, and top-quark excesses

Abstract

In this article, we propose the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mi mathvariant="normal">Δ</a:mi> <a:mn>2</a:mn> <a:mi>HDM</a:mi> <a:mi mathvariant="normal">S</a:mi> </a:mrow> </a:math> as a combined explanation of several excesses and anomalies observed at the LHC. Especially, <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mi>t</e:mi> <e:mover accent="true"> <e:mi>t</e:mi> <e:mo stretchy="false">¯</e:mo> </e:mover> </e:math> differential distributions point towards the associated production of new electroweak scale Higgs bosons decaying into bottom quarks and <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"> <i:mi>W</i:mi> </i:math> bosons ( <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"> <k:mo>&gt;</k:mo> <k:mn>5</k:mn> <k:mi>σ</k:mi> </k:math> ) with masses consistent with the diphoton excesses at <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:mo>≈</m:mo> <m:mn>95</m:mn> <m:mtext> </m:mtext> <m:mtext> </m:mtext> <m:mi>GeV</m:mi> </m:math> and <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"> <o:mo>≈</o:mo> <o:mn>151.5</o:mn> <o:mtext> </o:mtext> <o:mtext> </o:mtext> <o:mi>GeV</o:mi> </o:math> ( <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"> <q:mn>3.8</q:mn> <q:mi>σ</q:mi> </q:math> and <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"> <s:mn>4.9</s:mn> <s:mi>σ</s:mi> </s:math> , respectively). Furthermore, CMS found indications for resonant <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"> <u:mi>t</u:mi> <u:mover accent="true"> <u:mi>t</u:mi> <u:mo stretchy="false">¯</u:mo> </u:mover> </u:math> production at <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline"> <y:mo>≈</y:mo> <y:mn>400</y:mn> <y:mtext> </y:mtext> <y:mtext> </y:mtext> <y:mi>GeV</y:mi> </y:math> ( <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline"> <ab:mn>3.5</ab:mn> <ab:mi>σ</ab:mi> </ab:math> ) and both ATLAS and CMS reported elevated four-top and <cb:math xmlns:cb="http://www.w3.org/1998/Math/MathML" display="inline"> <cb:mi>t</cb:mi> <cb:mover accent="true"> <cb:mi>t</cb:mi> <cb:mo stretchy="false">¯</cb:mo> </cb:mover> <cb:mi>W</cb:mi> </cb:math> cross sections. The <gb:math xmlns:gb="http://www.w3.org/1998/Math/MathML" display="inline"> <gb:mrow> <gb:mi mathvariant="normal">Δ</gb:mi> <gb:mn>2</gb:mn> <gb:mi>HDM</gb:mi> <gb:mi mathvariant="normal">S</gb:mi> </gb:mrow> </gb:math> is obtained by supplementing the SM Higgs ( <kb:math xmlns:kb="http://www.w3.org/1998/Math/MathML" display="inline"> <kb:msub> <kb:mi>H</kb:mi> <kb:mn>2</kb:mn> </kb:msub> </kb:math> ) with a second scalar doublet ( <mb:math xmlns:mb="http://www.w3.org/1998/Math/MathML" display="inline"> <mb:msub> <mb:mi>H</mb:mi> <mb:mn>1</mb:mn> </mb:msub> </mb:math> ), real scalar singlet ( <ob:math xmlns:ob="http://www.w3.org/1998/Math/MathML" display="inline"> <ob:mi>S</ob:mi> </ob:math> ), and a Higgs triplet with zero hypercharge ( <qb:math xmlns:qb="http://www.w3.org/1998/Math/MathML" display="inline"> <qb:mi mathvariant="normal">Δ</qb:mi> </qb:math> ). We fix the masses of the neutral tripletlike and the singletlike scalars by the diphoton excesses, i.e., <tb:math xmlns:tb="http://www.w3.org/1998/Math/MathML" display="inline"> <tb:msub> <tb:mi>m</tb:mi> <tb:msup> <tb:mi mathvariant="normal">Δ</tb:mi> <tb:mn>0</tb:mn> </tb:msup> </tb:msub> <tb:mo>=</tb:mo> <tb:mn>151.5</tb:mn> <tb:mtext> </tb:mtext> <tb:mtext> </tb:mtext> <tb:mi>GeV</tb:mi> </tb:math> and <wb:math xmlns:wb="http://www.w3.org/1998/Math/MathML" display="inline"> <wb:msub> <wb:mi>m</wb:mi> <wb:mi>S</wb:mi> </wb:msub> <wb:mo>=</wb:mo> <wb:mn>95</wb:mn> <wb:mtext> </wb:mtext> <wb:mtext> </wb:mtext> <wb:mi>GeV</wb:mi> </wb:math> , respectively. <yb:math xmlns:yb="http://www.w3.org/1998/Math/MathML" display="inline"> <yb:mrow> <yb:mi>H</yb:mi> </yb:mrow> </yb:math> , the <ac:math xmlns:ac="http://www.w3.org/1998/Math/MathML" display="inline"> <ac:mi>C</ac:mi> <ac:mi>P</ac:mi> </ac:math> -even component of <cc:math xmlns:cc="http://www.w3.org/1998/Math/MathML" display="inline"> <cc:msub> <cc:mi>H</cc:mi> <cc:mn>1</cc:mn> </cc:msub> </cc:math> , is produced via gluon fusion from a top-loop and decays dominantly to <ec:math xmlns:ec="http://www.w3.org/1998/Math/MathML" display="inline"> <ec:mi>S</ec:mi> <ec:mo>+</ec:mo> <ec:msup> <ec:mi mathvariant="normal">Δ</ec:mi> <ec:mn>0</ec:mn> </ec:msup> </ec:math> whose subsequent decays to <hc:math xmlns:hc="http://www.w3.org/1998/Math/MathML" display="inline"> <hc:msup> <hc:mi>W</hc:mi> <hc:mo>+</hc:mo> </hc:msup> <hc:msup> <hc:mi>W</hc:mi> <hc:mo>−</hc:mo> </hc:msup> </hc:math> and <jc:math xmlns:jc="http://www.w3.org/1998/Math/MathML" display="inline"> <jc:mi>b</jc:mi> <jc:mover accent="true"> <jc:mi>b</jc:mi> <jc:mo stretchy="false">¯</jc:mo> </jc:mover> </jc:math> explain the differential <nc:math xmlns:nc="http://www.w3.org/1998/Math/MathML" display="inline"> <nc:mi>t</nc:mi> <nc:mover accent="true"> <nc:mi>t</nc:mi> <nc:mo stretchy="false">¯</nc:mo> </nc:mover> </nc:math> distributions for <rc:math xmlns:rc="http://www.w3.org/1998/Math/MathML" display="inline"> <rc:mi>σ</rc:mi> <rc:mo stretchy="false">(</rc:mo> <rc:mi>p</rc:mi> <rc:mi>p</rc:mi> <rc:mo stretchy="false">→</rc:mo> <rc:mi>H</rc:mi> <rc:mo stretchy="false">→</rc:mo> <rc:mi>S</rc:mi> <rc:msup> <rc:mi mathvariant="normal">Δ</rc:mi>

Topics & Concepts