Bio

I joined the faculty at the University of Colorado Boulder in the Department of Physics in the fall of 2017. Previously, I was an assistant professor at Texas A&M University, and before that was a postdoctoral research associate at the University of Colorado Boulder, where I also obtained my Ph.D. in 2007. My undergraduate degree is from Amherst College. I live with my wife, son, and daughter.

Research

I pursue research in experimental elementary particle physics, which explores the fundamental constituents of matter and their interactions. I work on the CMS experiment at the Large Hadron Collider (LHC) at the CERN laboratory in Geneva, Switzerland. At CMS, we record the results of very high energy proton-proton collisions provided by the LHC, which are analyzed to study fundamental interactions.

My current effort is focused on searches for evidence of physics beyond the standard model of particle physics motivated by a potential new symmetry of nature known as supersymmetry, which may help explain such fundamental questions as the nature of dark matter and the origin of electroweak symmetry breaking.

My research group is active in analysis of current 13 TeV LHC data as well as research and development for future upgrades of the CMS detector. The group currently consists of postdoctoral research associates Dr. Georgios Karathanasis and Dr. Alexx Perloff, graduate students Emily MacDonald, Claire Savard, and Noah Zipper, and electrical engineer Filippo Marini. I am always looking for talented and enthusiastic new members of the group. Please contact me if you'd like to discuss possible opportunities to contribute.

Current Projects

• Leader of the CMS Global Track Trigger project for L1 Trigger upgrade (2020-present)
• Coordinator US-CMS Trigger/DAQ upgrade project for CMS Phase 2 upgrades (2018-present). Related publications: CERN-LHCC-2020-004
• Search for boosted supersymmetry with jet substructure (2016-present). Related publications: JHEP 2020, 149 (2020), PRL 120, 241801 (2018)
• Research and Development toward Level 1 Track Trigger and track standalone objects (CMS Phase 2 upgrade) (2014-present). Related publications: JINST 15 06, P06024 (2020), NIM A 935, 95 (2019)
• Search for Higgsino production in hadronic final states (2013-present). Related publications: JHEP 03, 160 (2018), PRD 97, 032007 (2018), PRD 90, 092007 (2014)

Previous Projects

• Search for inclusive hadronic signatures of supersymmetry with b-tagged jets (2012-2019). Related publications: JHEP 1910, 244 (2019), PRD 96, 032003 (2017), PLB 758 152 (2016), PLB 725 243 (2013), and PRD 86, 072010 (2012)
• Co-convener of CMS Supersymmetry group (2014-2015)
• Co-convener of CMS Supersymmetry Gluino group (2013)
• First observation of B_s→μμ, Nature 522 68 (2015), and PRL 111 101804 (2013)
• Co-convener of CMS exclusive B decays group (2011-2012)
• Measurements of B meson and baryon production properties, PLB 714, 136 (2012), and PRL 106, 252001 (2011)
• Measurement of strange particle production properties and displaced track reconstruction performance, JHEP 05 (2011) 064
• Silicon tracker commissioning with cosmic rays, JINST 9, P10009 (2014), EPJC 70, 1165 (2010), JINST 5, T03008 (2010), JINST 5, T03007 (2010), and JINST 4, P05004 (2009)
• First observation of mixing-induced CP-violation in charmless B decays, PRL 98, 031801 (2007), Ph.D thesis

Teaching

Starting in 2018, I have taught a range of physics classes at the University of Colorado Boulder, including PHYS 2210 a sophomore-level course in Newtonian mechanics, PHYS 4420 an advanced undergradue course in Nuclear and Particle Physics, PHYS 2130 a modern physics class for non-majors, and PHYS 2150 a modern physics laboratory course. In 2020, I received the CU Department of Physics teacher of the year award in part for development of python-based computing exercises in particle physics based on CMS open data.

From 2015-2017 I taught Physics 218 at Texas A\&M University, the first semester introductory course in Newtonian Mechanics. In Fall 2015, I was very happy to have several of my 218 students named as Pearson Mechanics Scholars!

In Spring 2017 I helped start a program to utilize undergraduate learning assistants in the Physics 218 recitation sections, which was featured in an article in the Texas A&M College of Science website.

Awards

• CU Physics Outstanding Teacher of the Year (2019-2020)
• Montague Center for Teaching Excellence Scholar (2016)
• CERN Scientific Associate (2015)
• CMS LHC Physics Center (LPC) Distinguished Researcher (2014)
• Walker Prize (mathematics) Amherst College (1997)

Professional Service

• Member of advisory board for the LHC Physics Center (LPC) at Fermilab (2021-2022)
• Organizer for APS Four Corners Section annual meeting, University of Colorado, Boulder, Colorado (October 2021)
• Convener and chair for Supersymmetry sessions at SUSY2019 conference, Corpus Christi, Texas (May 2019)
• Convener for Beyond Standard Model working group at CERN LPCC Workshop on the physics of LH-LHC and perspectives at HE-LHC CERN (2017-2018). Related publications: arXiv:1812.07831, arXiv:1812.07638, and arXiv:1902.00134
• Member CMS Conference Committee (2016-2020)
• Member CMS publications board (2012, 2016-2020)
• Convener for Supersymmetry sessions at "Experimental Challenges for the LHC Run II" workshop at the Kavli Institute for Theoretical Physics, University of California, Santa Barbara (May 2016)
• Organizer and host for annual USCMS Collaboration Meeting, Texas A&M University, College Station, Texas (May 2016)
• Convener and chair of Supersymmetry sessions at the Large Hadron Collider Physics (LHCP) conference, St. Petersburg, Russia (Sept. 2015)
• Organized CMS Supersymmetry workshops in Lisbon, Portugal (Mar. 2014) and Fermilab (Nov. 2014)
• Instructor CMS Data Analysis School, Fermilab (Jan. 2014)
• Organizing chair of "Physics Beyond the Standard Model" sessions at 2013 APS Division of Particles and Fields meeting, University of California, Santa Cruz (Aug. 2013)
• Organizer of "SUSY signatures with Higgs" workshop, Fermilab (June 2013)
• Organizing chair of "CHICAGO 2012 Workshop on LHC Physics in the Higgs Era" session on heavy flavor, University of Chicago (Nov. 2012)
• Peer reviewer for Department of Energy, European Physical Journal C, Journal of High Energy Physics, Physics Letters B, and Physical Review D

Conference and Invited Talks

• The Higgs Boson as a Tool for Discovery at the LHC Physics Department Colloquium, Idaho State University, Pocatello, Idaho, USA, March 2021.
• Searching for Supersymmetry at the Large Hadron Collider Annual Meeting of the APS Four Corners Section, University of New Mexico, Albuquerque, New Mexico, USA, October 2020.
• The Higgs Boson as a Tool for Discovery at the LHC Physics Department Colloquium, University of Colorado, Boulder, Colorado, USA, October 2020.
• Searching for Supersymmetry at the LHC Physics Department Colloquium, Colorado State University, Fort Collins, Colorado, USA, December 2019.
• Search for lepton and electroweak gauge boson partners with CMS 27th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY19), Corpus Christi, Texas, May 2019.
• Supersymmetry experimental status and outlook Aspen 2019 Winter Conference "In Pursuit of New Particles and Paradigms," Aspen, Colorado, USA, March 2019.
• Prospects for Physics Beyond the Standard Model at the HL-LHC and HE-LHC International Linear Collider Workshop, University of Texas, Arlington, Texas, USA, October 2018.
• Supersymmetry Searches at CMS 25th International Conference on Supersymmetrty and Unification of Fundamental Interactions (SUSY17), Tata Institute of Fundamental Research, Mumbai, India, December 2017.
• Experimental challenges for BSM physics Workshop on the Physics of the HL-LHC, and Perspectives at HE-LHC, CERN, Switzerland, October 2017.
• Searching for Supersymmetry with Higgs Bosons at the LHC Annual Meeting of the APS Four Corners Section, Colorado State University, Fort Collins, Colorado, October 2017.
• Searches for supersymmetry in hadronic final states Collider and Dark Matter Physics 2017, Mitchell Institute, Texas A&M University, College Station, Texas, May 2017.
• Searching for Supersymmetry at the LHC Physics Colloquium, Baylor University, Waco, Texas, USA, March 2017.
• Searching for Supersymmetry at the LHC Physics Colloquium, University of Colorado, Boulder, Colorado, USA, March 2017.
• Experience from Run 1 SUSY Searches at CMS Experimental Challenges for the LHC Run 2 workshop, Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California, USA, April 2016.
• CMS Physics and Outlook CMS Data Analysis School, Fermilab, Batavia, Illinois, January 2016.
• Supersymmetry: Experimental Status Large Hadron Collider Physics Conference, St. Petersburg, Russia, September 2015. Proceedings: arXiv:1601.03774.
• CMS Supersymmetry Group: Overview and Strategy CMS SUSY Workshop, Fermilab, Batavia, Illinois, November 2014.
• Preparing for discovery: Supersymmetry searches at the LHC High Energy Physics Seminar, Texas A&M University, College Station, Texas, USA, May 2014.
• Searching for Dark Matter at the LHC Physics Colloquium, Texas A&M University, College Station, Texas, USA, April 2014.
• Preparing for discovery: Supersymmetry searches at the LHC Research Progress Meeting Seminar, Lawrence Berkeley National Laboratory, Berkeley, California, USA, April 2014.
• Preparing for discovery: Supersymmetry searches at the LHC High Energy Seminar, University of Illinois, Urbana-Champaign, USA, February 2014.
• Future sensitivity studies for supersymmetry searches at √s = 14 TeV from CMS American Physical Society Division of Particles and Fields 2013 Meeting, Santa Cruz, California, USA, August 2013. Proceedings: arXiv:1310.0781.
• Measurement of the B_s→μμ branching fraction at CMS Fermilab Joint Experimental-Theoretical (Wine & Cheese) Seminar, Fermilab, Batavia, Illinois, USA, August 2013.
• Search for supersymmetry in final states with multiple b-quarks European Physical Society Conference on High Energy Physics, Stockholm,Sweden, July 2013. Proceedings: arXiv:1310.2588.
• SUSY searches with heavy flavor from CMS and ATLAS CHICAGO 2012 Workshop on LHC Physics in the Higgs Era, University of Chicago, Chicago, Illinois, USA, November 2012.
• Searching for the Higgs: The origin of mass? Physics Colloquium, University of Denver, Denver, Colorado, USA, November 2012.
• Studies of rare beauty and charm decays with the CMS experiment 36th International Conference on High Energy Physics (ICHEP), Melbourne, Australia, July 2012. Proceedings: arXiv:1301.4690.
• Studies of exotic charmonium and bottomonium states with the CMS experiment 36th International Conference on High Energy Physics (ICHEP), Melbourne, Australia, July 2012. Proceedings: arXiv:1301.4686.
• Recent heavy flavor results from CMS Fermilab Joint Experimental-Theoretical (Wine & Cheese) Seminar, Fermilab, Batavia, Illinois, USA, June 2012.
• sbottom and stop production at CMS Workshop on SUSY with 5 fb^-1 at the LHC, Brookhaven National Laboratory, Upton, New York, USA, May 2012.
• 3rd generation supersymmetry production at CMS USCMS Collaboration Meeting, Boulder, Colorado, USA, May 2012.
• Searches for new physics in b hadron decays at CMS Joint Theory-Experiment Workshop on Searches for New Physics Via Heavy Quark Physics in Hadron Colliders, University of Washington, Seattle, Washington, USA, May 2012.
• Search for B_s→μμ with the CMS experiment Supersymmetry 2011, Fermilab, Batavia, Illinois, USA, August 2011.
• Heavy flavor production at CMS Rencontres de Moriond QCD and High Energy Interactions, La Thuile, Italy,March 2011. Proceedings: arXiv:1106.2528.
• Hadron production at CMS in pp collisions at √s = 0.9, 2.4 and 7.0 TeV 35th InternationalConference on High Energy Physics (ICHEP), Paris, France, July 2010. Proceedings: PoS ICHEP2010, 355 (2010).
• Tracking performance of the CMS detector in 2009 collision data 2010 Lake Louise Winter Institute, Lake Louise, Alberta, Canada, February 2010. Proceedings: arXiv:1006.1123.
• Heavy flavor physics at CMS 8th International Conference on Hyperons, Charm, and Beauty Hadrons, University of South Carolina, June 2008. Proceedings: Nucl. Phys. Proc. Suppl. 187, 57 (2009).
• Measurements of CKM angle β from BaBar 2007 Lake Louise Winter Institute, Lake Louise, Alberta, Canada, February 2007. Proceedings: arXiv:0705.2998.
• CP-violating asymmetries in b→s penguins American Physical Society Division of Particles and Fields 2006 Meeting, Honolulu, HI, October 2006.
• Rare B Meson decays to ηK^*, η'K^*, ηρ, η'ρ, ηπ⁰, η'π⁰, ωπ⁰,and φπ⁰ American Physical Society April Meeting 2004, Denver, CO, May 2004.

Publications

The list below represents papers to which I made significant personal contributions. My full publication list can be found in INSPIRE.

• A. Tumasyan et al. [CMS Collaboration], "Search for electroweak production of charginos and neutralinos at √s = 13 TeV in final states containing hadronic decays of WW, WZ, or WH and missing transverse momentum," Submitted to Phys. Lett. B (2022).
• A. Tumasyan et al. [CMS Collaboration], "Search for higgsinos decaying to two Higgs bosons and missing transverse momentum in proton-proton collisions at √s = 13 TeV,'' Submitted to JHEP (2022) arXiv:2201.04206.
• A. M. Sirunyan et al. [CMS Collaboration], "Search for supersymmetry in proton-proton collisions at √s = 13 TeV in events with high-momentum Z bosons and missing transverse momentum," JHEP 2020, 149 (2020) arXiv:2008.04422.
• CMS Collaboration, "The Phase-2 Upgrade of the CMS Level-1 Trigger," Technical Design Report, CERN-LHCC-2020-004, CMS-TDR-021 (2020).
• E. Bartz et al., "FPGA-based tracking for the CMS Level-1 trigger using the tracklet algorithm," JINST 15, no. 06, P06024 (2020) arXiv:1910.09970.
• A. M. Sirunyan et al. [CMS Collaboration], "Combined search for supersymmetry with photons in proton-proton collisions at √s = 13 TeV," Phys. Lett. B 801, 135183 (2020) arXiv:1907.00857.
• A. M. Sirunyan et al. [CMS Collaboration], "Search for supersymmetry in proton-proton collisions at 13 TeV innal states with jets and missing transverse momentum," JHEP 1910, 244 (2019) arXiv:1908.04722.
• E. Clement et al. "A high-performance tracktter for use in ultra-fast electronics," Nucl. Instrum. Meth. A 935, 95 (2019) arXiv:1809.10467.
• X. Cid Vidal et al., "Beyond the Standard Model Physics at the HL-LHC and HE-LHC," CERN Yellow Rep. Monogr. 7, 585 (2019) arXiv:1812.07831.
• M. Cepeda et al., "Higgs Physics at the HL-LHC and HE-LHC," CERN Yellow Rep. Monogr. 7, 221 (2019) arXiv:1902.00134.
• A. Cerri et al., "Opportunities in Flavour Physics at the HL-LHC and HE-LHC," CERN Yellow Rep. Monogr. 7, 867 (2019) arXiv:1812.07638.
• A. M. Sirunyan et al. [CMS Collaboration], "Combined search for electroweak production of charginos and neutralinos in proton-proton collisions at √s = 13 TeV," JHEP 03, 160 (2018) arXiv:1801.03957.
• A. M. Sirunyan et al. [CMS Collaboration], "Search for physics beyond the standard model in events with high-momentum Higgs bosons and missing transverse momentum in proton-proton collisions at 13 TeV," Phys. Rev. Lett. 120, 241801 (2018) arXiv:1712.08501.
• CMS Collaboration, "First Level Track Jet Trigger for Displaced Jets at High Luminosity LHC," CMS-PAS-FTR-18-018 (2018).
• V. Khachatryan et al. [CMS Collaboration], "Search for higgsino pair production in pp collisions at √s = 13 TeV in final states with large missing transverse momentum and two Higgs bosons decaying via H→bb," Phys. Rev. D 97, 032007 (2018) arXiv:1709.04896.
• A. M. Sirunyan et al. [CMS Collaboration], "Search for supersymmetry in multijet events with missing transverse momentum in proton-proton collisions at 13 TeV," Phys. Rev. D 96, 032003 (2017) arXiv:1704.07781.
• V. Khachatryan et al. [CMS Collaboration], "Search for supersymmetry in the multijet and missing transverse momentum final state in pp collisions at 13 TeV," Phys. Lett. B 758, 152 (2016) arXiv:1602.06581.
• V. Khachatryan et al. [CMS Collaboration], "Angular analysis of the decay B⁰→K*μμ from pp collisions at s = 8 TeV," Phys. Lett. B 753, 424 (2016) arXiv:1507.08126..
• S. Chatrchyan et al. [CMS and LHCb collaborations], "Observation of the rare B_s→μμ decay from the combined analysis of CMS and LHCb data," Nature 522, 68 (2015) arXiv:1411.4413.
• S. Chatrchyan et al. [CMS Collaboration], "Searches for supersymmetry based on events with b jets and four W bosons in pp collisions at 8 TeV," Phys. Lett. B 745, 5 (2015) arXiv:1412.4109.
• V. Khachatryan et al. [CMS Collaboration], "Technical Proposal for the Phase-II Upgrade of the Compact Muon Solenoid," CERN-LHCC-2015-010 (2015).
• S. Chatrchyan et al. [CMS Collaboration], "Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV," Phys. Rev. D90, 092007 (2014) arXiv:1409.3168.
• CMS Collaboration, "Supersymmetry discovery potential in future LHC and HL-LHC running with the CMS detector," CMS-SUS-14-012 (2014).
• S. Chatrchyan et al. [CMS Collaboration], "Description and performance of track and primary-vertex reconstruction with the CMS tracker," JINST 9, P10009 (2014) arXiv:1405.6569.
• S. Chatrchyan et al. [CMS Collaboration], "Angular analysis and branching fraction measurement of the decay B⁰→K*μμ," Phys. Lett. B 727, 77 (2013) arXiv:1308.3409.
• S. Chatrchyan et al. [CMS Collaboration], "Measurement of the B_s→μμ branching fraction and search for B⁰→μμ with the CMS Experiment," Phys. Rev. Lett. 111, 101804 (2013) arXiv:1307.5025.
• S. Chatrchyan et al. [CMS Collaboration], "Search for gluino mediated bottom- and top-squark production in multijet final states in pp collisions at √s = 8 TeV," Phys. Lett. B 725, 243 (2013) arXiv:1305.2390.
• S. Chatrchyan et al. [CMS Collaboration], "Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at √s = 7 TeV," Phys. Rev. D 86, 072010 (2012) arXiv:1208.4859.
• S. Chatrchyan et al. [CMS Collaboration], "Measurement of the Λ_b cross section and the anti-Λ_b to Λ_b ratio with Λ_b to J/ψ Λ decays in pp Collisions at √s = 7 TeV," Phys. Lett. B 714, 136 (2012) arXiv:1205.0594.
• S. Chatrchyan et al. [CMS Collaboration], "Measurement of the B⁰ production cross section in pp Collisions at √s = 7 TeV," Phys. Rev. Lett. 106, 252001 (2011) arXiv:1104.2892.
• V. Khachatryan et al. [CMS Collaboration], "Strange Particle Production in pp Collisions at √s = 0.9 and 7 TeV," JHEP 1105, 064 (2011) arXiv:1102.4282.
• V. Khachatryan et al. [CMS Collaboration], "CMS Tracking Performance Results from early LHC Operation," Eur. Phys. J. C 70, 1165 (2010) arXiv:1007.1988.
• S. Chatrchyan et al. [CMS Collaboration], "Commissioning and Performance of the CMS Silicon Strip Tracker with Cosmic Ray Muons," JINST 5, T03008 (2010) arXiv:0911.4996.
• S. Chatrchyan et al. [CMS Collaboration], "Commissioning and Performance of the CMS Pixel Tracker with Cosmic Ray Muons," JINST 5, T03007 (2010) arXiv:0911.5434.
• W. Adam et al. [CMS Tracker Collaboration], "Stand-alone Cosmic Muon Reconstruction Before Installation of the CMS Silicon Strip Tracker," JINST 4, P05004 (2009) arXiv:0902.1860.
• B. Aubert et al. [BABAR Collaboration], "Branching fraction and CP-violation charge asymmetry measurements for B-meson decays to ηK, ηπ, η'K, η'π, ωK and ωπ," Phys. Rev. D 76, 031103 (2007) arXiv:0706.3893.
• B. Aubert et al. [BABAR Collaboration], "Observation of CP violation in B⁰ → η' K⁰ decays," Phys. Rev. Lett. 98, 031801 (2007) arXiv:hep-ex/0609052.
• B. Aubert et al. [BABAR Collaboration], "Measurements of CP-violating asymmetries and branching fractions in B decays to ω K and ω π," Phys. Rev. D 74, 011106 (2006) arXiv:hep-ex/0603040.
• B. Aubert et al. [BABAR Collaboration], "B meson decays to η'K^*, η' ρ, η' π⁰, ω π⁰, and φ π⁰," Phys. Rev. D 70, 032006 (2004) arXiv:hep-ex/0403025.
• L. R. Hunter, S. E. Maxwell, K. A. Ulmer, N. D. Charney, S. K. Peck, D. Krause, S. Ter-Avetisyan, and D. DeMille, "Detailed spectroscopy of the a(1)[³Σ⁺] state of PbO," Phys. Rev. A 65, 030501 (2002).

Outreach and Popular Media

• CERN website write up announcing release of CMS Phase 2 Level 1 Trigger Technical Design Report (July 2020)
• CERN website write up highlighting recent supersymmetry results for European Physical Society 2019 conference (July 2019)
• Saturday Physics Series public lecture "The Higgs Boson and Beyond" University of Colorado Boulder (Oct. 2018)
• Article in Texas A&M Science webpage highlighting undergraduate learning assistant program (May 2017)
• Physics and Engineering Festival demonstration coordinator, Texas A&M University (April 2016)
• Saturday Morning Physics talk "The Higgs Boson and Beyond" Texas A&M University (Feb. 2016)
• Article I co-wrote for CERN website featuring recent CMS Supersymmetry results (Aug. 2014)
• Fermilab Today write up on recent B→K*μμ results at CMS (Oct. 2013)
• Article I co-wrote for the CERN Courier on the B_s→μμ observation (Aug. 2013)
• Feature on recent B_s→μμ results from CMS in Fermilab Today (Aug. 2013)
• Fermilab Today "Frontier Science Result" on hadronic SUSY search at CMS (June 2013)
• CMS "Result of the Month" on strange particle production (March 2010)
• Recognition of commissioning of CMS tracker with cosmic rays in Fermilab Today (Nov. 2009)
• Article I co-wrote on the first observation of CP-violation in penguin decays in SLAC Today (Sept. 2006)