We present an analysis of the sensitivity of current and future LHC searches for new spin-0 particles in top–anti-top-quark $$ \left(t\overline{t}\right) $$ final states, focusing on generic axion-like particles (ALPs) that are coupled to top quarks and gluons. As a first step, we derive new limits on the effective ALP Lagrangian in terms of the Wilson coefficients and $$ {c}_{\overset{\sim }{G}} $$ based on the results of the CMS search using 35 9 fb 1 of data, collected at $$ \sqrt{s} $$ = 13 TeV. We then investigate how the production of an ALP with generic couplings to gluons and top quarks can be distinguished from the production of a pseudoscalar which couples to gluons exclusively via a top-quark loop. To this end, we make use of the invariant $$ t\overline{t} $$ mass distribution and angular correlations that are sensitive to the $$ t\overline{t} $$ spin correlation. Using a mass of 400 GeV as an example, we find that already the data collected during Run 2 and Run 3 of the LHC provides an interesting sensitivity to the underlying nature of a possible new particle. We also analyze the prospects for data anticipated to be collected during the high-luminosity phase of the LHC. Finally, we compare the limits obtained from the $$ t\overline{t} $$ searches to existing experimental bounds from LHC searches for narrow di-photon resonances, from measurements of the production of four top quarks, and from global analyses of ALP–SMEFT interference effects.

Germany

Afiq Anuar

Anke Biekötter

Spain

Thomas Biekötter

Alexander Grohsjean

Sven Heinemeyer

Laurids Jeppe

Christian Schwanenberger

Georg Weiglein

ALP-ine quests at the LHC: hunting axion-like particles via peaks and dips in

The quest for supersymmetric (SUSY) particles is among the main search channels currently pursued at the LHC. Particularly, electroweak (EW) particles with masses as low as a few hundred GeV are still viable. Recent searches for the “golden channel”,  $$pp \rightarrow \tilde{\chi }_{2}^0 \tilde{\chi }_{1}^\pm \rightarrow \tilde{\chi }_{1}^0 Z^{(*)} \, \tilde{\chi }_{1}^0 W^{\pm (*)}$$  <math> <mrow> <mi>p</mi> <mi>p</mi> <mo>→</mo> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>2</mn> </mrow> <mn>0</mn> </msubsup> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>1</mn> </mrow> <mo>±</mo> </msubsup> <mo>→</mo> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>1</mn> </mrow> <mn>0</mn> </msubsup> <mmultiscripts> <mi>Z</mi> <mrow></mrow> <mrow> <mo>(</mo> <mrow></mrow> <mo>∗</mo> <mo>)</mo> </mrow> </mmultiscripts> <mspace width="0.166667em"></mspace> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>1</mn> </mrow> <mn>0</mn> </msubsup> <mmultiscripts> <mi>W</mi> <mrow></mrow> <mrow> <mo>±</mo> <mo>(</mo> <mrow></mrow> <mo>∗</mo> <mo>)</mo> </mrow> </mmultiscripts> </mrow> </math>   show consistent excesses between ATLAS and CMS in the 2 lepton, 3-lepton and mono-jet searches, assuming      and  $$\Delta m:= m_{\tilde{\chi }_{2}^0} - m_{\tilde{\chi }_{1}^0} \approx 20 \,\, \textrm{GeV}$$  <math> <mrow> <mi>Δ</mi> <mi>m</mi> <mo>:</mo> <mo>=</mo> <msub> <mi>m</mi> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>2</mn> </mrow> <mn>0</mn> </msubsup> </msub> <mo>-</mo> <msub> <mi>m</mi> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>1</mn> </mrow> <mn>0</mn> </msubsup> </msub> <mo>≈</mo> <mn>20</mn> <mspace width="0.166667em"></mspace> <mspace width="0.166667em"></mspace> <mtext>GeV</mtext> </mrow> </math>  . This mass configuration arises naturally in SUSY scenarios with wino/bino Dark Matter (DM) or higgsino DM. In these scenarios the lightest supersymmetric particle (LSP), assumed to be the lightest neutralino,  $$\tilde{\chi }_{1}^0$$  <math> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>1</mn> </mrow> <mn>0</mn> </msubsup> </math>  , as a DM candidate is in good agreement with the observed limits on the DM content of the universe, as well as with negative results from Direct Detection (DD) experiments. We analyze these two scenarios with respect to the observed excesses, taking into account all relevant experimental constraints. We show that in particular wino/bino DM with different signs of the SU(2) and U(1) soft SUSY-breaking parameters can describe well the experimental excesses, while being in agreement with all other constraints.

United Kingdom

Manimala Chakraborti

India

Ipsita Saha

Consistent excesses in the search for  $$\varvec{\tilde{\chi }_{2}^0\tilde{\chi }_{1}^\pm :}$$  <math> <mrow> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>2</mn> </mrow> <mn>0</mn> </msubsup> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>1</mn> </mrow> <mo>±</mo> </msubsup> <mo>:</mo> </mrow> </math>   wino/bino vs. Higgsino dark matter

CMS and ATLAS have reported small excesses in the search for low-mass Higgs bosons in the diphoton decay channel at exactly the same mass, 95.4 GeV. These searches rely on improved analysis techniques, enhancing in particular the discrimination against the <math><mrow><mi>Z</mi><mo>→</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> background. In models beyond the Standard Model (SM) that extend the Higgs sector with triplets, doubly charged Higgs bosons are predicted which can contribute substantially to the diphoton decay rate of a light Higgs boson. The Georgi-Machacek (GM) Model is of particular interest in this context, since despite containing Higgs triplets it preserves the electroweak <math><mi>ρ</mi></math>-parameter to be 1 at the tree level. We show that within the GM model, a Higgs boson with a mass of <math><mo>∼</mo><mn>95</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> with a diphoton decay rate as observed by CMS and ATLAS can be well-described. We discuss the diphoton excess in conjunction with an excess in the <math><mi>b</mi><mover><mi>b</mi><mo>¯</mo></mover></math> final state observed at LEP and an excess observed by CMS in the ditau final state, which have been found at comparable masses with local significances of about <math><mn>2</mn><mi>σ</mi></math> and <math><mn>3</mn><mi>σ</mi></math>, respectively. The presence of a Higgs boson at about 95 GeV within the GM model would imply good prospects of the searches for additional light Higgs bosons. In particular, the observed excess in the diphoton channel would be expected to be correlated in the GM model with a light doubly charged Higgs boson in the mass range between 100 and 200 GeV, which motivates dedicated searches in upcoming LHC Runs.

United States

Ting-Kuo Chen

China

Cheng-Wei Chiang

95 GeV Higgs boson in the Georgi-Machacek model

Slepton coannihilation is one of the most promising scenarios that can bring the predicted Dark Matter (DM) abundance in the the Minimal Supersymmetric Standard Model (MSSM) into agreement with the experimental observation. In this scenario, the lightest supersymmetric particle (LSP), usually assumed to be the lightest neutralino,  $$\tilde{\chi }_{1}^0$$  <math> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>1</mn> </mrow> <mn>0</mn> </msubsup> </math>   can serve as a Dark Matter (DM) candidate while the sleptons as the next-to-LSPs (NLSPs) lie close in mass. In our previous studies analyzing the electroweak sector of MSSM, a degeneracy between the three generations of sleptons was assumed for the sake of simplicity. In case of slepton coannihilation this directly links the smuons involved in the explanation for  $$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>   to the coannihilating NLSPs required to explain the DM content of the universe. On the other hand, in well-motivated top-down models such degeneracy do not hold, and often the lighter stau turns out to be the NLSP at the electroweak (EW) scale, with the smuons (and selectrons) somewhat heavier. In this paper we analyze such a scenario at the EW scale assuming non-universal slepton masses where the first two generations of sleptons are taken to be mass-degenerate and heavier than the staus, enforcing stau coannihilation. We analyze the parameter space of the electroweak MSSM in the light of a variety of experimental data namely, the DM relic density and direct detection limits, LHC data and especially, the discrepancy between the experimental result for the anomalous magnetic moment of the muon,  $$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>  , and its Standard Model (SM) prediction. We find an upper limit on the lightest neutralino mass, the lighter stau mass and the mass of the tau sneutrino of about  $$\sim 550 \,\, {\textrm{GeV}}$$  <math> <mrow> <mo>∼</mo> <mn>550</mn> <mspace width="0.166667em"></mspace> <mspace width="0.166667em"></mspace> <mtext>GeV</mtext> </mrow> </math>  . In contrast to the scenario with full degeneracy among the three families of sleptons, the upper limit on the light smuon/selectron mass moves up by  $$\sim 200 \,\, {\textrm{GeV}}$$  <math> <mrow> <mo>∼</mo> <mn>200</mn> <mspace width="0.166667em"></mspace> <mspace width="0.166667em"></mspace> <mtext>GeV</mtext> </mrow> </math>  . We analyze the DD prospects as well as the physics potential of the HL-LHC and a future high-energy  $$e^+e^-$$  <math> <mrow> <msup> <mi>e</mi> <mo>+</mo> </msup> <msup> <mi>e</mi> <mo>-</mo> </msup> </mrow> </math>   collider to investigate this scenario further. We find that the combination DD experiments and  $$e^+e^-$$  <math> <mrow> <msup> <mi>e</mi> <mo>+</mo> </msup> <msup> <mi>e</mi> <mo>-</mo> </msup> </mrow> </math>   collider searches with center of mass energies up to  $$\sqrt{s} \sim 1100 \,\, {\textrm{GeV}}$$  <math> <mrow> <msqrt> <mi>s</mi> </msqrt> <mo>∼</mo> <mn>1100</mn> <mspace width="0.166667em"></mspace> <mspace width="0.166667em"></mspace> <mtext>GeV</mtext> </mrow> </math>   can fully cover this scenario.

$$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>   and stau coannihilation: dark matter and collider analysis

The ATLAS Collaboration has recently reported the results of a low-mass Higgs-boson search in the diphoton final state based on the full Run 2 dataset. The results are based on an improved analysis with respect to the previous analysis, which included a part of the Run 2 data, with a substantially better sensitivity. The “model-dependent” search carried out by ATLAS shows an excess of events at a mass of about 95.4 GeV with a local significance of <math><mn>1.7</mn><mi>σ</mi></math>. The results are compatible with a previously reported excess at the same mass, but with somewhat higher significance of <math><mn>2.9</mn><mi>σ</mi></math>, from the CMS collaboration, also based on the full Run 2 dataset. Combining the two results (neglecting possible correlations), we find a signal strength of <math><msubsup><mi>μ</mi><mrow><mi>γ</mi><mi>γ</mi></mrow><mrow><mi>ATLAS</mi><mo>+</mo><mi>CMS</mi></mrow></msubsup><mo>=</mo><msubsup><mn>0.24</mn><mrow><mo>−</mo><mn>0.08</mn></mrow><mrow><mo>+</mo><mn>0.09</mn></mrow></msubsup></math>, corresponding to an excess of <math><mn>3.1</mn><mi>σ</mi></math>. In this work, we investigate the implications of this result, updating a previous analysis based solely on the CMS Run 2 data. We demonstrate that the ATLAS/CMS combined diphoton excess can be interpreted as the lightest Higgs boson in a Two-Higgs doublet model that is extended by a complex singlet (S2HDM) of Yukawa types II and IV, while being in agreement with all other experimental and theoretical constraints.

95.4 GeV diphoton excess at ATLAS and CMS

Recently the ATLAS collaboration has reported the first results of searches for heavy scalar resonances decaying into a Z boson and a lighter new scalar resonance, where the Z boson decays leptonically and the lighter scalar decays into a top-quark pair, giving rise to   <math> <msup> <mi>ℓ</mi> <mo>+</mo> </msup> <msup> <mi>ℓ</mi> <mo>−</mo> </msup> <mi>t</mi> <mover> <mi>t</mi> <mo>¯</mo> </mover> </math>  $$ {\ell}^{+}{\ell}^{-}t\overline{t} $$  final states. This had previously been identified as a smoking-gun signature at the LHC for a first-order electroweak phase transition (FOEWPT) within the framework of two Higgs doublet models (2HDMs). In addition, ATLAS also presented new limits where the Z boson decays into pairs of neutrinos and the lighter scalar resonance into bottom-quark pairs, giving rise to the   <math> <mi>ννb</mi> <mover> <mi>b</mi> <mo>¯</mo> </mover> </math>  $$ \nu \nu b\overline{b} $$  final state. We analyze the impact of these new searches on the 2HDM parameter space, with emphasis on their capability to probe currently allowed 2HDM regions featuring a strong FOEWPT. We also study the complementarity of these new searches with other LHC probes that could target the FOEWPT region of the 2HDM. Remarkably, the ATLAS search in the   <math> <msup> <mi>ℓ</mi> <mo>+</mo> </msup> <msup> <mi>ℓ</mi> <mo>−</mo> </msup> <mi>t</mi> <mover> <mi>t</mi> <mo>¯</mo> </mover> </math>  $$ {\ell}^{+}{\ell}^{-}t\overline{t} $$  final state shows a local 2.85 σ excess (for masses of about 650 GeV and 450 GeV for the heavy and light resonance) in the 2HDM parameter region that would yield a FOEWPT in the early universe, which could constitute the first experimental hint of baryogenesis at the electroweak scale. We analyze the implications of this excess, and discuss the detectability prospects for the associated gravitational wave signal from the FOEWPT. Furthermore, we project the sensitivity reach of the   <math> <msup> <mi>ℓ</mi> <mo>+</mo> </msup> <msup> <mi>ℓ</mi> <mo>−</mo> </msup> <mi>t</mi> <mover> <mi>t</mi> <mo>¯</mo> </mover> </math>  $$ {\ell}^{+}{\ell}^{-}t\overline{t} $$  signature for the upcoming runs of the LHC. Finally, we introduce the python package thdmTools, a state-of-art tool for the exploration of the 2HDM.

Jose No

Kateryna Radchenko

France

María Olea Romacho

First shot of the smoking gun: probing the electroweak phase transition in the 2HDM with novel searches for A → ZH in   <math> <msup> <mi>ℓ</mi> <mo>+</mo> </msup> <msup> <mi>ℓ</mi> <mo>−</mo> </msup> <mi>t</mi> <mover> <mi>t</mi> <mo>¯</mo> </mover> </math>  $$ {\ell}^{+}{\ell}^{-}t\overline{t} $$  and   <math> <mi>ννb</mi> <mover> <mi>b</mi> <mo>¯</mo> </mover> </math>  $$ \nu \nu b\overline{b} $$  final states

The CMS collaboration has recently reported the results of a low-mass Higgs-boson search in the di-photon final state based on the full Run 2 data set with refined analysis techniques. The new results show an excess of events at a mass of about 95 GeV with a local significance of <math><mn>2.9</mn><mspace width="0.2em"></mspace><mi>σ</mi></math>, confirming a previously reported excess at about the same mass and similar significance based on the first-year Run 2 plus Run 1 data. The observed excess is compatible with the limits obtained in the corresponding ATLAS searches. In this work, we discuss the di-photon excess and show that it can be interpreted as the lightest Higgs boson in the Two-Higgs doublet model that is extended by a complex singlet (S2HDM) of Yukawa types II and IV. We show that the second-lightest Higgs boson is in good agreement with the current LHC Higgs-boson measurements of the state at 125 GeV, and that the full scalar sector is compatible with all theoretical and experimental constraints. Furthermore, we discuss the di-photon excess in conjunction with an excess in the <math><mi>b</mi><mover><mrow><mi>b</mi></mrow><mrow><mo>¯</mo></mrow></mover></math> final state observed at LEP and an excess observed by CMS in the di-tau final state, which were found at comparable masses with local significances of about 2σ and 3σ, respectively. We find that the <math><mi>b</mi><mover><mrow><mi>b</mi></mrow><mrow><mo>¯</mo></mrow></mover></math> excess can be well described together with the di-photon excess in both types of the S2HDM. However, the di-tau excess can only be accommodated at the level of 1σ in type IV. We also comment on the compatibility with supersymmetric scenarios and other extended Higgs sectors, and we discuss how the potential signal can be further analyzed at the LHC and at future <math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></math> colliders.

The CMS di-photon excess at 95 GeV in view of the LHC Run 2 results

$${\mathcal {C}}{\mathcal {P}}$$  <math> <mrow> <mi>C</mi> <mi>P</mi> </mrow> </math>   violation in the Higgs couplings to fermions is an intriguing, but not yet extensively explored possibility. We use inclusive and differential LHC Higgs boson measurements to fit the  $${\mathcal {C}}{\mathcal {P}}$$  <math> <mrow> <mi>C</mi> <mi>P</mi> </mrow> </math>   structure of the Higgs Yukawa couplings. Starting with simple effective models featuring  $${\mathcal {C}}{\mathcal {P}}$$  <math> <mrow> <mi>C</mi> <mi>P</mi> </mrow> </math>   violation in a single Higgs–fermion coupling, we probe well-motivated models with up to nine free parameters. We also investigate the complementarity of LHC constraints with the electron electric dipole moment bound, taking into account the possibility of a modified electron Yukawa coupling, and assess to which extent  $${\mathcal {C}}{\mathcal {P}}$$  <math> <mrow> <mi>C</mi> <mi>P</mi> </mrow> </math>   violation in the Higgs–fermion couplings can contribute to the observed baryon asymmetry of the universe. Even after including the recent analysis of angular correlations in  $$H\rightarrow \tau ^+\tau ^-$$  <math> <mrow> <mi>H</mi> <mo>→</mo> <msup> <mi>τ</mi> <mo>+</mo> </msup> <msup> <mi>τ</mi> <mo>-</mo> </msup> </mrow> </math>   decays, we find that a complex tau Yukawa coupling alone may be able to account for the observed baryon asymmetry, but with large uncertainties in the baryogenesis calculation. A combination of complex top and bottom quark Yukawa couplings yields a result four times larger than the sum of their separate contributions, but remains insufficient to account for the observed baryon asymmetry.

Henning Bahl

CERN

Elina Fuchs

Judith Katzy

Marco Menen

Krisztian Peters

Matthias Saimpert

Constraining the  $${\mathcal {C}}{\mathcal {P}}$$  <math> <mrow> <mi>C</mi> <mi>P</mi> </mrow> </math>   structure of Higgs-fermion couplings with a global LHC fit, the electron EDM and baryogenesis

The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for a variety of experimental data. The EW particles with masses of a few hundred GeV evade the LHC searches owing to their small production cross sections. Such a light EW sector can in particular explain the reinforced  $$4.2\,\sigma $$  <math> <mrow> <mn>4.2</mn> <mspace width="0.166667em"></mspace> <mi>σ</mi> </mrow> </math>   discrepancy between the experimental result for the anomalous magnetic moment of the muon,  $$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>  , and its Standard Model (SM) prediction. The lightest supersymmetric particle (LSP), assumed to be the lightest neutralino,  $${\tilde{\chi }_{1}}^0$$  <math> <msup> <mrow> <msub> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mn>1</mn> </msub> </mrow> <mn>0</mn> </msup> </math>  , as a Dark Matter (DM) candidate is furthermore in agreement with the observed limits on the DM content of the universe. Here the Next-to LSP (NLSP) serves as a coannihilation partner and is naturally close in mass to the LSP. Such scenarios are also to a large extent in agreement with negative results from Direct Detection (DD) experiments. The DM relic density can fully be explained by a nearly pure bino or a mixed bino/wino LSP. Relatively light wino and higgsino DM, on the other hand, remains easily below the DM relic density upper bound. Using the improved limits on  $$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>  , we explore the mass ranges of the LSP and the NLSP in their correlation with the DM relic density for bino, bino/wino, wino and higgsino DM. In particular, we analyze the sensitivity of future DM DD experiments to these DM scenarios. We find that higgsino, wino and one type of bino scenario can be covered by future DD experiments. Mixed bino/wino and another type of bino DM can reach DD cross sections below the neutrino floor. In these cases we analyze the complementarity with the (HL-)LHC and future  $$e^+e^-$$  <math> <mrow> <msup> <mi>e</mi> <mo>+</mo> </msup> <msup> <mi>e</mi> <mo>-</mo> </msup> </mrow> </math>   linear colliders. We find that while the prospects for the HL-LHC are interesting, but not conclusive, an  $$e^+e^-$$  <math> <mrow> <msup> <mi>e</mi> <mo>+</mo> </msup> <msup> <mi>e</mi> <mo>-</mo> </msup> </mrow> </math>   collider with  $$\sqrt{s} \lesssim 1 \,\, \mathrm {TeV}$$  <math> <mrow> <msqrt> <mi>s</mi> </msqrt> <mo>≲</mo> <mn>1</mn> <mspace width="0.166667em"></mspace> <mspace width="0.166667em"></mspace> <mi>TeV</mi> </mrow> </math>   can cover effectively all points of the MSSM that may be missed by DD experiments.

Poland

Japan

Christian Schappacher

$$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>   and SUSY dark matter: direct detection and collider search complementarity

The electroweak (EW) sector of the Minimal Supersymmetric extension of the Standard Model (MSSM), assuming the lightest neutralino as Dark Matter (DM) candidate, can account for a variety of experimental results. This includes the DM direct detection limits, the searches for EW superpartners at the LHC, and in particular the discrepancy between the experimental result for the anomalous magnetic moment of the muon,  $$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>  , and its Standard Model (SM) prediction. The new “MUON G-2” result, combined with the older BNL result on  $$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>  , yields a deviation from the SM prediction of  $$\Delta a_\mu = ({25.1}\pm {5.9}) \times 10^{-10}$$  <math> <mrow> <mi>Δ</mi> <msub> <mi>a</mi> <mi>μ</mi> </msub> <mo>=</mo> <mrow> <mo>(</mo> <mrow> <mn>25.1</mn> </mrow> <mo>±</mo> <mrow> <mn>5.9</mn> </mrow> <mo>)</mo> </mrow> <mo>×</mo> <msup> <mn>10</mn> <mrow> <mo>-</mo> <mn>10</mn> </mrow> </msup> </mrow> </math>  , corresponding to  $${4.2}\,\sigma $$  <math> <mrow> <mrow> <mn>4.2</mn> </mrow> <mspace width="0.166667em"></mspace> <mi>σ</mi> </mrow> </math>  . Using this updated bound, together with the other constraints, we calculate the MSSM prediction for the mass of the W boson,  $$M_W$$  <math> <msub> <mi>M</mi> <mi>W</mi> </msub> </math>  . We assume contributions only from the EW sector, i.e. the colored sector of the MSSM, in agreement with the search limits, is taken to be heavy. We investigate five scenarios, distinguished by the mechanisms which yield a relic DM density in agreement with the latest Planck bounds. We find that with the new  $$(g-2)_\mu $$  <math> <msub> <mrow> <mo>(</mo> <mi>g</mi> <mo>-</mo> <mn>2</mn> <mo>)</mo> </mrow> <mi>μ</mi> </msub> </math>   result taken into account and depending on the scenario, values up to      are reached. The largest values are obtained for wino DM and in the case of slepton co-annihilation, where points well within the  $$1\,\sigma $$  <math> <mrow> <mn>1</mn> <mspace width="0.166667em"></mspace> <mi>σ</mi> </mrow> </math>   range of the experimental world average of  $$M_W^{\mathrm {exp}}= 80.379 \pm 0.012 \,\, \mathrm {GeV}$$  <math> <mrow> <msubsup> <mi>M</mi> <mi>W</mi> <mi>exp</mi> </msubsup> <mo>=</mo> <mn>80.379</mn> <mo>±</mo> <mn>0.012</mn> <mspace width="0.166667em"></mspace> <mspace width="0.166667em"></mspace> <mi>GeV</mi> </mrow> </math>   are reached, whereas the SM predicts a too small value of  $$M_W^{\mathrm {SM}}= 80.353 \,\, \mathrm {GeV}$$  <math> <mrow> <msubsup> <mi>M</mi> <mi>W</mi> <mi>SM</mi> </msubsup> <mo>=</mo> <mn>80.353</mn> <mspace width="0.166667em"></mspace> <mspace width="0.166667em"></mspace> <mi>GeV</mi> </mrow> </math>  . We analyze the dependence of  $$M_W^{\mathrm {MSSM}}$$  <math> <msubsup> <mi>M</mi> <mi>W</mi> <mi>MSSM</mi> </msubsup> </math>   on the relevant masses of the EW superpartners and demonstrate that future  $$M_W$$  <math> <msub> <mi>M</mi> <mi>W</mi> </msub> </math>   measurements, e.g. at the ILC, could distinguish between various MSSM realizations. Sizable contributions to  $$M_W^{\mathrm {MSSM}}$$  <math> <msubsup> <mi>M</mi> <mi>W</mi> <mi>MSSM</mi> </msubsup> </math>   are associated with a relatively light  $$\tilde{\chi }_{1}^0$$  <math> <msubsup> <mover> <mi>χ</mi> <mo>~</mo> </mover> <mrow> <mn>1</mn> </mrow> <mn>0</mn> </msubsup> </math>  , accompanied by either a light chargino or a light smuon, setting interesting targets for future collider searches.

Emanuele Bagnaschi

Interdependence of the new “MUON G-2” result and the W-boson mass