Ian Howley's Homepage UTA Logo Tribe Pride

Ian Howley

High Energy Physics Group
The University of Texas at Arlington


Hello. I have graduated from UTA and am now a postdoc with the Cosmic Ray Physics Group at the University of Maryland. During my graduate studies I was a member of the DØ Collaboration at Fermilab. I worked primarily with the Stony Brook group, under the instruction of Paul Grannis, on a Higgs search in the standard model channel H → eτ jj. I was also responsible for the Run II tauID certification, working closely with Abid Patwa and Fabrice Couderc. My academic advisor at UTA was Andrew Brandt; we also were involved with laser testing of MCP-PMTs for an ATLAS upgrade.

Golfing in Scotland DØ


As a postdoc I have no teaching responsibilities.

Current Work

The DØ Collaboration is a worldwide collaboration of over 80 universities and laboratories. Our detector is a 5,000 ton general purpose detector. It collected data in two periods: Run I (1992-1996) where DØ along with CDF discovered the top quark (the most massive standard model quark with a mass roughly the same as a gold nucleus!), and Run II (2001-2011). I am currently analyzing the 10fb-1 of data from Run II and plan to graduate in 2013.

The SM Higgs search H → eτ jj describes any process in which the final state is and electron (e) coming from the leptonic decay of a tau lepton, a τ which decays hadronically and is reconstructed as a jet, and two jets (j). It is sensitive to three Higgs production processes: (1) associated production, (2) vector boson fusion, and (3) gluon gluon fusion, and to Higgs decays to ττ, bb and WW. There are a number of background processes which make it quite difficult to discern signal from background including multi-jets, W/Z+ jets, and dibosons. To increase our signal to background ratio we employ boosted decision trees (BDT) which are trained to separate signal from background.

My service task to the collaboration has been to perform the tauID certification for the most current datasets. The Monte Carlo (MC) simulation of our detector is not perfect, and its performace must be corrected based on observations of real data. These corrections decrease the overal systematic uncertainties of any measurement that uses a tau, which include many prominent Higgs searches.

The plots for my tau certification can be found here: Tau_ID

ATLAS Forward Proton
A group of a dozen universities from several countries are proposing to build a detector specifically designed to detect forward scattered protons originating from collisions in the center of the ATLAS detector at the Large Hadron Collider (LHC) in Geneva, Switzerland. The proton detector system consists of a novel silicon tracking detector, and a precision time-of-flight counter. The UTA group is leading the development of this time-of-flight detector (TOF).

Since August 2008 we have designed and implemented a series of lenses, filters, and mirrors that split the laser signal. We focus the split laser beam on two different PMT channels and measure the time difference using a LeCroy 6 GHz oscilloscope. This setup allows us to measure the response of the PMT as a function of high voltage and light intensity. By isolating the individual components of the detector in this fashion we can fully characterize each device's response.

Laser-based tests of the PMT and electronics are on going. We recently had a test beam at CERN, and are currently working on analyzing that data. With this new information we plan to finalize our detector concept for installation at the LHC in 2014.


Dissertation Documents

Previous Research

In fulfillment of my undergraduate senior research requirement I worked with Dr. Jeff Nelson on the MINERνA Experiment. The goal of this experiment is to measure low energy neutrino interactions, in order to support neutrino oscillation experiments and also to study the strong dynamics of the nucleons and nucleus that affect these interactions. The high-energy group at William and Mary is currently analyzing data collected from MINERνA. All components are functioning smoothly and quality physics results are constantly being produced.

Science Undergraduate Laboratory Internships
In Summer 2006 I participated in the SULI program at TJNAF in Newport News, VA. Under the supervision of Dr Harut Avagyan. Over a ten week period I analyzed the asymmetry in exclusive πo production. We weres able to measure the asymmetry with good precision. The results of my research were later used as a baseline subtraction for various studies conducted in Hall B at JLab.


Search for the Higgs boson in lepton, tau and jets final states Phys. Rev. Lett. D, vol. 88, issue 5, pp. ## Sept. 2013
Search for the standard model Higgs boson in tau lepton pair final states Phys. Rev. Lett. B, vol. 714, issues 2-5, pp. 237 245, Aug. 2012
Study of Beam Spin Asymmetry in Exclusive πo Production The Department of Energy's Journal of Undergraduate Research, Vol. 7, 2006


Search for the SM Higgs in Final States PhD Defense, March 29, 2013
Search for the SM Higgs in ττ Final States APS April Meeting, April 2012
The Effect of Dark Matter on Universal Evolution Cosmology, December 2011
Higgs → ττ LHC Seminar, December 2010
The Big Bang General Relativity, December 2010
CP Violation Particle Physics II Final Exam, May 2010
ATLAS Forward Proton Time of Flight Detector Development APS 'April' Meeting, February 2010
ATLAS Forward Proton Time of Flight UTA ACES, March 2009
MINERνA Detector Construction and Testing W&M Senior Thesis Talk, May 2008
Study of Beam Spin Asymmetry in Exclusive πo Production AAAS Annual Meeting, February 2007

UTA Planetarium

Have you ever wondered about the phases of the moon? Extra solar planets? The origins of the universe? Well you're in luck. I am currently an educator of the UTA Planetarium . I have always had an interest in the stars and love to teach and discus these topics with just about anyone. Please come see me at the planetarium! Or if you have a burning question that can't wait, feel free to send me an email.

Earth rise from Apollo command module.

Other Interests

A W&M Club Team Match         


Contact Information

High Energy Physics Group
New York Giants The Physics Department at The University of Texas at Arlington
Ian Howley

Last modified: April 2, 2013

Remember, 3+3=7 for sufficiently large values of 3!