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News

September 27, 2017: Observation of correlated anisotropy flow in pp and pPb collisions!

A new CMS paper led by Maxime Guilbaud shed new light on the origin of long-range collective correlations observed in pp and pPb collisions. The observed correlations among v2, v3 and v4 anisotropy Fourier harmonics in pPb are found to be similar to those in PbPb collisions, supporting a common origin possibly related to the fluctuating initial-state geometry. Congratulations! The paper has been submitted to Physical Review Letter and arXiv (arXiv:1709.09189).

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August 29, 2017: New insights to the search for the chiral magnetic wave!

A new CMS paper led by our undergraduate SangEon Park and Kong Tu provided new insights to the search for the chiral magnetic wave in heavy ion collisions. Congratulations! The paper has been submitted to Physical Review Letter and arXiv (arXiv:1708.08901).

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August 4, 2017: New Constraints on the Chiral Magnetic Effect!

A new CMS paper led by Kong Tu sets the most stringent constraints on the chiral magnetic effect in heavy ion collisions. Congratulations! The paper has been submitted to Physical Review C and arXiv (arXiv:1708.01602).

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May 12, 2017: Zhoudunming (Kong) Tu and Benjamin Tran won Dunlap and Heaps Awards!

At the annual departmental award ceremony, Kong received the Henry F. and Margaret Dunlap Fellowship for showing exceptional performance in research.

Ben received the Heaps Prize for excellence in a recent research project, often one leading to the senior thesis and Distinction in Research in Physics and Astronomy for a research accomplishment of exceptional quality. Congratulations!

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April 24, 2017: Congratulations to Dr. Chen!

Congratulations to Zhenyu Chen for successfully defending his PhD thesis on "Collective long-range correlations in proton-proton and proton-nucleus collisions at the LHC with the CMS experiment"!

Zhenyu's work has led to two high-impact publications, which provide key evidence for collective phenomena in pp and pPb collisions.

April 24, 2017: Congratulations to Benjamin Tran!

Congratulations to Benjamin Tran for successfully defending his senior thesis on "Extraction of v2 azimuthal anistropic harmonic of Xi baryons produced in pPb collisions at LHC energies"!

April 10, 2017: New paper on the "search" for the chiral magnetic effect in pPb highlighted in PRL

A new paper on "Observation of charge-dependent azimuthal correlations in pPb collisions and its implication for the search for the chiral magnetic effect" has been published and highlighted in PRL 118 (2017) 122301

This work is led by Kong. New results provide novel insights to the search for the chiral anomalous effect, induced by the magnetic field or angular momentum, in heavy ion collisions. Congratulations!

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February 10, 2017: Zhoudunming (Kong) Tu won Young Scientist Award at Quark Matter 2017!

Congratulations to Kong for winning the prestigious Young Scientist award from the Elsevier Journal of Nuclear Physics A for the best experimental talk at the Quark Matter 2017 conference held in Chicago. Kong presented his results on the study of chiral magnetic effect in proton-nucleus collisions from the CMS collaboration, a highlight of the conference. Kong was selected from about 180 high-quality presentations.

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February 5-11, 2017: Quark Matter 2017

Quark Matter 2017 conference was held in Chicago, USA, on February 5 - 11, 2017. Approximately 800 physicists gathered together in this most important event of relativistic heavy ion physics to present and discuss the latest progress in the field. Rice group presented one plenary talk and four contributed talks on latest CMS results in pp, pPb and PbPb collisions at the LHC.

On the first day of the conference, Wei Li presented an overview of collective flow phenomena from proton-proton to heavy ion collisions in a plenary talk. Wei summarized the current status in understanding the collective phenomena from small to large systems, and laid out new challenges and opportunities of this subject in the future.

During the parallel sessions, collective flow and QGP in small systems continues being a popular topic. Zhenyu Chen reported the observation of key features of collectivity in high-multiplicity pp collisions. Maxime Guilbaud presented the first result of pPb data at 8.16 TeV, just collected in Winter 2016, on correlations between anisotropy flow harmonics. Zhenyu and Maxime's new findings provide key insights to unveil the origin of collective phenomena in pp, pPb and PbPb systems.

Kong and Sang Eon's talks opened a new direction in exploring the chiral anomalous effects using proton-nucleus collisions, a topic under intense discussion and debate at the conference. Kong presented the observation of charge-dependent azimuthal correlations, and Sang Eon reported the observation of charge asymmetry dependence of anisotropy flow in pPb collisions. Both results posed a challenge to the presence of the chiral magnetic effect (CME) and chiral magnetic wave (CMW) in heavy ion collisions. They also provided a new means of constraining the background correlations in the search for the CME and CMW.

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February 2, 2017: New paper on high-pT azimuthal anisotropy in PbPb collisions

CMS submitted a new paper on " Azimuthal anisotropy of charged particles with transverse momentum up to 100 GeV in PbPb collisions at sqrt(s[NN]) = 5.02 TeV" to Physics Letters B and arXiv (arXiv:1702.00630), the first submission from CMS in 2017!

This work is led by Maxime. The new measurement extended the pT reach of elliptic and triangular flow anisotropy harmonics to an unprecedented 100 GeV/c region, imposing new stringent constraints on the modeling of path length dependence of parton energy loss inside a QGP medium. Congratulations!

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January 9, 2017: Wei Li won 2017 PECASE Award!

Wei Li is among recipients of the 2017 Presidential Early Career Awards for Scientists and Engineers (PECASE)!

September 1, 2016: Aobo Zhang joined as a graduate student

Welcome Aobo to become a new member of the group!

August 12, 2016: Observation of collective phenomena in pp collisions featured in CERN Courier!

In the latest issue of CERN Courier (September 2016), recent CMS observation of collective phenomena, led by Zhenyu and Maxime, in pp collisions has been featured!

June 20, 2016: New paper on collectivity in pp collisions!

New paper on "Evidence for collectivity in pp collisions at the LHC" has been submitted to Physics Letters B (PLB 765 (2017) 193) and arXiv (arXiv:1606.06198). This work is led by Zhenyu and Maxime, which provided clear evidence for collective phenomena in high-multiplicity pp collisions. Congratulations for this remarkable achievement!

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May 21, 2016: New paper on strangeness production in pp, pPb and PbPb collisions

CMS submitted a new paper on "Multiplicity and rapidity dependence of strange hadron production in pp, pPb, and PbPb collisions at the LHC" to Physics Letters B and arXiv (arXiv:1605.06699). This work is led by Kong. Congratulations!

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May 13, 2016: Zhenyu and Sang Eon won Dunlap and Bonner Book Awards

Congratulations to Zhenyu for winning the Henry F. and Margaret Dunlap Fellowship, and to Sang Eon for winning the Bonner Book Award for Juniors.

December 15, 2015: Maxime Guilbaud won a CMS Achievement Award 2015

Maxime won a CMS Achievement Award 2015 for "outstanding contributions to the development and operation of the upgraded Level-1 calorimeter trigger for heavy-ion and proton-proton collisions in 2015." Congratulations!

September 27 - October 4, 2015: Quark Matter 2015

Quark Matter 2015 conference was held in Kobe, Japan, on September 27 - October 4, 2015. Rice group presented two oral talks and one poster on latest CMS results in pp, pPb and PbPb data.

Zhenyu Chen presented new exciting results of elliptic and triangular flow in high-multiplicity pp collisions, as a function of transverse momentum and multiplicity, for different particle species. This is the first time anisotropy flow is studied in pp collisions! Maxime Guilbaud discussed CMS findings on event plane fluctuations in the longitudinal direction, which convincingly showed that large part of pseudorapidity dependence of anisotropy flow can be explained for by this effect. Zhoudunming (Kong) Tu presented a poster on his work of strange particle production in pp, pPb and PbPb, which provide a direct evidence of a stronger radial flow developed in smaller colliding systems.

Finally, congratulations to Zhenyu on winning a Young Scientist Award by Nucl. Phys. A for the best parallel presentation! Well done!

September 26, 2015: Review article on collective phenomena in small colliding systems

Wei Li, together with coauthors Kevin Dusling and Bjoern Schenke, wrote a review article on " Novel Collective Phenomena in High-Energy Proton-Proton and Proton-Nucleus Collisions" (arXiv:1509.07939). Comments are welcome!

June 12, 2015: Kong successfully defended his master thesis and passed the PhD candidacy exam. Congratulations!

March 10, 2015: Zhenyu Chen successfully defended his master thesis and passed the PhD candidacy exam. Congratulations!

March 6, 2015: Evidence for transverse momentum and pseudorapidity dependent event plane fluctuations in PbPb and pPb collisions

CMS reported evidence for event plane fluctuations in transverse momentum and pseudorapidity space in PbPb and pPb collisions. This work provides new insights to the detailed three-dimensional modeling of initial-state fluctuations and the hydrodynamic evolution in PbPb and pPb collisions. The paper is submitted to PRC.

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February 23, 2015: Wei Li named a 2015 Sloan Research Fellow

sloan Wei Li is among the 126 American and Canadian scholars awarded the prestigious 2015 Sloan Research Fellowships.

February 18, 2015: Evidence for collective multi-particle correlations in pPb collisions

CMS reported the direct evidence for collective multi-particle correlations in high-multiplicity pPb collisions, a milestone toward eventually understanding the origin of the long-range azimuthal correlations in small systems! The paper is submitted to PRL.

October 3, 2014: paper led by Zhenyu Chen featured in Fermilab Today

The paper led by Zhenyu on "Long-range two-particle correlations of strange hadrons with charged particles in pPb and PbPb collisions at LHC energies" (arXiv:1409.3392) is featured in Fermilab Today. Well done!

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September 11, 2014: long-range particle correlations of strange hadrons in pPb collisions

CMS submitted a new paper on "Long-range two-particle correlations of strange hadrons with charged particles in pPb and PbPb collisions at LHC energies" to Physics Letters B and arXiv (arXiv:1409.3392). This work is mainly led by Zhenyu. Congratulations!

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May 19-24, 2014: Quark Matter 2014 Conference in Darmstadt

Quark Matter 2014 Conference was held in Darmstadt, Germany. CMS reported new results of elliptic flow in pPb collisions using four-, six-, eight- and all-particle correlations, which provided direct evidence of collective nature of ridge correlations!

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May 16, 2014: Wei Li won DOE Early Career Award

doe Wei Li won the prestigious DOE Early Career Award.

February 1, 2014: Maxime Guilbaud joined the group as a post-doctoral research associate

Welcome Maxime to become a new member of the group!

December 6, 2013: Flow phenomena in ultra-central PbPb collisions

CMS reported the measurement of hydrodynamic flow phenomena in ultra-central PbPb collisions, led by our group, which yielded new constraints on the shear viscosity of the QGP medium (JHEP 02 (2014) 088).

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August 26, 2013: Zhoudunming (Kong) Tu joined as a graduate student

Welcome Kong to become a new member of the group!

May 3, 2013: Elliptic and triangular flow in pPb collisions

Following the pilot pPb run last year, the LHC delivered a high luminosity pPb run this January/February. CMS submitted the first paper of the new pPb data on detailed measurement of elliptic and triangular flow phenomena from two- and four-particle correlations in pPb collisions (PLB 724 (2013) 213), led by our group. The results are directly compared to PbPb data, which revealed striking similarities between the two collision systems.

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October 19, 2012: Discovery of the "Ridge" in pPb collisions!

The novel "Ridge" long-range correlations is discovered again by CMS in high-multiplicity pPb collisions (PLB 718 (2013) 795), led by our group. The measurement is based on a data sample of 2 million events from a pilot proton-lead run at the LHC. A new era of studying particle production in pA collisions (article in physicsworld.com)!

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October 15, 2012: Zhenyu Chen and Michael Northup joined as graduate students

Welcome Zhenyu and Michael to become new members of the group!