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Neutrino thermalization via randomization on a quantum processor
No full textThe dynamical evolution of neutrino flavor in supernovae can be modeled by an all-to-all spin Hamiltonian with random couplings. Simulating such two-local Hamiltonian dynamics remains a major challenge, as methods with controllable accuracy require circuit depths that increase at least linearly with system size, exceeding the capabilities of current quantum devices. The eigenstate thermalization hypothesis predicts that these systems should thermalize, a behavior confirmed in small-scale classical simulations. In this work, we investigate flavor thermalization in much larger systems using random quantum circuits as an empirical tool to emulate the non-local dynamics, and demonstrate that the thermal behavior can be reproduced using a depth independent of the system size. By simulating dynamics of over one hundred qubits, we find that the thermalization time grows approximately as the square root of the system size, consistent with predictions from semi-classical methods. Beyond this specific result, our study illustrates that near-term quantum devices are useful tools to test and validate empirical classical methods. It also highlights a new application of random circuits in physics, providing insight into complex many-body dynamics that are classically intractable
A Novel Low Sidelobe Level Uniform Transmit/Receive Antenna Arrays for RFID Applications
No full textThe presence of higher minor lobes in RFID reader antennas results in interference, while the utilization of separate antennas for transmission and reception increases the hardware cost and complexity. To address these limitations, a shared aperture antenna array with low sidelobe levels (SLLs) using a two-way array factor is presented. The proposed array utilizes uniform feeding for both the transmit and receive arrays to minimize the design feeding network complexity. The combinatorial analysis is used to turn OFF some of the receive array elements, placing its nulls with the peak SLLs of the transmit array, ensuring optimum suppression in the peak SLL of the two-way array pattern. The proposed antenna array achieves a significant improvement in SLL of about 14.9 dB at the cost of only 1.12 dB loss in the directivity compared to the conventional arrays. Furthermore, about 9 dB and 0.28 dB improvement in SLL and directivity, respectively, is observed compared to the state-of-the-art solutions
Detectors for Relativistic Nuclear Collisions
No full textDetectors for relativistic nuclear interactions have significantly increased in size and sophistication over the last few decades, primarily owing to rising collision energies and rates. Common across most particle physics experiments is the need to measure collision vertex, particle momentum, and particle energy. To accurately measure momenta at the very low level of 100 MeV/c, tracking detectors with a very low material budget are required. Additionally, particle identification requires detector systems that use time-of-flight, energy loss, and Cherenkov radiation measurements. Compared to high-luminosity proton–proton experiments, these detectors face considerably lower radiation levels, enabling the use of a wider range of sensor technologies and leading to innovative developments in this area. Technological advancements in data transport and processing over recent decades now enable continuous data readout and online processing, eliminating the need for selective triggering, which has significantly enhanced detector performance. This article provides an overview of current and future detectors for relativistic nuclear collisions along with a discussion of key technological advancements in this context. Given the similarity in detector requirements for future e + e − Higgs factories, the conclusions drawn here are also relevant to developments in that domain
ttWj EW and tt asymmetry EFT results
No full textThis presentation reports two recent ATLAS results interpreted in the framework of the Standard Model Effective Field Theory (SMEFT). The first is the search for electroweak production of t\bar{t}Wj This analysis provides the ATLAS constraints on the SMEFT operators \mathcal{O}{Ht} and \mathcal{O}{HQ}^{(1)}, which are among the least constrained in the top sector, and demonstrates how the inclusion of t\bar{t}Wj_{\mathrm{EW}} information helps resolve parameter degeneracies that remain when interpreting t\bar{t}Z data alone. The second study presents a combined EFT interpretation of charge (A_Y) and energy (A_E) asymmetry measurements in t\bar{t} production. The combination constrains six dimension-6 four-fermion operators and provides enhanced sensitivity by breaking degeneracies between colour-singlet and colour-octet coefficients. Both results are consistent with the Standard Model within current uncertainties. Together, they illustrate the complementarity of top-quark processes in probing higher-dimensional operators and demonstrate the potential of global SMEFT combinations as a model-independent approach to new-physics searches in the top sector
Search for the production of a Higgs boson in association with a single top quark in collisions at √s = 13 TeV with the ATLAS detector
No full textSearch for the production of a Higgs boson in association with a single top quark in collisions at √s = 13 TeV with the ATLAS detecto
Recent measurements of top-associated cross sections in low pileup conditions in pp collisions at 5.02 TeV
No full textWe present the most recent measurements of top production cross sections in proton-proton collisions at a center-of-mass (CM) energy of 5.02~TeV. The dataset used was recorded by the CMS experiment at the LHC in special runs recorded in 2017, featuring a low-pileup environment, which offers a clean setting for precise cross-section measurements. More precisely, the two dominant top quark production processes, pair production () and single top production in the so-called channel are measured. The measured cross section for the pair production case is ~pb, consistent with Standard Model (SM) predictions. For the single top quark production in the channel, a cross section of ~pb is measured. In addition, the top quark and antiquark cross sections are extracted and found to be ~pb and ~pb, respectively. Finally, their ratio is also measured to be . These measurements are in good agreement with the SM
The Inner Tracker upgrade of the CMS Experiment for the HL-LHC: design and validation via system tests
No full textThe CMS Collaboration is building a new Inner Tracker to fully exploit the high-luminosity upgrade of the LHC (HL-LHC), aimed at delivering by 2041 an integrated luminosity between and , and to cope with its more challenging operating conditions, such as the unprecedented radiation damage and the average pileup up to 200. The Inner Tracker features six times the granularity of the current Pixel Tracker of CMS, with pixel cells, the support for hit rates from particles up to , and an improved radiation hardness to a total ionizing dose of and to a -neutron-equivalent fluence of . This contribution will discuss the performance requirements for the modules of the Inner Tracker, and the main detector design choices to achieve a reduced material budget (e.g., the serial powering architecture and the evaporative cooling with CO2). The validation of these technological solutions in on-going test setups, integrating multiple (quasi-)final components of the full system, will be presented, focusing in particular on those relative to the Tracker Barrel Pixel (TBPX)
