Contact Information

UC Santa Barbara
CERN
5125 Broida Hall
Physics Department
University of California
Santa Barbara, CA 93106
Mailbox J02400
CH-1211 Gen�ve 23
Switzerland
Office: B510 1-011 or 1-015
+1 805 893 8802 +41 22 76 71748 or 79496 
claudio@physics.ucsb.edu
Claudio.Campagnari@cern.ch

Research

I am an experimental high energy physicist.  I am a member of the CMS collaboration at the Large Hadron Collider (LHC) at CERN.   For non-experts, a good starting point to learn about the LHC and its physics program is the LHC Wikipedia page.

My group in CMS has been involved for many years in several searches for supersymmetry (SUSY). We searched for SUSY with the "classic" jets + missing energy signature, and also in dilepton final states (both same and opposite signs), and for pair production of relatively light top squarks favored by naturalness arguments. In the past we contributed directly to the discovery of the Higgs boson by studying the WW mode. In addition, we have made measurements of Standard Model (SM) processes such as top pair and W pair production, searched for 4th generation top-like quarks, and for production of same sign top pairs. I co-led the CMS top and SUSY analysis groups for two years, starting in 2008 and 2015, respectively.

More recently we have started on a program towards the first observation of SM four-top production, we studied Higgs boson production in conjunction with a top-antitop pair, we measured the Higgs width, we have searched for long lived particles decaying into muon pairs, and also for flavor changing neutral current interactions of top quarks and Higgs bosons.  The selected publications listed below gives a flavor for the kind of physics that we have been doing.

Going forward, our scientific program at CMS will be centered on Higgs boson studies, as well as searches for exotic new physics signatures.

On the more technical side, a few years ago we completed an upgrade of some of the electronics for the CMS muon system, and we are currently engaged in a further upgrade. We continue to contribute to the maintenace and operation of the muon detectors.   We have recently started to work on the new CMS precision timing detector for the high luminosity LHC era. Earlier we had worked on muon identification and reconstruction, missing transverse energy studies, photon coversion identification, physics dataset definition, and the development of event visualization tools.  Furthermore, a large fraction of the modules for the CMS tracker were assembled in our lab on the UCSB campus between 2003 and 2006.  

Somewhat separately from CMS, we are involved in the planning and prototyping for the Millqan experiment, with first results from a "demonstrator" already published in Physical Review. Data with a more complete detector will be collected during Run 3 of the LHC.

On a completely different front, I am involved in a multidisciplinary program to apply Machine Learning tools to clinical medical problems.

You are welcome to contact me if you would like further information.

Current Group Members

  • Xuli (Sebastian) Yan (Postdoc)
  • Keegan Downham (Grad Student)
  • Jason Guo (Grad Student)
  • Jeremiah Ockenfuss (Grad Student)
  • Shane Tobin (Undergrad Student)
Note: the full UCSB CMS group also includes the groups of Professors Incandela, Richman, and Stuart.

Teaching

At UCSB I have taught physics at all levels: from lower division physics for life science majors to particle physics for 2nd year graduate students.   This quarter (Fall 2024) I am teaching Physics 110B, the second quarte of Electromagnetism for Junior/Senior Physics majors. I am also teaching a honors seminar for non-physics majors: From nuclei, to quarks, to Higgs bosons (Int 84BK).

Opportunities for Students

There are openings in my group for students interested in pursuing a PhD in experimental high energy physics at CMS.

NOTE: Admissions to the UCSB Physics PhD program are handled centrally, not by individual faculty. Please do not send application materials (CVs, transcripts, research statements etc.) to me.
Instead follow the instructions given in the webpage below:
UCSB Physics PHD Applications

There are often opportunities for motivated UCSB undergraduates to do research with us, hopefully leading to a senior thesis. However at the moment I do not have anything to offer. This may change in the future (and this page will be updated accordingly.

I do not have any research/internship opportunities for non-UCSB students.

Selected Publications

A Machine Learning Derived Risk Score Improves Prediction of Outcomes Post-LVAD Implantation: An Analysis of the INTERMACS database Journal of Cardiac Failure, Volume XX, pages XX, (in press) (2024).

Performance of Risk Models to Predict Mortality Risk for Patients with Heart Failure: Evaluation in an Integrated Health System Clinical Research in Cardiology, Volume 113, pages 1343–1354, (2024).

A machine learning-derived risk score predicts mortality in East Asian patients with acute heart failure. European Journal of Heart Failure doi:10.1002/ejhf.3059 (2023).

Mortality Prediction in Patients With or Without Heart Failure Using a Machine Learning Model Journal of the American College of Cardiology JACC:Advances Vol 2, Issue 7, 100554 (2023).

Search for a high-mass dimuon resonance produced in association with b-quarkjets at root-S=13 TeV JHEP 10 (2023) 43.

Improving clinical trial efficiency using a machine learning-based risk score to enrich study populations Eur J Heart Fail. doi:10.1002/ejhf2155 (2022).

Perspective: An upset to the standard model Science 376 p. 136 (2022).

First evidence for off-shell production of the Higgs boson and measurement of its width. Nat. Phys. DOI : 10.1038/s41567-022-01682-0.

Search for flavor-changing neutral current interactions of the top quark and Higgs boson in final states with two photons in proton-proton collisions at sqrt-s=13 TeV Phys. Rev. Lett. 129, 032001 (2022) .

Search for long-lived particles decaying into muon pairs in proton-proton collisions at sqrt-s=13 TeV JHEP 04 (2022).

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at sqrt-s = 13 TeV Eur. Phys. J. C81 (2021) 970.

Machine Learning Applications in Heart Failure Disease Management: Hype or Hope? Current Treatment Options in Cardiovascular Medicine, Vol. 23, N. 6, 35 (2021).

Sensitivity to millicharged particles in future proton-proton collisions at the LHC. Phys. Rev. D104 (2021) 032002.

Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at sqrt-s = 13 TeV JHEP 07 (2021) 027.

A Machine Learning risk score predicts mortality across the spectrum of Left Ventricular Ejection Fraction Eur J Heart Fail. doi:10.1002/ejhf.2155 (2021).

Search for millicharged particles in proton-proton collisions at sqrt(s)=13 TeV. Phys. Rev. D102 (2020) 3, 032002.

Measurements of ttbarH production and the CP structure of the Yukawa interaction between the Higgs boson and top quark in the diphoton decay channel. Phys. Rev. Lett. 125 (2020) 6, 061801.

Reinterpretation of LHC Results for New Physics: Status and Recommendations after Run 2 SciPost Phys. 9, 022 (2020), arXiv:2003.07868.

Search for physics beyond the standard model in events with jets and two same-sign or at least three charged leptons in proton-proton collisions at sqrt(s) = 13 TeV Eur. Phys. J. C80 (2020) 8, 752.

Search for direct top squark pair production in events with one lepton, jets, and missing transverse momentum at 13 TeV with the CMS experiment. JHEP 05 (2020) 032.

Improving risk prediciton in heart failure using machine learning. Eur J Heart Fail. doi:10.1002/ejhf.1628 (2019). Addendum with link to online calculator for health care providers.

Searches for physics beyond the standard model with the MT2 variable in hadronic final states with and without disappearing tracks in proton-proton collisions at sqrt(s)=13 TeV Eur. Phys. J. C 80 (2020) 3.

Search for production of four top quarks in final states with same-sign or multiple leptons in proton-proton collisions at sqrt(s) = 13 TeV Eur.Phys.J. C80 (2020) no.2, 75.

Search for the production of W±W±W∓ events at sqrt(s) = 13 TeV Phys. Rev. D100 (2019) 012004.

Constraints on models of scalar and vector leptoquarks decaying to a quark and a neutrino at sqrt(s)=13 Phys. Rev. D98 (2018) 032005.

Search for standard model production of four top quarks with same-sign and multilepton final states in proton-proton collisions at sqrt(s)=13 TeV Eur.Phys.J. C78 (2018) 140.

Search for top squark production in pp collisions at sqrt(s) = 13 TeV using single lepton events. JHEP 10 (2017) 019.

Search for electroweak production of charginos and neutralinos in WH events in proton-proton collisions at sqrt(s) =13 TeV JHEP 11 (2017) 029.

Search for new phenomena with the MT2 variable in the all-hadronic final state produced in proton-proton collisions at sqrt(s)=13 TeV. Eur.Phys.J. C77 (2017) 710.

Search for physics beyond the standard model in events with two leptons of same sign, missing transverse momentum, and jets in proton-proton collisions at sqrt(s)=13 TeV Eur.Phys.J. C77 (2017) 578.

Searches for pair production of third generation squarks in sqrt(s) = 13 TeV pp collisions Eur.Phys.J. C77 (2017) 327.

Search for new physics in final states with two opposite-sign, same flavor leptons, jets, and missing transverse momentum in pp collisions at sqrt(s) = 13 TeV JHEP 13 (2016) 1612.

Search for new physics in same sign dilepton events in pp collisions at sqrt(s) = 13 TeV Eur. Phys. J. C76 (2016) 439.

A Letter of Intent to install a milli-charged particle detector at LHC P5, A. Ball et al., arXiv:1607.04669.

Search for new physics with the MT2 variable in all-jets final states produced in pp collisions at sqrt(s) = 13 TeV JHEP 10 (2016) 006.

Measurements of t t-bar charge asymmetry using dilepton final states in pp collisions at sqrt(s) = 8 TeV Phys. Lett. B760 (2016) 365.

Measurement of top quark-antiquark pair production in association with a W or Z boson in pp collisions at sqrt(s) = 8 TeV Eur. Phys.J. C74 (2014) 3060.

Measurements of the t t-bar charge asymmetry using the dilepton decay channel in pp collisions at sqrt(s) = 7 TeV JHEP 04 (2014) 191.

Measurement of Higgs boson production and properties in the WW decay channel with leptonic final states JHEP 01 (2014) 055 .

Search for new physics in events with same-sign dileptons and jets in pp collisions at sqrt(s)=8 TeV JHEP 01 (2014) 163 .

Measurements of t t-bar spin correlations and top-quark polarization using dilepton final states in pp collisions at 7 TeV Phys. Rev. Lett. 112 182001 (2014) .

Search for top-squark pair production in the single-lepton final state in pp collisions at sqrt(s) = 8 TeV Eur.Phys. J. C73 (2013) 2677 .

Search for new physics in events with same-sign dileptons and b jets in pp collisions at sqrt(s) = 8 TeV JHEP03(2013)037 .

Search for electroweak production of charginos and neutralinos using leptonic final states in pp collisions at sqrt(s) = 7 TeV JHEP 1211(2012) 147.

Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC Phys. Lett. B716, 30 (2012).

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy Phys. Rev. Lett. 109, 071803 (2012).

Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV Phys. Lett B718, 815 (2013)

Search for new physics in events with same-sign dileptons and b-tagged jets in pp collisions at sqrt(s)=7 TeV JHEP08(2012)110.

Search for physics beyond the standard model in events with a Z boson, jets, and missing transverse energy in pp collisions at sqrt(s)=7 TeV Phys. Lett. B716, 260 (2012).

Search for heavy, top-like quark pair production in the dilepton final state in pp collisions at sqrt(s)=7 TeV Phys. Lett. B716, 103 (2012).

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV JHEP 1203 (2012) 040.

Search for the standard model Higgs boson decaying to a W pair in the fully leptonic final state in pp collisions at sqrt(s) = 7 TeV Phys. Lett. B710 91 (2012).

Search for Same-Sign Top-Quark Pair Production at sqrt(s) = 7 TeV and Limits on Flavour Changing Neutral Currents in the Top Sector JHEP 1108 (2011) 005.

Measurement of the t t-bar production cross section and the top quark mass in the dilepton channel in pp collisions at sqrt(s) =7 TeV JHEP 1107 (2011) 049.

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy at the LHC JHEP06(2011)077

Search for Physics Beyond the Standard Model in Opposite-Sign Dilepton Events at sqrt(s) = 7 TeV JHEP 1106 (2011) 026.

Measurement of WW Production and Search for the Higgs Boson in pp Collisions at sqrt(s) = 7 TeV Phys. Lett. B699 25 (2011).

First Measurement of the Cross Section for Top-Quark Pair Production in Proton-Proton Collisions at sqrt(s)=7 TeV Phys. Lett. B695 424 (2011).

Missing ET in 0.9 and 2.36 TeV pp Collisions CMS-PAS-JME-10-002

Performance of Track-Corrected Missing Transverse Energy in CMS CMS-PAS-JME-09-010

Performance of CMS Muon Reconstruction in Cosmic-Ray Events  JINST 5 T03022 2010.

Search for rare quark-annihilation decays, B-→Ds(*)-ϕ   Phys. Rev. D 73, 011103 (2006).

Study of the decay anti-B0 → D*+ ωπ-   Phys. Rev. D74 012001 (2006). 

Measurement of the Charge Collection Efficiency after Heavy Non-Uniform Irradiation in BaBar Silicon Detectors  arXiv:physics/0411182     IEEE Trans. Nucl. Sci., 52, 1054 (2005)

Search for b→u transitions in B-→D0K- and B-→D*0K-  Phys. Rev.D 72, 032004 (2005)

Search for B± → [K∓ π±]DK± and upper limit on the b → u amplitude in B± → D K± Phys. Rev. Lett. 93 131804 (2004)

Silicon Tracker Module Assembly at UCSB CMS PUBLIC Note 2004/010 (2004).

Measurement of the branching fraction and polarization for the decay B- → D*0 K*-   Phys. Rev. Lett. 92 141801 (2004).

The design and construction of the BaBar Silicon Vertex TrackeR   Nucl. Inst. Meth A447 15 (2000).

Measurement of the CP asymmetry amplitude sin2β with B0 mesons  Phys. Rev. Lett. 89 201802 (2002).

Measurement of branching fractions for exclusive B decays to charmonium final states   Phys. Rev. D65 032001 (2002).

The discovery of the top quark  Rev. Mod. Phys. 69 137 (1997).

Observation of top quark production in ppbar collisions with the CDF detector at Fermilab  Phys. Rev. Lett. 74 2626 (1995).

Evidence for top quark production in p-pbar collisions at root-S = 1.8 TeV   Phys. Rev. Lett. 73 225 (1994) and Phys. Rev. D50 2966 (1994)

A measurement of the bottom quark production cross section in 1.8 TeV p-pbar collisions using muons from b-quark decays   Phys. Rev.Lett. 71 2396 (1993).

Limit on the top quark mass from proton-antiproton collisions at root-S = 1.8 TeV Phys. Rev. D45 3921 (1992).

Search for W'→ e ν and W'→ μ ν in p-pbar collision at root-S=1.8 TeV   Phys. Rev. Lett. 67 2609 (1991).

Measurement of σ(W → e ν) and σ(Z → ee) in p-pbar collisions at root-S=1800 GeV   Phys. Rev. D44 29 (1991).

 Measurement of the ratio σ(W → e ν)/σ(Z → ee) in p-pbar collision at root-S=1.8 TeV   Phys. Rev. Lett. 64 152 (1990).

A search for the decay K+ → π+ μ+e-    Phys. Rev.Lett. 61 2062 (1988).

Search for short lived neutral particle emitted in K+ decay Phys. Rev. Lett. 59 2832 (1987).