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Abdollah Mohammadi

Publications and source records attributed to Abdollah Mohammadi.

7 recordsLinked to original sources

MAIA: A new detector concept for a 10 TeV muon collider

Muon colliders offer a compelling opportunity to explore the TeV scale and conduct precision tests of the Standard Model, all within a relatively compact geographical footprint. This paper introduces a new detector concept, MAIA (Muon Accelerator Instrumented Apparatus), optimized for $\sqrt{s}=10$ TeV $μ^+ μ^-$ collisions. The detector features an all-silicon tracker immersed in a 5T solenoid field. High-granularity silicon-tungsten and iron-scintillator calorimeters surrounding the solenoid capture high-energy electronic and hadronic showers, respectively, and support particle-flow reconstruction. The outermost subsystem comprises an air-gap muon spectrometer, which contributes to muon identification. The performance of the MAIA detector is evaluated in terms of differential particle reconstruction efficiencies and resolutions. Beam-induced background and incoherent pair production simulations are overlaid to single particle gun samples to assess detector reconstruction capabilities under realistic experimental conditions. Even in the presence of backgrounds, reconstruction efficiencies exceed approximately 95\% for energetic tracks, photons, and charged pions in the central region of the detector. This paper outlines promising avenues for future work, including forward region optimization, opportunities for enhanced flavor tagging and boosted object reconstruction, and technological developments needed to achieve the desired detector performance.

physics.ins-det↗

Improving TauFinder Reconstruction at a 10 TeV Muon Collider with the MAIA Detector Concept

This study aims to improve the TauFinder reconstruction algorithm for the MAIA detector concept. Through this work, we seek to increase the reconstruction efficiency and identification of hadronically decaying tau leptons. Through our work, we introduce a dynamic signal cone, known as a shrinking cone, which adjusts its size based on the transverse momentum of the tau candidate. In addition to the already studied one charged hadron and three charged hadron decay modes we extend TauFinder to include decays that consist of one charged hadron and up to two neutral pions. Furthermore, we have developed a tagger that prevents electrons being misidentified as one-prong tau candidates. Applying this tagger results in near-perfect electron rejection with negligible decrease in one-prong tau reconstruction efficiency.

physics.ins-det↗

Measurement of the differential Higgs boson production cross sections in ATLAS and CMS experiments

A comprehensive set of studies has been conducted to measure the fiducial differential cross sections of Higgs boson production by the ATLAS and CMS experiments. These analyses are based on proton-proton collision data collected by both experiments at the CERN LHC, with a center-of-mass energy of 13 TeV. The data sample corresponds to an integrated luminosity of up to 140 fb$^{-1}$. Fiducial Differential cross sections are measured for various observables sensitive to the production and decay of the Higgs boson. All measurements align with Standard Model predictions. The results are used to constrain potential anomalous interactions between the Higgs boson and other Standard Model particles.

hep-ex↗

Focus topics for the ECFA study on Higgs / Top / EW factories

In order to stimulate new engagement and trigger some concrete studies in areas where further work would be beneficial towards fully understanding the physics potential of an $e^+e^-$ Higgs / Top / Electroweak factory, we propose to define a set of focus topics. The general reasoning and the proposed topics are described in this document.

hep-ph↗

Radiative corrections to the mass of the Kink: a small modification due to the different renormalization procedure

We compute of the lowest order quantum radiative correction to the mass of the kink in $ϕ^4$ theory in 1+1 dimensions using an alternative renormalization procedure which has been introduced earlier. We use the standard mode number cutoff in conjunction with the above program. Our results show a small correction to the previously reported values.[The paper has been withdraw by the authors because a new version is been written to better emphasize on renormalization in problems with nontrivial background. The new version has been submitted by our new co-author (arXiv:1205.2775).]

hep-th↗

Observation of W to tau and neutrino Production in pp Collisions at sqrt(s) = 7 TeV

The production of W bosons decaying into a tau lepton and a neutrino with the tau lepton decaying hadronically has been observed in LHC pp collisions at sqrt(s) = 7 TeV with the CMS detector. The selection criteria provide a statistically significant signal on the top of QCD multi-jet and electroweak backgrounds. A data-driven method for the estimation of the QCD multi-jet background has been employed.

hep-ex↗

A Renormalized perturbation theory for problems with nontrivial boundary conditions or backgrounds in two space-time dimensions

In this paper we discuss the effects of nontrivial boundary conditions or backgrounds, including non-perturbative ones, on the renormalization program for systems in two dimensions. Here we present an alternative renormalization procedure such that these non-perturbative conditions can be taken into account in a self-contained and, we believe, self-consistent manner. These conditions have profound effects on the properties of the system, in particular all of its $n$-point functions. To be concrete, we investigate these effects in the $λϕ^4$ model in two dimensions and show that the mass counterterms turn out to be proportional to the Green's functions which have nontrivial position dependence in these cases. We then compute the difference between the mass counterterms in the presence and absence of these conditions. We find that in the case of nontrivial boundary conditions this difference is minimum between the boundaries and infinite on them. The minimum approaches zero when the boundaries go to infinity. In the case of nontrivial backgrounds, we consider the kink background and show that the difference is again small and localized around the kink.

hep-th↗