Bulletin of the American Physical Society
2020 Annual Meeting of the APS Four Corners Section (Virtual)
Volume 65, Number 16
Friday–Saturday, October 23–24, 2020; Albuquerque, NM (Virtual)
Session J05: DM/HEP IILive
|
Hide Abstracts |
Chair: Jonathan Cornell, Weber State |
Saturday, October 24, 2020 8:00AM - 8:24AM Live |
J05.00001: Beyond the Standard Model Global Fits with GAMBIT Invited Speaker: Jonathan Cornell The wide range of probes of particle physics beyond the standard model (BSM) leads to the need for tools that combine experimental results to make robust statements about the validity of theories of new physics and the preferred regions of their parameter space. In this talk, I will describe the code we have built for such analyses: GAMBIT, the Global and Modular BSM Inference Tool. GAMBIT is a flexible and extensible framework for global fits of essentially any BSM theory. The code currently contains results from collider searches for new physics, cosmology, neutrino experiments, astrophysical and terrestrial dark matter searches, and precision measurements. I will give a brief introduction to the capabilities of the code and discuss some recent analyses that have been undertaken using it. [Preview Abstract] |
Saturday, October 24, 2020 8:24AM - 8:36AM Live |
J05.00002: Charge Collection in Irradiated 3D Silicon Sensors Adam Yanez, Martin Hoeferkamp, Sally Seidel A new type of particle detector is needed to withstand the high radiation environment at the High Luminosity Large Hadron Collider (HL-LHC). With the planned High Luminosity upgrade, 3D silicon sensors are expected to receive 10 to 20 times more radiation over their lifetime than before. This research examines how bulk damage produced by protons affects charge collection in these sensors. Sensors that exhibit controlled charge multiplication would be able to replace charge lost to radiation-induced traps. The signals they produce may lead to new discoveries in physics. Charge multiplication is measured by taking charge collection measurements of the sensors. Four different geometries of devices are examined, each subjected to varying levels of proton or gamma radiation. Charge collection rates will be measured using beta particles from a Sr-90 source that create electron-hole pairs in the sensor that can be collected. The charge collected can be compared to predicted values to determine whether charge multiplication is occurring. The goal for this project is to observe controlled charge multiplication in small-pitch 3D sensors irradiated with protons at fluences up to 3.0 x 10$^{\mathrm{16}}$ neq. [Preview Abstract] |
Saturday, October 24, 2020 8:36AM - 8:48AM Live |
J05.00003: Study of the rare decays of $B^0_s$ and $B^0$ mesons into muon pairs using data collected during 2015 and 2016 with the ATLAS detector Andrew Forbes A study of the decays $B^0_s \to \mu^+\mu^-$ and $B^0 \to \mu^+\mu^-$ has been performed using 26.3 fb$^{−1}$ of 13 TeV LHC proton-proton collision data collected with the ATLAS detector in 2015 and 2016. Since the detector resolution in $\mu^+\mu^-$ invariant mass is comparable to the $B_{s}^{0}-B^0$ mass difference, a single fit determines the signal yields for both decay modes. This results in a measurement of the branching fraction ${\cal B}(B^0_s \to \mu^+\mu^-) = \left( 3.2^{+1.1}_{-1.0} \right) \times 10^{-9}$ and an upper limit ${\cal B}(B^0 \to \mu^+\mu^-) < 4.3 \times 10^{-10}$ at 95% confidence level. The result is combined with the Run 1 ATLAS result, yielding ${\cal B}(B^0_s \to \mu^+\mu^-) = \left( 2.8^{+0.8}_{-0.7} \right) \times 10^{-9}$ and ${\cal B}(B^0 \to \mu^+\mu^-) < 2.1 \times 10^{-10}$ at 95\% confidence level. The combined result is consistent with the Standard Model prediction within 2.4 standard deviations. [Preview Abstract] |
Saturday, October 24, 2020 8:48AM - 9:00AM Live |
J05.00004: Measurement of the $\textbf{\emph{{CP}}}$-violating phase $\boldsymbol{\phi_s}$ in $\boldsymbol{B_s^0\rightarrow J/\psi\phi}$ decays in ATLAS at 13~TeV Easwar Anand Narayanan A measurement of the $B_s^0\rightarrow J/\psi\phi$ decay parameters using 80.5 $\mathrm{fb}^{-1}$ of integrated luminosity collected with the ATLAS detector from 13~TeV proton–proton collisions at the LHC is presented. The measured parameters include the $CP$-violating phase $\phi_s$, the width difference $\Delta\Gamma_s$ between the $B_s^0$ meson mass eigenstates and the average decay width $\Gamma_s$. The values measured for the physical parameters are combined with those from 19.2~$\mathrm{fb}^{-1}$ of 7 TeV and 8 TeV data, leading to the following: \\ \begin{center} \begin{equation*} \begin{matrix} \phi_s &= &-0.087 &\pm& 0.036~(\mathrm{stat.})&\pm &0.019~(\mathrm{syst.})~\mathrm{rad}\\ \Delta\Gamma_s &= &0.0641&\pm&0.0043~(\mathrm{stat.})&\pm &0.0024~(\mathrm{syst.})~\mathrm{ps}^{-1}\\ \Gamma_s &= &0.6697&\pm&0.0014~(\mathrm{stat.})&\pm &0.0015~(\mathrm{syst.})~\mathrm{ps}^{-1} \end{matrix} \end{equation*} \end{center} Results for $\phi_s$ and $\Delta\Gamma_s$ are also presented as 68\% confidence level contours in the $\phi_s-\Delta\Gamma_s$ plane. Furthermore the transversity amplitudes and corresponding strong phases are measured. $\phi_s$ and $\Delta\Gamma_s$ measurements are in agreement with the Standard Model predictions. [Preview Abstract] |
Saturday, October 24, 2020 9:00AM - 9:12AM |
J05.00005: Hunting for Scalar Lepton Partners at Future $e^+e^-$ Colliders Pearl Sandick, Sebastian Baum, Patrick Stengel New physics close to the electroweak scale is well motivated by a number of theoretical arguments. However, colliders, most notably the Large Hadron Collider (LHC), have failed to deliver evidence for physics beyond the Standard Model. While it is possible that the scale of new physics is beyond the reach of the LHC, it is also possible that new electroweak-scale particles are lurking in a blind spot of the LHC. Prime examples of models that could have thus far gone undetected include those where the new states are charged only under electromagnetism and not under the strong force. Future $e^+e^−$ colliders are prime tools to study such new physics. In this talk I will discuss the sensitivity of $e^+e^−$ colliders to scalar partners of the charged leptons, known as sleptons in supersymmetric extensions of the Standard Model. In order to allow such scalar lepton partners to decay, we consider models with an additional neutral fermion, which may also play the role of dark matter. A future lepton collider would be capable of directly (and immediately) discovering many of these promising new physics scenarios. [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