Personal Information

Glennys Farrar
Professor of Physics
Collegiate Professor and Julius Silver, Roslyn S. Silver, and Enid Silver Winslow Professor
Ph.D. 1971, Princeton
B.A. 1968, California Berkeley
Theoretical Particle Physics, Astrophysics and Cosmology
Contact Information
Phone:(212) 992-8787
Email:gf25 AT
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Prof. Glennys Farrar received her Ph. D. in theoretical physics from Princeton University in 1971, breaking the gender-barrier in physics at Princeton in the process. She was a member of the Institute for Advanced Study and on the faculties of the California Institute of Technology and Rutgers University before moving to NYU in 1998. Among her accomplishments in particle physics, Farrar is perhaps best known for pioneering the phenomenological study of supersymmetry. With P. Fayet and others, she developed most of the present search techniques for superparticles, gave the first limits on SUSY breaking and superpartner masses from accelerator experiments and precision observables such as g-2, identified and clarified the role of R-parity, initiated the study of cosmological effects of SUSY. She has stressed the interest of light gaugino scenarios and has lead the effort to constrain them from experiment. Her other work has ranged from QCD and hadron physics to electroweak baryogenesis and the study of dark matter. She made a number of predictions whose experimental confirmation played an important role in establishing the Standard Model. The scaling dependence of exclusive scattering was the first clear demonstration that quarks are dynamical degrees of freedom, and not merely a mathematical device realizing current algebras. Other predictions which play an important role in QCD phenomenology today include copious direct production of photons in hadronic collisions, the ratio of up to down quarks and the dependence of quark and gluon distributions at large x-Bjorken, color-transparency, the normalization of the pion form wavefunction, and helicity dependence of hadron scattering.

Farrars current work focuses mainly on problems at the intersection of astrophysics, cosmology and particle physics, including ultrahigh energy cosmic rays, the nature of dark matter and dark energy, and the origin of the asymmetry between matter and antimatter. UHECRs: Farrar and collaborators use existing UHECR data to deduce properties of their sources and cosmic magnetic fields. Another thrust of NYU research is to improve simulation and reconstruction of cosmic ray air showers. H. Drescher, a postdoc in Farrars group, developed the shower simulation code SENECA; it gives a more realistic description of individual events and is 40 times faster than previous codes. Farrar and Drescher have used it to check the reliability and model independence of UHECR energy calibrations; with Courant grad student D. Krasnov, more powerful methods to identify and reconstruct a primary cosmic rays energy are being developed. Dark Matter and Cosmological Dynamics: Farrar and Peebles showed the mass of dark matter could arise from a Higgs-type interaction with the dark energy field, producing interesting variants to the standard LCDM cosmological model. Farrar is now engaged in several related projects, simulating the impact of such interactions on the formation of structure and using observations of large-scale structure and galactic dynamics to constrain the possibility that dark matter experiences non-gravitational forces. Novel models of Dark Matter: Farrar and Spergel are studying models in which DM is normal matter on a different brane. Farrar and grad student G. Zaharijas have shown that the baryon asymmetry of the universe may be only an asymmetry in "packaging", with the baryon number in nucleons balanced by anti-baryonic dark matter. Observational constraints on such DM have been obtained and are found to be consistent with the expected DM properties. In one such scenario the DM consists of H and anti-H dibaryons, impelling a renewed study of a long-lived H dibaryon.

Selected Publications:
Selected papers, grouped by topic

Auger papers not included; [Google Scholar citations on 03/17/22 ]

1. “Scaling Laws at Large Transverse Momentum”, S. J. Brodsky and G. R. Farrar, Phys. Rev. Lett. 31, 1153 1973 [2335] and “Scaling Laws for Large Momentum Transfer Processes”, Phys. Rev. D 11, 1309 1975. [1162]

2. “Particle Ratios in Energetic Hadron Collisions”, J. D. Bjorken and G. R. Farrar, Phys. Rev. D 9, 1449 1974. [142]

3. “Pion and Nucleon Structure Functions Near x=1”, G. R. Farrar and D. R. Jackson, Phys. Rev. Lett. 35, 1416 1975. [673]

4. “Copious Direct Photon Production as a Possible Resolution of the Prompt Lepton Puz- zle”, G. R. Farrar and S. C. Frautschi, Phys. Rev. Lett. 36, 1017 1976. [135]

5. “Phenomenology of the Production, Decay, and Detection of New Hadronic States Asso- ciated with Supersymmetry”, G. R. Farrar and P. Fayet, Phys. Lett. B 76, 575 1978 [3181] and “Bounds on R-hadron production from calorimetry experiments”, Phys. Lett. B 79, 442 1978 [159] and “Searching for the spin-0 leptons of supersymmetry”, Phys. Lett. B 89, 191 1980 [133]

6. “The Pion Form-Factor”, G. R. Farrar and D. R. Jackson, Phys. Rev. Lett. 43, 246 1979. [544]

7. An alternative to perturbative grand unification: How asymptotically non-free theorues can successfully predict low-energy gauge couplings, N. Cabbibo and G. R. Farrar, Phys. Lett. B 110, 107 1982 [62].

8. Supersymmetry at ordinary energies. II. invariance, Goldstone bosons, and gauge-fermion masses, G. R. Farrar and S. Weinberg, Phys. Rev. D 27, 2732 1983 [151]

9. “Transparency in Nuclear Quasiexclusive Processes with Large Momentum Transfer”, G. R. Farrar, H. Liu, L. L. Frankfurt and M. I. Strikman, Phys. Rev. Lett. 61, 686 1988. [312]

10. Recursive stratified sampling for multidimensional Monte Carlo integration, W. H. Press and G. R. Farrar, Computers in Physics 4,202 1990. [137]

11. “Light gluinos”, G. R. Farrar, Phys. Rev. Lett. 53, 1029 1984. [97] “Experiments to find or exclude a long lived, light gluino”, Phys. Rev. D 51, 3904 1995 [153] and “Detecting gluino-containing hadrons”, Phys. Rev. Lett. 76, 4111 1996. [191]

12. “Determining the gluonic content of isoscalar mesons”, F. E. Close, G. R. Farrar and Z. p. Li, Phys. Rev. D 55, 5749 1997 [271]

13. “SUSY and the electroweak phase transition”, G. R. Farrar and M. Losada, Phys. Lett. B406, 60 1997 [105]

14. “Baryon asymmetry of the universe in the minimal Standard Model,” G. R. Farrar and M. E. Shaposhnikov, Phys. Rev. Lett. 70, 2833-2836 1993 [370] and “Baryon asymmetry of the universe in the standard electroweak theory,” Phys. Rev. D 50, 774 1994 [441]

15. “Soft Yukawa couplings in supersymmetric theories”, F. Borzumati, G. R. Farrar, N. Polonsky and S Thomas, Nucl. Phys. B555,53 1999. [232]

16. “Self-interacting dark matter”, B .D. Wandelt, R. Dave, G. R. Farrar, D. N. Spergel and P. J. Stein- hardt, Sources and detection of dark matter and dark energy in the universe, pp 263-274 2001. [143]

17. “Interacting dark matter and dark energy”, G. R. Farrar and P. J. E. Peebles. Astrophys. J. 604, 1 2004. [487]

18. “The 2dF Galaxy Redshift Survey: luminosity functions by density environment and galaxy type”, D. J. Croton, G. R. Farrar et al, MNRAS 356,1155 2005 [324] and “Where do ‘red and dead’ early-type void galaxies come from?”, MNRAS 386, 2285 2008.[62]

19. “Window in the dark matter exclusion limits”, Phys. Rev. D 72, 083502 2005 [90.]

20. “Dark matter and the baryon asymmetry”, G. R. Farrar and G. Zaharijas. Phys. Rev. Lett. 96, 041302 2006. [179]

21. “A New Force in the Dark Sector?” G. R. Farrar and R. A. Rosen, Phys. Rev. Lett. 98, 171302 2007, [101] “The Speed of the bullet in the merging galaxy cluster 1E0657-56”, V. Springel and G. Farrar. Mon. Not. Roy. Astron. Soc. 380, 911 2007; [240] “Constrained Simulation of the Bullet Cluster” C. Lage and G. R. Farrar, Astrophys. J., 787,14 2014 [48] and “The Bullet Cluster is not a Cosmological Anomaly”, JCAP 2,38 2015. [29]

22. “Giant AGN flares and cosmic ray bursts”, G R Farrar and A. Gruzinov Astrophysical J. 693, 329 2009. [168]

23. “Optical discovery of probable stellar tidal disruption flares”, S. van Velzen, G. R. Farrar, et al., Astrophysical J. 741, 73 2011 [317] and “Measurement of the rate of stellar tidal disruption flares,” S. van Velzen and G. R. Farrar, Astrophys. J. 792, 53 2014 [125] and “A tidal disruption event coincident with a high-energy neutrino,” R. Stein, S. Van Velzen, M. Kowalski, ... G. Farrar et al., Nature Astron. 5, no.5, 510-518 2021 [65].

24. “A New Model of the Galactic Magnetic Field”, R. Jansson and G. R. Farrar, Astrophys. J., 757,144 2012 [633] and “The Galactic Magnetic Field,” Astrophys. J. Lett. 761, L11 2012 [580].

25. “Origin of the ankle in the ultrahigh energy cosmic ray spectrum, and of the extragalactic protons below it”, M. Unger, G. R. Farrar, L. A. Anchordoqui Phys. Rev. D 92 , 123001 2015 [136] and “Probing the environments surrounding ultrahigh energy cosmic ray accelerators and their implications for astrophysical neutrinos,” M. S. Muzio, G. R. Farrar and M. Unger, Phys. Rev. D 105, no.2, 023022 2022.

26. “Testing hadronic interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory”, The Pierre Auger Collaboration, G. R. Farrar corresponding author, Phys. Rev. Lett. 117,192001 2016. [223]

27. “Multi-messenger Observations of a Binary Neutron Star Merger,”, B. P. Abbott et al. [LIGO Scientific, Virgo, Fermi GBM, INTEGRAL, IceCube, AstroSat Cadmium Zinc Telluride Im- ager Team, IPN, Insight-Hxmt, ANTARES, Swift, AGILE Team, 1M2H Team, Dark Energy Camera GW-EM, DES, DLT40, GRAWITA, Fermi-LAT, ATCA, ASKAP, Las Cumbres Observatory Group, OzGrav, DWF Deeper Wider Faster Program, AST3, CAASTRO, VINROUGE, MASTER, J-GEM, GROWTH, JAGWAR, CaltechNRAO, TTU-NRAO, NuSTAR, Pan-STARRS, MAXI Team, TZAC Consortium, KU, Nordic Optical Telescope, ePESSTO, GROND, Texas Tech University, SALT Group, TOROS, BOOTES, MWA, CALET, IKI-GW Follow-up, H.E.S.S., LOFAR, LWA, HAWC, Pierre Auger, ALMA, Euro VLBI Team, Pi of Sky, Chandra Team at McGill University, DFN, ATLAS Tele- scopes, High Time Resolution Universe Survey, RIMAS, RATIR and SKA South Africa/MeerKAT], Astrophys. J. Lett. 848, no.2, L12 2017. [2056]

28. “Dark Matter that Interacts with Baryons: Density Distribution within the Earth and New Constraints on the Interaction Cross-section”, D. A. Neufeld, G. R. Farrar and C. F. Mc- Kee, Astrophys. J., 866,111 2018. [21]

29. “Gas-rich dwarf galaxies as a new probe of dark matter interactions with ordinary mat- ter,” D. Wadekar and G. R. Farrar, Phys. Rev. D 103, no.12, 123028 2021 [14].

30. “The Imprint of Large Scale Structure on the Ultra-High-Energy Cosmic Ray Sky”, C. Ding, N. Globus and G. R. Farrar, Astrophysical J. Letters, 913, L13, 2021 [5].

31. “Resonant Scattering between Dark Matter and Baryons: Revised Direct Detection and CMB Limits,”, X. Xu and G. R. Farrar, [arXiv:2101.00142 [hep-ph]] and “Constraints on GeV Dark Matter interaction with baryons, from a novel Dewar exper- iment,” [arXiv:2112.00707 [hep-ph]].

32. A Stable Sexaquark: Overview and Discovery Strategies, G R Farrar, [arXiv:2201.01334 [hep-ph]].