A Tera-Z factory, such as FCC-ee or CEPC, will have indirect sensitivity to heavy new physics up to the tens of TeV scale through higher-order loop contributions to precision measurements at the Z-pole. These provide complementary sensitivity to potential deviations from the Standard Model typically thought to best be constrained at leading order at higher energies above the Z-pole, leading to...
The Standard Model Effective Field Theory (SMEFT) is an essential tool for probing physics beyond the Standard Model. With New Physics signals remaining elusive, deriving constraints on SMEFT Wilson coefficients is increasingly important in order to pinpoint its low-energy effects. This talk presents comprehensive global fits of SMEFT under the Minimal Flavour Violation (MFV) hypothesis. We...
Motivated by the recent evidence of an excess in the rare decay $B\to K E_{\rm miss}$ presented by the Belle II collaboration we discuss possible new physics (NP) scenarios in which light invisible states participate in flavour-changing $b\to s$ transitions. Based on a model-independent EFT framework to describe the new light states, we study the signatures given by the differential...
Self-organised criticality, realised through cosmological dynamics in the early universe, is an alternative paradigm for addressing the electroweak hierarchy problem. In this scenario, an unnaturally light Higgs boson is the result of dynamics driving the electroweak vacuum towards a near-critical metastable point where the Higgs mass is bounded from above by the vacuum instability scale. To...
We investigate a novel collider signature within the minimal Left-Right Symmetric Model, featuring a Higgs sector composed of a bi-doublet and two triplets. Our study focuses on a region of the parameter space where the $SU(2)_R$ charged gauge boson $W_R$ lies in the multi-TeV regime (3-100 TeV) and the additional Higgs states play a significant role. In this scenario, a heavy neutral Higgs...
We present a new application of Graph Neural Networks (GNNs) for LHC searches that aims to improve event classification by representing entire datasets as graphs, with events as nodes and kinematically similar events connected by edges. The strategy builds from our development of graph convolutions and graph attention mechanisms, where we apply scalable solutions for training various GNN...
Exotic Higgs decays are among the most promising areas to be explored at the High-Luminosity LHC, given the unprecedentedly large amount $(\sim 3 \times 10^8)$ of 125 GeV Higgs bosons that will be produced. In this context, we propose a new search channel for which the Higgs boson decays to a (leptonically decaying) $Z$ boson and a light BSM pseudoscalar $a$, which subsequently decays to a...
In the first part of the talk, we will introduce the main model building ideas, namely flavour non-universality and Higgs compositeness, that are central to our model, as well as the theoretical and experimental motivations for exploring these BSM avenues. In the second part of the talk, we present a flavour non-universal extension of the Standard Model combined with the idea of Higgs...
One of the great open questions in modern physics is the origin of the matter-antimatter asymmetry. This requires baryon-number violation, which has never been experimentally observed. Baryon-number violation may arise in the neutron sector as the direct conversion between neutrons and antineutrons, or with a sterile/mirror neutron.
This process will be probed with the proposed HIBEAM/NNBAR...
In modern experiments on flavour physics it is possible to search for the decays of $B$’s, $D$’s, or $\tau$’s into final states with heavy neutrinos $N$ (a.k.a. heavy neutral leptons). I present a common study of theorists and experimentalists from Belle II on constraints on $B \rightarrow D^{*} \ell N$. Next I discuss the status of the theory predictions of the various $N$ decay rates. In...
The current Large Hadron Collider (LHC) data shows no clear indication of new physics yet and only incremental improvements are anticipated in the foreseeable future. LHC has been constraining TeV scale physics but new physics could be hiding below the electroweak scale. There are well-motivated dark matter models which predict a light mediator, coupled with Standard Model (SM) fermions and...
Future e$^+$e$^-$ colliders provide a unique opportunity for long-lived particle (LLP) searches. We present a full simulation study of LLP searches using the International Large Detector (ILD), a detector concept for a future Higgs factory, with a gaseous time projection chamber as its main tracking device. Signatures of displaced vertices and kinked tracks are explored. We study challenging...
The search for weakly interacting massive particles (WIMPs) remains a central goal of the High Luminosity Large Hadron Collider (HL-LHC). In this work, we explore radiative neutralino decays within the framework of the Z₃-invariant Next-to-Minimal Supersymmetric Standard Model (NMSSM), focusing on scenarios where the lightest supersymmetric particle (LSP) is a singlino-dominated neutralino. In...
Motivated by the long-standing discrepancy in lepton flavor universality ratios $R_D$ and $R_{D^{\ast}}$ we assess the status of scalar leptoquark states $R_2$, $\widetilde R_2$ and $S_1$ which can in principle provide a desired enhancement of $\mathcal{B}(B\to D^{(\ast )}\tau \nu)$ in a minimal setup with two Yukawa couplings only. We consider unavoidable low-energy constraints, $Z$-pole...
In the absence of direct evidence for new physics in targeted searches, model-independent strategies are becoming increasingly important. In this talk, we present recent results of model-agnostic searches that are facilitated by advanced machine learning techniques, opening a new avenue for unbiased detection of potential new physics signals.
We analyze publicly available $K^+ \to \pi^+ \nu \bar{\nu}$ data collected by NA62 from 2016 to 2022 to constrain the vectorial axion-down-strange coupling or, equivalently, the Peccei-Quinn scale $f_a$ rescaled by this coupling, obtaining $|(F_{V})_{23}| > 1.1 \times 10^{12}$ GeV. We also discuss the potential of applying the same approach to $K^+ \to \pi^+ \pi^0 \nu \bar{\nu}$ data, from...
We consider a NP scenario with a new heavy neutral gauge boson Z’ and the associated gauge symmetry U(1)’. The heavy Z’ gauge boson has flavour non-universal quark and lepton couplings fixed in a such a way that the gauge anomalies generated by the presence of an additional U(1)’ gauge symmetry cancel. This implies correlations between FCNC processes within the quark sector, within the lepton...
A wide variety of searches for Supersymmetry have been performed by experiments at the Large Hadron Collider. In this talk, we focus on searches for Supersymmetric particles in events with missing energy signatures.
A search for a new heavy particle produced in association with top quarks and exclusively decaying into a top quark pair is presented, based on proton-proton collision data taken with the CMS experiment from 2016 to 2018 at 13 TeV and 2022 at 13.6 TeV.
The two top quarks from the new particle are expected to be highly Lorentz-boosted. The particle mass is reconstructed from a pair of...
The COMET experiment at J-PARC facility in JAPAN is designed to search for charged lepton flavour violation (cLFV), one of the most promising way of looking for physics beyond the Standard Model. Specifically, it will search for the coherent, neutrinoless conversion of a muon to an electron in the field of an aluminum nucleus, a process that is forbidden in the Standard Model and highly...
Various theories beyond the Standard Model predict new, long-lived particles with unique signatures involving jets, which are difficult to reconstruct and for which estimating the background rates is also a challenge. These include emerging jets, semi-visible, and soft unclustered energy patters. The talk will focus on the most recent results from ATLAS
We present searches from the CMS experiment, performed with data collected during LHC Run 2 at a centre-of-mass energy of 13 TeV, for additional Higgs bosons. A variety of states are searched for, at masses both above and below 125 GeV.
Many extensions of the standard model predict new particles with macroscopic lifetimes. Such particles produce different kinds of non-conventional signatures in the detector, for example, jets originating away from the primary proton-proton (pp) interaction vertex, known as displaced jets. Searches exploring the lifetime frontier using displaced jet signatures have become increasingly...
Many new physics models such as compositeness, extra dimensions, extended Higgs sectors, supersymmetry, and dark sectors are expected to manifest themselves in the final states with photons and/or leptons. This talk presents searches in CMS for new phenomena in such final states, focusing on the recent results obtained using the full Run-II and Run-III data-set collected by the CMS Experiment...
The quest for new physics is a major aspect of the CMS experimental program. This includes a myriad of theoretical models involving resonances that can decay to massive bosons, photons, leptons or jets. This talk presents an overview of such analyses with an emphasis on new results and the novel techniques developed by the CMS collaboration to boost the search sensitivity. The searches are...
Results from the CMS experiment are presented for supersymmetry searches targeting so-called compressed spectra, with small mass splittings between the different supersymmetric partners. Such a spectrum presents unique experimental challenges. This talk describes the new techniques utilized by CMS to address such difficult scenarios and presents results based on these techniques.
Within the framework of a general non-linear effective field theory describing the electroweak symmetry breaking, we perform a detailed analysis of the next-to-leading contributions to the electroweak oblique parameters S and T from hypothetical heavy resonance states strongly coupled to Standard Model fields. This work extends our previous results by including parity-odd operators in the...
Despite the large amount of data generated by the Large Hadron Collider (LHC) so far, searches for new physics have not yet provided any clear evidence of beyond the Standard Model (BSM) physics. Most of these experimental searches focus on exclusive channels, looking for excesses in specific final states. However, new physics could manifest as a dispersed signal over many channels. It...
The direct pair-production of the superpartner of the $\tau$-lepton, the $\widetilde{\tau}$,
is one
of the most interesting channels to search for SUSY in:
the $\widetilde{\tau}$ is
likely to be the lightest of the scalar leptons,
and is one of the most experimentally challennging ones.
The current model-independent $\widetilde{\tau}$ limits come from LEP,
while limits obtained at the...
Some effects induced by SMEFT operators at one-loop have been fully computed, in particular, the renormalization of divergences by physical operators in single insertions of dimension-six operators. Important non-logarithmically enhanced contributions remain to be calculated. We discuss dimensional regularization in the Breitenlohner-Maison 't Hooft-Veltman scheme. The goal here consists of...
Incorporating self-energy corrections via Dyson resummation can quantify the deviations from the fixed-width approximation, to an extent such that one can assess their implications on the myriad of collider observables. In this talk, I shall highlight the BSM reach of momentum-dependent particle widths and propagators of gauge and Higgs bosons, and the top quark using the SMEFT framework....
In this talk, we revisit a class of lepton-flavor non-universal gauge extensions of the Standard Model that provide a compelling framework for generating neutrino masses and mixing angles via a high-scale seesaw mechanism, while ensuring exact proton stability to all orders in the effective field theory. This setup naturally accommodates minimal thermal leptogenesis, offering a robust...
We present a discussion of model-independent contributions to the EDM of the electron.
We focus on those contributions that can emerge from an extended heavy scalar sector, and in particular we explore the decoupling limit of the aligned 2HDM.
In this model, Barr-Zee diagrams with a fermion loop produce logarithmically-enchanced contributions that are proportional to potentially large...
The Electric Dipole Moment of the electron (eEDM) is typically investigated in experiments using paramagnetic molecules. However, the physical observable in these searches consists of a linear combination of CP-violating interactions, rather than the eEDM alone, which is commonly referred to as the equivalent EDM of the system. Assuming the presence of new CP-odd physics from heavy degrees of...
Phase-0 of the MoEDAL-MAPP Facility began with installing the MoEDAL detector at IP8 on the LHC ring in 2010. In 2021, as part of Phase-1, CERN approved MoEDAL’s reinstallation for Run-3 with key upgrades: a tenfold lower detection threshold, a fivefold luminosity increase, and a center-of-mass energy boost from 13 TeV to 13.6 TeV. MoEDAL will continue searching for highly ionizing particles...
We explore the prospects of exclusive $W^+W^-$ production via
photon-photon fusion at the LHeC, operating at a center-of-mass energy
of 1.2 TeV [1]. Utilizing the clean experimental environment and high
luminosity of the LHeC [2,3], this process could provide a powerful
probe of electroweak interactions and possible deviations from SM,
particularly through anomalous quartic gauge...
