Search results for "ATLAS"

Observation of an Excited $B^{\pm}_c$ Meson State with the ATLAS Detector

2014

A search for excited states of the B±c meson is performed using 4.9 fb-1 of 7 TeV and 19.2 fb-1 of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay B±c→J/ψπ±. The state appears in the m(Bc±π+π-)-m(Bc±)-2m(π±) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5 MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the B±c meson, B±c(2S).

Big Data Processing in the ATLAS Experiment: Use Cases and Experience

2015

Abstract The physics goals of the next Large Hadron Collider run include high precision tests of the Standard Model and searches for new physics. These goals require detailed comparison of data with computational models simulating the expected data behavior. To highlight the role which modeling and simulation plays in future scientific discovery, we report on use cases and experience with a unified system built to process both real and simulated data of growing volume and variety.

Multi-channel search for squarks and gluinos in root s=7 TeV pp collisions with the ATLAS detector at the LHC

2013

A search for supersymmetric particles in final states with zero, one, and two leptons, with and without jets identified as originating from b-quarks, in 4.7 fb[superscript −1] of √s = 7 TeV pp collisions produced by the Large Hadron Collider and recorded by the ATLAS detector is presented. The search uses a set of variables carrying information on the event kinematics transverse and parallel to the beam line that are sensitive to several topologies expected in supersymmetry. Mutually exclusive final states are defined, allowing a combination of all channels to increase the search sensitivity. No deviation from the Standard Model expectation is observed. Upper limits at 95 % confidence level…

C57BL/6-specific conditions for efficient in utero electroporation of the central nervous system.

2014

Abstract Background In utero electroporation is a fast an efficient tool to specifically address gene expression in the murine central nervous system. This technique was originally established in ICR/CD-1 outbred mice. Neuroanatomical differences between the different mouse strains and variations in gestation length require the optimization of the conditions for each strain to avoid severe complications. Furthermore the relevant position information is currently only scarcely standardized and not always easy to transfer to C57BL/6 mice. New method In this study we present an improved method for in utero electroporation of C57BL/6 including a detailed atlas that allows for specific and effic…

Alignment of the ATLAS Inner Detector and Single Top Studies

2016

Alineamiento del detector interno de ATLAS y estudios del single top Esta tesis esta compuesta por dos partes bien diferenciadas. La primera trata de los estudios de alineamiento del detector interno del experimento ATLAS en el CERN. La segunda se centra en los estudios sobre el quark top cuando es producido como partícula aislada. ATLAS es uno de los grandes experimentos del LHC (Gran colisionador de hadrones) situado en el CERN. ATLAS es un detector de propósito general. Se diseñó para aprovechar la alta energía disponible en el LHC y observar fenómenos de física a muy altas energías. ATLAS está formado por varios sub-sistemas, como el detector interno de trazas, los calorímetros electrom…

Update on the TowerJazz CMOS DMAPS development for the ATLAS ITk

2019

The upgrade of the ATLAS tracking detector for the High-Luminosity Large Hadron Collider at CERN requires the development of novel radiation hard silicon sensor technologies. For the de- velopment of depleted CMOS sensors for ATLAS we combined small electrodes with minimal capacitance and advanced processing for fully depleted active sensor volume to achieve radiation hard CMOS sensors in line with ATLAS ITk specifications. Based on initial studies on the prototype sensor “TowerJazz Investigator” we have now developed, produced and tested a first full-size depleted CMOS sensor based on the 180nm TowerJazz imag- ing process, the so-called “MALTA” sensor. The sensor combines special low-noise…

Atlas Lingüístico de la Península Ibérica (ALPI): Estudi i edició del País Valencià

2001

La tesi doctoral “Atlas Lingüístico de la Península Ibérica (ALPI): Estudi i edició del País Valencià” pretén recuperar un material lingüístic (fonètic, morfosintàctic i lèxic) inèdit recollit al País Valencià entre 1934 (pobles castellanoparlants) i 1935 (pobles valencianoparlants) per investigadors de la talla de M. Sanchis Guarner i F. de B. Moll. La recuperació d’aquest material està feta de forma digital, escrita (edició de les enquestes) i il·lustrada per mapes lingüístics (cartografia selectiva). Es tracta d’unes enquestes lingüístiques projectades pel Centre d’Estudis Històrics de Madrid (precedent de l’actual CSIC), presidit per R. Menéndez Pidal, qui va encarregar el projecte al m…

The TileCal Optical Multiplexer Board 9U

2011

Abstract TileCal is the hadronic calorimeter of the ATLAS experiment at LHC/CERN. The system contains roughly 10,000 channels of read-out electronics, whose signals are gathered and digitized in the front-end electronics and then transmitted to the counting room through two redundant optical links. Then, the data is received in the back-end system by the Optical Multiplexer Board (OMB) 9U which performs a CRC check to the redundant data to avoid Single Event Upsets errors. A real-time decision is taken on the event-to-event basis to transmit single data to the Read-Out Drivers (RODs) for processing. Due to the low dose level expected during the first years of operations in ATLAS it was deci…

2007

Performance of jet substructure techniques for large-$R$ jets in proton-proton collisions at $\sqrt{s}$ = 7 TeV using the ATLAS detector

2013

This paper presents the application of a variety of techniques to study jet substructure. The performance of various modified jet algorithms, or jet grooming techniques, for several jet types and event topologies is investigated for jets with transverse momentum larger than 300 GeV. Properties of jets subjected to the mass-drop filtering, trimming, and pruning algorithms are found to have a reduced sensitivity to multiple proton-proton interactions, are more stable at high luminosity and improve the physics potential of searches for heavy boosted objects. Studies of the expected discrimination power of jet mass and jet substructure observables in searches for new physics are also presented.…