Academic Appointments

  • Associate Professor, Particle Physics and Astrophysics

Boards, Advisory Committees, Professional Organizations

  • Executive Committee Member at Large, APS Division of Particles and Fields (2019 - Present)
  • Experimental Advisory Committee member, SNOLAB (2012 - 2015)

Professional Education

  • PhD, Harvard University, Physics (2007)
  • S.B., MIT, Physics and Mathematics (2003)

2020-21 Courses

Stanford Advisees

  • Doctoral Dissertation Reader (AC)
    William DeRocco, Saarik Kalia, Dylan Rueter, Kelly Stifter
  • Doctoral Dissertation Advisor (AC)
    Kevin Zhou

All Publications

  • Axion dark matter detection by superconducting resonant frequency conversion JOURNAL OF HIGH ENERGY PHYSICS Berlin, A., D'Agnolo, R., Ellis, S. R., Nantista, C., Neilson, J., Schuster, P., Tantawi, S., Toro, N., Zhou, K. 2020
  • A high efficiency photon veto for the Light Dark Matter eXperiment JOURNAL OF HIGH ENERGY PHYSICS Akesson, T., Blinov, N., Bryngemark, L., Colegrove, O., Collura, G., Dukes, C., Dutta, V., Echenard, B., Eichlersmith, T., Group, C., Hiltbrand, J., Hitlin, D. G., Incandela, J., Krnjaic, G., Lazaro, J., Li, A., Mans, J., Masterson, P., McCormick, J., Moreno, O., Mullier, G., Nagar, A., Nelson, T., Niendorf, G., Oyang, J., Petersen, R., Pottgen, R., Schuster, P., Siegel, H., Toro, N., Tran, N., Whitbeck, A. 2020
  • Lepton-nucleus cross section measurements for DUNE with the LDMX detector PHYSICAL REVIEW D Ankowski, A. M., Friedland, A., Li, S., Moreno, O., Schuster, P., Toro, N., Tran, N. 2020; 101 (5)
  • Directly Deflecting Particle Dark Matter PHYSICAL REVIEW LETTERS Berlin, A., D'Agnolo, R., Ellis, S. R., Schuster, P., Toro, N. 2020; 124 (1): 011801


    We propose a new strategy to directly detect light particle dark matter that has long-ranged interactions with ordinary matter. The approach involves distorting the local flow of dark matter with time-varying fields and measuring these distortions with shielded resonant detectors. We apply this idea to sub-MeV dark matter particles with very small electric charges or coupled to a light vector mediator, including the freeze-in parameter space targeted by low mass direct detection efforts. This approach can probe dark matter masses ranging from 10 MeV to below a meV, extending beyond the capabilities of existing and proposed direct detection experiments.

    View details for DOI 10.1103/PhysRevLett.124.011801

    View details for Web of Science ID 000505495300008

    View details for PubMedID 31976725

  • Dark matter, millicharges, axion and scalar particles, gauge bosons, and other new physics with LDMX PHYSICAL REVIEW D Berlin, A., Blinov, N., Krnjaic, G., Schuster, P., Toro, N. 2019; 99 (7)
  • Search for a dark photon in electroproduced e(+)e(-) pairs with the Heavy Photon Search experiment at JLab PHYSICAL REVIEW D Adrian, P. H., Baltzell, N. A., Battaglieri, M., Bondi, M., Boyarinov, S., Bueltmann, S., Burkert, V. D., Calvo, D., Carpinelli, M., Celentano, A., Charles, G., Colaneri, L., Cooper, W., Cuevas, C., D'Angelo, A., Dashyan, N., De Napoli, M., De Vita, R., Deur, A., Dupre, R., Egiyan, H., Elouadrhiri, L., Essig, R., Fadeyev, Field, C., Filippi, A., Freyberger, A., Garcon, M., Gevorgyan, N., Girod, F. X., Graf, N., Graham, M., Griffioen, K. A., Grillo, A., Guidal, M., Herbst, R., Holtrop, M., Jaros, J., Kalicy, G., Khandaker, M., Kubarovsky, Leonora, E., Livingston, K., Maruyama, T., McCarty, K., McCormick, J., McKinnon, B., Moffeit, K., Moreno, O., Camacho, C., Nelson, T., Niccolai, S., Odian, A., Oriunno, M., Osipenko, M., Paremuzyan, R., Paul, S., Randazzo, N., Raydo, B., Reese, B., Rizzo, A., Schuster, P., Sharabian, Y. G., Simi, G., Simonyan, A., Sipala, Sokhan, D., Solt, M., Stepanyan, S., Szumila-Vance, H., Toro, N., Uemura, S., Ungaro, M., Voskanyan, H., Weinstein, L. B., Wojtsekhowski, B., Yale, B., Heavy Photon Search Collaboration 2018; 98 (9)
  • Dark sectors at the Fermilab SeaQuest experiment PHYSICAL REVIEW D Berlin, A., Gori, S., Schuster, P., Toro, N. 2018; 98 (3)
  • Cosmology and accelerator tests of strongly interacting dark matter PHYSICAL REVIEW D Berlin, A., Blinov, N., Gori, S., Schuster, P., Toro, N. 2018; 97 (5)
  • Analyzing the Discovery Potential for Light Dark Matter PHYSICAL REVIEW LETTERS Izaguirre, E., Krnjaic, G., Schuster, P., Toro, N. 2015; 115 (25): 251301


    In this Letter, we determine the present status of sub-GeV thermal dark matter annihilating through standard model mixing, with special emphasis on interactions through the vector portal. Within representative simple models, we carry out a complete and precise calculation of the dark matter abundance and of all available constraints. We also introduce a concise framework for comparing different experimental approaches, and use this comparison to identify important ranges of dark matter mass and couplings to better explore in future experiments. The requirement that dark matter be a thermal relic sets a sharp sensitivity target for terrestrial experiments, and so we highlight complementary experimental approaches that can decisively reach this milestone sensitivity over the entire sub-GeV mass range.

    View details for DOI 10.1103/PhysRevLett.115.251301

    View details for Web of Science ID 000366484900001

    View details for PubMedID 26722912

  • Testing GeV-scale dark matter with fixed-target missing momentum experiments PHYSICAL REVIEW D Izaguirre, E., Krnjaic, G., Schuster, P., Toro, N. 2015; 91 (9)
  • A new class of particle in 2+1 dimensions PHYSICS LETTERS B Schuster, P., Toro, N. 2015; 743: 224–27
  • The Heavy Photon Search test detector NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT Battaglieri, M. a., Boyarinov, S. b., Bueltmann, S. c., Burkert, V. b., Celentano, A. a., CHARLES, G. F., COOPER, W. D., Cuevas, C. b., Dashyan, N. e., DeVita, R. a., Desnault, C. f., Deur, A. b., Egiyan, H. b., Elouadrhiri, L. b., Essig, R. g., Fadeyev, V. h., Field, C. i., Freyberger, A. b., Gershtein, Y. j., Gevorgyan, N. E., Girod, F. b., Graf, N. i., Graham, M. I., Griffioen, K. k., Grillo, A. h., Guidal, M. f., Haller, G. i., Adrian, P. H., Herbst, R. i., Holtrop, M. l., Jaros, J. i., Kaneta, S. b., Khandaker, M. M., Kubarovsky, A. n., Kubarovsky, V. b., Maruyama, T. i., McCormick, J. I., Moffeit, K. i., Moreno, O. H., Neal, H. i., Nelson, T. i., Niccolai, S. f., Odian, A. i., Oriunno, M. i., Paremuzyan, R. e., Partridge, R. i., Phillips, S. K., Rauly, E. f., Raydo, B. b., REICHERT, J. J., Rindel, E. f., Rosier, P. F., Salgado, C. M., Schuster, P. o., Sharabian, Y. b., Sokhan, D. p., Stepanyan, S. b., Toro, N. o., Uemura, S. i., Ungaro, M. b., Voskanyan, H. E., Walz, D. i., Weinstein, L. B., Wojtsekhowski, B. B. 2015; 777: 91-101
  • Continuous-spin particle field theory with helicity correspondence PHYSICAL REVIEW D Schuster, P., Toro, N. 2015; 91 (2)
  • Physics motivation for a pilot dark matter search at Jefferson Laboratory PHYSICAL REVIEW D Izaguirre, E., Krnjaic, G., Schuster, P., Toro, N. 2014; 90 (1)
  • New electron beam-dump experiments to search for MeV to few-GeV dark matter PHYSICAL REVIEW D Izaguirre, E., Krnjaic, G., Schuster, P., Toro, N. 2013; 88 (11)
  • A gauge field theory of continuous-spin particles JOURNAL OF HIGH ENERGY PHYSICS Schuster, P., Toro, N. 2013
  • On the theory of continous-spin particles: helicity correspondence in radiation and forces JOURNAL OF HIGH ENERGY PHYSICS Schuster, P., Toro, N. 2013
  • On the theory of continous-spin particles: wavefunctions and soft-factor scattering amplitudes JOURNAL OF HIGH ENERGY PHYSICS Schuster, P., Toro, N. 2013
  • Study of LHC searches for a lepton and many jets JOURNAL OF HIGH ENERGY PHYSICS Lisanti, M., Schuster, P., Strassler, M., Toro, N. 2012
  • Sommerfeld-enhanced annihilation in dark matter substructure: Consequences for constraints on cosmic-ray excesses PHYSICAL REVIEW D Slatyer, T. R., Toro, N., Weiner, N. 2012; 86 (8)
  • Simplified models for LHC new physics searches JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS Alves, D., Arkani-Hamed, N., Arora, S., Bai, Y., Baumgart, M., Berger, J., Buckley, M., Butler, B., Chang, S., Cheng, H., Cheung, C., Chivukula, R. S., Cho, W. S., Cotta, R., D'Alfonso, M., El Hedri, S., Essig, R., Evans, J. A., Fitzpatrick, L., Fox, P., Franceschini, R., Freitas, A., Gainer, J. S., Gershtein, Y., Gray, R., Gregoire, T., Gripaios, B., Gunion, J., Han, T., Haas, A., Hansson, P., Hewett, J., Hits, D., Hubisz, J., Izaguirre, E., Kaplan, J., Katz, E., Kilic, C., Kim, H., Kitano, R., Koay, S. A., Ko, P., Krohn, D., Kuflik, E., Lewis, I., Lisanti, M., Liu, T., Liu, Z., Lu, R., Luty, M., Meade, P., Morrissey, D., Mrenna, S., Nojiri, M., Okui, T., Padhi, S., Papucci, M., Park, M., Park, M., Perelstein, M., Peskin, M., Phalen, D., Rehermann, K., Rentala, V., Roy, T., Ruderman, J. T., Sanz, V., Schmaltz, M., Schnetzer, S., Schuster, P., Schwaller, P., Schwartz, M. D., Schwartzman, A., Shao, J., Shelton, J., Shih, D., Shu, J., Silverstein, D., Simmons, E., Somalwar, S., Spannowsky, M., Spethmann, C., Strassler, M., Su, S., Tait, T., Thomas, B., Thomas, S., Toro, N., Volansky, T., Wacker, J., Waltenberger, W., Yavin, I., Yu, F., Zhao, Y., Zurek, K. 2012; 39 (10)
  • Multiphotons and photon jets from new heavy vector bosons PHYSICAL REVIEW D Toro, N., Yavin, I. 2012; 86 (5)
  • Search for a New Gauge Boson in Electron-Nucleus Fixed-Target Scattering by the APEX Experiment PHYSICAL REVIEW LETTERS Abrahamyan, S., Ahmed, Z., Allada, K., Anez, D., Averett, T., Barbieri, A., Bartlett, K., Beacham, J., Bono, J., Boyce, J. R., Brindza, P., Camsonne, A., Cranmer, K., Dalton, M. M., de Jager, C. W., Donaghy, J., Essig, R., Field, C., Folts, E., Gasparian, A., Goeckner-Wald, N., Gomez, J., Graham, M., Hansen, J., Higinbotham, D. W., Holmstrom, T., Huang, J., Iqbal, S., Jaros, J., Jensen, E., Kelleher, A., Khandaker, M., LeRose, J. J., Lindgren, R., Liyanage, N., Long, E., Mammei, J., Markowitz, P., Maruyama, T., Maxwell, V., Mayilyan, S., McDonald, J., Michaels, R., MOFFEIT, K., Nelyubin, V., Odian, A., Oriunno, M., Partridge, R., Paolone, M., Piasetzky, E., POMERANTZ, I., Qiang, Y., Riordan, S., Roblin, Y., Sawatzky, B., Schuster, P., Segal, J., Selvy, L., Shahinyan, A., Subedi, R., Sulkosky, V., Stepanyan, S., Toro, N., Walz, D., Wojtsekhowski, B., Zhang, J. 2011; 107 (19)


    We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'→ e+ e- reaction, and set an upper limit of α'/α ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.

    View details for DOI 10.1103/PhysRevLett.107.191804

    View details for Web of Science ID 000297006700004

    View details for PubMedID 22181599

  • An electron fixed target experiment to search for a new vector boson A ' decaying to e(+)e(-) JOURNAL OF HIGH ENERGY PHYSICS Essig, R., Schuster, P., Toro, N., Wojtsekhowski, B. 2011
  • High energy electron signals from dark matter annihilation in the Sun PHYSICAL REVIEW D Schuster, P., Toro, N., Weiner, N., Yavin, I. 2010; 82 (11)
  • Discovering new light states at neutrino experiments PHYSICAL REVIEW D Essig, R., Harnik, R., Kaplan, J., Toro, N. 2010; 82 (11)
  • Physics with the KLOE-2 experiment at the upgraded DA Phi NE EUROPEAN PHYSICAL JOURNAL C Amelino-Camelia, G., Archilli, F., Babusci, D., Badoni, D., Bencivenni, G., Bernabeu, J., Bertlmann, R. A., Boito, D. R., Bini, C., Bloise, C., BOCCI, V., Bossi, F., Branchini, P., Budano, A., BULYCHJEV, S. A., Campana, P., Capon, G., Ceradini, F., Ciambrone, P., Czerwinski, E., Czyz, H., D'Ambrosio, G., Dane, E., De Lucia, E., De Robertis, G., De Santis, A., De Simone, P., De Zorzi, G., Di Domenico, A., Di Donato, C., Di Micco, B., Domenici, D., Eidelman, S. I., Erriquez, O., Escribano, R., Essig, R., Fedotovich, G. V., Felici, G., Fiore, S., Franzini, P., Gauzzi, P., Giacosa, F., Giovannella, S., Gonnella, F., Graziani, E., Happacher, F., Hiesmayr, B. C., Hoistad, B., Iarocci, E., Ivashyn, S., Jacewicz, M., Jegerlehner, F., Johansson, T., Lee-Franzini, J., Kluge, W., Kulikov, V. V., Kupsc, A., Lehnert, R., Loddo, F., Lukin, P., Martemianov, M. A., Martini, M., Matsyuk, M. A., Mavromatos, N. E., Mescia, F., Messi, R., Miscetti, S., Morello, G., Moricciani, D., Moskal, P., Mueller, S., Nguyen, F., Passemar, E., Passera, M., Passeri, A., Patera, V., Pennington, M. R., Prades, J., Quintieri, L., Ranieri, A., Reece, M., Santangelo, P., Sarkar, S., Sarra, I., Schioppa, M., Schuster, P. C., Sciascia, B., Sciubba, A., Silarski, M., Taccini, C., Toro, N., Tortora, L., Venanzoni, G., Versaci, R., Wang, L., Wislicki, W., Wolke, M., ZDEBIK, J. 2010; 68 (3-4): 619-681
  • Terrestrial and solar limits on long-lived particles in a dark sector PHYSICAL REVIEW D Schuster, P., Toro, N., Yavin, I. 2010; 81 (1)
  • New fixed-target experiments to search for dark gauge forces PHYSICAL REVIEW D Bjorken, J. D., Essig, R., Schuster, P., Toro, N. 2009; 80 (7)
  • Probing dark forces and light hidden sectors at low-energy e(+)e(-) colliders PHYSICAL REVIEW D Essig, R., Schuster, P., Toro, N. 2009; 80 (1)
  • Constructing the tree-level Yang-Mills S-matrix using complex factorization JOURNAL OF HIGH ENERGY PHYSICS Schuster, P. C., Toro, N. 2009
  • Simplified models for a first characterization of new physics at the LHC PHYSICAL REVIEW D Alwall, J., Schuster, P. C., Toro, N. 2009; 79 (7)