Constraints on anomalous Higgs boson couplings from its production and decay using the WW channel in proton-proton collisions at s= \sqrt{s} = 13 TeV

A study of the anomalous couplings of the Higgs boson to vector bosons, including CP-violation effects, has been conducted using its production and decay in the WW channel. This analysis is performed on proton-proton collision data collected with the CMS detector at the CERN LHC during 2016-2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 fb$^{-1}$. The different-flavor dilepton ($\mathrm{e}\mu$) final state is analyzed, with dedicated categories targeting gluon fusion, electroweak vector boson fusion, and associated production with a W or Z boson. Kinematic information from associated jets is combined using matrix element techniques to increase the sensitivity to anomalous effects at the production vertex. A simultaneous measurement of four Higgs boson couplings to electroweak vector bosons is performed in the framework of a standard model effective field theory. All measurements are consistent with the expectations for the standard model Higgs boson and constraints are set on the fractional contribution of the anomalous couplings to the Higgs boson production cross section.A study of the anomalous couplings of the Higgs boson to vector bosons, including $CP$-violation effects, has been conducted using its production and decay in the WW channel. This analysis is performed on proton-proton collision data collected with the CMS detector at the CERN LHC during 2016-2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 fb$^{-1}$. The different-flavor dilepton (e$\mu$) final state is analyzed, with dedicated categories targeting gluon fusion, electroweak vector boson fusion, and associated production with a W or Z boson. Kinematic information from associated jets is combined using matrix element techniques to increase the sensitivity to anomalous effects at the production vertex. A simultaneous measurement of four Higgs boson couplings to electroweak vector bosons is performed in the framework of a standard model effective field theory. All measurements are consistent with the expectations for the standard model Higgs boson and constraints are set on the fractional contribution of the anomalous couplings to the Higgs boson production cross section

Combined measurements of Higgs couplings, cross-sections and interpretation at the ATLAS experiment

Simplified template cross-sections provide a detailed description of the properties of Higgs boson production at the LHC. They are most precisely determined in the combination of the measurements performed in the different Higgs boson decay channels. This article presents these combined measurements, as well as their interpretations in the context of specific scenarios of physics beyond the Standard Model, as well as generic extensions within the framework of the Standard Model Effective Field Theory. A combination of measurements of the branching fraction of Higgs boson decays into invisible particles is also presented, and interpreted as constraints on the cross section of WIMP dark matter interactions with nucleons. Through the combination between the analyses from ATLAS and CMS experiments, the evidence of Higgs decay into a Z boson and a photon is established

SoC Interest Group Meeting

A comprehensive co-simulation framework for System-on-Chip (SoC) serves as an invaluable tool for testing and verifying heterogeneous designs that incorporate complex HDL (Hardware Description Language) and operating systems under real-world conditions. This approach facilitates an in-depth exploration of the interactions between HDL, software, and real-world scenarios in ways that are unattainable through other means, while also streamlining the debugging process on actual hardware platforms. In this presentation, we will showcase the implementation of co-simulation within the CROME system, employing a combination of a mixed-language RTL (Register Transfer Level) simulator, libsystemctlm, and QEMU. We will elucidate how these components integrate, highlight the compromises involved, and provide guidance on developing a similar co-simulation environment for your projects

Calibration and performance studies of the readout ASIC for the LHCb SciFi Tracker

The LHCb experiment will perform a major upgrade of the detector during the LHC’s Long Shutdown 2 from 2019 to 2020. The upgrade will enable the detector to operate at an increased instantaneous luminosity and to record data at the LHC bunch crossing rate of 40 MHz. The new operating conditions require the replacement of the complete tracking system. The tracking stations downstream of the magnet will be replaced by the SciFi Tracker, a large, high granular scintillating fibre tracker, readout by arrays of silicon photomultipliers (SiPMs). The signals are processed by a custom 64-channel ASIC called PACIFIC. Each channel implements an analogue processing chain and three comparators with adjustable thresholds for digitisation. The comparator thresholds need to be calibrated with respect to the connected SiPM channel to ensure a high performance of the detector. A calibration method, based on an analytical description of the SiPM pulse height spectrum, has been investigated and several factors that impair the calibration have been identified. The performance of a full detector slice of the SciFi Tracker regarding the hit efficiency, hit resolution, and spillover has been studied on data obtained during a test beam campaign at the CERN SPS in July 2018

Measurement of neutron spectra for various thicknesses of concrete and steel shielding at 24-GeV/c proton beam facility using Bonner sphere spectrometer

Neutron energy spectra down to thermal energy were measured using a Bonner sphere spectrometer (BSS) for various thicknesses of concrete and steel shielding at the CERN/CHARM facility, where high-energy neutrons were produced by 24-GeV/c protons incident on a thick copper target. The thicknesses of the concrete and steel shielding blocks ranged from 40 cm to 200 cm and from 20 cm to 80 cm, respectively. The BSS consisted of a spherical 3He proportional counter and five polyethylene moderators with diameters of 7.62 cm, 10.2 cm, 12.7 cm, 17.8 cm, and 24.1 cm, respectively. In addition, polyethylene moderators combined with a lead or copper inner shell were used to increase the sensitivity to high-energy neutrons. The neutron energy spectra were deduced using an unfolding method. The initial guesses were obtained using the PHITS code for each experimental geometry. The response function for the BSS was determined using the MCNP6.2 code with JENDL-4.0/HE. The neutron energy spectra over the entire energy region from 10−4 eV to 10 GeV were successfully obtained for the different shielding conditions. The validity of the response function and the contribution of each moderator are discussed referring to previous studies and tests at the standard neutron fields of AIST

Local Interaction Region Coupling Correction for the LHC

In order to further expand our knowledge of the structure of matter and the workings of our universe, scientists are constantly seeking to collide particles at ever-increasing energies and with higher luminosity. So is the task of the Large Hadron Collider (LHC) at CERN, the highest energy particle accelerator and collider to date, and the goal of its future upgrade into the High-Luminosity Large Hadron Collider (HL-LHC). This constant progress in performance requires more intense beams and smaller beam sizes at collisions points as well as a tight control of these parameters. Thus, successful operation of large-scale particle colliders heavily depends on the precise correction of magnet field or alignment errors present in the machine. In the LHC, transverse betatron coupling has been shown to have a significant impact on both the beam dynamics and luminosity production due to uncompensated sources close to the Interaction Points (IPs). However, current measurement methods are not sufficient for precise local coupling measurement at the IP, and the impact of these sources has so far been left uncompensated. This thesis covers work done in an effort to determine and correct Interaction Region (IR) local coupling. A key tool presented in this document is the designed Rigid Waist Shift (RWS), a new optics configuration which allows the determination of local coupling corrections based on correlated global variables such as the closest tune approach |C−|. The validity of this new method has been demonstrated through simulations and experimental measurements taken during the LHC Run 3 commissioning in 2022, where determined corrections were applied and led to a measured luminosity increase of 9.7 % and 3.5 % at the ATLAS and CMS detectors, respectively. Additionally, the application of machine learning techniques for high complexity problems such as the detection of coupling sources in the LHC has been explored, yielding promising results but requiring some more improvements to be operationally viable. Finally, optics studies which revealed avenues for improvements in the optics measurements done at the LHC are also presented

Search for the decay of the Higgs boson to a pair of light pseudoscalar bosons in the final state with four bottom quarks in proton-proton collisions at s= \sqrt{s} = 13 TeV

A search is presented for the decay of the 125 GeV Higgs boson (H) to a pair of new light pseudoscalar bosons ($\mathrm{a}$), followed by the prompt decay of each a boson to a bottom quark-antiquark pair, $\mathrm{H}\to\mathrm{a}\mathrm{a}\to\mathrm{b}\overline{\mathrm{b}}\mathrm{b}\overline{\mathrm{b}}$. The analysis is performed using a data sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. To reduce the background from standard model processes, the search requires the Higgs boson to be produced in association with a leptonically decaying W or Z boson. The analysis probes the production of new light bosons in a 15 $< m_{\mathrm{a}} <$ 60 GeV mass range. Assuming the standard model predictions for the Higgs boson production cross sections for pp $\to$ WH and ZH, model independent upper limits at 95% confidence level are derived for the branching fraction $\mathcal{B}(\mathrm{H}\to\mathrm{a}\mathrm{a}\to\mathrm{b}\overline{\mathrm{b}}\mathrm{b}\overline{\mathrm{b}})$. The combined WH and ZH observed upper limit on the branching fraction ranges from 1.10 for $m_{\mathrm{a}} =$ 20 GeV to 0.36 for $m_{\mathrm{a}} =$ 60 GeV, complementing other measurements in the $\mu\mu\tau\tau$, $\tau\tau\tau\tau$ and $\mathrm{b}\mathrm{b}\ell\ell$ ($\ell=\mu$, $\tau$) channels.A search is presented for the decay of the 125 GeV Higgs boson (H) to a pair of new light pseudoscalar bosons (a), followed by the prompt decay of each a boson to a bottom quark-antiquark pair, H $\to$ aa $\to$$\mathrm{b\bar{b}b\bar{b}}$. The analysis is performed using a data sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. To reduce the background from standard model processes, the search requires the Higgs boson to be produced in association with a leptonically decaying W or Z boson. The analysis probes the production of new light bosons in a 15 $\lt$$m_\mathrm{a}$$\lt$ 60 GeV mass range. Assuming the standard model predictions for the Higgs boson production cross sections for pp $\to$ WH and ZH, model independent upper limits at 95% confidence level are derived for the branching fraction $\mathcal{B}$(H $\to$ aa $\to$ $\mathrm{b\bar{b}b\bar{b}}$). The combined WH and ZH observed upper limit on the branching fraction ranges from 1.10 for $m_\mathrm{a} =$ 20 GeV to 0.36 for $m_\mathrm{a} =$ 60 GeV, complementing other measurements in the $\mu\mu\tau\tau$, $\tau\tau\tau\tau$ and bb$\ell\ell$ ($\ell=$ $\mu$,$\tau$) channels

Informal talk with Dr. Robert Cailliau at IdeaSquare

Often one has a small task to do that involves some computing, is not terribly complex, but too tedious and perhaps too time-consuming to perform manually. It is then faster to write a small app, but only if the time and effort to make that app is much smaller than the manual effort. Most app development systems are too unwieldy to get results fast. Dr. Robert Cailliau, co-author of the first hypertext system, presented during an informal talk at IdeaSquare, a solution for the rapid development of such apps. During this talk, participants from the CERN community and students were able to see how to make an app by constructing the user interface and the program code at the same time, using object-oriented programming techniques. Dr. Cailliau regularly hosts talks at IdeaSquare on several topics, often challenging students and other participants in their assumptions about technologies, and allowing them to take a critical look at their development and history