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Direct-Photon Production and Correlations in Pb–Pb Collisions at TeV
No full textIn this overview, the recent results on direct-photon production and correlations in Pb–Pb collisions at TeV obtained by the ALICE collaboration are presented. The invariant yields of direct photons have been measured in a wide range of transverse momentum () from 0.4 to 16 GeV/ in different centrality classes from central to peripheral collisions. Obtained spectra are consistent with perturbative Quantum Chromodynamics (pQCD) calculations and hydrodynamic predictions. Promising measurements of direct-photon correlations have been performed, resulting in estimation of the correlation radii of the emitting source in central and semicentral collisions. In addition, two-photon correlations are used to extend the -dependent invariant yields of direct photons down to 250 MeV/
Euclid: From Galaxies to Gravitational Waves – Forecasting Stochastic Gravitational Wave Background Anisotropies and Their Cross-Correlation
No full textWe estimate the amplitude and spatial anisotropy in the stochastic gravitational wave background (SGWB) energy density due to compact binary coalescence (CBC) events: binary black holes (BBH), binary neutron stars (BNS), and black hole-neutron star (BHNS) mergers. Our starting point is the Flagship Simulation Galaxy Catalogue developed by the Euclid Consortium. For each galaxy in the Catalogue, we use the simulated mass and starformation to constrain the galaxy's star-formation history, and predict its contribution to the gravitational-wave energy density through CBC mergers. Combining such contributions from all galaxies in the Catalogue results in a prediction for the frequency spectrum and spatial anisotropy of the CBC SGWB. We also compare this prediction to semi-analytical models of SGWB generated by compact binaries. We identify a set of effective parameters that capture the key features of these models, and we apply a Bayesian framework to infer these parameters assuming an ideal scenario of cosmic variance-limited search. This represents the first step toward developing a comprehensive framework that will eventually enable the correlation of SGWB anisotropy and \textit{Euclid} galaxy data, potentially allowing us to extract valuable astrophysical information from this new observable
Worldsheet for Generalized Veneziano Amplitudes
No full textWe present a worldsheet action that reproduces a class of dual resonance amplitudes discussed in the literature, which generalize the Veneziano amplitude for open strings. Our proposal builds on the chiral composite linear dilaton introduced recently. We further compute higher-point extensions and closed-string analogs, which exhibit partial crossing symmetry
9th General Meeting of the LHC EFT Working Group
No full textThe Standard Model Effective Field Theory (SMEFT) provides a powerful framework for parameterizing potential new physics in a model-independent way. To analyze data from experiments across different energy scales and to reliably extrapolate ultraviolet (UV) physics effects, it is crucial to know the renormalization group evolution (RGE) of SMEFT operators.
In this talk, I will present the complete set of two-loop SMEFT -functions up to dimension-six in the baryon number-conserving sector, calculated with an anti-commuting , and discuss the methods used to compute them as well as the challenges encountered in this process. In particular, -odd traces involving six or more ordinary -matrices require special care, since cyclicity is lost. This subtlety can lead to potentially inconsistent results, which I will discuss in detail.
Our results provide the first complete two-loop SMEFT running up to dimension-six in the baryon number-conserving sector, representing a key ingredient for next-to-leading order (NLO) SMEFT analyses. They enable precision studies of new physics across energy scales and thus significantly extend the SMEFT toolkit available for phenomenological applications
Summary of Higgs coupling measurements (Run 2 summary and available Run 3 results) from ATLAS and CMS
No full textNo abstract
Upgrade of the CMS Drift Tube system for the High Luminosity LHC
No full textThe Large Hadron Collider (LHC) will undergo a major upgrade during its third Long Shutdown (LS3) period, after which the High-Luminosity LHC (HL-LHC) era will begin. During the HL-LHC phase, proton-proton collisions are expected to be delivered at 5 to 7 times the nominal LHC instantaneous luminosity. Also, the number of collisions per proton bunch crossing will reach values up to 200. The CMS experiment will undergo a substantial upgrade as well. The harsher radiation environment and the much higher number of overlapping events will require CMS to upgrade both the detector technologies and electronics. The Drift Tubes (DT) chambers - the muon detectors instrumenting the barrel region - will remain the same throughout the HL-LHC era. However, legacy detector readout and trigger electronics are not capable of sustaining the trigger rate, which is expected to increase from present 100 kHz up to 750 kHz, and to tolerate the higher level of radiation. New On-detector Board for DT (OBDT) will primarily perform time-to-digital conversion forwarding up to 240 time digitization channels to the backend system without data losses. A new backend system will implement the DT trigger primitive algorithm capable of using the OBDT streamline data and performing the DT muon track reconstruction in the available latency and with a resolution similar to offline. A small fraction of the DT chambers have been already operated in parallel with both legacy and upgraded electronics during Run 3 data-taking. This early integration enabled CMS to validate the new electronics and evaluate its performances. This report will give an overview of the status of the DT electronics upgrade as well as a report on the upgraded electronics performance using latest Run 3 proton-proton collision data
TrackHHL: A Quantum Computing Algorithm for Track Reconstruction at the LHCb
No full textIn the future high-luminosity LHC era, high-energy physics experiments face unprecedented computational challenges for event reconstruction. Employing the LHCb vertex locator as a case study we investigate a novel approach for charged particle track reconstruction. The algorithm hinges on minimizing an Ising-like Hamiltonian using matrix inversion. Solving this matrix inversion classically achieves reconstruction efficiencies akin to current stateof-the-art algorithms. Exploiting the Harrow-Hassidim-Lloyd (HHL) quantum algorithm for linear systems holds the promise of an exponential speedup in the number of input hits over its classical counterpart, contingent on the conditions of efficient quantum phase estimation (QPE) and effectively reading out the algorithm’s output. This contribution builds on previous work by Nicotra et al. [1] and strives to fulfill these conditions and further streamlines the algorithm’s circuit depth by a factor up to 104. Our version of the HHL algorithm restricts the QPE precision to one bit, largely reducing circuit depth and addressing HHL’s readout issue. Furthermore, this allows for the implementation of a post-processing algorithm that reconstructs event Primary Vertices (PVs). The findings presented here aim to further illuminate the potential of harnessing quantum computing for the future of particle track reconstruction in high-energy physics.In the future high-luminosity LHC era, high-energy physics experiments face unprecedented computational challenges for event reconstruction. Employing the LHCb vertex locator as a case study we investigate a novel approach for charged particle track reconstruction. The algorithm hinges on minimizing an Ising-like Hamiltonian using matrix inversion. Solving this matrix inversion classically achieves reconstruction efficiencies akin to current state-of-the-art algorithms. Exploiting the Harrow-Hassidim-Lloyd (HHL) quantum algorithm for linear systems holds the promise of an exponential speedup in the number of input hits over its classical counterpart, contingent on the conditions of efficient quantum phase estimation (QPE) and effectively reading out the algorithm's output. This contribution builds on previous work by Nicotra et al and strives to fulfill these conditions and further streamlines the algorithm's circuit depth by a factor up to . Our version of the HHL algorithm restricts the QPE precision to one bit, largely reducing circuit depth and addressing HHL's readout issue. Furthermore, this allows for the implementation of a post-processing algorithm that reconstructs event Primary Vertices (PVs). The findings presented here aim to further illuminate the potential of harnessing quantum computing for the future of particle track reconstruction in high-energy physics
Precision measurement of CP violation and branching fractions in decays and search for the rare decay
No full textAn analysis of the decays and is performed using proton-proton collision data collected by the LHCb experiment at a center-of-mass energy of , corresponding to an integrated luminosity of 5.4fb. The CP asymmetries are determined to be and , and the branching fraction ratio is measured to be , where the first uncertainties are statistical and the second are systematic. These results are the most precise measurements of these quantities to date. A search for the rare decay is also performed. No significant signal is observed, and the upper limit on the product of the branching fraction ratio and the fragmentation-fraction ratio is set to be 0.015 (0.016) at the 90% (95%) confidence level.An analysis of the decays and is performed using proton--proton collision data collected by the LHCb experiment at a center-of-mass energy of 13TeV, corresponding to an integrated luminosity of 5.4fb. The CP asymmetries are determined to be and , and the branching-fraction ratio is measured to be , where the first uncertainties are statistical and the second systematic. These results are the most precise measurements of these quantities to date. A search for the rare decay is also performed. No significant signal is observed, and the upper limit on the product of the branching-fraction ratio and the fragmentation-fraction ratio is set to be 0.015 (0.016) at the 90% (95%) confidence level