Conveners
Beyond the Standard Model: 1
- Archil Kobakhidze (The University of Sydney)
Beyond the Standard Model: 2
- Jeonghyeon Song (Konkuk U.)
Beyond the Standard Model: 3
- Paul Douglas Jackson (University of Adelaide)
Beyond the Standard Model: 4
- Myeonghun Park (SNUT)
Beyond the Standard Model: 5
- Archil Kobakhidze (The University of Sydney)
Beyond the Standard Model: 6
- K.C. Kong (University of Kansas)
Beyond the Standard Model: 7
- Bumseok Kyae (Pusan Nat'l. U.)
Beyond the Standard Model: 8
- Thomas Flacke (IBS CTPU)
Beyond the Standard Model: 9
- Mihoko Nojiri (Theory Center, IPNS, KEK)
Beyond the Standard Model: 10
- Ian Lewis (The University of Kansas)
Beyond the Standard Model: 11
- Hyejung Stoeckinger-Kim (TU Dresden)
Beyond the Standard Model: 12
- Sung Won Lee (Texas Tech University (US))
Current measurements of the branching fractions for b --> c tau nu processes yield results that are more than 4 standard deviations higher than the standard-model expectations. This motivates exploration of potential new physics in these decays, including searches for CP violation. A CP-violating asymmetry requires interference between amplitudes with different CP-violating and CP-conserving...
The phenomenology of dark matter would be complicated if dark matter is a composite particle as a hadron under a dark gauge group. Once a dark parton is produced at a high energy collider, it eventually evolves to a jet-like object and provides a collider signature depending on interactions with the Standard Model particles. For example, a finite lifetime of dark hadron would provide a...
We proposed the possiblity of spontaneous CP-violation in the simplest little Higgs (SLH) model. Based on the continuum effective field theory (CEFT) framework, we derived the properties of the scalar potential of this model. We carefully discussed the theoretical and experimental constraints on this model, and showed it is still alive. We also discussed the collider tests of CP-violation in...
Heavy vectorlike quarks (VLQs) in many new physics models are very attractive as they can play the key role in the model building and easily fit in with the Higgs measurement as well as the electroweak precision data. We study their loop level effects on the phenomenological signatures of a heavy scalar boson $S$. Under some conditions, loop induced decays of $S$ are significantly...
We propose a spectral decomposition to systematically extract information of dark matter at hadron colliders. The differential cross section of events with missing transverse energy (MET) can be expressed by a linear combination of basis functions. In the case of s-channel mediator models for dark matter particle production, basis functions are identified with the differential cross sections...
The existence of tiny neutrino masses and flavor mixings can be explained naturally in various seesaw models, many of which typically having additional Majorana type SM gauge singlet right handed neutrinos ($N$). If they are at around the electroweak scale and furnished with sizeable mixings with light active neutrinos, they can be produced at high energy colliders, such as the Large Hadron...
We discuss the LHC sensitivity to top partner production in a model where the Standard Model (SM) is extended by an SU(2) singlet top partner and a SM gauge singlet scalar.
Unlike most searches for top partners which are concerned with three conventional decay modes, Wb, tZ and tH, the decay pattern of the top partner in this model can be significantly altered with new decay modes, gluon +...
MoEDAL, is a pioneering LHC experiment designed to search for anomalously ionizing messengers of new physics such as magnetic monopoles or massive (pseudo-)stable charged particles, that are predicted to existing a plethora of models beyond the Standard Model. It started data taking at the LHC at a centre-of-mass energy of 13 TeV, in 2015. Its ground breaking physics program defines a number...
Most searches for top partners, T, are concerned with top partner pair production. However, as these bounds become increasingly stringent, the LHC energy will saturate and single top partner production will become more important. We study the LHC sensitivity to single top partner production in a model where the Standard Model (SM) is extended by an SU(2) singlet top partner and a SM gauge...
The alignment phenomenon, that the 125 GeV $h^0$ boson so resembles the Standard Model Higgs boson, can be understood in a two Higgs doublet model without discrete symmetry. The Yukawa couplings $\rho_{tt}$ and $\rho_{tc}$ offer new probes for the extra scalar $H^0$ and pseudoscalar $A^0$. We propose to search for $cg \to tH^0$, $tA^0$ followed by $H^0$, $A^0 \to t\bar t$, $t\bar c$, where...
Many Standard Model extensions which address the hierarchy problem contain Dirac-fermion partners of the top quark at the TeV scale. Searches for these vector-like quarks mostly focus on their decay into electroweak gauge bosons and a Standard Model quark.
In this talk we discuss several classes of composite Higgs models with top partners which have underlying descriptions in terms of a...
Searches for supersymmetry at the LHC have pushed the mass limits for strongly-produced sparticles to the TeV level and make the reconstruction and identification of boosted objects to an essential tool for current and future searches for supersymmetry. These objects can originate from the final stage of a short decay chain, or arise heavy gauge or Higgs bosons produced in a decay chain. The...
Searches for the pair-production of colored supersymmetric particles are presented. The results cover different scenarios of gluino and squark production, including models of split supersymmetry that predict long-lived gluinos. The results are based on proton-proton collisions recorded at sqrt(s) = 13 TeV with the CMS detector.
Despite the absence of experimental evidence, weak-scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarises recent ATLAS results on inclusive searches for supersymmetric squarks of the first two generations, and gluinos in R-parity conserving models that predict dark matter candidates. The searches target final states including jets,...
Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. The phenomenology ranges from final states of top or bottom quark pairs and two dark matter candidates, to more complex scenarios involving non-prompt sparticle decays or R-parity violating signatures. This...
Many extensions of the standard model including SUSY predict new particles with long lifetimes, such that the position of their decay is measurably displaced from their production vertex, and particles giving rise to other non-conventional signatures. We present recent results of searches for long-lived particles and other non-conventional signatures obtained using data recorded by the CMS...
Many supersymmetric scenarios feature final states with non-standard final state objects. The production of massive sparticles can lead to the production of boosted top quarks or vector bosons, high-pt b-jets. At the same time, transitions between nearly mass-degenerate sparticles can challenge the standard reconstruction because of the presence of very soft leptons or jets. The talk will...
The existence of physics beyond the standard model (BSM) is established with the observation of neutrino flavor oscillations. Germanium detectors with their excellent energy response and sub-keV sensitivities [1] provide a unique tool to probe a class of BSM scenarios. The TEXONO Collaboration [2] has been pursuing these studies experimentally, complemented by adaptation of advanced atomic...
Fine-tuning arguments suggest the mass of the supersymmetric partner of the Higgs boson, the higgsino, is not too far from the weak scale. The search for higgsinos represents an experimental challenge due to the near mass-degeneracy resulting in soft decay products, and the low production cross section. This talk presents recent ATLAS results of analyses explicitly targeting the higgsino with...
Many supersymmetry models feature gauginos and sleptons with masses less than a few hundred GeV. These can give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents recent ATLAS results from searches for slepton pair production.
In supersymmetric models where colored sparticles are beyond the reach of the LHC, the electroweak production of SUSY particles may constitute the dominant SUSY processes that could be observed at the LHC. In this talk, I will discuss the results of CMS searches for electroweakinos and sleptons. These searches are challenging because of the low production cross sections, however the growing...
Dark matter could be produced at the LHC if it interacts weakly with the Standard Model. The search for dark matter can be performed either directly, by looking for a signature of large missing transverse momentum coming from the dark matter candidates escaping the detector, or more indirectly by looking for the intermediate mediators which would couple the dark matter particles to the...
Results of searches for new physics in the dijet and multijet final states are presented. These include model-independent and model-specific searches using the dijet invariant mass spectrum and the dijet angular distributions, searches for black holes, quantum and microscopic, in multijet events, as well as searches for RPV SUSY in events with paired dijets. This talk focuses on the recent...
Events with two hadronic jets in the final state are of particular interest in the search for physics beyond the Standard Model: new phenomena produced in parton collisions are likely to produce final states with (at least) two partons. In this talk several searches performed by the ATLAS collaboration are presented. The very high mass and the low mass regions have both been investigated, by...
Results of searches for new particles such as leptoquarks, heavy neutrinos, and W bosons with right-handed couplings in final states with leptons (charged or neutral) and jets are presented. The emphasis is given to the recent results obtained using data collected at Run-II of the LHC.
Many theories of beyond the Standard Model (BSM) physics predict unique signatures which are difficult to reconstruct and the background rates are also a challenge. Signatures from displaced vertices anywhere from the inner detector to the muon spectrometer as well as those of new particles with fractional or multiple value of the charge of the electron or high mass stable charged particles...
In some class of BSM models, such as SUSY , DM may be searched using high pT jets + missing ET, where DM (X) may be
produced from the decay of a heavy particle H. If mH is close to mX, the signature is ISR , and may be monojet like, and there are much
information on the nature of H and X. I will discuss leading jet distribution contains the information of both mH, color representation...
Rare decays are powerful probes for Physics beyond the Standard Model (SM), as new particles can have a large impact on physics observables. Recent results on lepton universality tests and measurements of branching fractions and angular distributions of rare b->sll decays have shown tensions with the SM predictions. The LHCb experiment is ideally suited for the study of the these flavour...
Vector like quarks appear in many theories beyond the Standard Model as a way to cancel the mass divergence for the Higgs boson. The current status of the ATLAS searches for the production of vector like quarks will be reviewed for proton-proton collisions at 13 TeV. This presentation will address the analysis techniques, in particular the selection criteria, the background modeling and the...
We present results of searches for massive vector-like top and bottom quark partners using proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. Single and pair production of vector-like quarks are studied, with decays into a variety of final states, containing top and bottom quarks, electroweak gauge and Higgs bosons. We search...
A flexible trigger system, excellent vertex locator, particle identification detectors, and forward acceptance allow unique searches for long-lived particles to be performed at LHC energies using data collected with the LHCb detector. A summary of results will be presented, including searches for long-lived particles decaying into lepton or jets or coming from B meson decays.
Many theories beyond the Standard Model predict new s-channel resonances decaying into two bosons (WW,ZZ,WZ,WH,ZH) and possibly leptons (ll, lv), such as a new heavy scalar singlet, a new heavy vector-boson triplet, or a heavy spin-2 graviton in the bulk Randall-Sundrum model. This talk will summarize relevant ATLAS searches at the LHC using proton-proton collision data collected at a...
A summary of searches for heavy resonances with masses exceeding 1 TeV decaying into dibosons is presented, performed on data produced by LHC pp collisions at $\sqrt{s}$ = 13 TeV and collected with the CMS detector during 2016 and 2017. The common feature of these analyses is the boosted topology, namely the decay products of the considered bosons (both electroweak W, Z bosons and the Higgs...
The High-Luminosity Large Hadron Collider (HL-LHC) is expected to deliver an integrated luminosity of up to 3000 fb-1. The very high instantaneous luminosity will lead to about 200 proton-proton collisions per bunch crossing (“pileup”) superimposed to each event of interest, therefore providing extremely challenging experimental conditions. The sensitivity to find new physics Beyond the...
Searches for new resonances that decay either to pairs of top quarks or a top and a b-quark will be presented. The searches are performed with the ATLAS experiment at the LHC using proton-proton collision data collected at a centre-of-mass energy of 13 TeV. The invariant mass spectrum of hypothetical resonances are examined for local excesses or deficits that are inconsistent with the...
We present an overview of searches for new physics with top and bottom quarks in the final state, using proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV. The results cover non-SUSY based extensions of the SM, including heavy gauge bosons or excited third generation quarks. Decay channels to vector-like top partner quarks, such as...
Many theories beyond the Standard Model predict new phenomena which decay to well isolated, high-pt leptons. Searches for new physics models with these signatures are performed using the ATLAS experiment at the LHC. The results reported here use the pp collision data sample collected by the ATLAS detector at the LHC with a centre-of-mass energy of 13 TeV.
Numerous new physics models, e.g., theories with extra dimensions and various gauge-group extensions of the standard model, predict the existence of new particles decaying to leptons and photons. This talk presents CMS searches for new resonances in the dilepton, lepton+MET, diphoton, and other final states that include leptons and photons, focusing on the recent results obtained using data...
Many new physics models, e.g., compositeness, see-saw, and extra dimensions models, are expected to manifest themselves in the final states with leptons and photons. This talk presents searches for new non-resonant phenomena in the final states that include leptons and photons, focusing on the recent results obtained using data collected at Run-II of the LHC.
The Heavy Photon Search experiment (HPS) at Jefferson Lab seeks to discover evidence for a new dark-force mediator. A new U(1) vector boson could couple to the Standard Model photon through kinetic mixing and could be produced by an electron beam in a dense target in a process similar to bremsstrahlung. Subsequent decays into e+e- pairs, if kinematically allowed, would enable discovery either...
Dark sector models can explain the relic abundance of our universe and are attractive scenarios after 13TeV LHC results on new physics searches. We are testing two broad categories of theories, those that: couple to electron and that only couple to heavy-flavor muons or taus. In the first category, we are looking for the dark photon that decays into leptons or hadrons in the radiative process....
We report on a search for single-photon events in 53 fb$^{-1}$ of data collected with the BABAR detector. We look for events consistent with production of a dark photon ($A^\prime$) through the process $e^+e^- \to \gamma A^\prime$, $A^\prime \to$ invisible. Such particles are motivated by theories applying a $U(1)$ gauge symmetry to dark matter. We find no evidence for this process and set...
Many extensions of the Standard Model (SM) include particles that are neutral, weakly coupled, and long-lived that can decay to hadronic and leptonic final states. Long-lived particles (LLPs) can be detected at colliders as displaced decays from the interaction point (IP), or missing energy if they escape. ATLAS, CMS, and LHCb have performed searches at the LHC and significant exclusion limits...
The high-precision HERA data are used to search for Beyond
the Standard Model contributions to electron-quark scattering
in the framework of eeqq contact interactions (CI). Combined measurements
of the inclusive deep inelastic cross sections in neutral and charged
current $ep$ scattering are considered, corresponding to a luminosity
of around 1 fb$^{-1}$. The analysis of the inclusive $ep$...
We study a recently proposed dilaton-assisted composite Higgs model, which addresses a new solution to the Higgs naturalness problem, relying the scale symmetry of the dilator-Higgs effective theory. The model predicts a heavy U(1) axial vector boson and two massive, oppositely charged, pseudo Nambu-Goldstone bosons. We discuss the phenomenology of new particles, which might be accessible at LHC.
Little Higgs models - which can most easily be thought of as a variant of
composite Higgs models - explain a light Higgs boson at 125 GeV as an
pseudo-Nambu-Goldstone boson of a spontaneously broken global symmetry.
The mechanism of collective symmetry breaking shifts the UV scale of
these models to the 10 TeV scale and higher. T-parity is introduced as
a discrete symmetry to remove tree-level...
We investigate a general two Higgs doublet model imposing both the unitarity conditions and the bounded-from-below conditions. In the work we show that these conditions can be written in terms of invariants. Both conditions make restrictions on the ranges of the model parameters. We study model in the Higgs basis, together with the experimental bounds of oblique parameter T, to produce scalar...
The Light Dark Matter eXperiment (LDMX) proposes a high-statistics search for low-mass dark matter in fixed-target electron-nucleus collisions. Ultimately, LDMX will explore thermal relic dark matter over most of the viable sub-GeV mass range to a decisive level of sensitivity. To achieve this goal, LDMX employs the missing momentum technique, where electrons scattering in a thin target can...
The scenario of light dark matter fermion under a massive U(1) group has attracted some attention lately. It was proposed recently that different chiralities of the DM can lead to different showering patterns, resulting in distinguishable signatures in LHC. This can be helpful in understanding the origin of the dark photon mass and the DM mass. Here we study this subject further by examining...
Motivated the absence of dark matter signal in dark matter direct detection and
new physics signals at LHC, we study how to hear the echoes of the new physics, especially the dark matter and baryogenesis by new approaches beyond the particle colliders, such as the pulsar timing array experiments (such as SKA) and Laser Interferometer experiments (such as LISA).
Semi-annihilation describes processes with an initial state of two dark matter particles, and a final state of one plus standard model states. It is a generic feature of dark matter whenever the symmetry group enforcing stability is not a discrete $Z_2$. Semi-annihilation changes the expected signals in current dark matter searches, weakening limits from direct and collider searches, but can...
During the last years several Dark Sector Models have been proposed in order to address striking astrophysical observations which fail standard intepretations.
In the minimal case a new vector particle, the so called dark photon or U-boson, is introduced, with small coupling with Standard Model particles. Also, the existence of a dark Higgs boson h' is postulated, in analogy with the Standard...
The three main successes of supernumerary are: naturlaness, gauge coupling unification, and a thermal dark matter candidate. Although experimental constraints on supersymmetry has pushed it to a region of parameter space which is less natural, the other two motivations for supersymmetry are still in tact. I will discuss under what conditions can we still get a good thermal dark matter...
We investigate the electroweak vacuum stability in an extended version of the Standard Model which incorporates two additional singlet scalar fields and three right handed neutrinos. One of these extra scalars plays the role of dark matter while the other scalar not only helps in making the electroweak vacuum stable but also opens up the low mass window of the scalar singlet dark matter (< 500...
In Supersymmetric Standard Models, bino-like or singlino-like neautralino dark matter (DM) can achieve the right thermal relic density through Z boson or Higgs boson resonant annihilations with tiny higgsino component, which makes it very hard to be detected. In this work we focus on the reach for such scenarios at High-Luminosity LHC and their interplay with DM direct detection experiments....
GAMBIT is an open-source and highly modular tool for performing large-scale global fits of BSM theories. We give a brief introduction to GAMBIT and present results from global fits of seven- and nine-dimensional parameterisations of the Minimal Supersymmetric Standard Model (MSSM). We explore the MSSM parameter space in high detail using an efficient differential evolution algorithm. Among...
SuperIso Relic is a public computing program for the calculation of flavour observables and relic density in supersymmetry (MSSM and NMSSM). We present new extensions of the code dedicated to the calculation of dark matter direct and indirect detection constraints from the latest experiment results. Contrary to most of the existing programs, this new version allows the user to consider the...
In the development of atomic clocks, some atomic transition frequencies are measured with remarkable precision. These measured spectra may include effects of a new force mediated by a weakly interacting boson. Such effects might be distilled out from possible violation of a linear relation in isotope shifts between two transitions, as known as King's linearity, with relatively suppressed...
Chiral electroweak anomalies predict fermion interactions that violate baryon (B) and lepton number (L), and can be dressed with large numbers of Higgs and weak gauge bosons. The estimation of the total B+L violating rate from an initial two-particle state --potentially observable at colliders-- has been the subject of an intense discussion, mainly centered on the resummation of boson...
Muonium is the bound state of a positive muon and an electron. MuSEUM (Muonium Spectroscopy Experiment Using Microwave) is a new precise measurement of muonium hyperfine structure (MuHFS) at J-PARC (Japan Proton Accelerator Research Complex). MuSEUM determines the MuHFS and muon magnetic moment with a ten times better precision than the precursor experiments at Los Alamos Meson Physics...
The universal law of gravity has undergone stringent tests for a long time over a significant range of length scale, from an atomic scale to a planetary scale [1]. Of particular interest is the short distance regime, where modifications to Newtonian gravity may arise from axion-like particles [2] and extra dimensions [1]. We have constructed a precision force sensor based on...
We analyze the lepton number violating (LNV) meson decays that arise in a TeV scale Left Right Symmetry model. The right handed Majorana neutrino $N$ along with the right handed or Standard Model gauge bosons mediate the meson decays and provide a resonant enhancement of the rates if the mass of $N$ ($M_N$) lies in the range $\sim (100\, \rm{MeV}-5\, \rm{GeV})$. Using the expected upper...
The muon anomalous magnetic moment can be both measured and computed with high precision, providing a sharp tool in testing the robustness of the Standard Model and searching for new physics. The previous measurement by the Brookhaven E821 experiment found a 3.6 standard deviation discrepancy from the predicted value. The new generation Muon g-2 experiment at Fermi National Laboratory has...
ATLAS and CMS have performed a large number of searches for physics beyond the Standard Model (BSM). The results are typically presented in the context of simplified models, containing only a few new particles with fixed decay branching ratios, and yielding generic upper limits on the cross section as a function of particle masses. The interpretation of these limits within realistic BSM...
We investigated the muon g-2 in the two-Higgs doublet model (2HDM), employing the recent full two-loop computation and making comprehensive use of experimental constraints from Higgs and flavour physics. In the talk we present the result of detailed analysis in the flavour-aligned 2HDM and
characterize the parameter regions possible to explain the current $3\sigma$ deviation. Particularly we...
We address the question of whether non-trivial boundary conditions (Scherk - Schwartz twists) acting on fields from the extra compactified dimensions can give a SM low energy spectrum with a "naturally" broken SUSY? We explore a variety of minimal and non-minimal models, confronting current experimental bounds, and discuss progress in formulating more contained and elegant models.
The precision measurement of the anomalous magnetic moment of the muon presently exhibits a 3.5σ discrepancy with the Standard Model (SM) prediction. In the next few years this measurement will reach an even higher precision at Fermilab and J-PARC. While the QED and electroweak contributions to the muon g-2 can be determined very precisely, the leading hadronic (HLO) correction is affected by...
A recently proposed search for milli-charged particles produced at the LHC is discussed. The experiment, named milliQan, is expected to obtain sensitivity to charges of between 0.1e and 0.001e for masses in 0.1 - 100 GeV range. The detector is composed of 3 stacks of 80 cm long plastic scintillator arrays read out by PMTs. It will be installed in an existing tunnel 33 m from the CMS...
Supersymmetry is one of the most searched-for extensions of the Standard Model. In its minimal realization, the Minimal Supersymmetric Standard Model, it predicts a new bosonic (fermionic) partner for each fundamental standard Model fermion (boson), as well as an additional Higgs doublet. The sector of sparticles with only electroweak interactions contains charginos, neutralinos, sleptons, and...
The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric $e^+ e^-$ collider. The accelerator has already successfully completed the first phase of commissioning in 2016 and first electron positron collisions in Belle II are expected for April 2018. The design luminosity of SuperKEKB is $8 \times 10^{35}$ cm$^{-2}$s$^{-1}$ and...
ndications for lepton flavour violation in the mode B → D() tau nu have triggered substantial interest and could be a hint for New Physics effects such as a charged Higgs or leptoquark current. We report new results from the Belle experiment at the KEKB e+e- collider on R(D), R(D) and on the longitudinal polarisations of the D and tau in the decay B → D tau nu. Belle results on the purely...
BABAR, Belle, and LHCb measure the rates for the decays $B \to D^{(*)} \tau \nu$ and $B_c\to J/\psi \tau \nu$ to be higher than the SM expectations, with a combined discrepancy of $4.1 \sigma$ (for $B \to D^{(*)} \tau \nu$ only) or $\sim 4.3 \sigma$ (including all modes). In the coming years, Belle II and LHCb will greatly improve the measurement precision, to the level that systematic...
The decay $K^+ \rightarrow \pi^+ \nu \nu$, with a very precisely predicted branching ratio of less than 10-10, is one of the best candidates to reveal indirect effects of new physics at the highest mass scales. The NA62 experiment at CERN SPS is designed to measure the branching ratio of the $K^+ \rightarrow \pi^+ \nu \nu$ with a decay-in-flight technique, novel for this channel. NA62 took...
Anomalies in B-meson decays reported by the LHC experiment suggest a violation of lepton universality. This could be explained by introducing a heavy neutral gauge boson Z' that selectively couples to third generation quarks and second generation leptons. While the performance of experimental searches for such models is good for large Z' masses, the low-mass region sensitivity is aversely...
We investigate the muon anomalous magnetic moment, the $\mu \to e \gamma$ branching ratio and the $\mu \to e$ conversion rate in the nuclei from the point of view of the planned $\mu \to e$ conversion experiments.
In the MSSM these processes are strongly correlated through $\tan \beta$ enhanced contributions. We demonstrate how in the Minimal R-symmetric Supersymmetric Standard Model the $\mu...
I will review the ongoing studies on BSM physics at Future Colliders. I will cover a broad range of new physics scenarios for several collider configurations, ranging from High Luminosity LHC, passing through a potential 27 TeV LHC upgrade, the High Energy LHC, and arriving to the FCC collider program, both in its ee and pp configurations. I will report advances from the recent and ongoing...
Energy-frontier DIS can be realised at CERN through an energy recovery linac that would produce 60 GeV electrons to collide with the HL-LHC or later HE-LHC (LHeC) or eventually the FCC hadron beams (FCC-eh). It would deliver electron-proton collisions with centre-of-mass energies in the range 1.2-3.5 TeV, and luminosities exceeding $10^{34}$ cm$^{−2}$s$^{−1}$. In this talk we present new...
SHiP is a new general purpose fixed target facility, whose Technical Proposal has been recently reviewed by the CERN SPS Committee and by the CERN Research Board. The two boards recommended that the experiment proceeds further to a Comprehensive Design phase in the context of the new CERN Working group "Physics Beyond Colliders", aiming at presenting a CERN strategy for the European Strategy...
A coupling of a dark photon $A'$ from a $U(1)_{A'}$ with the standard model (SM) particles can be generated through kinetic mixing represented by a parameter $\epsilon$. A non-zero $\epsilon$ also induces a mixing between $A'$ and $Z$ if dark photon mass $m_{A'}$ is not zero. This mixing can be large when $m_{A'}$ is close to $m_Z$ even if the parameter $\epsilon$ is small. Many efforts have...
The high-intensity setup, trigger system flexibility, and detector
performance -- high-frequency tracking of beam particles, redundant
PID, ultra-high-efficiency photon vetoes ― make NA62 particularly
suitable for searching new-physics effect from different
scenarios. Results from a search for invisible dark photons produced
from pi0 decays are given. Fixed target experiments are...
In many models with extended Higgs sectors, e.g. in Two Higgs Doublet Models, in the NMSSM as well as in Randall Sundrum models, there exists an additional scalar h, which can easily be lighter than the Standard Model (SM) like Higgs. Its coupling to the Z boson is expected to be small if the 125 GeV Higgs boson is SM like. Such a light scalar with suppressed couplings to the Z boson would...
Data from the LHC at 7, 8, and 13 TeV, have, so far, yielded no evidence for new particles beyond the Standard Model Higgs boson. However, the complementary nature of physics with e+e- collisions still offers many interesting scenarios in which new particles can be discovered at the ILC. These scenarios take advantage of the capability of e+e- collisions to observe particles with missing...
The Compact Linear Collider (CLIC) is a mature option for a future electron-positron collider operating at centre-of-mass energies of up to 3 TeV. CLIC will be built and operated in a staged approach with three centre-of-mass energy stages currently assumed to be 380 GeV, 1.5 TeV and 3 TeV. This talk discusses the prospects for CLIC to make direct and indirect measurements, or limits, of...
Discovery of charged Higgs boson indicates a clear and unambiguous signal of the beyond standard model. The signal of charged boson is well studied for lower mass range in the dominant $\tau\nu$ decay channel. For higher mass range, signal is difficult to probe because of its predominant decays in
the top and bottom quark. We attempt to investigate the signature of heavy charged Higgs...
Decay modes with two oppositely charged leptons of different flavor correspond to lepton flavor violating (LFV) decays and are essentially forbidden in the Standard Model (SM) because they can occur only through lepton mixing. Decay modes with two leptons of the same charge are lepton-number violating (LNV) decays and are forbidden in the SM. Hence, decays of the form $D^0 \to hh'll’$ provide...
