Development of Silicon Sensor Characterization System for Future High Energy Physics Experiments

The Compact Muon Solenoid (CMS) is one of the general purpose experiments at the Large Hadron Collider (LHC), CeRN and has its tracker built of all silicon strip and pixel sensors. Si sensors are expected to play extremely important role in the upgrades of the existing tracker for future high luminosity environment and will also be used in future lepton colliders. however, properties of the silicon sensors have to be carefully understood before they can be put in the extremely high luminosity condition. At Delhi university (DU), we have been working on the development of Si sensor characterization system, as part of the collaboration with the CMS experiment and RD50 collaboration. this works reports the installation of current-voltage (I-V) and capacitance-voltage (C-V) systems at DU

"Mother-weights" and lost fathers: parents in South Asian American literature

That parent-child relationships should play a significant role within South Asian American literature is perhaps no surprise, since this is crucial material for any writer. But the particular forms they so often take – a dysfunctional mother-daughter dynamic, leading to the search for maternal surrogates; and the figure of the prematurely deceased father – are more perplexing. Why do families adhere to these patterns in so many South Asian American texts and what does that tell us about this œuvre? More precisely, why are mothers subjected to a harsher critique than fathers and what purpose does this critique serve? How might we interpret the trope of the untimely paternal death? In this article I will seek to answer these questions – arguably key to an understanding of this growing body of writing – by considering works produced between the 1990s and the early twenty-first century by a range of South Asian American writers

New results on charmonium like states at Belle

New results on charmonium-like states measured by the Belle experiment at the KEKB asymmetric e+e- collider are presented, in particular (a) Search for the Zc pair production in ϒ(1S), ϒ(2S)$\Upsilon (1{\rm{S}}),\,\Upsilon (2S)$ decays and in e+e- s$\sqrt s$ of 10.52, 10.58, and 10.867 GeV. (b) Measurement of the absolute branching fractions of B+→Xcc¯K+${B^ + } \to {X_{c\overline c }}{K^ + }$ decays. (c) Observation of Ξc(2930)0 in the updated measurement of B−→K−ΛcΛ¯c¯.${B^ - } \to {K^ - }{\Lambda _c}{\overline \Lambda _{\overline c }}.$ (d) Angular analysis of e+e−→D(*)±D*∓${e^ + }{e^ - } \to {D^{(*) \pm }}{D^{* \mp }}$ process near the open charm threshold using initial state radiation

Simulations of Inter-Strip Capacitance and Resistance for the Design of the CMS Tracker Upgrade

An upgrade of the LHC accelerator, the high luminosity phase of the LHC (HL-LHC), is foreseen for 2023. The tracking system of the CMS experiment at HL-LHC will face a more intense radiation environment than the present system was designed for. This requires an upgrade of the full tracker, which will be equipped with higher granularity as well as radiation harder sensors, which can withstand higher radiation levels and occupancies.\\ In order to address the problems caused by the intense radiation environment, extensive measurements and simulation studies have been initiated for investigating these different design and material options for Silicon micro-strip sensors.\\ The simulation studies are based on commercial packages (Silvaco and Synopsys TCAD) and aim to investigate sensor characteristics before and after irradiation for fluences up to $1.5 \cdot 10^{15}\,\rm{n_{eq}/cm}^2$. A defect model was developed to implement the radiation damage and tuned to fit experimental measurements.\\ This paper covers the simulation of the inter-strip capacitance and resistance both before and after irradiation. Both properties are crucial for the design of future sensors, being responsible for strip noise and isolation, in turn affecting resolution. A detailed understanding of these parameters is required for an optimal sensor design for the future CMS tracker

\title{Development of Radiation Damage Models for Irradiated Silicon Sensors Using TCAD Tools}

Abstract. During the high luminosity upgrade of the LHC (HL-LHC) the CMS tracking system will face a more intense radiation environment than the present system was designed for. In order to design radiation tolerant silicon sensors for the future CMS tracker upgrade it is fundamental to complement the measurement with device simulation. This will help in both the understanding of the device performance and in the optimization of the design parameters. One of the important ingredients of the device simulation is to develop a radiation damage model incorporating both bulk and surface damage. In this paper we will discuss the development of a radiation damage model by using commercial TCAD packages (Silvaco and Synopsys), which successfully reproduce the recent measurements like leakage current, depletion voltage, interstrip capacitance and interstrip resistance, and provides an insight into the performance of irradiated silicon strip sensors

Performance of the Belle II Silicon Vertex Detector

The Belle II experiment at the SuperKEKB collider of KEK (Japan) will accumulate 50 ab−1 of e+e− collision data at an unprecedented instantaneous luminosity of 8 ×1035 cm−2s−1, about 40 times larger than its predecessor. The Belle II vertex detector plays a crucial role in the rich Belle II physics program, especially for time-dependent measurements. It consists of two layers of DEPFET-based pixels and four layers of double sided silicon strips detectors(SVD). The vertex detector has been recently completed and installed in Belle II for the physics run started in spring 2019. We report here results on the commissioning of the SVD and its performance measured with the first collision data set