J. F. de Trocóniz

We propose a new collider probe for axionlike particles (ALPs), and more generally for pseudo-Goldstone bosons: nonresonant searches that take advantage of the derivative nature of their interactions with Standard Model particles. ALPs can participate as off shell mediators in the s channel of 2→2 scattering processes at colliders like the LHC. We exemplify the power of this novel type of search by deriving new limits on ALP couplings to gauge bosons via the processes pp→ZZ, pp→γγ, and pp→jj using run 2 CMS public data, probing previously unexplored areas of the ALP parameter space. In addition, we propose future nonresonant searches involving the ALP coupling to other electroweak bosons and/or the Higgs particle.

We present a new, completely revised calculation of the muon anomalous magnetic moment ${a}_{\ensuremath{\mu}}=({g}_{\ensuremath{\mu}}\ensuremath{-}2)/2$ comparing it with the more recent experimental determination of this quantity; this furnishes an important test of theories of strong, weak, and electromagnetic interactions. These theoretical determinations give the very precise numbers, ${10}^{11}\ifmmode\times\else\texttimes\fi{}{a}_{\ensuremath{\mu}}=116\text{ }591\text{ }806\ifmmode\pm\else\textpm\fi{}50\ifmmode\pm\else\textpm\fi{}10(\mathrm{rad})\ifmmode\pm\else\textpm\fi{}30(\ensuremath{\ell}\ifmmode\times\else\texttimes\fi{}\ensuremath{\ell})\text{ }\phantom{\rule{0ex}{0ex}}[\mathrm{Theory},\mathrm{no}\text{ }\text{ }\ensuremath{\tau}]$ and ${10}^{11}\ifmmode\times\else\texttimes\fi{}{a}_{\ensuremath{\mu}}=116\text{ }591\text{ }889\ifmmode\pm\else\textpm\fi{}49\ifmmode\pm\else\textpm\fi{}10(\mathrm{rad})\ifmmode\pm\else\textpm\fi{}30(\ensuremath{\ell}\ifmmode\times\else\texttimes\fi{}\ensuremath{\ell})\text{ }[\mathrm{Theory},\ensuremath{\tau}]$ to be compared with the experimental number, ${10}^{11}\ifmmode\times\else\texttimes\fi{}{a}_{\ensuremath{\mu}}=116\text{ }592\text{ }080\ifmmode\pm\else\textpm\fi{}60$. In the theoretical evaluations, the first quantity does not, and the second one does, use information from $\ensuremath{\tau}$ decay. The first errors for the theoretical evaluations include statistical plus systematic errors; the other ones are the estimated errors due to incomplete treatment of radiative corrections and the estimated error in the light-by-light scattering contribution. We thus have a significant mismatch between theory and experiment. We also use part of the theoretical calculations to give a precise evaluation of the electromagnetic coupling on the $Z$, ${\overline{\ensuremath{\alpha}}}_{\mathrm{QED}}({M}_{Z}^{2})$, of the masses and widths of the (charged and neutral) rho resonances, of the scattering length and effective range for the $P$ wave in $\ensuremath{\pi}\ensuremath{\pi}$ scattering, and of the quadratic radius and second coefficient of the pion form factor.

A bstract We propose a new search for Axion-Like Particles (ALPs), targeting Vector Boson Scattering (VBS) processes at the LHC. We consider nonresonant ALP-mediated VBS, where the ALP participates as an off-shell mediator. This process occurs whenever the ALP is too light to be produced resonantly, and it takes advantage of the derivative nature of ALP interactions with the electroweak Standard Model bosons. We study the production of ZZ , Zγ , W ± γ , W ± Z and W ± W ± pairs with large diboson invariant masses in association with two jets. Working in a gauge-invariant framework, upper limits on ALP couplings to electroweak bosons are obtained from a reinterpretation of Run 2 public CMS VBS analyses. The constraints inferred on ALP couplings to ZZ , Zγ and W ± W ± pairs are very competitive for ALP masses up to 100 GeV. They have the advantage of being independent of the ALP coupling to gluons and of the ALP decay width. Simple projections for LHC Run 3 and HL-LHC are also calculated, demonstrating the power of future dedicated analyses at ATLAS and CMS.

Four prototype modules following the same design as the ZEUS forward calorimeter (FCAL) modules have been constructed and tested with electrons, hadrons and muons in the momentum range of 1 to 100 GeV/c. The main topics under investigation were: calibration, uniformity of response, noise, light yield, energy resolution and the electron to hadron response (e/h ratio). The result of the measurements is presented and the expected performance of the FCAL is discussed in the light of these results.

A new combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 10 to 300 GeV at an incident angle θ of about 12° is well described by the expression σ/E=((41.9±1.6)%/E+(1.8±0.1)%)⊕(1.8±0.1)/E, where E is in GeV. The response to electrons and muons was evaluated. Shower profiles, shower leakage and the angular resolution of hadronic showers were also studied. Results are compared with those from the previous beam test.

The 40 MHz bunched muon beam set up at CERN was used in May 2003 to make a full test of the drift tubes local muon trigger. The main goal of the test was to prove that the integration of the various devices located on a muon chamber was adequately done both on the hardware and software side of the system. Furthermore the test provided complete information about the general performance of the trigger algorithms in terms of efficiency and noise. Data were collected with the default configuration of the trigger devices and with several alternative configurations at various angles of incidence of the beam. Tests on noise suppression and di-muon trigger capability were performed.

In October 2001 the first produced CMS Barrel Drift Tube (DT) Muon Chamber was tested at the CERN Gamma Irradiation Facility (GIF) using a muon beam. A Resistive Plate Chamber (RPC) was attached to the top of the DT chamber, and, for the first time, both detectors were operated coupled together. The performance of the DT chamber was studied for several operating conditions, and for gamma rates similar to the ones expected at LHC. In this paper we present the data analysis; the results are considered fully satisfactory.

Two drift tubes (DTs) chambers of the CMS muon barrel system were exposed to a 40 MHz bunched muon beam at the CERN SPS, and for the first time the whole CMS Level-1 DTs-based trigger system chain was tested. Data at different energies and inclination angles of the incident muon beam were collected, as well as data with and without an iron absorber placed between the two chambers, to simulate the electromagnetic shower development in CMS. Special data-taking runs were dedicated to test for the first time the Track Finder system, which reconstructs track trigger candidates by performing a proper matching of the muon segments delivered by the two chambers. The present paper describes the results of these measurements.

Muons are among the decay products of many new particles that may be discovered at the CERN Large Hadron Collider. At the first trigger level the identification of muons and the determination of their transverse momenta and location are performed by the Drift Tube Trigger Track Finder in the central region of the CMS (Compact Muon Solenoid) experiment, using track segments detected in the Drift Tube muon chambers. Track finding is performed both in pseudorapidity and azimuth. Track candidates are ranked and sorted, and the best four are delivered to the subsequent stage, the Global Muon Trigger, which combines them with candidates found in the two complementary muon systems of CMS, the Resistive Plate Chambers and the Cathode Strip Chambers. The concept, design, control and simulation software as well as tests and the expected performance of the Drift Tube Trigger Track Finder system are described.

In this work we study the indirect effects of squarks and gluinos via supersymmetric QCD radiative corrections in the decays of Higgs particles within the minimal supersymmetric standard model. We consider a heavy supersymmetric spectrum and focus on the main nondecoupling effects. We propose a set of observables that are sensitive to these corrections and that will be accessible at the CERN Large Hadron Collider and Fermilab Tevatron. These observables are the ratios of Higgs boson branching ratios into quarks divided by the corresponding Higgs boson branching ratios into leptons, and both theoretical and experimental uncertainties are expected to be minimized. We show that these nondecoupling corrections are sizable for all the proposed observables in the large $\mathrm{tan}\ensuremath{\beta}$ region and are highly correlated. A global analysis of all these observables will allow the experiments to reach the highest sensitivity to indirect supersymmetric signals.

The drift tubes based CMS barrel muon trigger, which uses self-triggering arrays of drift tubes, is able to perform the identification of the muon parent bunch crossing using a rather sophisticated algorithm. The identification is unique only if the trigger chain is correctly synchronized. Some beam test time was devoted to take data useful to investigate the synchronization of the trigger electronics with the machine clock. Possible alternatives were verified and the dependence on muon track properties was studied.

Hadron Outer (HO) scintillators located around the CMS coil are sensitive to muons. They can be used in coincidence with RPC chambers for the Muon Trigger. This paper contains a brief description of the two systems and the proposal of how they can be integrated. Backgrounds, efficiencies, and trigger rates have been calculated. The conclusion is that rate reduction factors as high as 100 can be obtained for ∼90% efficiency.

The CMS drift tubes (DT) muon detector, built for withstanding the LHC expected integrated and instantaneous luminosities, will be used also in the High Luminosity LHC (HL-LHC) at a 5 times larger instantaneous luminosity and, consequently, much higher levels of radiation, reaching about 10 times the LHC integrated luminosity. Initial irradiation tests of a spare DT chamber at the CERN gamma irradiation facility (GIF++), at large (∼ O(100)) acceleration factor, showed ageing effects resulting in a degradation of the DT cell performance. However, full CMS simulations have shown almost no impact in the muon reconstruction efficiency over the full barrel acceptance and for the full integrated luminosity. A second spare DT chamber was moved inside the GIF++ bunker in October 2017. The chamber was being irradiated at lower acceleration factors, and only 2 out of the 12 layers of the chamber were switched at working voltage when the radioactive source was active, being the other layers in standby. In this way the other non-aged layers are used as reference and as a precise and unbiased telescope of muon tracks for the efficiency computation of the aged layers of the chamber, when set at working voltage for measurements. An integrated dose equivalent to two times the expected integrated luminosity of the HL-LHC run has been absorbed by this second spare DT chamber and the final impact on the muon reconstruction efficiency is under study. Direct inspection of some extracted aged anode wires presented a melted resistive deposition of materials. Investigation on the outgassing of cell materials and of the gas components used at the GIF++ are underway. Strategies to mitigate the ageing effects are also being developed. From the long irradiation measurements of the second spare DT chamber, the effects of radiation in the performance of the DTs expected during the HL-LHC run will be presented.

During the High Luminosity LHC, the Drift Tube chambers installed in the CMS detector need to operate with an integrated dose ten times higher than expected at the LHC due to the increase in integrated luminosity from 300 fb-1 to 3000 fb-1. Irradiations have been performed to assess the performance of the detector under such conditions and to characterize the radiation aging of the detector. The presented analysis focuses on the behaviour of the high voltage currents and the dose measurements needed to extrapolate the results to High Luminosity conditions, using data from the photon irradiation campaign at GIF++ in 2016 as well as the efficiency analysis from the irradiation campaign started in 2017. Although the single-wire loss of high voltage gain observed of 70% is very high, the muon reconstruction efficiency is expected to decrease less than 20% during the full duration of High Luminosity LHC in the areas under highest irradiation.

We discuss nonresonant axion-like particle (ALP) searches in diboson production at the LHC, a collider probe for ALPs which takes advantage of the derivative nature of their interactions with Standard Model particles; here ALPs participate as off-shell mediators in the scattering process.The power of this novel type of search has been tested with gluon-initiated diboson nonresonant production processes, using CMS and ATLAS Run 2 data, probing previously unexplored areas of the ALP parameter space.In addition, new studies on nonresonant ALP-mediated vector boson scattering (VBS) and preliminary results based on recently published CMS data are presented.Expectations for LHC Run 3 and HL-LHC are derived.

The Compact Muon Solenoid (CMS) is a general purpose experiment designed to study proton-proton collisions at the Large Hadron Collider (LHC). The CMS L1 Trigger must select interesting collisions at a rate smaller than 100 kHz. The CMS Drift Tube (DT) Barrel Muon Trigger performs a full muon tracking analysis in real time for the CMS L1 Trigger. The DT Trigger motivation, hardware implementation, and performance are presented.

The CMS Drift Tubes readout system has been upgraded during the 2017-2018 technical stop to a new MicroTCA-based system to deliver the performance required by the increase of LHC luminosity. It comprises 3 µTCA crates with up to 25 boards, each processing 3 sectors from each CMS wheel. The µROS board is built around a Virtex-7 FPGA, and is able to receive 72 input links. The 240-Mbps inputs are deserialized using oversampling and adaptative phase detection. Event building, synchronization, data integrity monitoring and error correction have been implemented. The uROS system is fully operational, taking collision data satisfactorily.

We present a summary of the results of two recent precise calculations of the muon anomalous magnetic moment ($g_{\mu}-2$) and the electromagnetic coupling on the $Z$ ($\bar{\alpha}_{\rm Q.E.D.}(M^2_{Z})$). The main sources of uncertainty are underlined.

We present a summary of the results of two recent precise calculations of the muon anomalous magnetic moment ($g_μ-2$) and the electromagnetic coupling on the $Z$ ($\barα_{\rm Q.E.D.}(M^2_{Z})$). The main sources of uncertainty are underlined.

The phenomenology of the electroweak symmetry breaking sector is expected to involve resonances decaying preferentially into heavy fermions. Three recent CDF analyses are reviewed and used to constrain Higgs and Technicolor models.