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Pasquale Noli

Università degli Studi di Napoli "Federico II", Phisics, Teacher

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Papers by Pasquale Noli

EGMonitor primary dataset in AOD format from RunB of 2010 (/EGMonitor/Run2010B-Apr21ReReco-v1/AOD)

EGMonitor primary dataset in AOD format from RunB of 2010

Muography of the Volcanic Structure of the Summit of Vesuvius, Italy

Muography

Muons tomography applied to geosciences and volcanology

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012

Imaging the inner part of large geological targets is an important issue in geosciences with vari... more Imaging the inner part of large geological targets is an important issue in geosciences with various applications. Different approaches already exist (e.g. gravimetry, electrical tomography) that give access to a wide range of informations but with identified limitations or drawbacks (e.g. intrinsic ambiguity of the inverse problem, time consuming deployment of sensors over large distances). Here we present an alternative and complementary tomography method based on the measurement of the cosmic muons flux attenuation through the geological structures. We detail the basics of this muon tomography with a special emphasis on the photo-active detectors.

3D Muography for the Search of Hidden Cavities

Scientific Reports, 2019

Muography (or muon radiography) is a technique that exploits the penetration capability of muons,... more Muography (or muon radiography) is a technique that exploits the penetration capability of muons, elementary particles similar to electrons but with a mass about 200 times larger. High energy muons are naturally produced in the interactions of cosmic rays with the Earth atmosphere. The measurement of their absorption in matter allows the imaging of the inner structure of large bodies. The technological developments in the detection of elementary particles have opened the way to its application in various fields, such as archaeology, studies of geological structures, civil engineering and security issues. We have developed a new approach to the three-dimensional muography of underground structures, capable of directly localising hidden cavities and of reconstructing their shape in space. Our measurements at Mt. Echia, the site of the earliest settlement of the city of Naples in the 8th century BC, have led us to the discovery of a hidden underground cavity, whose existence was not ev...

The MURAVES telescope front-end electronics and data acquisition

Annals of Geophysics, 2017

The MURAVES detector is a 4 m 2 muon tracker equipped with a low power consumption electronic and... more The MURAVES detector is a 4 m 2 muon tracker equipped with a low power consumption electronic and designed to work in volcanic areas. Due to the great amount of channels (~1500) the detector is equipped with a multilayer electronic for data acquisition. It consists of 12 slave boards and 1 master board per square meter of detector and a single Raspberry Pi board that rules the whole set of one-square-meter detectors. Because of this modularity, we can enlarge in principle the detector surface by adding more one-square-meter elements. In the present work, we resume the main features of the MURAVES detector designed for the muography of volcanoes and, more generally, for the imaging of the underground. We focus on the capability to fine tune every single channel of the detector and the precise measure of the time of flight of the muons. The latter uses a time expansion technique and it should allow us to make a background rejection never obtained until now.

The MURAVES muon telescope: technology and expected performances

Annals of Geophysics, 2017

The MURAVES project aims to study the inner structure of the upper part of the Mt. Vesuvius volca... more The MURAVES project aims to study the inner structure of the upper part of the Mt. Vesuvius volcano by muon radiography (muography) technique. Very high energy muons, produced by cosmic rays in the atmosphere, can penetrate large thickness of rocks. By measuring the attenuation of the muons flux trough the volcano cone is possible to obtain a 2D image of the density structure. Internal discontinuities, with a spatial resolution of about 10 m, can be, in principle, resolved. An absolute average density measurement can be provided too. The project, funded by the Italian Ministry of University, Research and Education (MIUR), is led by INGV and INFN. In this article the mechanical structure of the detectors and background suppression techniques are reported.

Imaging of underground cavities with cosmic-ray muons from observations at Mt. Echia (Naples)

Scientific Reports, 2017

Muography is an imaging technique based on the measurement of absorption profiles for muons as th... more Muography is an imaging technique based on the measurement of absorption profiles for muons as they pass through rocks and earth. Muons are produced in the interactions of high-energy cosmic rays in the Earth’s atmosphere. The technique is conceptually similar to usual X-ray radiography, but with extended capabilities of investigating over much larger thicknesses of matter thanks to the penetrating power of high-energy muons. Over the centuries a complex system of cavities has been excavated in the yellow tuff of Mt. Echia, the site of the earliest settlement of the city of Naples in the 8th century BC. A new generation muon detector designed by us, was installed under a total rock overburden of about 40 metres. A 26 days pilot run provided about 14 millions of muon events. A comparison of the measured and expected muon fluxes improved the knowledge of the average rock density. The observation of known cavities proved the validity of the muographic technique. Hints on the existence ...

Joint measurement of the atmospheric muon flux through the Puy de Dôme volcano with plastic scintillators and Resistive Plate Chambers detectors

Journal of Geophysical Research: Solid Earth, 2015

The muographic imaging of volcanoes relies on the measured transmittance of the atmospheric muon ... more The muographic imaging of volcanoes relies on the measured transmittance of the atmospheric muon flux through the target. An important bias affecting the result comes from background contamination mimicking a higher transmittance. The MU-RAY and TOMUVOL collaborations measured independently in 2013 the atmospheric muon flux transmitted through the Puy de Dôme volcano using their early prototype detectors, based on plastic scintillators and on Glass Resistive Plate Chambers, respectively. These detectors had three (MU-RAY) or four (TOMUVOL) detection layers of 1 m 2 each, tens (MU-RAY) or hundreds (TOMUVOL) of nanosecond time resolution, a few millimeter position resolution, an energy threshold of few hundreds MeV, and no particle identification capabilities. The prototypes were deployed about 1.3 km away from the summit, where they measured, behind rock depths larger than 1000 m, remnant fluxes of 1.83±0.50(syst)±0.07(stat) m −2 d −1 deg −2 (MU-RAY) and 1.95±0.16(syst)±0.05(stat) m −2 d −1 deg −2 (TOMUVOL), that roughly correspond to the expected flux of high-energy atmospheric muons crossing 600 meters water equivalent (mwe) at 18 ∘ elevation. This implies that imaging depths larger than 500 mwe from 1 km away using such prototype detectors suffer from an overwhelming background. These measurements confirm that a new generation of detectors with higher momentum threshold, time-of-flight measurement, and/or particle identification is needed. The MU-RAY and TOMUVOL collaborations expect shortly to operate improved detectors, suitable for a robust muographic imaging of kilometer-scale volcanoes. 1. Muon Imaging of Volcanoes Volcanic hazard assessment and risk mitigation remain two very important scientific subjects with heavy implications both on the population safety and economic development [Brown et al., 2015]. Anticipating future activity of volcanoes requires monitoring of their activity as well as information on their past behavior and their internal structure. Monitoring volcano activity, which may be regarded as dynamic imaging of changes occurring inside and below the edifices, routinely uses a large number of methods [see, for example, Smith et al., 2009]. Structural geophysical studies, which may be considered as static imaging, aim at identifying and characterizing the architecture of the edifices, their plumbing systems, and the mechanical characteristics of rocks. They are inferred from internal distribution of various physical quantities such as electrical resistivity [

Assessing the feasibility of interrogating nuclear waste storage silos using cosmic-ray muons

Journal of Instrumentation, 2015

Muon radiography is a fast growing field in applied scientific research. In recent years, many de... more Muon radiography is a fast growing field in applied scientific research. In recent years, many detector technologies and imaging techniques using the Coulomb scattering and absorption properties of cosmic-ray muons have been developed for the nondestructive assay of various structures across a wide range of applications. This work presents the first results that assess the feasibility of using muon radiography to interrogate waste silos within the UK Nuclear Industry. Two such approaches, using different techniques that exploit each of these properties, have previously been published, and show promising results from both simulation and experimental data for the detection of shielded high-Z materials and density variations from volcanic assay. Both detector systems used are based on scintillator and photomultiplier technologies. Results from dedicated simulation studies using both these technologies and image reconstruction techniques are presented for an intermediate-sized legacy nuclear waste storage facility filled with concrete and an array of uranium samples. Both results highlight the potential to identify uranium objects of varying thicknesses greater than 5 cm within real-time durations of several weeks. Increased contributions from Coulomb scattering within the concrete matrix of the structure hinder the ability of both approaches to resolve similar objects of 2 cm dimensions even with increased statistics. These results are all dependent on both the position of the objects within the facility and the locations of the detectors. Results for differing thicknesses of concrete, which reflect the unknown composition of the structures under interrogation, are also presented alongside studies performed for a series of data collection durations. It is anticipated that with further research, muon radiography in one, or both of these forms, will play a key role in future industrial applications within the UK Nuclear Industry.

The MU-RAY project: Volcano radiography with cosmic-ray muons

Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams

Journal of Instrumentation, 2010

The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-takin... more The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-taking runs in 2008, and to estimate the level of detector noise. This paper describes the trigger components used, the algorithms that were executed, and the trigger synchronisation. Using data from extended cosmic ray runs, the muon, electron/photon, and jet triggers have been validated, and their performance evaluated. Efficiencies were found to be high, resolutions were found to be good, and rates as expected.

Performance of the CMS drift tube chambers with cosmic rays

Journal of Instrumentation, 2010

Performance of the CMS drift tube chambers with cosmic rays CMS Collaboration ABSTRACT: Studies o... more Performance of the CMS drift tube chambers with cosmic rays CMS Collaboration ABSTRACT: Studies of the performance of the CMS drift tube barrel muon system are described, with results based on data collected during the CMS Cosmic Run at Four Tesla. For most of these data, the solenoidal magnet was operated with a central field of 3.8 T. The analysis of data from 246 out of a total of 250 chambers indicates a very good muon reconstruction capability, with a coordinate resolution for a single hit of about 260 µm, and a nearly 100% efficiency for the drift tube cells. The resolution of the track direction measured in the bending plane is about 1.8 mrad, and the efficiency to reconstruct a segment in a single chamber is higher than 99%. The CMS simulation of cosmic rays reproduces well the performance of the barrel muon detector.

Performance of the CMS cathode strip chambers with cosmic rays

Journal of Instrumentation, 2010

Performance of the CMS cathode strip chambers with cosmic rays To cite this article: CMS Collabor... more

Commissioning and performance of the CMS pixel tracker with cosmic ray muons

Journal of Instrumentation, 2010

To cite this article: CMS Collaboration 2010 JINST 5 T03007 View the article online for updates a... more To cite this article: CMS Collaboration 2010 JINST 5 T03007 View the article online for updates and enhancements. Related content Alignment of the CMS silicon tracker during commissioning with cosmic rays CMS Collaboration-Fine synchronization of the CMS muon drift-tube local trigger using cosmic rays CMS Collaboration-Performance study of the CMS barrel resistive plate chambers with cosmic rays CMS Collaboration

Aligning the CMS muon chambers with the muon alignment system during an extended cosmic ray run

Journal of Instrumentation, 2010

ABSTRACT The alignment system for the muon spectrometer of the CMS detector comprises three indep... more ABSTRACT The alignment system for the muon spectrometer of the CMS detector comprises three independent subsystems of optical and analog position sensors. It aligns muon chambers with respect to each other and to the central silicon tracker. System commissioning at full magnetic field began in 2008 during an extended cosmic ray run. The system succeeded in tracking muon detector movements of up to 18 mm and rotations of several milliradians under magnetic forces. Depending on coordinate and subsystem, the system achieved chamber alignment precisions of 140-350 microns and 30-200 microradians, close to the precision requirements of the experiment. Systematic errors on absolute positions are estimated to be 340-590 microns based on comparisons with independent photogrammetry measurements.

Upsilon production cross section in pp collisions at √s=7TeV

Physical Review D, 2011

The Çð1SÞ, Çð2SÞ, and Çð3SÞ production cross sections in proton-proton collisions at ffiffi ffi s... more The Çð1SÞ, Çð2SÞ, and Çð3SÞ production cross sections in proton-proton collisions at ffiffi ffi s p ¼ 7 TeV are measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3:1 AE 0:3 pb À1. Integrated over the rapidity range jyj < 2, we find the product of the Çð1SÞ production cross section and branching fraction to dimuons to be ðpp ! Çð1SÞXÞ Á BðÇð1SÞ ! þ À Þ ¼ 7:37 AE 0:13 þ0:61 À0:42 AE 0:81 nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Çð1SÞ production. With the assumption of fully transverse or fully longitudinal production polarization, the measured cross section changes by about 20%. We also report the measurement of the Çð1SÞ, Çð2SÞ, and Çð3SÞ differential cross sections as a function of transverse momentum and rapidity.

Search for microscopic black hole signatures at the Large Hadron Collider

Physics Letters B, 2011

A search for microscopic black hole production and decay in pp collisions at a centerof-mass ener... more A search for microscopic black hole production and decay in pp collisions at a centerof-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb −1. Events with large total transverse energy are analyzed for the presence of multiple highenergy jets, leptons, and photons, typical of a signal expected from a microscopic black hole. Good agreement with the expected standard model backgrounds, dominated by QCD multijet production, is observed for various final-state multiplicities. Limits on the minimum black hole mass are set, in the range 3.5-4.5 TeV, for a variety of parameters in a model with large extra dimensions, along with model-independent limits on new physics in these final states. These are the first direct limits on black hole production at a particle accelerator.

$Research paper thumbnail of Search for physics beyond the standard model in opposite-sign dilepton events in pp collisions at $ \sqrt {s} = 7\,{\text{TeV}} $$

Search for physics beyond the standard model in opposite-sign dilepton events in pp collisions at $ \sqrt {s} = 7\,{\text{TeV}} $

Journal of High Energy Physics, 2011

A search is presented for physics beyond the standard model (SM) in final states with opposite-si... more A search is presented for physics beyond the standard model (SM) in final states with opposite-sign isolated lepton pairs accompanied by hadronic jets and missing transverse energy. The search is performed using LHC data recorded with the CMS detector, corresponding to an integrated luminosity of 34 pb −1. No evidence for an event yield beyond SM expectations is found. An upper limit on the non-SM contribution to the signal region is deduced from the results. This limit is interpreted in the context of the constrained minimal supersymmetric model. Additional information is provided to allow testing the exclusion of specific models of physics beyond the SM.

First measurement of the cross section for top-quark pair production in proton–proton collisions at s=7 TeV

Physics Letters B, 2011

The first measurement of the cross section for top-quark pair production in pp collisions at the ... more The first measurement of the cross section for top-quark pair production in pp collisions at the LHC at center-of-mass energy √ s = 7 TeV has been performed using 3.1 ± 0.3 pb −1 of data recorded by the CMS detector. This result utilizes the final state with two isolated, highly energetic charged leptons, large missing transverse energy, and two or more jets. Backgrounds from Drell-Yan and non-W/Z boson production are estimated from data. Eleven events are observed in the data with 2.1 ± 1.0 events expected from background. The measured cross section is 194 ± 72(stat.) ± 24(syst.) ± 21(lumi.) pb, consistent with next-to-leading order predictions.

First measurement of hadronic event shapes in pp collisions at s=7 TeV

Physics Letters B, 2011

EGMonitor primary dataset in AOD format from RunB of 2010 (/EGMonitor/Run2010B-Apr21ReReco-v1/AOD)

EGMonitor primary dataset in AOD format from RunB of 2010

Muography of the Volcanic Structure of the Summit of Vesuvius, Italy

Muography

Muons tomography applied to geosciences and volcanology

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012

Imaging the inner part of large geological targets is an important issue in geosciences with vari... more Imaging the inner part of large geological targets is an important issue in geosciences with various applications. Different approaches already exist (e.g. gravimetry, electrical tomography) that give access to a wide range of informations but with identified limitations or drawbacks (e.g. intrinsic ambiguity of the inverse problem, time consuming deployment of sensors over large distances). Here we present an alternative and complementary tomography method based on the measurement of the cosmic muons flux attenuation through the geological structures. We detail the basics of this muon tomography with a special emphasis on the photo-active detectors.

3D Muography for the Search of Hidden Cavities

Scientific Reports, 2019

Muography (or muon radiography) is a technique that exploits the penetration capability of muons,... more Muography (or muon radiography) is a technique that exploits the penetration capability of muons, elementary particles similar to electrons but with a mass about 200 times larger. High energy muons are naturally produced in the interactions of cosmic rays with the Earth atmosphere. The measurement of their absorption in matter allows the imaging of the inner structure of large bodies. The technological developments in the detection of elementary particles have opened the way to its application in various fields, such as archaeology, studies of geological structures, civil engineering and security issues. We have developed a new approach to the three-dimensional muography of underground structures, capable of directly localising hidden cavities and of reconstructing their shape in space. Our measurements at Mt. Echia, the site of the earliest settlement of the city of Naples in the 8th century BC, have led us to the discovery of a hidden underground cavity, whose existence was not ev...

The MURAVES telescope front-end electronics and data acquisition

Annals of Geophysics, 2017

The MURAVES detector is a 4 m 2 muon tracker equipped with a low power consumption electronic and... more The MURAVES detector is a 4 m 2 muon tracker equipped with a low power consumption electronic and designed to work in volcanic areas. Due to the great amount of channels (~1500) the detector is equipped with a multilayer electronic for data acquisition. It consists of 12 slave boards and 1 master board per square meter of detector and a single Raspberry Pi board that rules the whole set of one-square-meter detectors. Because of this modularity, we can enlarge in principle the detector surface by adding more one-square-meter elements. In the present work, we resume the main features of the MURAVES detector designed for the muography of volcanoes and, more generally, for the imaging of the underground. We focus on the capability to fine tune every single channel of the detector and the precise measure of the time of flight of the muons. The latter uses a time expansion technique and it should allow us to make a background rejection never obtained until now.

The MURAVES muon telescope: technology and expected performances

Annals of Geophysics, 2017

The MURAVES project aims to study the inner structure of the upper part of the Mt. Vesuvius volca... more The MURAVES project aims to study the inner structure of the upper part of the Mt. Vesuvius volcano by muon radiography (muography) technique. Very high energy muons, produced by cosmic rays in the atmosphere, can penetrate large thickness of rocks. By measuring the attenuation of the muons flux trough the volcano cone is possible to obtain a 2D image of the density structure. Internal discontinuities, with a spatial resolution of about 10 m, can be, in principle, resolved. An absolute average density measurement can be provided too. The project, funded by the Italian Ministry of University, Research and Education (MIUR), is led by INGV and INFN. In this article the mechanical structure of the detectors and background suppression techniques are reported.

Imaging of underground cavities with cosmic-ray muons from observations at Mt. Echia (Naples)

Scientific Reports, 2017

Muography is an imaging technique based on the measurement of absorption profiles for muons as th... more Muography is an imaging technique based on the measurement of absorption profiles for muons as they pass through rocks and earth. Muons are produced in the interactions of high-energy cosmic rays in the Earth’s atmosphere. The technique is conceptually similar to usual X-ray radiography, but with extended capabilities of investigating over much larger thicknesses of matter thanks to the penetrating power of high-energy muons. Over the centuries a complex system of cavities has been excavated in the yellow tuff of Mt. Echia, the site of the earliest settlement of the city of Naples in the 8th century BC. A new generation muon detector designed by us, was installed under a total rock overburden of about 40 metres. A 26 days pilot run provided about 14 millions of muon events. A comparison of the measured and expected muon fluxes improved the knowledge of the average rock density. The observation of known cavities proved the validity of the muographic technique. Hints on the existence ...

Joint measurement of the atmospheric muon flux through the Puy de Dôme volcano with plastic scintillators and Resistive Plate Chambers detectors

Journal of Geophysical Research: Solid Earth, 2015

The muographic imaging of volcanoes relies on the measured transmittance of the atmospheric muon ... more The muographic imaging of volcanoes relies on the measured transmittance of the atmospheric muon flux through the target. An important bias affecting the result comes from background contamination mimicking a higher transmittance. The MU-RAY and TOMUVOL collaborations measured independently in 2013 the atmospheric muon flux transmitted through the Puy de Dôme volcano using their early prototype detectors, based on plastic scintillators and on Glass Resistive Plate Chambers, respectively. These detectors had three (MU-RAY) or four (TOMUVOL) detection layers of 1 m 2 each, tens (MU-RAY) or hundreds (TOMUVOL) of nanosecond time resolution, a few millimeter position resolution, an energy threshold of few hundreds MeV, and no particle identification capabilities. The prototypes were deployed about 1.3 km away from the summit, where they measured, behind rock depths larger than 1000 m, remnant fluxes of 1.83±0.50(syst)±0.07(stat) m −2 d −1 deg −2 (MU-RAY) and 1.95±0.16(syst)±0.05(stat) m −2 d −1 deg −2 (TOMUVOL), that roughly correspond to the expected flux of high-energy atmospheric muons crossing 600 meters water equivalent (mwe) at 18 ∘ elevation. This implies that imaging depths larger than 500 mwe from 1 km away using such prototype detectors suffer from an overwhelming background. These measurements confirm that a new generation of detectors with higher momentum threshold, time-of-flight measurement, and/or particle identification is needed. The MU-RAY and TOMUVOL collaborations expect shortly to operate improved detectors, suitable for a robust muographic imaging of kilometer-scale volcanoes. 1. Muon Imaging of Volcanoes Volcanic hazard assessment and risk mitigation remain two very important scientific subjects with heavy implications both on the population safety and economic development [Brown et al., 2015]. Anticipating future activity of volcanoes requires monitoring of their activity as well as information on their past behavior and their internal structure. Monitoring volcano activity, which may be regarded as dynamic imaging of changes occurring inside and below the edifices, routinely uses a large number of methods [see, for example, Smith et al., 2009]. Structural geophysical studies, which may be considered as static imaging, aim at identifying and characterizing the architecture of the edifices, their plumbing systems, and the mechanical characteristics of rocks. They are inferred from internal distribution of various physical quantities such as electrical resistivity [

Assessing the feasibility of interrogating nuclear waste storage silos using cosmic-ray muons

Journal of Instrumentation, 2015

Muon radiography is a fast growing field in applied scientific research. In recent years, many de... more Muon radiography is a fast growing field in applied scientific research. In recent years, many detector technologies and imaging techniques using the Coulomb scattering and absorption properties of cosmic-ray muons have been developed for the nondestructive assay of various structures across a wide range of applications. This work presents the first results that assess the feasibility of using muon radiography to interrogate waste silos within the UK Nuclear Industry. Two such approaches, using different techniques that exploit each of these properties, have previously been published, and show promising results from both simulation and experimental data for the detection of shielded high-Z materials and density variations from volcanic assay. Both detector systems used are based on scintillator and photomultiplier technologies. Results from dedicated simulation studies using both these technologies and image reconstruction techniques are presented for an intermediate-sized legacy nuclear waste storage facility filled with concrete and an array of uranium samples. Both results highlight the potential to identify uranium objects of varying thicknesses greater than 5 cm within real-time durations of several weeks. Increased contributions from Coulomb scattering within the concrete matrix of the structure hinder the ability of both approaches to resolve similar objects of 2 cm dimensions even with increased statistics. These results are all dependent on both the position of the objects within the facility and the locations of the detectors. Results for differing thicknesses of concrete, which reflect the unknown composition of the structures under interrogation, are also presented alongside studies performed for a series of data collection durations. It is anticipated that with further research, muon radiography in one, or both of these forms, will play a key role in future industrial applications within the UK Nuclear Industry.

The MU-RAY project: Volcano radiography with cosmic-ray muons

Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams

Journal of Instrumentation, 2010

The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-takin... more The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-taking runs in 2008, and to estimate the level of detector noise. This paper describes the trigger components used, the algorithms that were executed, and the trigger synchronisation. Using data from extended cosmic ray runs, the muon, electron/photon, and jet triggers have been validated, and their performance evaluated. Efficiencies were found to be high, resolutions were found to be good, and rates as expected.

Performance of the CMS drift tube chambers with cosmic rays

Journal of Instrumentation, 2010

Performance of the CMS drift tube chambers with cosmic rays CMS Collaboration ABSTRACT: Studies o... more Performance of the CMS drift tube chambers with cosmic rays CMS Collaboration ABSTRACT: Studies of the performance of the CMS drift tube barrel muon system are described, with results based on data collected during the CMS Cosmic Run at Four Tesla. For most of these data, the solenoidal magnet was operated with a central field of 3.8 T. The analysis of data from 246 out of a total of 250 chambers indicates a very good muon reconstruction capability, with a coordinate resolution for a single hit of about 260 µm, and a nearly 100% efficiency for the drift tube cells. The resolution of the track direction measured in the bending plane is about 1.8 mrad, and the efficiency to reconstruct a segment in a single chamber is higher than 99%. The CMS simulation of cosmic rays reproduces well the performance of the barrel muon detector.

Performance of the CMS cathode strip chambers with cosmic rays

Journal of Instrumentation, 2010

Performance of the CMS cathode strip chambers with cosmic rays To cite this article: CMS Collabor... more

Commissioning and performance of the CMS pixel tracker with cosmic ray muons

Journal of Instrumentation, 2010

To cite this article: CMS Collaboration 2010 JINST 5 T03007 View the article online for updates a... more To cite this article: CMS Collaboration 2010 JINST 5 T03007 View the article online for updates and enhancements. Related content Alignment of the CMS silicon tracker during commissioning with cosmic rays CMS Collaboration-Fine synchronization of the CMS muon drift-tube local trigger using cosmic rays CMS Collaboration-Performance study of the CMS barrel resistive plate chambers with cosmic rays CMS Collaboration

Aligning the CMS muon chambers with the muon alignment system during an extended cosmic ray run

Journal of Instrumentation, 2010

ABSTRACT The alignment system for the muon spectrometer of the CMS detector comprises three indep... more ABSTRACT The alignment system for the muon spectrometer of the CMS detector comprises three independent subsystems of optical and analog position sensors. It aligns muon chambers with respect to each other and to the central silicon tracker. System commissioning at full magnetic field began in 2008 during an extended cosmic ray run. The system succeeded in tracking muon detector movements of up to 18 mm and rotations of several milliradians under magnetic forces. Depending on coordinate and subsystem, the system achieved chamber alignment precisions of 140-350 microns and 30-200 microradians, close to the precision requirements of the experiment. Systematic errors on absolute positions are estimated to be 340-590 microns based on comparisons with independent photogrammetry measurements.

Upsilon production cross section in pp collisions at √s=7TeV

Physical Review D, 2011

The Çð1SÞ, Çð2SÞ, and Çð3SÞ production cross sections in proton-proton collisions at ffiffi ffi s... more The Çð1SÞ, Çð2SÞ, and Çð3SÞ production cross sections in proton-proton collisions at ffiffi ffi s p ¼ 7 TeV are measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3:1 AE 0:3 pb À1. Integrated over the rapidity range jyj < 2, we find the product of the Çð1SÞ production cross section and branching fraction to dimuons to be ðpp ! Çð1SÞXÞ Á BðÇð1SÞ ! þ À Þ ¼ 7:37 AE 0:13 þ0:61 À0:42 AE 0:81 nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Çð1SÞ production. With the assumption of fully transverse or fully longitudinal production polarization, the measured cross section changes by about 20%. We also report the measurement of the Çð1SÞ, Çð2SÞ, and Çð3SÞ differential cross sections as a function of transverse momentum and rapidity.

Search for microscopic black hole signatures at the Large Hadron Collider

Physics Letters B, 2011

A search for microscopic black hole production and decay in pp collisions at a centerof-mass ener... more A search for microscopic black hole production and decay in pp collisions at a centerof-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb −1. Events with large total transverse energy are analyzed for the presence of multiple highenergy jets, leptons, and photons, typical of a signal expected from a microscopic black hole. Good agreement with the expected standard model backgrounds, dominated by QCD multijet production, is observed for various final-state multiplicities. Limits on the minimum black hole mass are set, in the range 3.5-4.5 TeV, for a variety of parameters in a model with large extra dimensions, along with model-independent limits on new physics in these final states. These are the first direct limits on black hole production at a particle accelerator.

$Research paper thumbnail of Search for physics beyond the standard model in opposite-sign dilepton events in pp collisions at $ \sqrt {s} = 7\,{\text{TeV}} $$

Search for physics beyond the standard model in opposite-sign dilepton events in pp collisions at $ \sqrt {s} = 7\,{\text{TeV}} $

Journal of High Energy Physics, 2011

A search is presented for physics beyond the standard model (SM) in final states with opposite-si... more A search is presented for physics beyond the standard model (SM) in final states with opposite-sign isolated lepton pairs accompanied by hadronic jets and missing transverse energy. The search is performed using LHC data recorded with the CMS detector, corresponding to an integrated luminosity of 34 pb −1. No evidence for an event yield beyond SM expectations is found. An upper limit on the non-SM contribution to the signal region is deduced from the results. This limit is interpreted in the context of the constrained minimal supersymmetric model. Additional information is provided to allow testing the exclusion of specific models of physics beyond the SM.

First measurement of the cross section for top-quark pair production in proton–proton collisions at s=7 TeV

Physics Letters B, 2011

The first measurement of the cross section for top-quark pair production in pp collisions at the ... more The first measurement of the cross section for top-quark pair production in pp collisions at the LHC at center-of-mass energy √ s = 7 TeV has been performed using 3.1 ± 0.3 pb −1 of data recorded by the CMS detector. This result utilizes the final state with two isolated, highly energetic charged leptons, large missing transverse energy, and two or more jets. Backgrounds from Drell-Yan and non-W/Z boson production are estimated from data. Eleven events are observed in the data with 2.1 ± 1.0 events expected from background. The measured cross section is 194 ± 72(stat.) ± 24(syst.) ± 21(lumi.) pb, consistent with next-to-leading order predictions.

First measurement of hadronic event shapes in pp collisions at s=7 TeV

Physics Letters B, 2011