Bulletin of the American Physical Society
2021 Joint Spring Meeting of the Texas Sections of APS, AAPT and Zone 13 of the SPS
Volume 66, Number 2
Thursday–Sunday, April 8–11, 2021; Virtual
Session A05: APS: Nuclear and Particle Physics-I |
Hide Abstracts |
Thursday, April 8, 2021 5:00PM - 5:12PM |
A05.00001: Search for gluino-mediated stop pair production in events with b-jets and large missing transverse momentum Egor Antipov A search for supersymmetry involving the pair production of gluions decaying via stop quarks into the lightest neutralino $\tilde{\chi}_{1}^{0}$ is reported. It uses LHC proton-proton collision data at the center-of-mass energy $\sqrt{s}=13 TeV$ with an integrated luminosity of $139 fb^{-1}$ collected with the ATLAS detector in 2015-2018. The search is performed in events containing large missing transverse momentum and several energetic jets, at least three of which must be identified as originating from b-quarks. The analysis is done in two final states, one of which is required to have at least 1 lepton, and the second one is required the veto on leptons. Expected exclusion limit for gluino and neutralino masses is evaluated using simplified signal model. It is found to be $800 GeV$ and below for neutralino masses with gluino masses of less than $2275 GeV$ at the $95\%$ confidence level. [Preview Abstract] |
Thursday, April 8, 2021 5:12PM - 5:24PM |
A05.00002: AMS-02 observations of antiprotons, and Planck limits on dark matter annihilation -- potential support for a multicomponent dark matter scenario Drue Lubanski, Bailey Tallman, Diego Cristancho Guerrero, Spencer Ellis, Sabrina Hernandez, Caden LaFontaine, Trevor Croteau, Brandon Torres, Roland Allen Several independent analyses of the antiprotons observed by AMS-02 suggest that the observations are consistent with the annihilation of dark matter particles with a mass somewhat below 100 GeV~[1-4]. We will describe a multicomponent dark matter scenario, with a subdominant neutralino and a dominant higgson~[5] of mass $\sim$75 GeV, which is fully consistent with these results, and also with the Planck limits~[6]. [1] Alessandro Cuoco, Michael Krämer, and Michael Korsmeier, Phys. Rev. Lett. 118, 191102 (2017). [2] Ming-Yang Cui, Qiang Yuan, Yue-Lin Sming Tsai, and Yi-Zhong Fan, Phys. Rev. Lett. 118, 191101 (2017). [3] Ilias Cholis, Tim Linden, and Dan Hooper, Phys. Rev. D 99, 103026 (2019), arXiv:1903.02549 [astro-ph.HE], and references therein.. [4] Alessandro Cuoco, Jan Heisig, Lukas Klamt, Michael Korsmeier, and Michael Kramer, Phys. Rev. D 99, 103014 (2019), arXiv:1903.01472 [astro-ph.HE], and references therein. [5] Reagan Thornberry, Gabriel Frohaug, Caden LaFontaine, Bailey Tallman, Alex Behne, Steven Sellers, Matthew Sadler, and Roland E. Allen, ``Present and potential future experimental evidence supporting a multicomponent dark matter scenario'', European Physical Journal Special Topics (in press), and references therein. [6] Planck Collaboration, arXiv:1807.06209. [Preview Abstract] |
Thursday, April 8, 2021 5:24PM - 5:36PM |
A05.00003: Polarized Drell-Yan Process to Study Sea Quarks at Fermilab E1039 Isla Casey The E1039/SpinQuest collaboration at Fermilab will measure the spin asymmetry in the quark sea. SpinQuest is the continuance of the E906/SeaQuest experiment which has studied the ratio of $\bar{u}$ to $\bar{d}$ in a proton using the Drell-Yan process to measure di-muons from quark-antiquark annihilation. The E1039 project has now upgraded the SeaQuest spectrometer with a polarized target and improved detectors to provide knowledge of the target proton’s spin. With this upgrade, SpinQuest can now search for a left-right spin asymmetry in Drell-Yan dimuons to make the world’s first measurement of the sea quark Sivers function, a correlation between the transverse momentum of the quark and the proton’s spin. Should the Sivers function turn out to be equal to zero, the spin of the proton and the transverse momentum of the sea quarks might then be independent of each other. However, if it is non-zero, this will suggest that sea quarks have orbital angular momentum, which may be one of the missing pieces to the proton spin puzzle. This presentation will discuss how the SpinQuest experiment will contribute to the understanding of the Sivers function in sea quarks. [Preview Abstract] |
Thursday, April 8, 2021 5:36PM - 5:48PM |
A05.00004: Optimizing Time-of-Flight Calculations to Identify Particles in p+p and p+A Collisions with the STAR Detector Bassam Aboona The Soleniodal Tracker at RHIC (STAR) at Brookhaven National Laboratory uses multiple techniques for particle identification. The time-of-flight (TOF) detector is one of the tools available, which provides high efficiency particle identification in A+A collisions. However, its capabilities are significantly reduced in p+p and p+A collisions because the existing analysis procedures are not optimized for high collision rates with low event multiplicities. In this presentation, we will discuss revised algorithms that provide significant improvements in both efficiency and resolution when using TOF in p+p and p+A systems. We will also share results from using these optimized algorithms in p+p and p+A data collected by STAR in 2015. [Preview Abstract] |
Thursday, April 8, 2021 5:48PM - 6:00PM |
A05.00005: Potential for discovery of a new dark matter WIMP at the present Large Hadron Collider Spencer Ellis, Sabrina Hernandez, Bailey Tallman, Drue Lubanski, Diego Cristancho Guerrero, Brandon Torres, Caden LaFontaine, Trevor Croteau, Roland Allen In this talk and another one at this conference~[1], we discuss the potential for discovery at a hadron or lepton collider of a new dark matter WIMP which we have proposed, called the higgson~[2] because it results from an extended Higgs sector. CMS and ATLAS have independently placed upper limits on the branching ratio for invisible Higgs decays to particles with a total mass of $<$ 125 GeV. The present particle has a small Higgs coupling, however, and the total mass of a pair should be $\sim$ 150 GeV, so it is consistent with experiment. There is still the possibility that the Higgs coupling is strong enough for creation through this mechanism at the present LHC. If not, the remaining predicted signature for collider detection is then $\sim$ 150 GeV of missing transverse energy resulting from vector boson fusion, which may be observable at future colliders~[1]. [1] Sabrina Hernandez et al., “Potential for discovery of a new dark matter WIMP at the High-Luminosity Large Hadron Collider or the Compact Linear Collider”, talk at this conference. [2] Reagan Thornberry, Gabriel Frohaug, Caden LaFontaine, Bailey Tallman, Alex Behne, Steven Sellers, Matthew Sadler, and Roland E. Allen, European Physical Journal Special Topics (in press). [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700