Search

The Future Circular Hadron Collider (FCC-hh) will probe unprecedented energy regimes, enabling direct searches for new elementary particles at a scale of tens of TeV. FCC-hh is currently in the planning stage, and one of its primary physics goals is to search for physics beyond the Standard Model by exploring a previously inaccessible kinematic domain. While venturing into uncharted high-energy territories promises excitement, reconstructing objects with enormous transverse momenta will require overcoming major experimental challenges. This work investigates the identification of boosted $W$ bosons and boosted top quarks in the context of three beyond the Standard Model scenarios: heavy vector-like quark ($B'$), heavy neutral gauge boson ($Z'$), and heavy neutral Higgs boson ($H$). We employ machine learning techniques, including eXtreme Gradient Boosting (XGBoost) and convolutional neural networks (CNN), to identify these ultra-boosted objects in the collider from their SM background counterpart. We evaluate the performance of these techniques in distinguishing $W$ jets and top jets from QCD jets at extremely high transverse momenta ($p_{T}$) values, demonstrating their potential for future FCC-hh analyses., Comment: 66 pages, 32 figures

The widespread adoption of language models (LMs) across multiple industries has caused huge surge in demand for GPUs. Training LMs requires tens of thousands of GPUs and housing them in the same datacenter (DCs) is becoming challenging. We focus on training such models across multiple DCs connected via Wide-Area-Network (WAN). We build ATLAS that speeds up such training time using novel temporal bandwidth sharing and many other design choices. While ATLAS improves the training time, it does not eliminate the bubbles (idle GPU cycles). We built BUBBLETEA that runs prefill-as-a-service (part of LM inference) during the bubbles that improves the GPU utilization substantially without any impact of training. Together, ATLAS and BUBBLETEA improve training time by up to 17X and achieve GPU utilization of up to 94%.

In this work, we performed a spectro-temporal investigation of the low-mass X-ray binary GX 9+9 using the Large Area X-ray Proportional Counter (LAXPC) and Soft X- ray Telescope (SXT) observation on board AstroSat. The source was detected in the soft state during the observation, which results in a disk dominating energy spectrum within the energy range of 0.7-25.0 keV. We carried out the analysis at different flux levels. In the temporal analysis, LAXPC data in all flux levels showed the presence of noise components, describing broad Lorentzian components. We modeled the energy-dependent temporal properties of the source in order to identify the radiative origin of the observed variability. This source is not a well-studied source; hence we attempt to estimate various source characteristics like inner-disk radius, flux, and inner-disk temperature., Comment: The manuscript is accepted for publication as a Conference paper in Physics Frontiers Bhawanipur Anchalik College, 2024, 4 pages, 3 figures

We examine the parameter space of the Next to Minimal Supersymmetric Standard Model (NMSSM) with Singlino-dominated neutralino $\widetilde\chi_1^0$ as the lightest supersymmetric particle (LSP). Our study focuses on identifying the regions within this parameter space that produce a thermal relic abundance of $\widetilde\chi_1^0$ smaller than the observed cold dark matter relic density while remaining consistent with constraints from LEP measurements, low-energy experiments, Higgs measurements, LHC data, and dark matter direct detection experiments. We identify the dominant annihilation modes of the LSP neutralino across varying LSP mass ranges $\sim \mathcal{O}(1)-\mathcal{O}(10^{3})~$GeV. Furthermore, we conduct a benchmark study to assess the production rates of triple-boson final states emerging from direct electroweakino pair production at the LHC. Drawing insights from these findings, we perform a detailed collider analysis to explore the future potential of probing the triple-boson final states involving a light Higgs boson at the high-luminosity LHC (HL-LHC)., Comment: 31 pages, 17 figures, 4 tables

Large-scale video conferencing services incur significant network cost while serving surging global demands. Our work systematically explores the opportunity to offload a fraction of this traffic to the Internet, a cheaper routing option offered already by cloud providers, from WAN without drop in application performance. First, with a large-scale latency measurement study with 3.5 million data points per day spanning 241K source cities and 21 data centers across the globe, we demonstrate that Internet paths perform comparable to or better than the private WAN for parts of the world (e.g., Europe and North America). Next, we present Titan, a live (12+ months) production system that carefully moves a fraction of the conferencing traffic to the Internet using the above observation. Finally, we propose Titan-Next, a research prototype that jointly assigns the conferencing server and routing option (Internet or WAN) for individual calls. With 5 weeks of production data, we show Titan-Next reduces the sum of peak bandwidth on WAN links that defines the operational network cost by up to 61% compared to state-of-the-art baselines. We will open-source parts of the measurement data.

We report results from a detailed study of the neutron star X-ray binary, 4U 1608-52 using observations with {\it AstroSat} (LAXPC/SXT) and {\it NICER} during its 2016 and 2020 outbursts. The 0.7--20.0 keV spectra could be well described with the disk blackbody and thermal Comptonization model. The best-fitting inner disk temperature is $\sim$ 1 keV and radius { $\sim$ 22.17$^{+2.57}_{-2.38}$--27.19$^{+2.03}_{-1.85}$} km and no significant evolution was observed in the disk radius after performing flux and time-resolved spectroscopy. We used a multi-Lorentzian approach to fit the power density spectra and obtained broad-band noise variability. We estimated the energy-dependent fractional root mean square and time-lag of the broad-band noise, and these variations are quantitatively modelled as being due to the coherent variation of the disk emission and the coronal heating rate. Thus, the rapid temporal modeling is consistent with the longer term spectral evolution where the inner disk radius does not vary, and instead the variations can be attributed to accretion rate variations which changes the inner disk temperature and the coronal heating rate., Comment: 17 pages, 13 figures, The manuscript has been accepted for publication in The Astrophysical Journal

In a previous publication, we studied the parameter space of the phenomenological Minimal Supersymmetric Standard Model (pMSSM) with a light neutralino thermal dark matter ($M_{\tilde{\chi}_1^0} \leq M_h/2$) and observed that the recent results from the dark matter and collider experiments put strong constraints on this scenario. In this work, we present in detail the arguments behind the robustness of this result against scanning over the large number of parameters in pMSSM. The Run-3 of LHC will be crucial in probing the surviving regions of the parameter space. We further investigate the impact of light staus on our parameter space and also provide benchmarks which can be interesting for Run-3 of LHC. We analyse these benchmarks at the LHC using the machine learning framework of \texttt{XGBOOST}. Finally, we also discuss the effect of non-standard cosmology on the parameter space., Comment: 34 pages, 22 figures, 8 tables

This work is the first study on the effects of attacks on cryptocurrencies as expressed in the sentiments and emotions of social media users. Our goals are to design the methodologies for the study including data collection, conduct volumetric and temporal analyses of the data, and profile the sentiments and emotions that emerge from the data. As a first step, we have created a first-of-its-kind comprehensive list of 31 events of 51% attacks on various PoW cryptocurrencies, showing that these events are quite common contrary to the general perception. We have gathered Twitter data on the events as well as benchmark data during normal times for comparison. We have defined parameters for profiling the datasets based on their sentiments and emotions. We have studied the variation of these sentiment and emotion profiles when a cryptocurrency is under attack and the benchmark otherwise, between multiple attack events of the same cryptocurrency, and between different cryptocurrencies. Our results confirm some expected overall behaviour and reactions while providing nuanced insights that may not be obvious or may even be considered surprising. Our code and datasets are publicly accessible.

The Internet is going through a massive infrastructural revolution with the advent of low-flying satellite networks, 5/6G, WiFi7, and hollow-core fiber deployments. While these networks could unleash enhanced connectivity and new capabilities, it is critical to understand the performance characteristics to efficiently drive applications over them. Low-Earth orbit (LEO) satellite mega-constellations like SpaceX Starlink aim to offer broad coverage and low latencies at the expense of high orbital dynamics leading to continuous latency changes and frequent satellite hand-offs. This paper aims to quantify Starlink's latency and its variations and components using a real testbed spanning multiple latitudes from the North to the South of Europe. We identify tail latencies as a problem. We develop predictors for latency and throughput and show their utility in improving application performance by up to 25%. We also explore how transport protocols can be optimized for LEO networks and show that this can improve throughput by up to 115% (with only a 5% increase in latency). Also, our measurement testbed with a footprint across multiple locations offers unique trigger-based scheduling capabilities that are necessary to quantify the impact of LEO dynamics., Comment: 16 pages

In the search for exotic events involving displaced particles at HL-LHC, the triggering at the level-1 (L1) system will pose a significant challenge. This is particularly relevant in scenarios where low mass long-lived particles (LLPs) are coupled to a Standard Model (SM)-like 125 GeV Higgs boson and they decay into jets. The complexity arises from the low hadronic activity resulting from LLP decay, and the existing triggers' inability to efficiently select displaced events. This study introduces a novel machine learning approach to address this challenge, utilizing a lightweight autoencoder architecture designed for low latency requirements at L1. Focusing on light LLPs with decay lengths ranging from 1 to 100 cm, this approach employs "Edge convolution" on L1 reconstructed tracks. The results show notable signal acceptance at the permissible background rate, primarily originating from minimum bias and QCD di-jet events. For LLPs of mass 10, 30, and 50 GeV at decay length of 5 cm, the signal efficiencies are 33%, 70%, and 80%, respectively. At a 50 cm decay length, these efficiencies are 20%, 39%, and 45% for the same respective masses., Comment: 28 pages, 14 figures, 3 tables

We investigate the R-parity violating (RPV) supersymmetric (SUSY) model at the High-Luminosity Large Hadron Collider (HL-LHC) in the context of compact muon solenoid (CMS) experiment assuming a total integrated luminosity of $\mathcal{L}=3000~\text{fb}^{-1}$ at $\sqrt{s}=$ 14 TeV. We focus on the pair production of electroweakinos, specifically, $\chi_2^0$ and $\chi_1^{\pm}$ in wino and higgsino states in a particular scenario where $\chi_2^0$ and $\chi_1^{\pm}$ decay into a Higgs boson and W boson, respectively, along the long-lived lightest supersymmetric particle (LSP), $\chi_1^0$, which decays to three quarks via $\lambda^{''}$ RPV couplings leading to the prompt as well as displaced signatures in the final state. To select events at the level-1 (L1) trigger system, we employ dedicated and standard triggers followed by an offline analysis integrating information from the tracker, electromagnetic calorimeter (ECAL) and minimum ionising particle (MIP) timing detector (MTD). We observe that wino-like $\chi_2^0/\chi_1^{\pm}$ with a mass of 1900 GeV and $\chi_1^0$ with a mass greater than 800 GeV can be probed across a decay length ranging from 1 cm to 200 cm. In the case of higgsino-like pair production of $\chi_2^0/\chi_1^{\pm}$, we can probe $\chi_2^0/\chi_1^{\pm}$ with a mass of 1600 GeV, and $\chi_1^0$ with a mass greater than 700 GeV, across a decay length range of 1 cm to 200 cm., Comment: 43 pages, 16 figures, 3 tables

Multiple low-Earth orbit satellite constellations, aimed at beaming broadband connectivity from space, are currently under active deployment. While such space-based Internet is set to augment, globally, today's terrestrial connectivity, and has managed to generate significant hype, it has been largely difficult for the community to measure, quantify, or understand the nuances of these offerings in the absence of a global measurement infrastructure -- the research community has mostly resorted to simulators, emulators, and limited measurements till now. In this paper, we identify an opportunity to use the social media `lens' to complement such measurements and mine user-centric insights on the evolving ecosystem at scale., Comment: 11 Pages

In this paper, we propose a dedicated forward detector, FOREHUNT (FORward~Experiment~for~HUNdred~TeV), for 100 TeV FCC-hh for the detection of light long-lived particles (LLP) coming from $B$-meson decay. We calculate the signal acceptance as a function of mass and proper decay length of the LLP for 100 TeV and interpret our result in terms of model parameters for models of dark Higgs scalar and heavy neutral leptons. We also compare the sensitivity with proposed transverse detectors like MATHUSLA, CODEX-b for HL-LHC, and DELIGHT (Detector for long-lived particles at high energy of 100 TeV) for FCC-hh. Our analysis reveals that if the LLP is light ($\lesssim 4.4$ GeV) and has a low proper decay length ($<10$ m), a forward detector like FOREHUNT is the best option to look for the decaying LLP, while DELIGHT is preferable for higher proper decay lengths., Comment: 42 pages, 19 figures, 5 tables. Version is published in Physical Review D (PHYS. REV. D 110, 015036 (2024))

The first observation of the paper is that methods for determining proportional representation in electoral systems may be suitable as alternatives to the pro-rata order matching algorithm used in stock exchanges. The main part of our work is to comprehensively consider various well known proportional representation methods and analyse in details their suitability for replacing the pro-rata algorithm. Our analysis consists of a theoretical study as well as simulation studies based on data sampled from a distribution which has been suggested in the literature as models of limit orders. Based on our analysis, we put forward the suggestion that the well known Hamilton's method is a superior alternative to the pro-rata algorithm for order matching applications.

We study the prospects for observing exotic decays of the Standard Model Higgs boson $h$ into light beyond the Standard Model scalars $a$ with mass $m_{a} \lesssim m_{h}/2$ in the single Higgs and Higgs pair production channels at the high luminosity run of the Large Hadron Collider (HL-LHC). Discovery prospects for single Higgs production in the gluon-gluon fusion and vector boson fusion modes with the Higgs boson decaying via the exotic mode $h \to aa \to 4\tau$ are analyzed at the HL-LHC. The projected sensitivity for exotic Higgs decays in the non-resonant Higgs pair production channel $pp \to hh \to (h \to b\bar{b})(h \to aa \to 4\tau) \to 2b4\tau$ at the HL-LHC and a future $\sqrt{s}=100~$TeV hadron collider (FCC-hh) are also estimated. Furthermore, we study HL-LHC's potential reach for the Higgs-strahlung process in the $2b4\tau$ channel, taking into account the contamination from non-resonant Higgs pair production. Finally, the potential reach for resonant Higgs pair production in the $2b4\tau$ channel %$pp \to H \to (h \to b\bar{b})(h \to aa \to 4\tau)$ at the HL-LHC is also explored for several choices of $\{m_{H},m_{a}\}$. Our studies suggest that significant improvements over existing bounds are achievable in several production channels, motivating new dedicated searches for $h \rightarrow aa \rightarrow 4 \tau$ at the HL-LHC and future colliders., Comment: 59 pages, 18 figures, 15 tables

The SECARB offshore partnership project seeks to screen deep saline aquifers and hydrocarbon reservoirs in the central Gulf of Mexico (GOM) for CO2 sequestration and CO2-driven enhanced oil and gas recovery and estimate the corresponding CO2 storage resources for select reservoirs. To this end, three major objectives have been completed: managing geological data from different sources, building a reservoir screening platform for CO2 storage, and ranking the reservoirs based on the estimated storage potential. First, the major geological characteristics of both shelf and deep-water areas of the central GOM were examined and compared to define the appropriate reservoir screening criteria. Consequently, the CO2 storage resources of the screened reservoirs were calculated and reported at the BOEM field level to identify fields with the highest storage potential. In the project's current phase, the assessment is being expanded to saline formations. Correlations are being identified, tested, and developed for a broad range of rock and fluid properties, including thickness, porosity, permeability, fluid saturation, and fluid chemistry. These correlations are developed for interfacial tension and CO2 saturated brine viscosity to improve the storage estimates and consider the capillary trapping and solubility of CO2 in reservoir fluids. SAS Viya software is used to make visualizations of these properties of the offshore reservoir and make comparisons and draw similarities between the experimental and estimated correlated measures. Using interactive plots, different conditions could be screened, making the analysis more attractive from a user's point of view., Comment: It is accepted in the conference 'Western Users of SAS Software (WUSS) 2022' and awaiting to be published