S. Gennai

There are many possibilities for new physics beyond the Standard Model that feature non-standard Higgs sectors. These may introduce new sources of CP violation, and there may be mixing between multiple Higgs bosons or other new scalar bosons. Alternatively, the Higgs may be a composite state, or there may even be no Higgs at all. These non-standard Higgs scenarios have important implications for collider physics as well as for cosmology, and understanding their phenomenology is essential for a full comprehension of electroweak symmetry breaking. This report discusses the most relevant theories which go beyond the Standard Model and its minimal, CP-conserving supersymmetric extension: two-Higgs-doublet models and minimal supersymmetric models with CP violation, supersymmetric models with an extra singlet, models with extra gauge groups or Higgs triplets, Little Higgs models, models in extra dimensions, and models with technicolour or other new strong dynamics. For each of these scenarios, this report presents an introduction to the phenomenology, followed by contributions on more detailed theoretical aspects and studies of possible experimental signatures at the LHC and other colliders.

The search for MSSM Higgs bosons will be an important goal at the LHC. We analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs bosons with an integrated luminosity of 30 or 60 fb-1. This is done by combining the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of the MSSM Higgs-boson properties. The results are interpreted in MSSM benchmark scenarios in terms of the parameters tan β and the Higgs-boson mass scale, MA. We study the dependence of the 5σ discovery contours in the MA–tan β plane on variations of the other supersymmetric parameters. The largest effects arise from a change in the higgsino mass parameter μ, which enters both via higher-order radiative corrections and via the kinematics of Higgs decays into supersymmetric particles. While the variation of μ can shift the prospective discovery reach (and correspondingly the ”LHC wedge” region) by about Δtan β=10, we find that the discovery reach is rather stable with respect to the impact of other supersymmetric parameters. Within the discovery region we analyze the accuracy with which the masses of the heavy neutral Higgs bosons can be determined. We find that an accuracy of 1–4% should be achievable, which could make it possible in favorable regions of the MSSM parameter space to experimentally resolve the signals of the two heavy MSSM Higgs bosons at the LHC.

We present a feasibility study for the use of a generative, probabilistic model, a Variational Autoencoder (VAE), to detect deviations from Standard Model (SM) physics in an electroweak process at the Large Hadron Collider (LHC). The new physics responsible for the anomalies is described through an Effective Field Theory (EFT) approach: the SM Lagrangian is Taylor-expanded and the higher order terms cause deviations in the kinematic distributions of the observables, and are thus identified by the model as anomalous contributions with respect to SM. Since the training of the model involves almost only SM events, the proposed strategy is largely independent from any assumption on the nature of the new physics signature. To test the proposed strategy we use parton level generations of Vector Boson Scattering (VBS) events at the LHC, assuming an integrated luminosity of 350 fb $$^{-1}$$ .

A new methodology to improve the sensitivity to new physics contributions to the Standard Model processes at LHC is presented. A Variational AutoEncoder trained on Standard Model processes is used to identify Effective Field Theory contributions as anomalies. While the output of the model is supposed to be very similar to the inputs for Standard Model events, it is expected to deviate significantly for events generated through new physics processes. The reconstruction loss can then be used to select a signal enriched region which is by construction independent of the nature of the chosen new physics process. In order to improve further the discrimination power, an adversarial layer is introduced with a cross entropy term added to the loss function, optimizing at the same time the reconstruction of the input variables of the Standard Model and classification of new physics processes. This procedure ensures that the model is optimized for discrimination, with a small price in terms of model dependency to physics process. In this work I will discuss in detail the above-mentioned method using generator level Vector Boson Scattering events produced at LHC assuming an integrated luminosity of 350/fb.

We describe an aperture emission mode scanning near-field optical microscope (SNOM), optimized for material surface science applications. This instrument can be operated in both transmission and reflection configurations, in order to investigate transparent as well as opaque samples. It employs optical shear-force detection for tip/sample distance control, designed to minimize interference with the probe light. The SNOM head has been fully integrated on a homemade atomic force microscope platform and is placed in a controlled atmosphere chamber for reduction of surface contaminants. Within the compactness and the versatility obtained in our instrument, we have been able to optically discriminate different materials with a λ/20 lateral resolution, and to distinguish polymeric aggregates, without damaging the surface, in spite of their rather poor optical contrast.

Results of an extensive R&D program aiming at radiation hard, small pitch, 3D pixel sensors are reported. The CMS experiment is supporting this R&D in the scope of the Inner Tracker upgrade for the High Luminosity phase of the CERN Large Hadron Collider (HL-LHC). In the HL-LHC the Inner Tracker will have to withstand an integrated fluence up to 2.3×1016neq/cm2. A small number of 3D sensors were interconnected with the RD53A readout chip, which is the first prototype of 65 nm CMOS pixel readout chip designed for the HL-LHC pixel trackers. In this paper results obtained in beam tests before and after irradiation are reported. The irradiation of a single chip module was performed up to a maximum equivalent fluence of about 1×1016neq/cm2. The analysis of the collected data shows excellent performance: the spatial resolution in not irradiated sensors can reach about 3 to 5 μm, for inclined tracks, depending on the pixel pitch. The measured hit detection efficiencies are close to 99% measured both before and after the above mentioned irradiation fluence.

There are many possibilities for new physics beyond the Standard Model that feature non-standard Higgs sectors. These may introduce new sources of CP violation, and there may be mixing between multiple Higgs bosons or other new scalar bosons. Alternatively, the Higgs may be a composite state, or there may even be no Higgs at all. These non-standard Higgs scenarios have important implications for collider physics as well as for cosmology, and understanding their phenomenology is essential for a full comprehension of electroweak symmetry breaking. This report discusses the most relevant theories which go beyond the Standard Model and its minimal, CP-conserving supersymmetric extension: two-Higgs-doublet models and minimal supersymmetric models with CP violation, supersymmetric models with an extra singlet, models with extra gauge groups or Higgs triplets, Little Higgs models, models in extra dimensions, and models with technicolour or other new strong dynamics. For each of these scenarios, this report presents an introduction to the phenomenology, followed by contributions on more detailed theoretical aspects and studies of possible experimental signatures at the LHC and other colliders.

Test beam results obtained with 3D pixel sensors bump-bonded to the RD53A prototype readout ASIC are reported. Sensors from FBK Italy and IMB-CNM (Spain) have been tested before and after proton-irradiation to an equivalent fluence of about 1 × 1016 ≠cm-2 (1 MeV equivalent neutrons). This is the first time that one single collecting electrode fine pitch 3D sensors are irradiated up to such fluence bump-bonded to a fine pitch ASIC. The preliminary analysis of the collected data shows no degradation on the hit detection efficiencies of the tested sensors after high energy proton irradiation, demonstrating the excellent radiation tolerance of the 3D pixel sensors. Thus, they will be excellent candidates for the extreme radiation environment at the innermost layers of the HL-LHC experiments.

Results obtained with 3D columnar pixel sensors bump-bonded to the RD53A prototype readout chip are reported. The interconnected modules have been tested in a hadron beam before and after irradiation to a fluence of about 1×1016 neq cm−2 (1 MeV equivalent neutrons). All presented results are part of the CMS R&D activities in view of the pixel detector upgrade for the High Luminosity phase of the LHC at CERN (HL-LHC) . A preliminary analysis of the collected data shows hit detection efficiencies around 97% measured after proton irradiation.

The work contained herein constitutes a report of the ''Beyond the Standard Model'' working group for the Workshop ''Physics at TeV Colliders'', Les Houches, France, 26 May-6 June, 2003. The research presented is original, and was performed specifically for the workshop. Tools for calculations in the minimal supersymmetric standard model are presented, including a comparison of the dark matter relic density predicted by public codes. Reconstruction of supersymmetric particle masses at the LHC and a future linear collider facility is examined. Less orthodox supersymmetric signals such as non-pointing photons and R-parity violating signals are studied. Features of extra dimensional models are examined next, including measurement strategies for radions and Higgs', as well as the virtual effects of Kaluza Klein modes of gluons. Finally, there is an update on LHC Z' studies.

Due to the large expected instantaneous luminosity, the future HL-LHC upgrade sets strong requirements on the radiation hardness of the CMS detector Inner Tracker. Sensors based on 3D pixel technology, with its superior radiation tolerance, comply with these extreme conditions. A full study and characterization of pixelated 3D sensors fabricated by FBK is presented here. The sensors were bump-bonded to RD53A readout chips and measured at several CERN SPS test beams. Results on charge collection and efficiency, for both non-irradiated and irradiated up to 1016 neq/cm2 samples, are presented. Two main studies are described: in the first the behaviour of the sensor is qualified as a function of irradiation, while kept under identical conditions; in the second the response is measured under typical operating conditions.

The work contained herein constitutes a report of the ``Beyond the Standard Model'' working group for the Workshop Physics at TeV Colliders, Les Houches, France, 26 May--6 June, 2003. The research presented is original, and was performed specifically for the workshop. Tools for calculations in the minimal supersymmetric standard model are presented, including a comparison of the dark matter relic density predicted by public codes. Reconstruction of supersymmetric particle masses at the LHC and a future linear collider facility is examined. Less orthodox supersymmetric signals such as non-pointing photons and R-parity violating signals are studied. Features of extra dimensional models are examined next, including measurement strategies for radions and Higgs', as well as the virtual effects of Kaluza Klein modes of gluons. An LHC search strategy for a heavy top found in many little Higgs model is presented and finally, there is an update on LHC $Z'$ studies.

We review theoretical and experimental results relevant to charm and bottom physics. In particular, we consider charmonium and open heavy-flavour production at Tevatron, LEP and HERA colliders, and in heavy-ion scattering. We study the prospect of future b-physics measurement at the LHC with the ATLAS and CMS detectors.

AI models are likely to become useful tools to support clinical decision-making especially in high mortality diseases such as lung cancer. However, the black-box nature of these models remains nowadays the main challenge to be addressed to employ AI in the clinic. This work describes the preliminary stages and results obtained by implementing a novel explainable approach in radiomics pipeline for local recurrence prediction of lung cancer and its technical validation relying on the high energy physics domain.

The High Luminosity upgrade of the CERN Large Hadron Collider (HL–LHC) calls for an upgrade of the CMS tracker detector to cope with the increased radiation levels while maintaining the excellent performance of the existing detector. Specifically, new high-radiation tolerant solid-state pixel sensors, capable of surviving irradiation fluences up to 1.9×1016neq/cm2 at 3 cm from the interaction point, need to be developed. For this purpose an R&D program involving different vendors have been pursued, aiming at the development of thin n-in-p type pixel sensors. The R&D covers both planar (manufactured by Fondazione Bruno Kessler, FBK; Hamamatsu Photonics, HPK and LFoundry) and single-sided 3D columnar (manufactured by FBK and Centro Nacional de Microelectronica, CNM) pixel devices. The target active thickness is 150μm while two different pixel cell dimensions are currently investigated (25 × 100 and 50×50μm2). Sensors presented in this article have been bump-bonded to the RD53A readout chip (ROC), the first prototype towards the development of a ROC to be employed during HL–LHC operation. Test beam studies, both of thin planar and 3D devices, have been performed by the CMS collaboration at the CERN, DESY and Fermilab test beam facilities. Results of modules performance before and after irradiation (up to 2.4×1016neq/cm2) are presented in this article.

The present understanding of large mass MSSM Higgs sector is reviewed. The most profitable channels: AH → ττ and H± → τν are considered; a glimpse of the trigger chain studied for events with tau lepton final states is presented. The MSSM Higgs discovery reach of the general-purpouse experiment CMS is summarised.

The High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC) calls for new highly radiation tolerant silicon pixel sensors, capable of withstanding fluences up to 2.3 × 1016 neq/cm2 (1 MeV equivalent neutrons). In this paper results obtained in beam test experiments with 3D and planar pixel sensors interconnected with the RD53A readout chip are reported. RD53A is the first prototype in 65 nm technology issued by the RD53 collaboration for the future readout chip to be used in the upgraded pixel detectors. The interconnected modules have been tested in an electron beam at DESY, before and after irradiation, which was performed at the CERN IRRAD facility for the 3D sensors or at the KIT Irradiation Center for the planar sensors, up to an equivalent fluence of 1 × 1016 neq/cm2. The sensors were made by FBK foundry in Trento, Italy, and their development was done in collaboration with INFN (Istituto Nazionale di Fisica Nucleare, Italy). The analysis of the collected data shows hit detection efficiencies around 99% measured after irradiation. All results are obtained in the framework of the CMS R&D activities.

The High Luminosity upgrade of the CERN LHC collider (HL-LHC) demands for a new, highradiation tolerant solid-state pixel sensor capable of surviving fluencies up to a few 10 16 n eq /cm 2 at ∼ 3 cm from the interaction point.To this extent the INFN ATLAS-CMS joint research activity, in collaboration with Fondazione Bruno Kessler (FBK), is aiming at the development of thin n-in-p type pixel sensors for the HL-LHC.The R&D covers both planar and single-sided 3D columnar pixel devices made with the Si-Si Direct Wafer Bonding technique, which allows for the production of sensors with 100 µm and 130 µm active thickness for planar sensors, and 130 µm for 3D sensors, the thinnest ones ever produced so far.Prototypes of hybrid modules, bumpbonded to the RD53A readout chip, have been tested on beam.First results on their performance before and after irradiation are presented.

There are many possibilities for new physics beyond the Standard Model that feature non-standard Higgs sectors. These may introduce new sources of CP violation, and there may be mixing between multiple Higgs bosons or other new scalar bosons. Alternatively, the Higgs may be a composite state, or there may even be no Higgs at all. These non-standard Higgs scenarios have important implications for collider physics as well as for cosmology, and understanding their phenomenology is essential for a full comprehension of electroweak symmetry breaking. This report discusses the most relevant theories which go beyond the Standard Model and its minimal, CP-conserving supersymmetric extension: two-Higgs-doublet models and minimal supersymmetric models with CP violation, supersymmetric models with an extra singlet, models with extra gauge groups or Higgs triplets, Little Higgs models, models in extra dimensions, and models with technicolour or other new strong dynamics. For each of these scenarios, this report presents an introduction to the phenomenology, followed by contributions on more detailed theoretical aspects and studies of possible experimental signatures at the LHC and other colliders.

The influence of the Pt_hat cutoff on the production of bB events in Pythia has been studied. Versions 5.75, 6.115 and 6.152 have been considered.

We review the prospects for bottom production physics at the LHC.