Skip to main content

Andre Rosowsky

Follower

1

Following

63

Public Views

I am a long-retired organic/medicinal chemist with 45 years of experience in the design, synthesis, and with the generous help of colleagues in other fields the preclinical evaluation of folate antagonists and nucleoside analogues as anticancer, antiparasitic, and antiviral agents.

less

University of Zagreb

Uppsala University

University of East London

Armando Marques-Guedes

UNL - New University of Lisbon

University of Leicester

Gwen Robbins Schug

University of North Carolina at Greensboro

Gabriel Gutierrez-Alonso

University of Salamanca

Macquarie University

Universidade Federal do Rio Grande do Sul

Swansea University

Uploads

Papers by Andre Rosowsky

Energy resolution of the barrel of the CMS Electromagnetic Calorimeter

Journal of Instrumentation, 2007

Evidence for b baryons in Z decays

Physics Letters B, 1992

In 160 000 hadronic Z decays recorded with the ALEPH detector at LEP, the yields of A£-and A~ ÷ c... more In 160 000 hadronic Z decays recorded with the ALEPH detector at LEP, the yields of A£-and A~ ÷ combinations have been measured. The observed excess of AJ~-over A£ + of 53 + 13 is interpreted as evidence for b baryons and their semileptonic decay. Assuming that three body decay processes such as Ab~A~ + ~-9 dominate the semileptonic decay of b baryons, this excess corresponds to a product branching ratio BR(b--,Ab) "BR(Ab-, A~ ÷ ~ -9) .BR(A¢ ÷ --,AX ) = (0.95 + 0.22 (stat.) + 0.21 (syst.) )%, where Ab and A~ + denote the bottom and charm baryons respectively.

Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

Journal of Instrumentation, 2008

Calibration of the relative response of the individual channels of the barrel electromagnetic cal... more Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated.

Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter

Journal of Instrumentation, 2010

Ensuring the radiation hardness of PbWO 4 crystals was one of the main priorities during the cons... more Ensuring the radiation hardness of PbWO 4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered.

Charged particle transverse momentum spectra in pp collisions at √s = 0:9 and 7 TeV

Journal of High Energy Physics, 2011

The charged particle transverse momentum (p T) spectra are presented for pp collisions at $ \sqrt... more

Performance of the CMS hadron calorimeter with cosmic ray muons and LHC beam data

Journal of Instrumentation, 2010

The CMS Hadron Calorimeter in the barrel, endcap and forward regions is fully commissioned. Cosmi... more The CMS Hadron Calorimeter in the barrel, endcap and forward regions is fully commissioned. Cosmic ray data were taken with and without magnetic field at the surface hall and after installation in the experimental hall, hundred meters underground. Various measurements were also performed during the few days of beam in the LHC in September 2008. Calibration parameters were extracted, and the energy response of the HCAL determined from test beam data has been checked.

Performance of CMS hadron calorimeter timing and synchronization using test beam, cosmic ray, and LHC beam data

Journal of Instrumentation, 2010

To cite this article: CMS Collaboration 2010 JINST 5 T03013 View the article online for updates a... more To cite this article: CMS Collaboration 2010 JINST 5 T03013 View the article online for updates and enhancements. Related content Performance of the CMS hadron calorimeter with cosmic ray muons and LHC beam data CMS Collaboration -Identification and filtering of uncharacteristic noise in the CMShadron calorimeter CMS Collaboration -Fine synchronization of the CMS muon drift-tube local trigger using cosmic rays CMS Collaboration -Recent citations New method of out-of-time energy subtraction for the CMS hadronic calorimeter Jay Lawhorn and on behalf of the CMS HCAL Collaboration -Operational experience with the CMS hadronic calorimeter system Taylan Yetkin (On behalf of the CMS Collaboration) -Identification and filtering of uncharacteristic noise in the CMS hadron calorimeter CMS Collaboration

Performance and operation of the CMS electromagnetic calorimeter

Journal of Instrumentation, 2010

To cite this article: CMS Collaboration 2010 JINST 5 T03010 View the article online for updates a... more To cite this article: CMS Collaboration 2010 JINST 5 T03010 View the article online for updates and enhancements. Related content Commissioning of the CMS experiment and the cosmic run at four tesla CMS Collaboration -Energy calibration and resolution of the CMS electromagnetic calorimeter in pp collisions at s = 7 TeV -Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams CMS Collaboration -Recent citations Calibration techniques and strategies for the present and future LHC electromagnetic calorimeters M. Aleksa -A segmented anode vacuum phototriode with position sensitivity S. Zahid et al -The role of the CMS electron and photon trigger in the study of the Higgs boson and high mass searches Thomas Strebler and On behalf of the CMS Collaboration

Identification and filtering of uncharacteristic noise in the CMS hadron calorimeter

Journal of Instrumentation, 2010

Commissioning studies of the CMS hadron calorimeter have identified sporadic uncharacteristic noi... more Commissioning studies of the CMS hadron calorimeter have identified sporadic uncharacteristic noise and a small number of malfunctioning calorimeter channels. Algorithms have been developed to identify and address these problems in the data. The methods have been tested on cosmic ray muon data, calorimeter noise data, and single beam data collected with CMS in 2008. The noise rejection algorithms can be applied to LHC collision data at the trigger level or in the offline analysis. The application of the algorithms at the trigger level is shown to remove 90% of noise events with fake missing transverse energy above 100 GeV, which is sufficient for the CMS physics trigger operation.

Commissioning of the CMS High-Level Trigger with cosmic rays

Journal of Instrumentation, 2010

The CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially i... more The CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially interesting events are recorded with high efficiency and good quality. This paper gives an overview of the HLT and focuses on its commissioning using cosmic rays. The selection of triggers that were deployed is presented and the online grouping of triggered events into streams and primary datasets is discussed. Tools for online and offline data quality monitoring for the HLT are described, and the operational performance of the muon HLT algorithms is reviewed. The average time taken for the HLT selection and its dependence on detector and operating conditions are presented. The HLT performed reliably and helped provide a large dataset. This dataset has proven to be invaluable for understanding the performance of the trigger and the CMS experiment as a whole.

Commissioning of the CMS experiment and the cosmic run at four tesla

Journal of Instrumentation, 2010

a month-long data-taking exercise known as the Cosmic Run At Four Tesla in late 2008 in order to ... more a month-long data-taking exercise known as the Cosmic Run At Four Tesla in late 2008 in order to complete the commissioning of the experiment for extended operation. The operational lessons resulting from this exercise were addressed in the subsequent shutdown to better prepare CMS for LHC beams in 2009. The cosmic data collected have been invaluable to study the performance of the detectors, to commission the alignment and calibration techniques, and to make several cosmic ray measurements. The experimental setup, conditions, and principal achievements from this data-taking exercise are described along with a review of the preceding integration activities.

$Research paper thumbnail of Dependence on pseudorapidity and on centrality of charged hadron production in PbPb collisions at $ \sqrt {{{s_{\text{NN}}}}} = 2.76 $ TeV$

Dependence on pseudorapidity and on centrality of charged hadron production in PbPb collisions at $ \sqrt {{{s_{\text{NN}}}}} = 2.76 $ TeV

Journal of High Energy Physics, 2011

A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a f... more A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a function of pseudorapidity and centrality, at a collision energy of 2.76 TeV per nucleon pair. The data sample is collected using the CMS detector and a minimum-bias trigger, with the CMS solenoid off. The number of charged hadrons is measured both by counting the number of reconstructed particle hits and by forming hit doublets of pairs of layers in the pixel detector. The two methods give consistent results. The charged hadron multiplicity density, dN ch /dη| η=0 , for head-on collisions is found to be 1612 ± 55, where the uncertainty is dominated by systematic effects. Comparisons of these results to previous measurements and to various models are also presented.

Measurement of αs from scaling violations in fragmentation functions in e+e− annihilation

Physics Letters B, 1995

Other e ects that must be controlled are the corrections that the fragmentation of the quarks (a ... more Other e ects that must be controlled are the corrections that the fragmentation of the quarks (a non-perturbative phenomenon) can induce in the perturbative equations describing the scaling violations. The work presented here uses inclusive scaled-energy distributions of stable charged particles measured at PEP, PETRA, TRISTAN and LEP together with ALEPH measurements of the distributions in bottom-, charm-and light-quark

Observation of monojet events and tentative interpretation

Physics Letters B, 1994

A data sample corresponding to almost two million hadronic Z decays collected by the ALEPH detect... more A data sample corresponding to almost two million hadronic Z decays collected by the ALEPH detector at LEP has been searched for monojet events. Three events were found, in agreement with the expectation from the process e + e ! , with ! ff. Two events are hadronic, the third one being an e + e pair. All monojet masses are in excess of 3 GeV/c 2 , and two of the events have large transverse momenta: 18.5 and 20.3 GeV/c. These kinematic characteristics are quite unlikely in the process e + e ! . The probability of their occurrence increases substantially when processes involving further Z or W exchanges are taken into account, but still remains at the 5% level.

Search for Quark Compositeness with the Dijet Centrality Ratio inppCollisions ats=7 TeV

Physical Review Letters, 2010

First Measurement of Bose-Einstein Correlations in Proton-Proton Collisions ats=0.9and 2.36 TeV at the LHC

Physical Review Letters, 2010

Observation and studies of jet quenching in PbPb collisions atsNN=2.76TeV

Physical Review C, 2011

Performance of the ALEPH detector at LEP

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1995

Charged-particle multiplicities inppinteractions measured with the ATLAS detector at the LHC

New Journal of Physics, 2011

Measurements are presented from proton-proton collisions at centre-of-mass energies of √ s = 0.9,... more Measurements are presented from proton-proton collisions at centre-of-mass energies of √ s = 0.9, 2.36 and 7 TeV recorded with the ATLAS detector at the LHC. Events were collected using a single-arm minimum-bias trigger. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the relationship between the mean transverse momentum and charged-particle multiplicity are measured. Measurements in different regions of phase-space are shown, providing diffraction-reduced measurements as well as more inclusive ones. The observed distributions are corrected to well-defined phase-space regions, using model-independent corrections. The results are compared to each other and to various Monte Carlo models, including a new AMBT1 pythia6 tune. In all the kinematic regions considered, the particle multiplicities are higher than predicted by the Monte Carlo models. The central charged-particle multiplicity per event and unit of pseudorapidity, for tracks with p T > 100 MeV, is measured to be 3.483 ± 0.009 (stat) ± 0.106 (syst) at √ s = 0.9 TeV and 5.630 ± 0.003 (stat) ± 0.169 (syst) at √ s = 7 TeV. 1 The ATLAS reference system is a Cartesian right-handed co-ordinate system, with the nominal collision point at the origin. The anti-clockwise beam direction defines the positive z-axis, while the positive x-axis is defined as pointing from the collision point to the centre of the LHC ring and the positive y-axis points upwards. The azimuthal angle φ is measured around the beam axis and the polar angle θ is measured with respect to the z-axis. The pseudorapidity is defined as η = -ln tan(θ/2). 2 The factor 2πp T in the p T spectrum comes from the Lorentz invariant definition of the cross section in terms of d 3 p. Our results could thus be interpreted as the massless approximation to d 3 p.

Measurement of Bose–Einstein correlations in pp collisions at the LHC with CMS

Journal of Physics G: Nuclear and Particle Physics, 2011

Bose-Einstein correlations between same charge particles are measured in samples of proton-proton... more Bose-Einstein correlations between same charge particles are measured in samples of proton-proton collisions at 0.9 and 7 TeV centre-of-mass energies, recorded by the CMS experiment at the LHC. The signal is observed in the form of an enhancement of number of pairs of same-sign charged particles with small relative momentum. The dependence of this enhancement on kinematic and topological features of the event is studied.

Energy resolution of the barrel of the CMS Electromagnetic Calorimeter

Journal of Instrumentation, 2007

Evidence for b baryons in Z decays

Physics Letters B, 1992

In 160 000 hadronic Z decays recorded with the ALEPH detector at LEP, the yields of A£-and A~ ÷ c... more In 160 000 hadronic Z decays recorded with the ALEPH detector at LEP, the yields of A£-and A~ ÷ combinations have been measured. The observed excess of AJ~-over A£ + of 53 + 13 is interpreted as evidence for b baryons and their semileptonic decay. Assuming that three body decay processes such as Ab~A~ + ~-9 dominate the semileptonic decay of b baryons, this excess corresponds to a product branching ratio BR(b--,Ab) "BR(Ab-, A~ ÷ ~ -9) .BR(A¢ ÷ --,AX ) = (0.95 + 0.22 (stat.) + 0.21 (syst.) )%, where Ab and A~ + denote the bottom and charm baryons respectively.

Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

Journal of Instrumentation, 2008

Calibration of the relative response of the individual channels of the barrel electromagnetic cal... more Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated.

Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter

Journal of Instrumentation, 2010

Ensuring the radiation hardness of PbWO 4 crystals was one of the main priorities during the cons... more Ensuring the radiation hardness of PbWO 4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered.

Charged particle transverse momentum spectra in pp collisions at √s = 0:9 and 7 TeV

Journal of High Energy Physics, 2011

The charged particle transverse momentum (p T) spectra are presented for pp collisions at $ \sqrt... more

Performance of the CMS hadron calorimeter with cosmic ray muons and LHC beam data

Journal of Instrumentation, 2010

The CMS Hadron Calorimeter in the barrel, endcap and forward regions is fully commissioned. Cosmi... more The CMS Hadron Calorimeter in the barrel, endcap and forward regions is fully commissioned. Cosmic ray data were taken with and without magnetic field at the surface hall and after installation in the experimental hall, hundred meters underground. Various measurements were also performed during the few days of beam in the LHC in September 2008. Calibration parameters were extracted, and the energy response of the HCAL determined from test beam data has been checked.

Performance of CMS hadron calorimeter timing and synchronization using test beam, cosmic ray, and LHC beam data

Journal of Instrumentation, 2010

To cite this article: CMS Collaboration 2010 JINST 5 T03013 View the article online for updates a... more To cite this article: CMS Collaboration 2010 JINST 5 T03013 View the article online for updates and enhancements. Related content Performance of the CMS hadron calorimeter with cosmic ray muons and LHC beam data CMS Collaboration -Identification and filtering of uncharacteristic noise in the CMShadron calorimeter CMS Collaboration -Fine synchronization of the CMS muon drift-tube local trigger using cosmic rays CMS Collaboration -Recent citations New method of out-of-time energy subtraction for the CMS hadronic calorimeter Jay Lawhorn and on behalf of the CMS HCAL Collaboration -Operational experience with the CMS hadronic calorimeter system Taylan Yetkin (On behalf of the CMS Collaboration) -Identification and filtering of uncharacteristic noise in the CMS hadron calorimeter CMS Collaboration

Performance and operation of the CMS electromagnetic calorimeter

Journal of Instrumentation, 2010

To cite this article: CMS Collaboration 2010 JINST 5 T03010 View the article online for updates a... more To cite this article: CMS Collaboration 2010 JINST 5 T03010 View the article online for updates and enhancements. Related content Commissioning of the CMS experiment and the cosmic run at four tesla CMS Collaboration -Energy calibration and resolution of the CMS electromagnetic calorimeter in pp collisions at s = 7 TeV -Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams CMS Collaboration -Recent citations Calibration techniques and strategies for the present and future LHC electromagnetic calorimeters M. Aleksa -A segmented anode vacuum phototriode with position sensitivity S. Zahid et al -The role of the CMS electron and photon trigger in the study of the Higgs boson and high mass searches Thomas Strebler and On behalf of the CMS Collaboration

Identification and filtering of uncharacteristic noise in the CMS hadron calorimeter

Journal of Instrumentation, 2010

Commissioning studies of the CMS hadron calorimeter have identified sporadic uncharacteristic noi... more Commissioning studies of the CMS hadron calorimeter have identified sporadic uncharacteristic noise and a small number of malfunctioning calorimeter channels. Algorithms have been developed to identify and address these problems in the data. The methods have been tested on cosmic ray muon data, calorimeter noise data, and single beam data collected with CMS in 2008. The noise rejection algorithms can be applied to LHC collision data at the trigger level or in the offline analysis. The application of the algorithms at the trigger level is shown to remove 90% of noise events with fake missing transverse energy above 100 GeV, which is sufficient for the CMS physics trigger operation.

Commissioning of the CMS High-Level Trigger with cosmic rays

Journal of Instrumentation, 2010

The CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially i... more The CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially interesting events are recorded with high efficiency and good quality. This paper gives an overview of the HLT and focuses on its commissioning using cosmic rays. The selection of triggers that were deployed is presented and the online grouping of triggered events into streams and primary datasets is discussed. Tools for online and offline data quality monitoring for the HLT are described, and the operational performance of the muon HLT algorithms is reviewed. The average time taken for the HLT selection and its dependence on detector and operating conditions are presented. The HLT performed reliably and helped provide a large dataset. This dataset has proven to be invaluable for understanding the performance of the trigger and the CMS experiment as a whole.

Commissioning of the CMS experiment and the cosmic run at four tesla

Journal of Instrumentation, 2010

a month-long data-taking exercise known as the Cosmic Run At Four Tesla in late 2008 in order to ... more a month-long data-taking exercise known as the Cosmic Run At Four Tesla in late 2008 in order to complete the commissioning of the experiment for extended operation. The operational lessons resulting from this exercise were addressed in the subsequent shutdown to better prepare CMS for LHC beams in 2009. The cosmic data collected have been invaluable to study the performance of the detectors, to commission the alignment and calibration techniques, and to make several cosmic ray measurements. The experimental setup, conditions, and principal achievements from this data-taking exercise are described along with a review of the preceding integration activities.

$Research paper thumbnail of Dependence on pseudorapidity and on centrality of charged hadron production in PbPb collisions at $ \sqrt {{{s_{\text{NN}}}}} = 2.76 $ TeV$

Dependence on pseudorapidity and on centrality of charged hadron production in PbPb collisions at $ \sqrt {{{s_{\text{NN}}}}} = 2.76 $ TeV

Journal of High Energy Physics, 2011

A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a f... more A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a function of pseudorapidity and centrality, at a collision energy of 2.76 TeV per nucleon pair. The data sample is collected using the CMS detector and a minimum-bias trigger, with the CMS solenoid off. The number of charged hadrons is measured both by counting the number of reconstructed particle hits and by forming hit doublets of pairs of layers in the pixel detector. The two methods give consistent results. The charged hadron multiplicity density, dN ch /dη| η=0 , for head-on collisions is found to be 1612 ± 55, where the uncertainty is dominated by systematic effects. Comparisons of these results to previous measurements and to various models are also presented.

Measurement of αs from scaling violations in fragmentation functions in e+e− annihilation

Physics Letters B, 1995

Other e ects that must be controlled are the corrections that the fragmentation of the quarks (a ... more Other e ects that must be controlled are the corrections that the fragmentation of the quarks (a non-perturbative phenomenon) can induce in the perturbative equations describing the scaling violations. The work presented here uses inclusive scaled-energy distributions of stable charged particles measured at PEP, PETRA, TRISTAN and LEP together with ALEPH measurements of the distributions in bottom-, charm-and light-quark

Observation of monojet events and tentative interpretation

Physics Letters B, 1994

A data sample corresponding to almost two million hadronic Z decays collected by the ALEPH detect... more A data sample corresponding to almost two million hadronic Z decays collected by the ALEPH detector at LEP has been searched for monojet events. Three events were found, in agreement with the expectation from the process e + e ! , with ! ff. Two events are hadronic, the third one being an e + e pair. All monojet masses are in excess of 3 GeV/c 2 , and two of the events have large transverse momenta: 18.5 and 20.3 GeV/c. These kinematic characteristics are quite unlikely in the process e + e ! . The probability of their occurrence increases substantially when processes involving further Z or W exchanges are taken into account, but still remains at the 5% level.

Search for Quark Compositeness with the Dijet Centrality Ratio inppCollisions ats=7 TeV

Physical Review Letters, 2010

First Measurement of Bose-Einstein Correlations in Proton-Proton Collisions ats=0.9and 2.36 TeV at the LHC

Physical Review Letters, 2010

Observation and studies of jet quenching in PbPb collisions atsNN=2.76TeV

Physical Review C, 2011

Performance of the ALEPH detector at LEP

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1995

Charged-particle multiplicities inppinteractions measured with the ATLAS detector at the LHC

New Journal of Physics, 2011

Measurements are presented from proton-proton collisions at centre-of-mass energies of √ s = 0.9,... more Measurements are presented from proton-proton collisions at centre-of-mass energies of √ s = 0.9, 2.36 and 7 TeV recorded with the ATLAS detector at the LHC. Events were collected using a single-arm minimum-bias trigger. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the relationship between the mean transverse momentum and charged-particle multiplicity are measured. Measurements in different regions of phase-space are shown, providing diffraction-reduced measurements as well as more inclusive ones. The observed distributions are corrected to well-defined phase-space regions, using model-independent corrections. The results are compared to each other and to various Monte Carlo models, including a new AMBT1 pythia6 tune. In all the kinematic regions considered, the particle multiplicities are higher than predicted by the Monte Carlo models. The central charged-particle multiplicity per event and unit of pseudorapidity, for tracks with p T > 100 MeV, is measured to be 3.483 ± 0.009 (stat) ± 0.106 (syst) at √ s = 0.9 TeV and 5.630 ± 0.003 (stat) ± 0.169 (syst) at √ s = 7 TeV. 1 The ATLAS reference system is a Cartesian right-handed co-ordinate system, with the nominal collision point at the origin. The anti-clockwise beam direction defines the positive z-axis, while the positive x-axis is defined as pointing from the collision point to the centre of the LHC ring and the positive y-axis points upwards. The azimuthal angle φ is measured around the beam axis and the polar angle θ is measured with respect to the z-axis. The pseudorapidity is defined as η = -ln tan(θ/2). 2 The factor 2πp T in the p T spectrum comes from the Lorentz invariant definition of the cross section in terms of d 3 p. Our results could thus be interpreted as the massless approximation to d 3 p.

Measurement of Bose–Einstein correlations in pp collisions at the LHC with CMS

Journal of Physics G: Nuclear and Particle Physics, 2011

Bose-Einstein correlations between same charge particles are measured in samples of proton-proton... more Bose-Einstein correlations between same charge particles are measured in samples of proton-proton collisions at 0.9 and 7 TeV centre-of-mass energies, recorded by the CMS experiment at the LHC. The signal is observed in the form of an enhancement of number of pairs of same-sign charged particles with small relative momentum. The dependence of this enhancement on kinematic and topological features of the event is studied.