A quantitative discussion on the future prospects of the 750 GeV resonance at the LHC experiment is given using a simple effective field theory analysis. The relative size of two effective operators relevant to diphoton decays can be probed by ratios of diboson signals in a robust way. We obtain the future sensitivities of $Zγ$, $ZZ$ and $WW$ resonance searches at the high luminosity LHC, rescaling from the current sensitivities at $\sqrt{s}=13$ TeV. Then, we show that a large fraction of parameter space in the effective field theory will be covered with 300 fb$^{-1}$ and almost the whole parameter space will be tested with 3000 fb$^{-1}$. This discussion is independent of production processes, other decay modes and total decay width.
I will review simplified models with leptoquarks, which can explain recent anomalies in $B$-meson physics, and I will indicate the High-Luminosity LHC prospects for testing these theories, with a special focus to the efficient channel of pair leptoquark production in the $t\bar t$ plus missing energy final state.
We show prospects on a search for invisible decays of a Higgs boson at the Large Hadron Collider (LHC) and High Luminosity LHC (HL-LHC). This search is performed on a Higgs boson produced in association with a Z boson. We expect that the branching ratio of 17-22% (6-14%) could be excluded at 95% confidence level with 300 fb^{-1} (3000 fb^{-1}) of data at sqrt(s)=14 TeV. The range indicates different assumptions on the control of systematic uncertainties. Interpretations with Higgs-portal dark matter models are also considered.
High-energy collisions at the LHC are now starting. The new physics agenda of the LHC is reviewed, with emphasis on the hunt for the Higgs boson (or whatever replaces it) and supersymmetry. In particular, the prospects for discovering new physics in the 2010-2011 run are discussed.
We review the prospects of measurements of the CKM matrix elements corresponding to the first two generations of quarks, as well as measurements of leptonic and semileptonic charm meson decays at LHCb. We review the status of searches for Lepton Non-Universality in the charm sector, and provide motivation to continue such searches.
We present the results and prospects for searches beyond the Standard Model (SM) at the LHC by the ATLAS and CMS collaborations. The minimal supersymmetric extension of the SM has been investigated in various configurations and lower limits are set on the s-particle masses. The searches for other scenarios of physics beyond the SM are also presented and lower limits on the mass scale are derived in a large variety of models (new heavy gauge bosons, extra-dimensions, compositeness or dark matter). The prospects for physics using 300 /fb and 3000 /fb of data at the high luminosity LHC are also s…
The High-Luminosity Large Hadron Collider is expected to deliver up to 3000 fb$^{-1}$ of proton-proton collisions at 14 TeV center-of-mass energy. We present prospects for selected heavy-ion, Standard Model and Higgs sector measurements with the CMS detector at the HL-LHC, and discuss potential sensitivity to several beyond-Standard Model new physics scenarios.
The discovery of the Higgs boson at the LHC opened up a new possibility to obtain a precise understanding of the origin of mass and the structure of the vacuum. Several theories beyond the Standard Model predict an extended Higgs sector, with additional scalar particles. We outline the complementary search possibilities for these beyond Standard Model Higgs bosons at the LHC and at possible future high-energy collider facilities.
This article summarizes a talk given at Higgs Hunting 2014 on projections of the sensitivity of the ATLAS and CMS experiments to beyond Standard Model Higgs physics at the High Luminosity Large Hadron Collider. We describe results on vector boson scattering, searches for additional neutral Higgs bosons in two Higgs doublet models and flavour changing neutral current top decays.
We discuss the implementation of the "minimal" type III seesaw model, i.e. with one fermionic triplet, in FeynRules/MadGraph. This is the first step in order to realize a real study of LHC data recorded in the LHC detectors. With this goal in mind, we comment on the possibility of discovering this kind of new physics at the LHC running at 7 TeV with a luminosity of few fb^-1.
The charge asymmetry in hadronic top-antitop-quark production is a powerful test observable of perturbative quantum chromodynamics. Since its origin in terms of Feynman diagrams is distinct from charge-symmetric top-antitop production, probing the charge asymmetry provides complementary information to cross section measurements. Furthermore, asymmetric observables offer new ways to distinguish new physics beyond the standard model. This article summarizes prospects to investigate the top-quark charge asymmetry at the LHC in and beyond the standard model. Particular attention is given to observ…
Run 1 of the LHC has provided three new motivations for supersymmetry: the need to stabilize the electroweak vacuum, the mass of the Higgs boson, and the fact that its couplings are Standard Model-like (so far). The prospects for discovering (and measuring) supersymmetry during future runs of the LHC are discussed in the frameworks of the constrained MSSM (CMSSM), models with non-universal soft supersymmetry-breaking contributions to Higgs masses (NUHM1,2) and the phenomenological MSSM with 10 arbitrary soft supersymmetry-breaking parameters (pMSSM10). In addition to the classic searches for m…
The document is prepared for the LCWS2016 conference proceedings. The expected status of Higgs physics at the end of Run-3 is presented. The current Run-2 status is briefly reviewed, and the expected Higgs reach after the HL-LHC period is also summarized for some channels.
This document is prepared for the LCWS2016 conference proceedings. It reviews the current results on the Higgs CP property measurements from both ATLAS and CMS experiments in the Higgs to diboson decays, and in the Vector Boson Fusion production of Higgs via the ditau decay channel. The projected sensitivity of the ditau signal in HL-LHC is briefly discussed. Finally, it gives the prospects for the CP measurement in the Higgs to ditau decay with the tau substructure developments at both collaborations.
The LHC Run-1 was very successful and included the discovery of a new particle with mass of about 125 GeV compatible with the Higgs boson predicted by the Standard Model. The prospects for Higgs physics at the high-luminosity LHC and at future colliders are presented. In particular, the ultimate precision attainable for the couplings measurements of the 125 GeV particle with elementary fermions and bosons is discussed along with prospects for self-coupling measurements, for the ATLAS and CMS detectors at the upgraded LHC.
Searches for Beyond the Standard Model Higgs processes in the context of Minimal Supersymmetric Standard Model and Next to MSSM are presented. The results are based on the first LHC run of pp collision data recorded by the ATLAS and CMS experiments at the CERN Large Hadron Collider at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of about 5 and 20 fb$^{-1}$ respectively. Current searches constrain large parts of the parameter space. No evidence for BSM Higgs is found.
LHCb is a dedicated detector for b and c physics at the LHC. I will present a concise review of the detector design and expected performance together with some first results on the commissioning of the different sub-systems based on cosmic data and particle beams delivered by the LHC during the summer of 2008. The experiment is ready to exploit first data expected from the LHC. An integrated luminosity of ~0.3fb-1, which should be collected during the first year of physics running, will already allow LHCb to perform a number of very significant mesurements with the potential of revealing New P…
The search for new physics is a major goal of the LHC physics program. As excitement grows for the upcoming start of Run 2, I review the CMS and ATLAS searches for physics beyond the Standard Model from Run 1 and present recent analyses. These searches have covered a wide range of new physics scenarios including Supersymmetry, new resonances, additional Higgs bosons, new hidden sectors, other Dark Matter, and multi-charged particles. In addition to reviewing some of the techniques that made the analyses possible, I will summarize what we have learned from the results and briefly discuss prospe…
We study the discovery potential of the $cg \to tA\to tZH$ process at the LHC, where $A$ and $H$ are CP-odd and even exotic scalars, respectively. The context is the general Two Higgs Doublet Model, where $cg \to tA$ is induced by the flavor changing neutral Higgs coupling $ρ_{tc}$. We find that the process $cg \to tA\to tZH$ can be discovered for $m_A \sim 400$ GeV, but would likely require high luminosity running of the LHC. Such a discovery would shed light on the mechanism behind the observed Baryon Asymmetry of the Universe. We also study $cg \to tA\to tZh$, where $h$ is the observed 125 …
A model that can simultaneously explain Dark Matter relic density and the apparent matter anti-matter imbalance of the universe has been recently proposed. The model requires $b$-hadron branching fractions to Dark Matter at the per mille level. The $b$-hadrons decay to a dark sector baryon, $ψ_{\rm{DS}}$, which has a mass in the region $940$ MeV/c$^{2} \leq m(ψ_{\rm{DS}}) \leq 4430$ MeV/c$^{2}$. In this paper, we discuss the sensitivity of the LHCb experiment to search for this dark baryon, covering different types of topology and giving prospects for Runs 3 and 4 of the LHC, as well as for th…
For a long time, global fits of the electroweak sector of the Standard Model (SM) have been used to exploit measurements of electroweak precision observables at lepton colliders (LEP, SLC), together with measurements at hadron colliders (Tevatron, LHC), and accurate theoretical predictions at multi-loop level, to constrain free parameters of the SM, such as the Higgs and top masses. Today, all fundamental SM parameters entering these fits are experimentally determined, including information on the Higgs couplings, and the global fits are used as powerful tools to assess the validity of the the…
Run 1 at the LHC was very successful with the discovery of a new boson. The boson's properties are found to be compatible with those of the Standard Model Higgs boson. It is now revealing the mechanism of electroweak symmetry breaking and (possibly) the discovery of physics beyond the Standard Model that are the primary goals of the just restarted LHC. The ultimate precision will be reached at the High-Luminosity LHC phase with a proton-proton centre-of-mass energy of 14 TeV. In this contribution physics prospects are presented for ATLAS for the integrated luminosities 300/fb and 3000/fb: the …
In this work, we aim to provide a comprehensive and largely model independent investigation on prospects to detect long-lived multiply charged particles at the LHC. We consider particles with spin 0 and $\frac{1}{2}$, with electric charges in range $1 \le |Q/e| \le 8$, which are singlet or triplet under $SU(3)_C$. Such particles might be produced as particle-antiparticle pairs and propagate through detectors, or form a positronium(quarkonium)-like bound state. We consider both possibilities and estimate lower mass bounds on new particles, that can be provided by ATLAS, CMS and MoEDAL experimen…
We analyze the Tevatron and Large Hadron Collider (LHC) reach for the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM) in the presence of explicit CP-violation. Using the most recent studies from the Tevatron and LHC collaborations, we examine the CPX benchmark scenario for a range of CP-violating phases in the soft trilinear and gluino mass terms and compute the exclusion/discovery potentials for each collider on the $(M_{H^+}, \tanβ)$ plane. Projected results from Standard Model (SM)-like, non-standard, and charged Higgs searches are combined to maximize the statistical signi…
We study the prospect for discovering the $cg\to bH^+\to b A W^+$ process at the LHC. Induced by the top-flavor changing neutral Higgs coupling $ρ_{tc}$, the process may emerge if $m_{H^+} > m_A + m_{W^+}$, where $H^+$ and $A$ are charged and $CP$-odd Higgs bosons in the general two Higgs Doublet Model (g2HDM). We show that the $cg\to bH^+\to b A W^+$ process can be discovered at LHC Run 3, while the full Run 2 data at hand can constrain the parameter space significantly by searching for the same-sign dilepton final state. The process has unique implications on the hint of $gg\to A \to t \bar …
Motivated by ATLAS diboson excess around 2 TeV, we investigate a phenomenology of spin-1 resonances in a model where electroweak sector in the SM is weakly coupled to strong dynamics. The spin-1 resonances, W' and Z', are introduced as effective degrees of freedom of the dynamical sector. We explore several theoretical constraints by investigating the scalar potential of the model as well as the current bounds from the LHC and precision measurements. It is found that the main decay modes are V' -> VV and V' -> Vh, and the V' width is narrow enough so that the ATLAS diboson excess can be explai…
We show that the predictivity of general gauge mediation (GGM) with TeV-scale stops is greatly increased once the Higgs mass constraint is imposed. The most notable results are a strong lower bound on the mass of the gluino and right-handed squarks, and an upper bound on the Higgsino mass. If the mu-parameter is positive, the wino mass is also bounded from above. These constraints relax significantly for high messenger scales and as such long-lived NLSPs are favored in GGM. We identify a small set of most promising topologies for the neutralino/sneutrino NLSP scenarios and estimate the impact …
We explore the discovery prospects for B'\bar{B}' pair production followed by direct decays B'->bX, where B' is a new quark and X is a long-lived neutral particle. We develop optimized cuts in the (m_B', m_X) plane and show that the 7 TeV LHC with an integrated luminosity of 1 (10) fb^-1 may exclude masses up to m_B' ~ 620 (800) GeV, completely covering the mass range allowed for new quarks that get mass from electroweak symmetry breaking. This analysis is applicable to other models with b\bar{b}+MET signals, including supersymmetric models with bottom squarks decaying directly to neutralinos,…
We assume that the 125 GeV Higgs discovered at the LHC is the heavy CP-even Higgs of the two-Higgs-doublet models, and examine the parameter space in the Type-I, Type-II, Lepton-specific and Flipped models allowed by the latest Higgs signal data, the relevant experimental and theoretical constraints. Further, we show the projected limits on $\tanβ$, $\sin(β-α)$, $Hf\bar{f}$ and $HVV$ couplings from the future measurements of the 125 GeV Higgs at the LHC and ILC, including the LHC with integrated luminosity of 300 fb$^{-1}$ (LHC-300 fb$^{-1}$) and 3000 fb$^{-1}$ (LHC-3000 fb$^{-1}$) as well as …
The prospects of observing the non-resonant di-Higgs production in the Standard Model at the proposed high energy upgrade of the LHC, $viz.$ the HE-LHC$~$($\sqrt{s}=27~{\rm TeV}$ and $\mathcal{L} = 15~{\rm ab^{-1}}$) is studied. Various di-Higgs final states are considered based on their cleanliness and signal yields. The search for the non-resonant double Higgs production at the HE-LHC is performed in the $b\bar{b}γγ$, $b\bar{b}τ^{+}τ^{-}$, $b\bar{b}WW^{*}$, $WW^{*}γγ$, $b\bar{b}ZZ^{*}$ and $b\bar{b}μ^{+}μ^{-}$ channels. The signal-background discrimination is performed through multivariate a…
The potential of the ALICE, ATLAS, CMS and LHCb detectors for the measurement of quarkonium in heavy-ion collisions, both in nucleus-nucleus (A-A) and in proton-nucleus (p-A) interactions, in the years 2015 until about 2030 in the LHC Runs 2, 3 and 4 with larger statistics and detector upgrades is described. A selection of newly available observables is discussed.
The ATLAS and CMS collaborations recently reported indication of a Higgs boson around 125 GeV. If we add extra vector-like quarks to the MSSM, such a relatively heavy Higgs can be naturally realized in the GMSB framework, simultaneously explaining the muon g-2 anomaly. I will discuss LHC prospects of this attractive model.
We briefly review the status of high precision QCD predictions available for LHC processes, focusing on corrections beyond NLO and ways to make the latter available in a convenient format. As a phenomenological example we discuss the two-loop corrections to Higgs boson pair production in gluon fusion.
Prospects for toponium formation at the LHC in the single-lepton mode
Sorbonne Université et CNRS（索邦大学与法国国家科学研究中心）；KEK Theory Center（高能加速器研究机构理论中心）；Xi’an University of Architecture and Technology（西安建筑科技大学）；The University of Osaka（大阪大学）
Constraints on the non-standard top-gluon couplings composed of the chromomagnetic- and chromoelectric-dipole moments of the top quark are updated by combining the latest data of top-pair productions from the Tevatron, 7-TeV LHC, and 8-TeV LHC. We find that adding the recent 8-TeV data to the analysis is effective to get a stronger constraint on the chromoelectric-dipole moment than the one from the Tevatron and 7-TeV LHC alone. We also discuss how those constraints on the non-standard couplings could be further improved when 14-TeV LHC results become available in the near future.
Hadron colliders are providing a unique opportunity for testing Lorentz invariance and CPT symmetry at high energy and in a laboratory. A first measurement in the top-quark sector was performed at the Tevatron. We present here prospective studies for testing Lorentz invariance in top-quark pair production at the LHC and future colliders. The b-quark sector was investigated recently at LHCb. Eventually, new bounds on photon parameters can be extracted from the observation of TeV photons at the LHC. We will conclude by highlighting other opportunities provided by hadron colliders.
In extensions of the Standard Model with compactified extra dimensions, perturbative unitarity of the longitudinal gauge bosons is maintained through the contribution of heavy KK excitations of the gauge fields, without the necessity of introducing a Higgs field. The Three-Site Higgsless Model represents a minimal approach in this respect, containing just one extra set of heavy gauge bosons Z'/W' in the spectrum. While the Z' can have robust couplings to SM fermions and hence may be detected within the first 1-20 1/fb of LHC data at 14 TeV, the coupling of the W' to light fermions is suppresse…
Measurements of the $W$ boson mass are planned by the ATLAS and CMS experiments, but for the time being, these may be unable to compete with the current world average precision of 15~MeV, due to uncertainties in the PDFs. We discuss the potential of a measurement by the LHCb experiment based on the charged lepton transverse momentum $p_T^{\ell}$ spectrum in $W \to μν$ decays. The unique forward acceptance of LHCb means that the PDF uncertainties would be anti-correlated with those of $p_T^{\ell}$ based measurements by ATLAS and CMS. We compute an average of ATLAS, CMS and LHCb measurements of …
The exploration of B-meson decays has reached an unprecedented level of sophistication, with a phase of even much higher precision ahead of us thanks to run 2 of the LHC and the future era of Belle II and the LHCb upgrade. For many processes, the theoretical challenge in the quest to reveal possible footprints of physics beyond the Standard Model will be the control of uncertainties from strong interactions. After a brief discussion of the global picture emerging from the LHC data, I will focus on the theoretical prospects and challenges for benchmark B decays to search for new sources of CP v…
Discovering the Higgs boson is one of the primary goals of both the Tevatron and the Large Hadron Collider (LHC). The present status of the Higgs search is reviewed and future prospects for discovery at the Tevatron and LHC are considered. This talk focuses primarily on the Higgs boson of the Standard Model and its minimal supersymmetric extension. Theoretical expectations for the Higgs boson and its phenomenological consequences are reviewed.
We discuss NMSSM scenarios in which the lightest Higgs boson $h_1$ is consistent with the small LEP excess at about 98 GeV in $e^+e^- \to Zh$ with $h\to b\anti b$ and the heavier Higgs boson $h_2$ has the primary features of the LHC Higgs-like signals at 125 GeV, including an enhanced $γγ$ rate. Verification or falsification of the 98 GeV $h_1$ may be possible at the LHC during the 14 TeV run. The detection of the other NMSSM Higgs bosons at the LHC and future colliders is also discussed, as well as dark matter properties of the scenario under consideration.
This paper investigates a signature of Lorentz invariance violation with the $t\bar{t}$ production at the LHC and future hadron colliders. Possible deviations from the Lorentz symmetry remain poorly constrained in the top quark sector. With a dedicated analysis of $t\bar{t}$ events produced at the LHC, bounds in the top sector can be improved by up to three orders of magnitude relative to Tevatron, the only measurement existing so far. The sensitivity will be even further enhanced at the HL-LHC and future colliders.
We present the prospects of an angular analysis of the $Λ_b \to Λ(1520)\ell^+\ell^-$ decay. Using the expected yield in the current dataset collected at the LHCb experiment, as well as the foreseen ones after the LHCb upgrades, sensitivity studies are presented to determine the experimental precision on angular observables related to the lepton distribution and their potential to identify New Physics. The forward-backward lepton asymmetry at low dilepton invariant mass is particularly promising. NP scenarios favoured by the current anomalies in $b\to s\ell^+\ell^-$ decays can be distinguished …
One of the early criterion proposed for naturalness was a relatively small Higgs mixing parameter $μ$ with $μ/M_Z$ order few. A relatively small $μ$ may lead to heavier Higgs masses ($H^0, A, H^{\pm}$ in MSSM) which are significantly lighter than other scalars such as squarks. Such a situation is realized on the hyperbolic branch of radiative breaking of the electroweak symmetry. In this analysis we construct supergravity unified models with relatively small $μ$ in the sense described above and discuss the search for the charged Higgs boson $H^{\pm}$ at HL-LHC and HE-LHC where we also carry ou…
