LBNL Physics Division Research Progress Meetings

J. Duarte (Caltech) "Naturalness Confronts Nature: Searches for Superparticles at CMS"
2015-11-10 16:00 - 17:00 (America/Los_Angeles)

Reserved (TBD)
2015-11-05 16:00 - 17:00 (America/Los_Angeles)

Ken Heller (Univ. Minnesota) "NOνA Begins – First Results from the NOvA Neutrino Oscillation Experiment"
2015-10-29 16:00 - 17:00 (America/Los_Angeles) | Zoom Talk, 50A-5132, Berkeley, ca, 94720
Abstract:
The NOνA long baseline neutrino oscillation experiment has just completed its initial data run and the analysis of that data. This run constitutes about 8% of the planned data. The first run resulted in a measurement of the oscillation of muon neutrinos into two modes. One the disappearance of muon neutrinos, the 2-3 oscillation, and the other the appearance of electron neutrinos, the 1-3 oscillation. In addition to describing the results and their impact on the neutrino mass ordering and CP violation, I will describe the construction and design of this unique 14 kiloton detector.

Simon Fiorucci (Brown Univ.) "The latest on the LUX dark matter experiment: How it got there, and where it is going"
2015-10-08 16:00 - 17:00 (America/Los_Angeles) | Zoom Talk, 50A-5132, Berkeley, ca, 94720
Abstract:
LUX has set the standard for direct dark matter detection experiments since its result announcement in 2013. In order to get there, several years of science planning and incremental successes had to happen. Today LUX serves a dual purpose:
– It is still the leading, currently operating experiment in the field. I will detail the strategy toward new exciting results in the near (and even immediate) future. I will also highlight those critical advances which have allowed LUX to keep its edge.
– It is a testbed and an incubator for the next generation of dark matter experiments, and specifically LZ. Aside from training up the next generation of physicists, there are extensive plans before the end of the experiment in 2016 which promise to yield very valuable data on detector technology options, calibration techniques and validity of simulation models. I will go over these and how they fit into both LUX and LZ strategies.

Zack Slepian (Harvard University) "The Baryon-Dark Matter Relative Velocity and a New Approach to the 3-Point Correlation Function"
2015-09-29 16:00 - 17:00 UTC
“The Baryon-Dark Matter Relative Velocity and a New Approach to the 3-Point Correlation Function”
Due to their different behaviors before decoupling (z~1020), at high redshift (z~50) there is a relative velocity between baryons and dark matter that is coherent on very large scales. If this relative velocity couples to galaxies today, it can shift the BAO peak in the galaxy-galaxy 2-point correlation function. Such a shift would systematically bias the expansion history inferred using the BAO method. I will give a configuration space picture of the relative velocity and show that the 3-point correlation function can be used to remove this systematic bias from the BAO method. I will then present a reformulation of the 3PCF that:

permits computing the 3PCF in N^2 not N^3 time, N the number of objects
allows analytic calculation of a highly accurate covariance matrix
gives perturbation theory predictions in excellent agreement with both mock catalogs and data

Using this approach on ~700,000 galaxies in SDSS DR12 constrains linear and non-linear bias and demonstrates a ~2.5 sigma BAO feature in the 3PCF. I’ll conclude with prospects for using this approach, and an analogous one for the anisotropic 2PCF, on DESI.

Special RPM - Yifang Wang (IHEP, China) "CEPC-SPPC: an initiative in China for the future of HEP"
2015-09-25 10:30 - 11:30 UTC | INPA Common Room (50-5026), 50-5026
Abstract:
Since the discovery of Higgs, the future of HEP is a key question to the community. Needless to say, accelerator-based energy frontier of HEP is still playing the central role, and a right approach is vital for the health of our field. We proposed in 2012 the following plan for the next several decades: a circular e+e- collider as a Higgs factory for the precision test of SM and search for hints beyond the SM, followed by a ~ 100 TeV proton collider in the same tunnel for direct searches. This is also a natural continuation of Beijing Electron-Positron Collider(BEPC) which will end its operation around 2022. Since then a preliminary design report for the accelerator, detector and civil construction is completed. I will report the status, progress and efforts towards a CDR and establishment of the international collaboration.

Miland Diwan (Brookhaven National Laboratory), "Challenges and Opportunities for a Long Baseline Neutrino Experiment "
2015-09-24 16:00 - 17:00 UTC
Title: Challenges and Opportunities for a Long Baseline Neutrino Experiment
Abstract: Neutrino mass and mixing is one of the few indications of new physics beyond the standard model, and new theoretical and experimental work is needed to understand neutrino properties and their role in the Universe as the most abundant particle of matter. I will briefly review the current state of understanding of neutrinos properties. I will then describe the current optimization for the Fermilab based LBNF/DUNE program focusing on most important technical challenges.

Benjamin Schmidt (KIT, Germany) "Background discrimination capabilities and recent results of the EDELWEISS-III direct dark matter search experiment"
2015-09-22 16:00 - 17:00 (America/Los_Angeles)
Abstract:
The EDELWEISS collaboration is operating a large set of 36 massive cryogenic Ge detectors for the direct detection of Weakly Interacting Massive Particles (WIMPs) in the underground laboratory of Modane, France (LSM). The twofold detector readout in ionization and phonons allows a discrimination between nuclear recoils from the scattering of neutrons or WIMPs and electron recoils from the scattering of γ- and β-particles. As part of the R&D for the current data taking in EDELWEISS-III a new data analysis framework has been developed and evaluated on a dedicated commissioning run. Results on the surface event rejection of the detectors with advanced electrode design (FID) from this data-set will be presented. WIMP search data taking has been ongoing since August 2014 and the latest results of a low mass WIMP analysis will be discussed.

Walter Hopkins - Using Direct Stop Searches at ATLAS to Constrain the Parameter Space of Supersymmetric Models
2015-09-01 16:00 - 17:00 (America/Los_Angeles)
Abstract:

A summary of the search for direct stop production in the 0-lepton channel is presented using 20 TeV data collected with the ATLAS experiment at the LHC. One of the stop decay modes considered is a stop decay to a top and a neutral lightest supersymmetric particle (LSP) resulting in signature with four or more jets and large missing energy. No excess is observed above the background expectation and limits are set on the stop and LSP masses and are presented as a function of stop decay branching fraction, combining the results from the 0 and 1-lepton channels. Additionally, the results are interpreted to confine the much larger parameters space of a more general supersymmetric model. Finally, outlook for stop searches for the LHC Run 2 will also be discussed.

Lifan Wang (Texas A&M)
2015-05-21 16:00 - 17:00 (America/Los_Angeles)
Title: The Latest Development of Optical/NIR Astronomy at Dome A, Antarctica
Abstract:
Dome A, the highest spot on Antarctic plateau is likely the best site for ground-based astronomy. I present in this talk an update on the recent progresses in building an astronomical observatory at Dome A. In the near term, the 68cm wide field Antarctic Survey Telescopes (AST3) will be collecting data that are continuous for more than 3 months during the Antarctic winter. A time-domain study in the NIR of supernovae and other transients will be enabled by an infrared version of AST3. We expect the AST3 data to be unique in terms of their time coverage. In the longer term, we expect to build one 2.5 meter optical/NIR telescope and one 5 meter THz telescope, and use these telescopes to discover supernova explosions at redshift far beyond what is possible with a conventional temperate telescope.

Jennifer Thomas (UCLA; Univ. of Wisconsin) " Cheap as CHIPS - Large Water Cherenkov Detectors: Faster and Cheaper"
2015-04-30 16:00 - 17:00 (America/Los_Angeles)
Title: Cheap as CHIPS – Large Water Cherenkov Detectors: Faster and Cheaper
Abstract:
CHIPS is an R&D program focused on designing and fabricating a cost-effective large water Cherenkov detector (WCD) to study neutrino oscillations. Traditional WCD’s with a low energy threshold have been built in special large underground caverns. Civil construction of such facilities is costly and the excavation phase significantly delays the detector installation although, in the end, it offers a well-shielded apparatus with versatile physics program. Following concepts developed for the LBNE WCD (arXiv:1204.2295), we propose to submerge a detector in a deep water reservoir, which avoids the excavation and exploits the directionality of an accelerator neutrino beam for optimizing the detector. Following the LOI (arXiv:1307.5918), we have submerged a small test detector in a mine pit in Minnesota, 7 mrad off NuMI axis. Borrowing technical ideas and solutions from IceCube and KM3Net, we are now focusing on designing a large (10-20kt) isolated water container to house photodetectors with underwater readout and triggering. We will describe the CHIPS concept and its physics potential in more detail, and will present the ongoing R&D activities.

Brian Hamilton (Univ. of Maryland) "New Results from LHCb"
2015-04-23 16:00 - 17:00 (America/Los_Angeles)
Title: New Results from LHCb
Abstract:
I will present several new results based on the full dataset collected by the LHCb detector during the 2011 and 2012 running periods. In particular, the first measurement from LHCb of the magnitude of the CKM matrix element Vub via semileptonic decays of the $Lambda_{b}$ baryon and its impact on contributions of right handed currents will be discussed. I will also present new results on the electroweak penguin decay $B to K^{*} mumu$ and the status of anomalies in this channel observed in the previous analysis which used a subset of the full data. Plans for the LHCb experiment during Run 2 of the LHC and beyond will also be discussed.
