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Title: Search for heavy, long-lived particles that decay to photons at CDF II

Abstract

The authors present the first search for heavy, long-lived particles that decay to photons at a hadron collider. They use a sample of {gamma} + jet + missing transverse energy events in p{bar p} collisions at {radical}s = 1.96 TeV taken with the CDF II detector. Candidate events are selected based on the arrival time of the photon at the detector. Using an integrated luminosity of 570 pb{sup -1} of collision data, they observe 2 events, consistent with the background estimate of 1.3 {+-} 0.7 events. While the search strategy does not rely on model-specific dynamics, they set cross section limits in a supersymmetric model with {tilde {chi}}{sub 1}{sup 0} {yields} {gamma}{tilde G} and place the world-best 95% C.L. lower limit on the {tilde {chi}}{sub 1}{sup 0} mass of 101 GeV/c{sup 2} at {tau}{sub {tilde {chi}}{sub 1}{sup 0}} = 5 ns.

Authors:
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Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
902545
Report Number(s):
FERMILAB-PUB-07-075-E
arXiv eprint number arXiv:0704.0760; TRN: US200721%%592
DOE Contract Number:
AC02-07CH11359
Resource Type:
Journal Article
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CROSS SECTIONS; DECAY; FERMILAB COLLIDER DETECTOR; HADRONS; LUMINOSITY; PHOTONS; TRANSVERSE ENERGY; Experiment-HEP

Citation Formats

Abulencia, A., /Illinois U., Urbana, Adelman, J., /Chicago U., Affolder, T., /UC, Santa Barbara, Akimoto, T., /Tsukuba U., Albrow, M.G., /Fermilab, Amerio, S., /Padua U., Amidei, D., /Michigan U., Anastassov, A., /Rutgers U., Piscataway, Anikeev, K., /Fermilab, Annovi, A., /Frascati, Antos, J., and /Comenius U. /Tsukuba U.. Search for heavy, long-lived particles that decay to photons at CDF II. United States: N. p., 2007. Web. doi:10.1103/PhysRevLett.99.121801.
Abulencia, A., /Illinois U., Urbana, Adelman, J., /Chicago U., Affolder, T., /UC, Santa Barbara, Akimoto, T., /Tsukuba U., Albrow, M.G., /Fermilab, Amerio, S., /Padua U., Amidei, D., /Michigan U., Anastassov, A., /Rutgers U., Piscataway, Anikeev, K., /Fermilab, Annovi, A., /Frascati, Antos, J., & /Comenius U. /Tsukuba U.. Search for heavy, long-lived particles that decay to photons at CDF II. United States. doi:10.1103/PhysRevLett.99.121801.
Abulencia, A., /Illinois U., Urbana, Adelman, J., /Chicago U., Affolder, T., /UC, Santa Barbara, Akimoto, T., /Tsukuba U., Albrow, M.G., /Fermilab, Amerio, S., /Padua U., Amidei, D., /Michigan U., Anastassov, A., /Rutgers U., Piscataway, Anikeev, K., /Fermilab, Annovi, A., /Frascati, Antos, J., and /Comenius U. /Tsukuba U.. Sun . "Search for heavy, long-lived particles that decay to photons at CDF II". United States. doi:10.1103/PhysRevLett.99.121801. https://www.osti.gov/servlets/purl/902545.
@article{osti_902545,
title = {Search for heavy, long-lived particles that decay to photons at CDF II},
author = {Abulencia, A. and /Illinois U., Urbana and Adelman, J. and /Chicago U. and Affolder, T. and /UC, Santa Barbara and Akimoto, T. and /Tsukuba U. and Albrow, M.G. and /Fermilab and Amerio, S. and /Padua U. and Amidei, D. and /Michigan U. and Anastassov, A. and /Rutgers U., Piscataway and Anikeev, K. and /Fermilab and Annovi, A. and /Frascati and Antos, J. and /Comenius U. /Tsukuba U.},
abstractNote = {The authors present the first search for heavy, long-lived particles that decay to photons at a hadron collider. They use a sample of {gamma} + jet + missing transverse energy events in p{bar p} collisions at {radical}s = 1.96 TeV taken with the CDF II detector. Candidate events are selected based on the arrival time of the photon at the detector. Using an integrated luminosity of 570 pb{sup -1} of collision data, they observe 2 events, consistent with the background estimate of 1.3 {+-} 0.7 events. While the search strategy does not rely on model-specific dynamics, they set cross section limits in a supersymmetric model with {tilde {chi}}{sub 1}{sup 0} {yields} {gamma}{tilde G} and place the world-best 95% C.L. lower limit on the {tilde {chi}}{sub 1}{sup 0} mass of 101 GeV/c{sup 2} at {tau}{sub {tilde {chi}}{sub 1}{sup 0}} = 5 ns.},
doi = {10.1103/PhysRevLett.99.121801},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Apr 01 00:00:00 EDT 2007},
month = {Sun Apr 01 00:00:00 EDT 2007}
}
  • We present the first search for heavy, long-lived particles that decay to photons at a hadron collider. We use a sample of {gamma} + jet + missing transverse energy events in pp collisions at {radical}(s)=1.96 TeV taken with the CDF II detector. Candidate events are selected based on the arrival time of the photon at the detector. Using an integrated luminosity of 570 pb{sup -1} of collision data, we observe 2 events, consistent with the background estimate of 1.3{+-}0.7 events. While our search strategy does not rely on model-specific dynamics, we set cross section limits in a supersymmetric model withmore » {chi}-tilde{sub 1}{sup 0}{yields}{gamma}G-tilde and place the world-best 95% C.L. lower limit on the {chi}-tilde{sub 1}{sup 0} mass of 101 GeV/c{sup 2} at {tau}{sub {chi}-tilde{sub 1}{sup 0}}=5 ns.« less
  • The authors present the results of the first hadron collider search for heavy, long-lived neutralinos that decay via {tilde {chi}}{sub 1}{sup 0} {yields} {gamma}{tilde G} in gauge-mediated supersymmetry breaking models. Using an integrated luminosity of 570 {+-} 34 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, they select {gamma}+jet+missing transverse energy candidate events based on the arrival time of a high-energy photon at the electromagnetic calorimeter as measured with a timing system that was recently installed on the CDF II detector. They find 2 events, consistent with the background estimate of 1.3 {+-} 0.7 events. While themore » search strategy does not rely on model-specific dynamics, they set cross section limits and place the world-best 95% C.L. lower limit on the {tilde {chi}}{sub 1}{sup 0} mass of 101 GeV/c{sup 2} at {tau}{sub {tilde {chi}}{sub 1}{sup 0}} = 5 ns.« less
  • We present the results of the first hadron collider search for heavy, long-lived neutralinos that decay via {chi}-tilde{sub 1}{sup 0}{yields}{gamma}G-tilde in gauge-mediated supersymmetry breaking models. Using an integrated luminosity of 570{+-}34 pb{sup -1} of pp collisions at {radical}(s)=1.96 TeV, we select {gamma}+jet+missing transverse energy candidate events based on the arrival time of a high-energy photon at the electromagnetic calorimeter as measured with a timing system that was recently installed on the CDF II detector. We find 2 events, consistent with the background estimate of 1.3{+-}0.7 events. While our search strategy does not rely on model-specific dynamics, we set cross sectionmore » limits and place the world-best 95% C.L. lower limit on the {chi}-tilde{sub 1}{sup 0} mass of 101 GeV/c{sup 2} at {tau}{sub {chi}}-tilde{sub 1{sup 0}}=5 ns.« less
  • We present the prospects of searches for neutral, long-lived particles that decay to photons using their time of arrival measured with a newly installed timing system on the electromagnetic calorimeter (EMTiming) of the Collider Detector at Fermilab (CDF). A Monte Carlo simulation shows that EMTiming can provide separation between decay photons from neutral, long-lived particles and prompt photons from standard model backgrounds. Using gauge mediated supersymmetry breaking (GMSB) {chi}-tilde{sub 1}{sup 0}{yields}{gamma}G-tilde models, we estimate a quasi-model-independent sensitivity using only direct neutralino pair production, and also estimate the expected 95% confidence level exclusion regions for all superpartner production as a functionmore » of the neutralino mass and lifetime. We find that a combination of single photon and diphoton analyses should allow the Tevatron in Run II to easily extend the exclusion regions from ALEPH at LEP II at high neutralino masses and lifetimes, and cover parts of the theoretically favored m{sub G-tilde}<few keV/c{sup 2} GMSB parameter space.« less
  • This dissertation presents the results of the first search for heavy, neutral, longlived particles that decay to photons at a hadron collider. We use a sample of +jet+missing transverse energy events inmore » $$p \bar{p}$$ collisions at √s = 1.96 TeV taken with the Collider Detector at Fermilab. Candidate events are selected based on the arrival time of a high-energy photon at the electromagnetic calorimeter as measured with a timing system that was recently installed. The final result is that we find 2 events, using 570±34 pb -1 of data collected during 2004-2005 at the Fermilab Tevatron, consistent with the background estimate of 1.3±0.7 events. While our search strategy does not rely on model-specific dynamics, we interpret this result in terms of cross section limits in a supersymmetric model with $$\vec{X}$$$0\atop{1}$$ eG and set a world-best e 01 mass reach of 101 GeV/c 2 at e = 5 ns. We can exclude any γ+jet+missing transverse energy signal that would produce more than 5.5 events.« less