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ABSTRACT: OBJECTIVE: To investigate the human limbic system using cortico-cortical evoked potential (CCEP), which reveals the brain networks. METHODS: Five patients with nonlesional medically intractable focal epilepsy with ictal onset outside the limbic system were enrolled. All patients underwent stereoelectroencephalogram electrode implantation in order to delineate the epileptogenic zone. Alternating 1Hz electrical stimuli were delivered to the hippocampus and posterior cingulate gyrus. A total of sixty stimuli were averaged in each trial to obtain CCEP responses. RESULTS: Hippocampal stimulation elicited prominent CCEP responses in the posterior cingulate gyrus. The latencies of early (N1) and late (N2) negative peak ranged 20-60ms and 102-175ms respectively. In addition, CCEP responses were observed in the posterior parahippocampal gyrus, medial superior frontal gyrus (SFG) and orbitofrontal cortex. Stimulation of posterior cingulate contacts induced CCEPs in the hippocampus with N1 and N2 latencies of 25-43ms and 90-234ms respectively in all five patients. CONCLUSION: This finding supports the assertion that the hippocampus is connected with the posterior cingulate gyrus, posterior parahippocampal gyrus, medial SFG and orbitofrontal cortex. The hippocampus and posterior cingulate gyrus have a bidirectional network through the cingulum. SIGNIFICANCE: The present study provides new insight into the human limbic network.
Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 03/2013; · 3.12 Impact Factor
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ABSTRACT: Simultaneous SEEG-MEG recording has the potential to define the epileptic spike source accurately. We present a case of a 55-year-old female with intractable left temporal lobe epilepsy in whom we evaluated the relationship between the amplitude recorded from SEEG electrodes, inserted in the lateral temporal region, and their distance from the MEG-modelled spike. We found a quadratic fall-off relationship between the amplitude and distance. This result supports the concept that the MEG dipoles reflect the "centre" of spike locations and may provide comprehensive information for SEEG which records spike activities directly but is inherently limited in spatial sampling.
Epileptic disorders: international epilepsy journal with videotape 08/2012; 14(3):298-303. · 1.50 Impact Factor
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Rei Enatsu, Yuichi Kubota,
Yosuke Kakisaka,
Juan Bulacio,
Zhe Piao,
Timothy Oʼconnor,
Karl Horning,
John Mosher,
Richard Burgess,
William E Bingaman,
Dileep Nair
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ABSTRACT: : It is well known that epilepsy is likely to cause atypical language organization and this phenomenon is clinically relevant in the epilepsy surgery to spare the language function. The purpose of this study is to investigate the precise definition of the connectivity associated with the reorganized language network in patients with temporal lobe epilepsy (TLE) using cortico-cortical evoked potential (CCEP), which reveals the brain networks.
: Six patients with intractable TLE who underwent chronic intracranial electrode placement and revealed an atypical distribution of posterior language areas (Wernicke's areas) were studied. Alternating 1 Hz electrical stimuli were delivered to the anterior language areas (Broca's areas). CCEPs were recorded by averaging electrocorticograms time-locked to stimuli from the subdural electrodes. We calculated the root mean square (RMS) of CCEP responses between 10 and 300 ms (1 ms slide) to evaluate the distribution of the anterior posterior language network. Thereafter, the posterior language areas identified by the electrical cortical mapping and CCEP distributions were compared.
: CCEP responses were observed in various areas within the temporal, temporo-parietal and temporo-occipital area, including the temporal pole, inferior temporal gyrus and temporo-occipital junction. The posterior language area was located within CCEP distribution in two patients, whereas parts of the language areas were outside CCEP-positive areas in four patients. In addition, larger CCEP responses were observed in the surrounding cortices rather than in posterior language areas in two patients.
: Our results suggest that the posterior language areas can shift to the cortices within or outside the anterior posterior language network. Language reorganization might be associated with a functional shift to the surrounding cortices outside of the anterior posterior language network as well as re-routing the language network.
Neurosurgery 08/2012; 71(2):E568-9. · 2.79 Impact Factor
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Rei Enatsu, Yuichi Kubota,
Yosuke Kakisaka,
Juan Bulacio,
Zhe Piao,
Timothy O'Connor,
Karl Horning,
John Mosher,
Richard C Burgess,
William Bingaman,
Dileep R Nair
[show abstract]
[hide abstract]
ABSTRACT: OBJECTIVE: To investigate the connectivity associated with the reorganized language network in patients with temporal lobe epilepsy (TLE) using cortico-cortical evoked potential (CCEP), which reveals the brain networks. METHODS: Six patients with intractable TLE who underwent chronic intracranial electrode placement and revealed an atypical distribution of posterior language areas (Wernicke's areas) were studied. Alternating 1Hz electrical stimuli were delivered to the anterior language areas (Broca's areas). CCEPs were recorded by averaging electrocorticograms time-locked to stimuli from the subdural electrodes. Thereafter, the posterior language areas identified by the electrical cortical mapping and CCEP distributions were compared by calculating the root mean square of CCEP responses. RESULTS: CCEP responses were observed in various areas within the temporal, temporo-parietal or temporo-occipital area. The correlation between CCEP distributions and posterior language areas revealed two patterns. In two patients, the posterior language areas were located within CCEP distribution, but out of the maximum responses in the temporal lobe. On the other hand, parts of the language areas were outside CCEP-positive areas in four patients. CONCLUSION: Our results suggest that language reorganization might be associated with a functional shift from the termination of anterior-posterior language connection to the surrounding cortices. It should be noted that language areas can be identified outside the anterior-posterior language connection.
Epilepsy research 07/2012; · 2.48 Impact Factor
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ABSTRACT: To better understand the process of ictal propagation in epilepsy by using cortico-cortical evoked potential (CCEP), which reveals the brain networks.
Intracranial EEG recordings of 11 seizures from 11 patients with pharmacoresistant focal epilepsy were studied to identify the propagation sites and times. Six patients had a history of secondary generalization (Gen (+) group) and five patients did not (Gen (-) group). Thereafter repetitive 1Hz bipolar electrical stimuli were applied to the ictal onset zones and CCEPs were recorded by averaging electrocorticograms.
The propagation of contiguous spread was significantly faster than non-contiguous spread (p=0.033). In four patients, CCEP amplitudes were significantly larger in the ictal propagation area than out of the propagation area. However, the distribution of CCEP responses was not necessarily consistent with the ictal propagation area as a whole. Furthermore, the ictal propagation areas out of CCEP-positive areas were significantly broader in Gen (+) group than Gen (-) group (p=0.017).
The present findings suggest that contiguous spread is faster than non-contiguous spread, which can be explained by the enhancement of excitability around the ictal onset area. Furthermore, there is a group of fibers that is "closed" during the seizures and secondary generalization might be more associated with the impairment of cortical inhibition over the broad cortical area rather than direct connection.
Epilepsy research 03/2012; 101(1-2):76-87. · 2.48 Impact Factor
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Dip Di Fisica Dell'universita,
Alberto Santoro,
Et Al,
Joel Butler,
David Christian,
Irwin Gaines,
Rob Kutshcke,
Peter Kasper,
Simon Kwan,
Paul Lebrun, [......],
Steve C. Timm,
Suny At Albany,
Marina Artuso Tomasz Skwarnicki,
Dario Menasce,
Luigi Moroni,
Daniele Pedrini,
Silvano Sala,
Infn Milano, Yuichi Kubota,
Walter Selove Kevin Sterner
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ABSTRACT: We propose to use the C0 interaction region to develop a prototype of the BTEV detector -- a second generation detector to perform in-depth studies of CP violation and rare B and charm decays. We will use this `proto-detector' to validate the key components of BTEV and to undertake a series of physics measurements which will be of interest in their own right but which will also provide an opportunity to analyze data taken under realistic conditions in the forward direction at the Tevatron. 0 contactpersons: Sheldon Stone, EMAIL: stone@suhep.phy.syr.edu and Joel Butler, EMAIL: butler@fnal.gov 1 Introduction This letter expresses the interest of the "BTEV" group to use the C0 interaction region to make a systematic sequence of detector studies and physics measurements. These will provide an evolutionary path to the development of a full detector for the study of CP violation and the search for rare B and charm decays. A sketch of a "baseline" BTEV detector is shown in figure 1. We ...
07/1996;
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Markus Friedl,
Rudolf Fruehwirth,
Vasile Mihai Ghete, [......],
Christos Lazaridis,
Jessica Leonard,
Richard Loveless,
Ajit Mohapatra,
Giovanni Polese,
Don Reeder,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
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ABSTRACT: Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at sqrt(s) = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN(charged)/d(eta) for |eta| < 0.5, are 3.48 +/- 0.02 (stat.) +/- 0.13 (syst.) and 4.47 +/- 0.04 (stat.) +/- 0.16 (syst.), respectively. The results at 0.9 TeV are in agreement with previous measurements and confirm the expectation of near equal hadron production in p-pbar and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
Jessica Leonard,
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
Giovanni Polese,
Don Reeder,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
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ABSTRACT: Bose-Einstein correlations have been measured using samples of proton-proton collisions at 0.9 and 2.36 TeV center-of-mass energies, recorded by the CMS experiment at the CERN Large Hadron Collider. The signal is observed in the form of an enhancement of pairs of same-sign charged particles with small relative four-momentum. The size of the correlated particle emission region is seen to increase significantly with the particle multiplicity of the event.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
Jessica Leonard,
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
Giovanni Polese,
Don Reeder,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
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ABSTRACT: Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at $\sqrt{s} = 7$~TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit-pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity \dnchdeta$|_{|\eta| < 0.5} = 5.78\pm 0.01\stat\pm 0.23\syst$ for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from $\sqrt{s} = 0.9$ to 7~TeV is $66.1\%\pm 1.0\%\stat\pm 4.2\%\syst$. The mean transverse momentum is measured to be $0.545\pm 0.005\stat\pm 0.015\syst\GeVc$. The results are compared with similar measurements at lower energies.
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Petar Adzic,
Reyes Alemany-Fernandez,
Nuno Almeida,
Georgios Anagnostou,
Daniel Andelin,
Marc Anfreville,
Ivan Anicin,
Zeljko Antunovic,
Roberta Arcidiacono,
Michael Wayne Arenton, [......],
Yong Yang,
Ignacio Yaselli,
Rachel Yohay,
Alexandre Zabi,
Nikolai Zamiatin,
Serguei Zelepoukine,
Jia-Wen Zhang,
Lin Zhang,
Kejun Zhu,
Ren-Yuan Zhu
[show abstract]
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ABSTRACT: 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 ECAL. The best intercalibration precision is expected to come from the analysis of events collected {\it 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.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
Jessica Leonard,
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
Giovanni Polese,
Don Reeder,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
Jessica Leonard,
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
Giovanni Polese,
Don Reeder,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
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ABSTRACT: A measurement of the underlying activity in scattering processes with pT scale in the GeV region is performed in proton-proton collisions at $\sqrt{s}$ = 0.9 TeV, using data collected by the CMS experiment at the LHC. Charged hadron production is studied with reference to the direction of a leading object, either a charged particle or a set of charged particles forming a jet. Predictions of several QCD-inspired models as implemented in PYTHIA are compared, after full detector simulation, to the data. The models generally predict too little production of charged hadrons with pseudorapidity |h| <2, pT >0.5 GeV/c, and azimuthal direction transverse to that of the leading object.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
Jessica Leonard,
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
Giovanni Polese,
Don Reeder,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The first LHC pp collisions at centre-of-mass energies of 0.9 and 2.36 TeV were recorded by the CMS detector in December 2009. The trajectories of charged particles produced in the collisions were reconstructed using the all-silicon Tracker and their momenta were measured in the 3.8 T axial magnetic field. Results from the Tracker commissioning are presented including studies of timing, efficiency, signal-to-noise, resolution, and ionization energy. Reconstructed tracks are used to benchmark the performance in terms of track and vertex resolutions, reconstruction of decays, estimation of ionization energy loss, as well as identification of photon conversions, nuclear interactions, and heavy-flavour decays.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
William Parker,
Don Reeder,
Ian Ross,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
[hide abstract]
ABSTRACT: Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (eta) and azimuthal angle ($\phi$). Short-range correlations in $\Delta\eta$, which are studied in minimum bias events, are characterized using a simple "independent cluster" parametrization in order to quantify their strength (cluster size) and their extent in $\eta$ (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 inverse nb data set at 7 TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate transverse momentum of 1-3 GeV/c, 2.0 < |$\Delta\eta$| < 4.8 and $\Delta\phi \approx 0$. This is the first observation of such a long-range, near-side feature in two-particle correlation functions in $pp$ or $p\overline{p}$ collisions.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
William Parker,
Don Reeder,
Ian Ross,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9 inverse pb collected by the CMS experiment at the LHC. Upper limits at the 95% confidence level (CL) are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% CL: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigluons, colorons, and E_6 diquarks, in specific mass intervals. This extends previously published limits on these models.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
William Parker,
Don Reeder,
Ian Ross,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A search for quark compositeness in the form of quark contact interactions, based on hadronic jet pairs (dijets) produced in proton-proton collisions at sqrt(s)=7 TeV, is described. The data sample of the study corresponds to an integrated luminosity of 2.9 inverse picobarns collected with the CMS detector at the LHC. The dijet centrality ratio, which quantifies the angular distribution of the dijets, is measured as a function of the invariant mass of the dijet system and is found to agree with the predictions of the Standard Model. A statistical analysis of the data provides a lower limit on the energy scale of quark contact interactions. The sensitivity of the analysis is such that the expected limit is 2.9 TeV; because the observed value of the centrality ratio at high invariant mass is below the expectation, the observed limit is 4.0 TeV at the 95% confidence level.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
William Parker,
Don Reeder,
Ian Ross,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The production of J/psi mesons is studied in pp collisions at sqrt(s)=7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 inverse nanobarns. The J/psi differential cross section is determined, as a function of the J/psi transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/psi) component. Integrated over J/psi transverse momentum from 6.5 to 30 GeV/c and over rapidity in the range |y| < 2.4, the measured cross sections, times the dimuon decay branching fraction, are 70.9 \pm 2.1 (stat.) \pm 3.0 (syst.) \pm 7.8(luminosity) nb for prompt J/psi mesons assuming unpolarized production and 26.0 \pm 1.4 (stat.) \pm 1.6 (syst.) \pm 2.9 (luminosity) nb for J/psi mesons from b-hadron decays.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
William Parker,
Don Reeder,
Ian Ross,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
[hide abstract]
ABSTRACT: Measurements of primary charged hadron multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of sqrt(s) = 0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from |eta|<0.5 to |eta|<2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and the 7 TeV run in 2010. The multiplicity distribution at sqrt(s) = 0.9 TeV is in agreement with previous measurements. At higher energies the increase of the mean multiplicity with sqrt(s) is underestimated by most event generators. The average transverse momentum as a function of the multiplicity is also presented. The measurement of higher-order moments of the multiplicity distribution confirms the violation of Koba-Nielsen-Olesen scaling that has been observed at lower energies.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
William Parker,
Don Reeder,
Ian Ross,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The results of the first search for long-lived gluinos produced in 7 TeV pp collisions at the CERN Large Hadron Collider are presented. The search looks for evidence of long-lived particles that stop in the CMS detector and decay in the quiescent periods between beam crossings. In a dataset with a peak instantaneous luminosity of 10^{32} cm^{-2} s^{-1}, an integrated luminosity of 10 inverse picobarns, and a search interval corresponding to 62 hours of LHC operation, no significant excess above background was observed. Limits at the 95% confidence level on gluino pair production over 13 orders of magnitude of gluino lifetime are set. For a mass difference between the gluino and the neutralino greater than 100 GeV/c^2, and assuming a branching ratio for gluino to gluon+neutralino of 100%, gluinos of mass less than 370 GeV/c^2 are excluded for lifetimes from 10 microseconds to 1000 s.
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Vardan Khachatryan,
Albert M. Sirunyan,
Armen Tumasyan,
Wolfgang Adam,
Thomas Bergauer,
Marko Dragicevic,
Janos Erö,
Christian Fabjan,
Markus Friedl,
Rudolf Fruehwirth, [......],
Jessica Leonard,
David Lomidze,
Richard Loveless,
Ajit Mohapatra,
Don Reeder,
Ian Ross,
Alexander Savin,
Wesley H. Smith,
Joshua Swanson,
Marc Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The differential cross section for the inclusive production of isolated prompt photons has been measured as a function of the photon transverse energy E_T-gamma in pp collisions at sqrt(s)=7 TeV using data recorded by the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.9 inverse picobarns. Photons are required to have a pseudorapidity |eta_gamma|<1.45 and E_T-gamma > 21 GeV, covering the kinematic region 0.006 < x_T < 0.086. The measured cross section is found to be in agreement with next-to-leading-order perturbative QCD calculations.
