CMS High Granularity Calorimeter (HGCAL) Hexaboards Successful Connectivity Tests

Jasmine Chhikara (TIFR, India) proudly shows one of the "Hexaboards" at the heart of the HGCAL, following its successful test using a novel system for checking connectivity from delicate bonding pads (eventually connected to silicon sensors) and the HGCROC processing chips, without touching the bonding pads

Summary of constraints on CP-odd contributions to the HVV coupling

A summary of recent ATLAS measurements and their interpretations as constraints on CP-odd contributions to the Higgs boson interaction with vector bosons (HVV) is presented

Measurement of transverse Λ\Lambda and Λˉ\bar\Lambda hyperon polarisation in ppPb collisions at sNN=5.02\sqrt{s_{NN}} = 5.02 TeV

The transverse polarization of $Λ$ and $\barΛ$ hyperons is measured in $p$Pb collisions collected by the LHCb experiment at a nucleon-nucleon center-of-mass energy of $5.02$ TeV. The polarization is averaged over hyperon transverse momentum in the range $0.15 < p_{T} < 6.00$ GeV/$c$, and Feynman-$x$ in the ranges $0.005 < x_{F} < 0.040$ (forward region) and $-0.10 < x_{F} < -0.01$ (backward region) defined relative to the proton beam direction. The transverse polarization is found to be compatible with zero for both $Λ$ and $\barΛ$ hyperons. The results are also measured as a function of $p_{T}$ and $x_{F}$ with no significant dependence on these variables observed. The results are compared with previous experimental measurements at different center-of-mass energies and collision environments

Search for the nonresonant and resonant production of a Higgs boson in association with an additional scalar boson in the γγττ \gamma\gamma\tau\tau final state in proton-proton collisions at s= \sqrt{s} = 13 TeV

The results of a search for the production of two scalar bosons in final states with two photons and two tau leptons are presented. The search considers both nonresonant production of a Higgs boson pair, HH, and resonant production via a new boson X which decays either to HH or to H and a new scalar Y. The analysis uses up to 138 fb$^{-1}$ of proton-proton collision data, recorded between 2016 and 2018 by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV. No evidence for signal is found in the data. For the nonresonant production, the observed (expected) upper limit at 95% confidence level (CL) on the HH production cross section is set at 930 (740) fb, corresponding to 33 (26) times the standard model prediction. At 95% CL, HH production is observed (expected) to be excluded for values of $\kappa_\lambda$ outside the range between-12 (-9.4) and 17 (15). Observed (expected) upper limits at 95% CL for the $\mathrm{X} \to \mathrm{H}\mathrm{H}$ cross section are found to be within 160 to 2200 (200 to 1800) fb, depending on the mass of X. In the $\mathrm{X} \to \mathrm{Y} (\tau\tau)\mathrm{H}(\gamma\gamma)$ search, the observed (expected) upper limits on the product of the production cross section and decay branching fractions vary between 0.059-1.2 fb (0.087-0.68 fb). For the $\mathrm{X} \to \mathrm{Y} (\gamma\gamma)\mathrm{H}(\tau\tau)$ search the observed (expected) upper limits on the product of the production cross section and $\mathrm{Y} \to \gamma\gamma$ branching fraction vary between 0.69-15 fb (0.73-8.3 fb) in the low Y mass search, tightening constraints on the next-to-minimal supersymmetric standard model, and between 0.64-10 fb (0.70-7.6 fb) in the high Y mass search.The results of a search for the production of two scalar bosons in final states with two photons and two tau leptons are presented. The search considers both nonresonant production of a Higgs boson pair, HH, and resonant production via a new boson X which decays either to HH or to H and a new scalar Y. The analysis uses up to 138 fb$^{-1}$ of proton-proton collision data, recorded between 2016 and 2018 by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV. No evidence for signal is found in the data. For the nonresonant production, the observed (expected) upper limit at 95% confidence level (CL) on the HH production cross section is set at 930 (740) fb, corresponding to 33 (26) times the standard model prediction. At 95% CL, HH production is observed (expected) to be excluded for values of $κ_λ$ outside the range between $-$12 ($-$9.4) and 17 (15). Observed (expected) upper limits at 95% CL for the XHH cross section are found to be within 160 to 2200 (200 to 1800) fb, depending on the mass of X. In the X $\to$ Y($γγ$)H($ττ$) search, the observed (expected) upper limits on the product of the production cross section and decay branching fractions vary between 0.059$-$1.2 fb (0.087$-$0.68 fb). For the X $\to$ Y($γγ$)H($ττ$) search the observed (expected) upper limits on the product of the production cross section and Y $to$ $γγ$ branching fraction vary between 0.69$-$15 fb (0.73$-$8.3 fb) in the low Y mass search, tightening constraints on the next-to-minimal supersymmetric standard model, and between 0.64$-$10 fb (0.70$-$7.6 fb) in the high Y mass search

Data Reduction of the strip detector of the CMS Experiment for heavy ion collisions and proton-proton collisions

Reducing event and data sizes is critical for experiments at the LHC, where high collision rates and increased detector granularity rapidly increase storage and processing requirements. In the CMS experiment, a recent development to address this challenge is the "Raw'" format: a new approach for recording silicon strip data in which only the reconstructed cluster's barycenter and average charge are stored, rather than the analog-to-digital converter counts from every strip. This format was successfully deployed online during Run-3 for PbPb collisions at CMS, achieving an event size reduction by nearly a factor of two and enabling CMS to record almost all hadronic minimum bias PbPb collisions. To further enhance Raw', we optimized the number of bits used to encode the cluster barycenter and average charge, using tracking efficiency and resolution as benchmarks. Comparing standard RAW with Raw' shows that refining the bit precision yields stronger compression while maintaining similar performance. Additionally, we introduce a lossy compression strategy that encodes distances between clusters instead of their absolute positions within a detector module. Unlike absolute positions, the distribution of these distances is peaked around zero, effectively reducing entropy of that variable. Consequently, the compression becomes more efficient, allowing even stronger data reduction than the current Raw' algorithms without losing much information integrity

Heavy-flavour results from ATLAS experiment

This talk will overview the recent results on heavy-flavour hadron production and decays and spectroscopy of heavy-flavour exotic states obtained with Run-2 data. It will cover the most precise measurement of the $B^0$ meson lifetime, measurement of charmed meson production cross-section, studies of resonant structures in di-charmonium spectrum