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Faculty Profiles

Marcus Hohlmann

Professor, Aerospace, Physics and Space Sciences

Dr. Hohlmann researches elementary particles and their interactions at the highest energies that can be achieved in the laboratory. His work centers on the study of high energy particle collisions at large accelerators and the construction of instrumentation, i.e. particle detectors, needed to carry out those studies. Currently he pursues this research with the CMS experiment at the Large Hadron Collider at CERN in Geneva, Switzerland, that discovered the Higgs boson in 2012. In the past, he worked at the Tevatron collider of the Fermi National Accelerator Lab (Fermilab), where he contributed to the discovery and study of the sixth and heaviest quark, the top quark, and at the HERA accelerator at DESY, where he helped to build a large tracking detector for the HERA-B experiment designed to study CP violation with bottom quarks.

With his students, Dr. Hohlmann builds and operates advanced gaseous particle detectors, such as GEM detectors for future nuclear physics experiments at an Electron-Ion Collider to be built in the U.S. in the 2020's and for muon tomography of nuclear contraband as a Homeland Security application. He and his students constructed and are operating Fl. Tech's only Grid Computing Cluster (see picture on the right), which is an official Tier-3 computing site on the Open Science Grid.

Personal Overview

Dr. Hohlmann serves as CERN team leader for the Florida Tech HEP group and as Florida Tech's representative on the Institution Board of the CMS Muon Detector Group .

He is a charter member of the RD51 collaboration at CERN, which is dedicated to developing Micro-Pattern Gaseous Detectors (MPGDs) for particle detection. He is Florida Tech's RD51 team leader and serves on the RD51 collaboration board.

Dr. Hohlmann co-founded Florida Tech's QuarkNet Center, which organizes HEP-related outreach activities for high school physics teachers and students, in 2002 and was the center's director from 2004-08.

He also advises the Badminton Club and used to pitch for the P/SS Department's Intramural Softball Team - the "InfraRed Sox".

Educational Background

Ph.D., University of Chicago, 1997.
Dipl. Phys., RWTH Aachen, Germany, 1991.
M.S., Purdue University, 1989.

Recognition & Awards

  • Mentor of Northrop-Grumman Science Championship Teams in 2014 & 2011
  • Excellence in Research Award, awarded by FIT Faculty Senate in 2010/11

Courses

  • PHY 5045 Introduction to Elementary Particle Phys. (Grad.)
  • PHY 5030 & 5031 Quantum Mechanics I & II (Grad.)
  • PHY 4071 Senior Laboratory
  • PHY 4030 Introduction to Subatomic Physics
  • PHY 4021 Optics Laboratory
  • PHY 3901 Research Experience in Physics
  • PHY 2002 Physics 2
  • PHY 1001 Physics 1

Professional Experience

Professor, Florida Inst. of Tech., 2015-present.

Associate Prof., Florida Inst. of Tech., 2007-2015.

Assistant Prof., Florida Inst. of Tech., 2002-2007.

Postdoctoral Research Fellow, HERA-B Experiment, Deutsches Elektronensynchrotron (DESY), Hamburg, Germany, 1997-2001.

Graduate Research Assistant, CDF group, Univ. of Chicago, 1994-1997.

Graduate Student Research Associate, CDF Experiment, HEP Division, Argonne National Laboratory (ANL), Argonne, IL, 1991-1994.

Current Research

Dr. Hohlmann has contributed to the construction of the CMS detector at the Large Hadron Collider (LHC) at CERN, the European Center for Particle Physics, in Geneva, Switzerland. With his research group at Florida Tech, he calibrated and commissioned an alignment system for the CMS experiment for monitoring the exact positions of the Endcap Muon System using a variety of analog and optical sensors. Using data from the system Hohlmann's students have aligned muon chambers of the CMS experiment to sub-millimeter accuracy.

After the turn-on of the CMS detector in 2009, he conducted searches for new particles such as the new gauge boson, Z', and for decays of Higgs boson into two tau leptons in the dimuon final state with his graduate students.  Currently, he is searching for long-lived dark matter particles that decay into dimuons.

Dr. Hohlmann also researches advanced gaseous particle detectors, such as GEM detectors for muon tomography of nuclear contraband as Homeland Security application and for an upgrade of the forward muon system of CMS.

With his students he has constructed and operates a computing cluster with over 180 CPU cores, 100 TB of data storage, and 10 Gbs data links that is used for detailed simulations of particle detectors using the GEANT4 simulation toolkit. The same cluster also serves as an official Tier-3 production site on the Open Science Grid. Back in June 2010, the site was reported as the world's largest Tier-3 site used by the CMS experiment.

Publications

Full publication list (INSPIRE HEP database)

Publications at Florida Tech (HEP site)

Publications on major discoveries in particle physics

  • Higgs Discovery at CERN (2012): 

S. Chatrchyan, et al. (CMS Coll.), Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC, Physics Letters B 716 (1), 30-61.  (12,871 cit.).

  • Top Quark Discovery at Fermilab (1995):

F Abe, et al. (CDF Coll.), Observation of Top Quark Production in Collisions with the Collider Detector at Fermilab, Physical Review Letters 74 (14), 2626 (1995) (4531 cit.).

F Abe, et al. (CDF Coll.), Evidence for top quark production in p-bar p collisions at √s =1.8 TeV, Physical Review D 50 (5), 2966 (1994) (1845 cit.).

Recent and Selected Other Publications:

S. Colafranceschi, M. Hohlmann with D. Abbaneo et al., Operational experience with the GEM detector assembly lines for the CMS forward muon upgrade, Proc. of IEEE Nucl. Sci. Symp. 2017, Altanta, GA, Trans. Nucl. Sci. Vol. 65, No. 11 (2018).

V. Bhopatkar, M. Hohlmann, et al. with CMS Coll., Measurement of the Z/γ*  -> τ τ cross section in pp collisions at √s = 13 TeV and validation of τ lepton analysis techniques, Eur. Phys. J. C (2018) 78:708.

A. Zhang, M. Hohlmann, B. Azmoun, M. Purschke, and C. Woody, A GEM readout with radial zigzag strips and linear charge-sharing responseNucl. Inst. Meth. A 887 (2018) 184-192.

T. Hebbeker, et al. (M. Hohlmann chapter editor), CMS Technical Design Report for the Phase-2 Upgrade of the CMS Muon Detectors, CERN-LHCC-2017-012, CMS-TDR-016, Sept. 12, 2017.

V. Bhopatkar, M. Hohlmann, A. Mohapatra, M. Phipps, J. Twigger, A. Zhang, et. al., Performance of a Large-Area GEM Detector Prototype for the Upgrade of the CMS Muon Endcap System, Proc. of IEEE Nucl. Sci. Symp. 2014, Seattle, WA, Nov 9-15, 2014, arXiv:1412.0228. 

Hohlmann M. with K. Gnanvo, et al., Detection and Imaging of High-Z Materials with a Muon Tomography Station Using GEM Detectors,  Proc. of IEEE Nucl. Sci. Symp. 2010, Knoxville, TN, 2010.

Hohlmann, M., Guragain, S., and Gomez, G. with the CMS Coll., Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run, J. Inst. 5:T03019, 2010.

Hohlmann, M., et al., GEANT4 Simulation of a Cosmic Ray Muon Tomography System with Micro-Pattern Gas Detectors for the Detection of High-Z Materials, IEEE Trans. Nucl. Sci. 56, 2009.

Hohlmann, M. with the CMS Coll., The CMS Experiment at the CERN LHC, J. Inst. 3, S08004, 2008.

Hohlmann, M., G. Baksay  with P. Achard et al. (L3 coll.), Measurement of the photon structure function F2γ with the L3 detector at LEP, Phys.Lett. B622, 2005 (based on Fl. Tech Ph.D. thesis by G. Baksay).

Hohlmann, M., C. Padilla, N. Tesch and M. Titov (editors), Proc. of International Workshop on Aging Phenomena in Gaseous Detectors, Nucl. Instr. and Meth. A515 (2003).

Hohlmann, M., A large ultra-clean gas system with closed loop for the high-rate Outer Tracker at HERA-B, Nucl. Instr. and Meth. A515 (2003) 132.

Hohlmann, M. with H. Albrecht, et al., Aging Studies for the large honeycomb drift tube system of the Outer Tracker of HERA-B, Nucl. Instr. and Meth. A515 (2003) 155.

Hohlmann, M. with T. Affolder, et al. (CDF Coll.), Search for the Charged Higgs Boson in the Decays of Top Quark Pairs in the eτ and μτ Channels at √s = 1.8 TeV, Phys. Rev. D 62, 2000.

Hohlmann, M., with F. Abe, et al. (CDF Coll.), The μτ and eτ decays of top quark pairs produced in p anti-p collisions at √s = 1.8 TeV, Phys.Rev.Lett.79, 1997.