We propose a method for probing CP-violation in the heavy (pseudo)scalar sector of an extended Higgs model, in which we make simultaneous use of the $\textit{HVV}$ ( $$V=W^\pm , Z$$ ) and $$Ht\bar{t}$$ interactions of a heavy Higgs state $\textit{H}$. The CP-even component of $\textit{H}$ can be probed through the tree-level $\textit{HVV}$ interaction, while the CP-odd component of $\textit{H}$ can be probed if the final $$t\bar{t}$$ pair can be tested to form a $$^1S_0$$ state. We can then confirm CP-violation if both CP-even and CP-odd components of $\textit{H}$ are discovered. This is possible at the Compact Linear Collider (CLIC) by exploiting $\textit{H}$ production from vector-boson fusion (VBF) and decay to $$t\bar{t}$$ pairs. We analyze the distribution of the azimuthal angle between the leptons coming from top and antitop quarks, which allows one to disentangle the CP nature of such a heavy Higgs state. We also show its implications for the two-Higgs-doublet model (2HDM) with CP-violation.

South Korea

Taiwan

Kingman Cheung

China

Ying-nan Mao

Sweden

United Kingdom

Stefano Moretti

Rui Zhang

Testing CP-violation in a heavy Higgs sector at CLIC

We explain the ATOMKI anomaly with a very light $\textit{Z}$′ state that features non-anomalous and non-flavour-universal vector and axial-vector couplings to all leptons. This $\textit{Z}$′ comes from a theoretical framework with a spontaneously broken U(1)′ symmetry in addition to the Standard Model gauge group and is compliant with current measurements of the anomalous magnetic moments of the electron and the muon as well as beam dump experiments. The lepton flavour structure of this model allows for $\textit{Z}$′ couplings to all light neutrinos, suggesting the possibility of $\textit{Z}$′-mediated Non-Standard Interactions (NSIs) of neutrinos in matter, so that measurements of the strength parameters of the NSIs can constrain the value of the couplings. We use experimental constraints on NSIs of neutrinos using older TEXONO data and newer IceCube data. The IceCube data, in particular, strongly constrain the flavour universality of the leptonic vector current. The constraints enable us to define the region of parameter space of this theoretical scenario that can be pursued in further phenomenological analyses.

Rikard Enberg

Türkiye

Yaşar Hiçyılmaz

Carlos Heros

Harri Waltari

Constraints on the $\textit{X}$17 boson from IceCube searches for non-standard interactions of neutrinos

In this paper, we tension the scope of the $$ q\overline{q} $$ , $\textit{gg}$ → $$ T\overline{T} $$ production process against that of the same-charge $\textit{uu}$ → $\textit{TT}$ one in searching for Vector-Like Quarks (VLQs) with electromagnetic charge +2/3 at the Large Hadron Collider (LHC). The study is conducted by considering a simplified model in which such new states couple exclusively to Standard Model quarks of the first generation through $\textit{W}$ , $\textit{Z}$ and $\textit{H}$ currents. We consider both left-handed or right-handed dominant chiralities, representative of SU(2) singlets or doublets, and the total widths are allowed to reach large values relatively to the VLQ masses. By deconstructing the signal into all its components, we assess current and projected constraints, emphasize the role of interference terms and isolate peculiar features which can be used for dedicated searches at the LHC or future colliders.

Italy

Luca Panizzi

Liangliang Shang

Vector-like tops from first generation quarks: the role of width and coupling chiralities in same-charge production at the LHC

<p>The supersymmetric custodial triplet model (SCTM), which is a fully supersymmetric generalization of the Georgi-Machacek (GM) model, is constructed by extending the Higgs sector of the minimal supersymmetric standard model by three triplet chiral superfields with hypercharge <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi><mo>=</mo><mn>0</mn><mo>,</mo><mo>±</mo><mn>1</mn></math>, in order to maintain the holomorphy of the superpotential and satisfy the requirements of anomaly cancellation. The global <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>2</mn><msub><mo stretchy="false">)</mo><mi>L</mi></msub><mo stretchy="false">⊗</mo><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>2</mn><msub><mo stretchy="false">)</mo><mi>R</mi></msub></math> symmetry has to be respected for the superpotential and soft supersymmetry breaking sector, where the former will only be broken by the Yukawa couplings and the latter one will be broken spontaneously to the custodial <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>2</mn><msub><mo stretchy="false">)</mo><mi>V</mi></msub></math> symmetry after electroweak symmetry breaking similar to the GM model. The ensuing complicated spectrum not only gives rich collider phenomenology but also provides more available weakly interacting massive particle (WIMP) dark matter (DM) candidates. In this paper, we explore the viability of WIMP solutions for DM in the SCTM, by considering the increasingly stringent constraints from direct detection DM experiments. Our numerical simulations show that a significant portion of the SCTM parameter space remains viable despite these constraints and will be fully tested in future experiments.</p>

Yuanping Wang

Xiaokang Du

Bingfang Yang

Triplet fermion WIMP dark matter in the general supersymmetric Georgi-Machacek model

<p>We study <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation (CPV) in the sneutrino sector within the B-L extension of the minimal supersymmetric Standard Model, wherein an inverse seesaw mechanism has been implemented. CPV arises from the new superpotential couplings in the (s)neutrino sector, which can be complex and the mixing of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> eigenstates induced by those couplings. CPV leads to asymmetries in so-called T-odd observables, but we argue that such asymmetries also lead to a wider distribution of those observables. We look at a final state where a sneutrino decays to a lepton, two jets, and missing transverse momentum at the Future Circular Collider operating in hadron-hadron mode at 100 TeV and with a luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>3</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>ab</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>. In order to exclude the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> conserving scenario we need to improve traditional analysis by introducing boosted decision trees using both standard kinematic variables and T-odd observables and we need <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> boson not too much above current bounds as a portal to produce sneutrinos efficiently.</p>

India

Arindam Basu

Amit Chakraborty

Yi Liu

Leptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation in the sneutrino sector of the BLSSM with an inverse seesaw mechanism

We propose an explanation for the observed excesses around 95 GeV in the diphoton and ditau invariant mass distributions, as reported by the CMS collaboration at the Large Hadron Collider. These findings are complemented by a long-standing discrepancy in the <math><mi>b</mi><mover><mi>b</mi><mo>¯</mo></mover></math> invariant mass at the Large Electron-Positron Collider. Additionally, the ATLAS collaboration has reported a corroborative excess in the diphoton final state within the same mass range, albeit with slightly lower significance. Our approach involves the superposition of <math><mi>C</mi><mi>P</mi></math>-even and <math><mi>C</mi><mi>P</mi></math>-odd Higgs bosons within the type-III two-Higgs doublet model to simultaneously explain these excesses at <math><mrow><mn>1</mn><mi>σ</mi></mrow></math> confidence level, while remaining consistent with current theoretical and experimental constraints.

Morocco

Rachid Benbrik

Mohammed Boukidi

Superposition of <math><mrow><mi>C</mi><mi>P</mi></mrow></math>-even and <math><mi>C</mi><mi>P</mi></math>-odd Higgs resonances: Explaining the 95 GeV excesses within a two-Higgs-doublet model

In this paper, we study the discovery potential of a Vector-Like B quark (VLB) via the process  $$pp \rightarrow B(\rightarrow bZ)j\rightarrow b(Z \rightarrow \nu _l\bar{\nu _l})j$$  <math> <mrow> <mi>p</mi> <mi>p</mi> <mo>→</mo> <mi>B</mi> <mrow> <mo>(</mo> <mo>→</mo> <mi>b</mi> <mi>Z</mi> <mo>)</mo> </mrow> <mi>j</mi> <mo>→</mo> <mi>b</mi> <mrow> <mo>(</mo> <mi>Z</mi> <mo>→</mo> <msub> <mi>ν</mi> <mi>l</mi> </msub> <mover> <mrow> <msub> <mi>ν</mi> <mi>l</mi> </msub> </mrow> <mrow> <mo>¯</mo> </mrow> </mover> <mo>)</mo> </mrow> <mi>j</mi> </mrow> </math>   at the Large Hadron Collider (LHC) with  $$\sqrt{s}=14$$  <math> <mrow> <msqrt> <mi>s</mi> </msqrt> <mo>=</mo> <mn>14</mn> </mrow> </math>   TeV. In the framework of a simplified model, we perform a scan over its parameter space and test its viability following a Monte Carlo analysis developed to include all production and decay dynamics. We use cut-and-count combined with Extreme Gradient Boosting (XGBoost) methods to classify the signal and background events in order to improve the efficiency of signal identification and background rejection. We find that this approach can reduce background events significantly while the signal retention rate is much higher than that of traditional methods, thereby improving the VLB discovery potential. We then calculate the exclusion and discovery capabilities for VLBs and find that the advantages of the cut-and-count plus XGBoost method especially lie in the high-mass region, i.e.,  $$m_B &gt; 1500 \text { GeV}$$  <math> <mrow> <msub> <mi>m</mi> <mi>B</mi> </msub> <mo>&gt;</mo> <mn>1500</mn> <mspace width="0.333333em"></mspace> <mtext>GeV</mtext> </mrow> </math>  . We finally obtain the following LHC results in terms of the coupling and chiral structure of a singlet heavy VLB interactions: (i) for  $$g^{*}=0.2$$  <math> <mrow> <mmultiscripts> <mi>g</mi> <mrow></mrow> <mrow> <mrow></mrow> <mo>∗</mo> </mrow> </mmultiscripts> <mo>=</mo> <mn>0.2</mn> </mrow> </math>   and  $$R_L=0$$  <math> <mrow> <msub> <mi>R</mi> <mi>L</mi> </msub> <mo>=</mo> <mn>0</mn> </mrow> </math>   with 3000 fb $$^{-1}$$  <math> <mmultiscripts> <mrow></mrow> <mrow></mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </mmultiscripts> </math>  , the B quark mass can be be excluded (discovered) up to 3000 GeV (2500 GeV); (ii) for  $$g^{*}=0.2$$  <math> <mrow> <mmultiscripts> <mi>g</mi> <mrow></mrow> <mrow> <mrow></mrow> <mo>∗</mo> </mrow> </mmultiscripts> <mo>=</mo> <mn>0.2</mn> </mrow> </math>   and  $$R_L=0.5$$  <math> <mrow> <msub> <mi>R</mi> <mi>L</mi> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </math>   with 3000 fb $$^{-1}$$  <math> <mmultiscripts> <mrow></mrow> <mrow></mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </mmultiscripts> </math>  , the exclusion (discovery) region can reach up to 4750 GeV (4250 GeV).

Zejun Li

Xinglong Jia

Search for single vector-like B quark production in hadronic final states at the LHC

The observed excesses in the search for neutralinos and charginos by ATLAS and CMS can be fitted simultaneously in the minimal supersymmetric standard model (MSSM) assuming a light higgsino mass, of magnitude less than about 250 GeV, and a compressed higgsino dominated neutralino and chargino spectrum, with 5–10% mass splittings. However, light higgsinos as dark matter would have far too large direct detection cross sections. We consider the Next-to-MSSM (NMSSM) with an additional singlino-like lightest supersymmetric particle (LSP) a few GeV below the next-to-lightest supersymmetric particle (NLSP). Sparticles prefer to decay first into the NLSP and remnants from the final decay into the LSP are too soft to contribute to the observed signals. Co-annihilation in the higgsino-sector can generate a relic density in the WMAP/Planck window. The singlino-like LSP has automatically a direct detection cross section below present and future sensitivities: a direct detection signal in the near future would exclude this scenario. The singlet-like Higgs scalar of the NMSSM can have a mass around 95 GeV and signal cross sections in the  $$b\bar{b}$$  <math> <mrow> <mi>b</mi> <mover> <mrow> <mi>b</mi> </mrow> <mrow> <mo>¯</mo> </mrow> </mover> </mrow> </math>   channel at LEP and in the  $$\gamma \gamma $$  <math> <mrow> <mi>γ</mi> <mi>γ</mi> </mrow> </math>   channel at the LHC compatible with the respective observations.

France

Ulrich Ellwanger

Cyril Hugonie

Stephen King

NMSSM explanation for excesses in the search for neutralinos and charginos and a 95 GeV Higgs boson

We study the time-honoured decay  $$H^\pm \rightarrow A W^\pm $$  <math> <mrow> <msup> <mi>H</mi> <mo>±</mo> </msup> <mo>→</mo> <mi>A</mi> <msup> <mi>W</mi> <mo>±</mo> </msup> </mrow> </math>   but for the first time, we do so for the case of both A and  $$W^\pm $$  <math> <msup> <mi>W</mi> <mo>±</mo> </msup> </math>   being off-shell, therefore computing a  $$1\rightarrow 4$$  <math> <mrow> <mn>1</mn> <mo>→</mo> <mn>4</mn> </mrow> </math>   body decay. We show that the corresponding decay rate not only extends the reach of  $$H^\pm $$  <math> <msup> <mi>H</mi> <mo>±</mo> </msup> </math>   searches to small masses of the latter but also that the results of our implementation differ significantly from the yield of the  $$1\rightarrow 3$$  <math> <mrow> <mn>1</mn> <mo>→</mo> <mn>3</mn> </mrow> </math>   body decay over the phase space region in which the latter is normally used. We show the phenomenological relevance of this implementation in the case of the so-called lepton-specific 2-Higgs Doublet Model (2HDM) over the mass region wherein the aforementioned  $$1\rightarrow 4$$  <math> <mrow> <mn>1</mn> <mo>→</mo> <mn>4</mn> </mrow> </math>   body decay can dominate just beyond the top (anti)quark mass. This mass region is accessible in the lepton-specific 2HDM as the Yukawa couplings are such that limits from  $$b \rightarrow s \gamma $$  <math> <mrow> <mi>b</mi> <mo>→</mo> <mi>s</mi> <mi>γ</mi> </mrow> </math>   and  $$\tau \rightarrow \mu \nu _{\tau } \bar{\nu _\mu }$$  <math> <mrow> <mi>τ</mi> <mo>→</mo> <mi>μ</mi> <msub> <mi>ν</mi> <mi>τ</mi> </msub> <mover> <mrow> <msub> <mi>ν</mi> <mi>μ</mi> </msub> </mrow> <mrow> <mo>¯</mo> </mrow> </mover> </mrow> </math>   observables on  $$M_{H^\pm }$$  <math> <msub> <mi>M</mi> <msup> <mi>H</mi> <mo>±</mo> </msup> </msub> </math>   are rather mild. However, we emphasize that similar effects may occur in other 2HDM types, as the  $$W^\pm H^\mp A$$  <math> <mrow> <msup> <mi>W</mi> <mo>±</mo> </msup> <msup> <mi>H</mi> <mo>∓</mo> </msup> <mi>A</mi> </mrow> </math>   vertex is 2HDM type independent.

Muyuan Song

Enhanced four-body decays of charged Higgs bosons into off-shell pseudoscalar Higgs and  $$W^\pm $$  <math> <msup> <mi>W</mi> <mo>±</mo> </msup> </math>   boson pairs in a lepton-specific 2-Higgs doublet model

Vectorlike quarks have been predicted in various new physics scenarios beyond the Standard Model. In a simplified modelling of a <math><mo>(</mo><mi>B</mi><mo>,</mo><mi>Y</mi><mo>)</mo></math> doublet including a vectorlike quark <math><mi>Y</mi></math>, with charge <math><mrow><mo>−</mo><mfrac><mrow><mn>4</mn></mrow><mrow><mn>3</mn></mrow></mfrac><mi>e</mi></mrow></math>, there are only two free parameters: the <math><mi>Y</mi></math> coupling <math><msub><mi>κ</mi><mi>Y</mi></msub></math> and mass <math><msub><mi>m</mi><mi>Y</mi></msub></math>. In the five flavor scheme, we investigate the single production of the <math><mi>Y</mi></math> state decaying into <math><mi>W</mi><mi>b</mi></math> at the Large Hadron Collider (LHC) run-III and High-Luminosity LHC (HL-LHC) operating at <math><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>14</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, the possible High-Energy LHC (HE-LHC) with <math><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>27</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> as well as the Future Circular Collider in hadron-hadron mode (FCC-hh) with <math><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>100</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>. Through detailed signal-to-background analyses and detector simulations, we assess the exclusion capabilities of the <math><mi>Y</mi></math> state at the different colliders. We find that this can be improved significantly with increasing collision energy, especially at the HE-LHC and FCC-hh, both demonstrating an obvious advantage with respect to the HL-LHC in the case of high <math><msub><mi>m</mi><mi>Y</mi></msub></math>. Assuming a 10% systematic uncertainty on the background event rate, the exclusion capabilities are summarized as follows: (1) the LHC run-III can exclude the correlated regions of <math><msub><mi>κ</mi><mi>Y</mi></msub><mo>∈</mo><mo>[</mo><mn>0.06</mn><mo>,</mo><mn>0.5</mn><mo>]</mo></math> and <math><msub><mi>m</mi><mi>Y</mi></msub><mo>∈</mo><mo>[</mo><mn>1500</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>,</mo><mn>3800</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>]</mo></math> with integrated luminosity <math><mi>L</mi><mo>=</mo><mn>300</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>; (2) the HL-LHC can exclude the correlated regions of <math><msub><mi>κ</mi><mi>Y</mi></msub><mo>∈</mo><mo>[</mo><mn>0.05</mn><mo>,</mo><mn>0.5</mn><mo>]</mo></math> and <math><msub><mi>m</mi><mi>Y</mi></msub><mo>∈</mo><mo>[</mo><mn>1500</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>,</mo><mn>3970</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>]</mo></math> with <math><mi>L</mi><mo>=</mo><mn>3</mn><mtext> </mtext><mtext> </mtext><mrow><msup><mrow><mi>ab</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>; (3) the HE-LHC can exclude the correlated regions of <math><msub><mi>κ</mi><mi>Y</mi></msub><mo>∈</mo><mo>[</mo><mn>0.06</mn><mo>,</mo><mn>0.5</mn><mo>]</mo></math> and <math><msub><mi>m</mi><mi>Y</mi></msub><mo>∈</mo><mo>[</mo><mn>1500</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>,</mo><mn>6090</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>]</mo></math> with <math><mi>L</mi><mo>=</mo><mn>3</mn><mtext> </mtext><mtext> </mtext><mrow><msup><mrow><mi>ab</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>; (4) the FCC-hh can exclude the correlated regions of <math><msub><mi>κ</mi><mi>Y</mi></msub><mo>∈</mo><mo>[</mo><mn>0.08</mn><mo>,</mo><mn>0.5</mn><mo>]</mo></math> and <math><msub><mi>m</mi><mi>Y</mi></msub><mo>∈</mo><mo>[</mo><mn>1500</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>,</mo><mn>10080</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>]</mo></math> with <math><mi>L</mi><mo>=</mo><mn>3</mn><mtext> </mtext><mtext> </mtext><mrow><msup><mrow><mi>ab</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>.

Yuxiao Yan

Single production of an exotic vectorlike <math><mrow><mi>Y</mi></mrow></math> quark at future high energy <math><mi>p</mi><mi>p</mi></math> colliders