http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/1932 Tue, 07 Apr 2026 20:29:34 GMT 2026-04-07T20:29:34Z http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/20389 Systematic study of CVD-growth parameters in NaCl-assisted growth of MoSe2 nanostructures: nanoribbons, dendrites and spirals Dey, Srijata MoSe2, a two-dimensional (2D) transition metal dichalcogenide (TMDC), has garnered significant interest in recent years due to its semiconducting properties and tunable band gap with potential applications in optoelectronics, photocatalysis and atomically thin devices. In this study, we report the controlled synthesis of MoSe2 nanocrystals using a custom 12-zone atmospheric pressure chemical vapour deposition (APCVD) system. NaCl is used as a seed promoter to facilitate the growth of monolayer, bilayer, and multilayer films, often as large as 200 μm. Additionally, the morphological evolution of the MoSe2 nanostructures is controlled by tuning different growth parameters based on insights, which we discuss in detail. The growth of dominant nanostructures, which include nanoribbons, snowflakes, monolayers and multilayer domains, among others, are discussed. High-resolution optical microscopy, field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) are used to image the as-grown crystals. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) are used to verify the quality and elemental composition of our as-grown MoSe2 crystals. Our findings brighten the prospect of growing novel 1D and 2D TMDC nanostructures with sufficient control to make them suitable for advanced optoelectronic and catalytic devices. Thu, 01 May 2025 00:00:00 GMT http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/20389 2025-05-01T00:00:00Z http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/20385 Search for new resonances decaying to pairs of merged diphotons in proton-proton collisions at √ = 13 tev Mukherjee, Sajal A search is presented for an extended Higgs sector with two new particles, 𝑋 and 𝜙 , in the process 𝑋→𝜙⁢𝜙→(𝛾⁢𝛾)⁢(𝛾⁢𝛾) . Novel neural networks classify events with diphotons that are merged and determine the diphoton masses. The search uses LHC proton-proton collision data at √𝑠=13  TeV collected with the CMS detector, corresponding to an integrated luminosity of 138  fb−1 . No evidence of such resonances is seen. Upper limits are set on the production cross section for 𝑚𝑋 between 300 and 3000 GeV and 𝑚𝜙/𝑚𝑋 between 0.5% and 2.5%, representing the most sensitive search in this channel. Wed, 01 Jan 2025 00:00:00 GMT http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/20385 2025-01-01T00:00:00Z http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/20382 Observation of W Z γ production and constraints on new physics scenarios in proton-proton collisions at √s = 13 TeV Mukherjee, Sajal A measurement of the 𝑊⁢𝑍⁢𝛾 triboson production cross section is presented. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of √𝑠 =13  TeV recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 138  fb−1 . The analysis focuses on the final state with three charged leptons, ℓ±⁢𝜈⁢ℓ+⁢ℓ− , where ℓ =𝑒 or 𝜇 , accompanied by an additional photon. The observed (expected) significance of the 𝑊⁢𝑍⁢𝛾 signal is 5.4 (3.8) standard deviations. The cross section is measured in a fiducial region, where events with an ℓ originating from a tau lepton decay are excluded, to be 5.48 ±1.11  fb , which is compatible with the prediction of 3.69 ±0.24  fb at next-to-leading order in quantum chromodynamics. Exclusion limits are set on anomalous quartic gauge couplings and on the production cross sections of massive axionlike particles. Tue, 01 Jul 2025 00:00:00 GMT http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/20382 2025-07-01T00:00:00Z http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/20381 Search for fractionally charged particles in proton-proton collisions at √s = 13 TeV Mukherjee, Sajal A search is presented for fractionally charged particles with charges below 1⁢𝑒 , using their small energy loss in the tracking detector as a key variable to observe a signal. The analyzed dataset corresponds to an integrated luminosity of 138  fb−1 of proton-proton collisions collected at √𝑠 =13  TeV in 2016–2018 at the CERN LHC. This is the first search at the LHC for new particles with a charge between 𝑒/3 and 0.9⁢𝑒, including an extension of previous results at a charge of 2⁢𝑒/3 . Masses up to 640 GeV and charges as low as 𝑒/3 are excluded at 95% confidence level. These are the most stringent limits to date for the considered Drell-Yan-like production mode. Tue, 01 Apr 2025 00:00:00 GMT http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/20381 2025-04-01T00:00:00Z