arXiv subjects

A. V. Kotwal

Publications and source records attributed to A. V. Kotwal.

11 recordsLinked to original sources

arXiv2022

Precision timing for collider-experiment-based calorimetry

In this White Paper for the 2021 Snowmass process, we discuss aspects of precision timing within electromagnetic and hadronic calorimeter systems for high-energy physics collider experiments. Areas of applications include particle identification, event and object reconstruction, and pileup mitigation. Two different system options are considered, namely cell-level timing capabilities covering the full detector volume, and dedicated timing layers integrated in calorimeter systems. A selection of technologies for the different approaches is also discussed.

physics.ins-det↗

arXiv2020

Physics potential of timing layers in future collider detectors

The physics potential of timing layers with a few tens of pico-second resolution in the calorimeters of future collider detectors is explored. These studies show how such layers can be used for particle identification and illustrate the potential for detecting new event signatures originating from physics beyond the standard model.

physics.ins-det↗

arXiv2019

Studies of granularity of a hadronic calorimeter for tens-of-TeV jets at a 100 TeV $pp$ collider

Jet substructure variables for hadronic jets with transverse momenta in the range from 2.5 TeV to 20 TeV were studied using several designs for the spatial size of calorimeter cells. The studies used the full Geant4 simulation of calorimeter response combined with realistic reconstruction of calorimeter clusters. In most cases, the results indicate that the performance of jet-substructure reconstruction improves with reducing cell size of a hadronic calorimeter from $Δη\times Δϕ= 0.087\times0.087$, which are similar to the cell sizes of the calorimeters of LHC experiments, by a factor of four, to $0.022\times0.022$.

physics.ins-det↗

arXiv2018

Jet Substructure Variables with the SiFCC Detector at 100 TeV

Future experiments beyond the LHC era will measure high-momentum bosons ($W$, $Z$, $H$) and top quarks with strongly collimated decay products that form hadronic jets. This paper describes the studies of the performance of jet substructure variables using the Geant4 simulation of a detector designed for high energy $pp$ collisions at a 100 TeV collider. The two-prong jets from $Z' \rightarrow WW$ and three-prong jets from $Z' \rightarrow t\bar{t}$ are compared with the background from light quark jets, assuming $Z'$ masses in the range 5 -- 40 TeV. Our results indicate that the performance of jet-substructure reconstruction improves with reducing transverse cell sizes of a hadronic calorimeter from $Δη\times Δϕ= 0.087\times0.087$ to $0.022\times0.022$ in most cases.

hep-ex↗

arXiv2017

Initial performance studies of a general-purpose detector for multi-TeV physics at a 100 TeV pp collider

This paper describes simulations of detector response to multi-TeV physics at the Future Circular Collider (FCC-hh) or Super proton-proton Collider (SppC) which aim to collide proton beams with a centre-of-mass energy of 100 TeV. The unprecedented energy regime of these future experiments imposes new requirements on detector technologies which can be studied using the detailed GEANT4 simulations presented in this paper. The initial performance of a detector designed for physics studies at the FCC-hh or SppC experiments is described with an emphasis on measurements of single particles up to 33 TeV in transverse momentum. The reconstruction of hadronic jets has also been studied in the transverse momentum range from 50 GeV to 26 TeV. The granularity requirements for calorimetry are investigated using the two-particle spatial resolution achieved for hadron showers.

hep-ex↗

arXiv2015

Comparison of Horace and Photos Algorithms for Multi-Photon Emission in the Context of the W Boson Mass Measurement

The W boson mass measurement is sensitive to QED radiative corrections due to virtual photon loops and real photon emission. The largest shift in the measured mass, which depends on the transverse momentum spectrum of the charged lepton from the boson decay, is caused by the emission of real photons from the final-state lepton. There are a number of calculations and codes available to model the final-state photon emission. We perform a detailed study, comparing the results from the Horace and Photos implementations of the final-state multi-photon emission in the context of a direct measurement of the W boson mass at the Tevatron. Mass fits are performed using a simulation of the CDF II detector.

hep-ph↗

arXiv2015

Double Higgs Production in the 4$τ$ channel from resonances in longitudinal vector boson scattering at a 100 TeV collider

We discuss the sensitivity of a 100 TeV $pp$ collider to heavy resonances produced in longitudinal vector boson scattering and decaying to a pair of Higgs bosons. A Monte Carlo study has been performed using the $H \to ττ$ decay channel for both Higgs bosons, comparing the kinematics of such a signal to the irreducible Standard Model backgrounds. The results are presented in the context of a phenomenological model of a resonance ($η$) coupling to goldstone modes, $V_L V_L \to η\to HH$, as can arise in composite Higgs models. With a fractional width of 70% (20%), the $5 σ$ discovery reach is 4.2 (2.9) TeV in resonance mass for 10 ab$^{-1}$ of integrated luminosity. We also discuss the dependence of the mass reach on the collider energy and integrated luminosity.

hep-ph↗

arXiv2015

Sensitivity to new high-mass states decaying to ttbar at a 100 TeV collider

We discuss the sensitivity of a 100 TeV pp collider to heavy particles decaying to top-antitop final states. This center-of-mass energy, together with an integrated luminosity of 10 ab-1, can produce heavy particles in the mass range of several tens of teraelectronvolts (TeV). A Monte Carlo study has been performed using boosted-top techniques to reduce QCD background for the reconstruction of heavy particles with masses in the range of 8-20 TeV, and various widths. In particular, we have studied two models that predict heavy states, a model with an extra gauge boson (Zprime) and with a Kaluza-Klein (KK) excitation of the gluon (gKK). We estimate the sensitive values of $σ\times$Br of about 2 (4) fb for Zprime (gKK), with a corresponding mass reach of 13 (20) TeV.

hep-ph↗

arXiv2013

Studies of Vector Boson Scattering And Triboson Production with DELPHES Parametrized Fast Simulation for Snowmass 2013

Multiboson production provides a unique way to probe Electroweak Symmetry Breaking (EWSB) and physics beyond the Standard Model (SM). With the discovery of the Higgs boson, the default model is that EWSB occurs according to the Higgs mechanism. Deviations from the SM in Higgs and gauge boson properties due to new physics at a higher energy scale can be parameterized by higher-dimension operators in an Effective Field Theory (EFT). We present sensitivity studies for dimension-6 and dimension-8 operators in an EFT by looking for anomalous vector boson scattering and triboson production, at proton-proton colliders with center-of-mass energies of 14 TeV, 33 TeV and 100 TeV, respectively.

physics.comp-ph↗

arXiv2009

New Techniques in the Search for Z' Bosons and Other Neutral Resonances

The search for neutral resonances at the energy frontier has a long and illustrious history, resulting in multiple discoveries. The canonical search scans the reconstructed invariant mass distribution of identified fermion pairs. Two recent analyses from the CDF experiment at the Fermilab Tevatron have applied novel methods to resonance searches. One analysis uses simulated templates to fit the inverse mass distribution of muon pairs, a quantity with approximately constant resolution for momenta measured with a tracking detector. The other analysis measures the angular distribution of electron pairs as a function of dielectron mass, gaining sensitivity over a probe of the mass spectrum alone. After reviewing several models that predict new neutral resonances, we discuss these CDF analyses and potential future applications.

hep-ex↗

arXiv2006

Data processing model for the CDF experiment

The data processing model for the CDF experiment is described. Data processing reconstructs events from parallel data streams taken with different combinations of physics event triggers and further splits the events into datasets of specialized physics datasets. The design of the processing control system faces strict requirements on bookkeeping records, which trace the status of data files and event contents during processing and storage. The computing architecture was updated to meet the mass data flow of the Run II data collection, recently upgraded to a maximum rate of 40 MByte/sec. The data processing facility consists of a large cluster of Linux computers with data movement managed by the CDF data handling system to a multi-petaByte Enstore tape library. The latest processing cycle has achieved a stable speed of 35 MByte/sec (3 TByte/day). It can be readily scaled by increasing CPU and data-handling capacity as required.

physics.ins-det↗