BEGIN:VCALENDAR VERSION:2.0 PRODID:-//LBNL Physics Division Research Progress Meetings - ECPv6.8.3//NONSGML v1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:LBNL Physics Division Research Progress Meetings X-ORIGINAL-URL:https://rpm.physics.lbl.gov X-WR-CALDESC:Events for LBNL Physics Division Research Progress Meetings REFRESH-INTERVAL;VALUE=DURATION:PT1H X-Robots-Tag:noindex X-PUBLISHED-TTL:PT1H BEGIN:VTIMEZONE TZID:America/Los_Angeles BEGIN:DAYLIGHT TZOFFSETFROM:-0800 TZOFFSETTO:-0700 TZNAME:PDT DTSTART:20170312T100000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0700 TZOFFSETTO:-0800 TZNAME:PST DTSTART:20171105T090000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20170103T160000 DTEND;TZID=America/Los_Angeles:20170103T170000 DTSTAMP:20260423T135309 CREATED:20161201T111459Z LAST-MODIFIED:20161201T111459Z UID:408-1483459200-1483462800@rpm.physics.lbl.gov SUMMARY:Zackay Barak (Weizmann Institute of Science) Algorithms for searching Fast radio bursts\, pulsars in tight binary systems and "Planet 9" DESCRIPTION:Abstract:\nFast radio bursts (FRB’s) are an exciting\, recently discovered\, astrophysical transients which their origins are unknown.\nCurrently\, these bursts are believed to be coming from cosmological distances\, potentially allowing us to probe the electron content on cosmological length scales. Even though their precise localization is crucial for the determination of their origin\, radio interferometers were not extensively employed in searching for them due to computational limitations.\nI will briefly present the Fast Dispersion Measure Transform (FDMT) algorithm\, allowing to reduce the operation count in blind incoherent dedispersion by 2-3 orders of magnitude.\nIn addition\, FDMT enables to probe the unexplored domain of sub-microsecond astrophysical pulses.Pulsars in tight binary systems are among the most important astrophysical objects as they provide us our best tests of general relativity in the strong field regime.\nI will provide a preview to a novel algorithm that enables the detection of pulsars in short binary systems using observation times longer than an orbital period.\nCurrent pulsar search programs limit their searches for integration times shorter than a few percents of the orbital period.\nUntil now\, searching for pulsars in binary systems using observation times longer than an orbital period was considered impossible as one has to blindly enumerate all options for the Keplerian parameters\, the pulsar rotation period\, and the unknown DM.\nUsing the current state of the art pulsar search techniques and all computers on the earth\, such an enumeration would take longer than a Hubble time. I will demonstrate that using the new algorithm\, (called Pruning) it is possible to conduct such an enumeration on a laptop using real data of the double pulsar\, PSR J0737-3039.\nAmong the other (astronomical) applications of the Pruning technique are:\n1) Searching for all pulsars on all sky positions in gamma ray observations of the Fermi LAT satellite.\n2) Blind searching for continuous gravitational wave sources emitted by pulsars with non-axis-symmetric matter distribution.\n\n3) Blind searching for planets in the outskirts of the solar system (AKA “Planet 9”)\, both in imaging data and on GAIA data (through astrometric deflection of background stars).\n \n4) Blind searching for asteroids and Kuiper belt objects in imaging data.\n \n5) Searching for stars in close orbits around the super massive black hole in the galactic center. \n\n\nPrevious attempts to conduct all of the above searches (if even considered) contained substantial sensitivity compromises. URL:https://rpm.physics.lbl.gov/event/zackay-barak-weizmann-institute-of-science-tba/ END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20170105T160000 DTEND;TZID=America/Los_Angeles:20170105T170000 DTSTAMP:20260423T135309 CREATED:20161201T111552Z LAST-MODIFIED:20161201T111552Z UID:410-1483632000-1483635600@rpm.physics.lbl.gov SUMMARY:Eleonora Di Valentino (Institut d'Astrophysique de Paris) "New Constraints on Extensions of the Standard Cosmological Model" DESCRIPTION:Abstract:\nThe Cosmic Microwave Background (CMB) temperature and polarization anisotropy measurements from the Planck mission have significantly improved previous constraints on the neutrino masses\, as well as the bounds on extended models with massive sterile neutrino states or extra particles\, as for example thermal axions. In this talk firstly I will show the recent constraints from cosmology for the thermal axion mass and the neutrino sector\, by considering several combination of datasets and scenarios. In particular\, I will show how the inclusion of additional low redshift priors is mandatory in order to sharpen the CMB neutrino bounds\, and that we are close to test the neutrino mass hierarchy with existing cosmological probes. Secondly\, I will discuss how these constraints can change by taking into account the possibility that the primordial power spectrum could assume a more general shape than the usual power law description. Finally\, I will present cosmological constraints in a significantly extended scenario\, varying up to 12 cosmological parameters simultaneously\, by looking for a new concordance model that should solve at the same time all the current tensions between the Planck data and the new direct measurements of the Hubble constant by Riess et al. 2016 and the parameters from weak lensing surveys\, such as CFHTLenS and KiDS-450. URL:https://rpm.physics.lbl.gov/event/eleonora-di-valentino-institut-dastrophysique-de-paris-tba/ LOCATION:Zoom Talk\, 50A-5132\, Berkeley\, ca\, 94720 END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20170110T160000 DTEND;TZID=America/Los_Angeles:20170110T170000 DTSTAMP:20260423T135309 CREATED:20160919T162238Z LAST-MODIFIED:20160919T162238Z UID:323-1484064000-1484067600@rpm.physics.lbl.gov SUMMARY:Michael James Wilson (Institute of Astronomy\, U. Edinburgh) "Extracting precision tests of gravity from the intricate pattern of galaxies" DESCRIPTION:ABSTRACT:\nGalaxy redshift surveys deliver increasingly precise tests of gravity on cosmological scales and shed light on the uncertain nature of Dark Energy. I will present the VIPERS (http://vipers.inaf.it) census of the galaxy distribution at redshift 0.8 and describe its consistency with the expansion history and rate of gravitational collapse predicted by General Relativity and a Planck (2015) cosmology. This is facilitated by the anisotropy of the observed clustering\, which is sensitive to both the coherent infall of galaxies towards clusters and the assumption of an expansion history differing from the true one.\nI will then present the results of including a simple density transform prior to this conventional analysis\, which suppresses the most massive structures and extends the validity of the simplest models. Moreover\, this has been shown to amplify signatures of modified gravity in ‘shielded’ theories and contains information beyond that available to the power spectrum. To do so requires correcting for many systematics that are characteristic of high-redshift surveys. I will describe the properties common to VIPERS\, eBOSS and DESI and the potential of a density-weighted analysis with these next-generation surveys.\nFinally\, tests of gravity have predominantly focused on the large-scale velocities of galaxies to date\, but that of clusters is imprinted on the Cosmic Microwave Background by the kinetic Sunyaev-Zel’dovich effect. The Simons Observatory and CMB-S4 experiments represent ideal test-beds for exploring the latter. I will discuss this and other future avenues for revealing the properties of Dark Energy with large-scale structure. URL:https://rpm.physics.lbl.gov/event/reserved-25/ LOCATION:50A-4133 (Director's Conference Room) END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20170112T160000 DTEND;TZID=America/Los_Angeles:20170112T170000 DTSTAMP:20260423T135309 CREATED:20161201T111821Z LAST-MODIFIED:20161201T111821Z UID:414-1484236800-1484240400@rpm.physics.lbl.gov SUMMARY:Siyuan Sun (Harvard) "Gaining Sensitivity to New Physics with a Compressed Mass Spectra at the ATLAS Experiment" DESCRIPTION:ABSTRACT\nThe ATLAS experiment at Large Hadron Collider (LHC) searches for experimental ev-\nidence of many new beyond the standard model physics at the TeV scale. As we collect\nmore data at the LHC we continue to extend our sensitivity to these new phenomenon\,\nparticularly probing increasingly more massive new particles. Despite this progress there\nare still regions of parameter space where constraints remain weak. One common cause of\nthis lack of sensitivity is because the new particle has a very small mass splitting between it\nand its decay products. The particle then has little energy left over to give momenta to its\ndecay products and the low momenta decay products are difficult to experimentally detect.\nThese regions of small mass splitting are called compressed regions. We are able to gain\nsensitivity to these difficult regions by searching for new particles produced in conjunction\nwith strong initial state radiation (ISR). The strong initial state radiation boosts the new\nparticle’s decay products and gives them momentum.\nIn this seminar\, I will cover in detail the search for the supersymmetric partner to the\ntop quark (stop) in the region when the stop and its decay products are nearly degenerate in\nmass. No searches prior to 2016 was sensitive to this region. We were able to exclude stops\nup to a mass of 425 GeV in this region with the 2015 and summer 2016 ATLAS dataset. I will\ndemonstrate a new and more accurate technique for identifying whole initial state radiation\nsystems instead of a single ISR jet. As the LHC provides more data and traditional search\nmethods rule out parameter space at higher masses\, it becomes more important that we also\ngain sensitivity to these compressed regions that are still unconstrained at low masses. I will\nshow that this initial state radiation identification technique is completely generalizable and\nuseful for many other searches that target small mass splittings. URL:https://rpm.physics.lbl.gov/event/siyuan-sun-harvard-tba/ LOCATION:Zoom Talk\, 50A-5132\, Berkeley\, ca\, 94720 END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20170117T160000 DTEND;TZID=America/Los_Angeles:20170117T170000 DTSTAMP:20260423T135309 CREATED:20160919T162406Z LAST-MODIFIED:20160919T162406Z UID:325-1484668800-1484672400@rpm.physics.lbl.gov SUMMARY:Aleksandra Dimitrievska (U. Belgrade) "Measurement of the W-boson mass with the ATLAS detector " DESCRIPTION:Abstract:\nThe precise measurements of the W boson\, the Higgs boson and the top quark masses enables to test the consistency of the Standard Model. Constraints on physics beyond the Standard Model are currently limited by the precision of the W-boson mass measurement. In this talk a measurement of the W-boson mass is presented with the data collected in 2011 at centre-of-mass energy of 7 TeV with the ALTAS detector corresponding to an integrated luminosity of 4.6 fb⁻¹. The measurement is based on about 8 and 6 million W candidates in the muon and electron channels\, respectively. The W-boson mass is extracted from the template fits to the transverse momentum of the charged lepton and to the transverse mass of the W boson distributions. This measurement yields a W-boson mass:\nmW = 80370 ± 7 (stat.) ± 11 (exp. syst.) ± 14 (mod. syst.) MeV = 80370 ± 19 MeV\,\nwhere the first uncertainty is statistical\, the second corresponds to the experimental systematic uncertainty\, and the third to the physics-modelling systematic uncertainty. URL:https://rpm.physics.lbl.gov/event/reserved-26/ END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20170119T160000 DTEND;TZID=America/Los_Angeles:20170119T170000 DTSTAMP:20260423T135309 CREATED:20160922T155941Z LAST-MODIFIED:20160922T155941Z UID:329-1484841600-1484845200@rpm.physics.lbl.gov SUMMARY:Kirit Karkare (Harvard) "B-Mode Polarization Results from BICEP/Keck Array and Beam Systematics in Current and Next-Generation CMB Experiments" DESCRIPTION:Abstract:\nThe BICEP/Keck Array cosmic microwave background (CMB) polarization experiments located at the South Pole are a series of small-aperture refracting telescopes focused on the degree-scale B-mode signature of inflationary gravitational waves.  I will present our latest results which have produced the most stringent constraints on the tensor-to-scalar ratio to date: sigma(r) = 0.024 and r < 0.09 from B-modes alone (r < 0.07 in combination with other datasets).  These constraints will rapidly improve with upcoming measurements at the multiple frequencies needed to separate Galactic foregrounds from the CMB\, and in combination with higher-resolution experiments to remove B-modes induced by gravitational lensing.  I will provide an update on our expanded frequency coverage and plans for future receivers.\nNext-generation CMB experiments with hundreds of thousands of detectors will require exquisite control of instrumental systematics.  I will review key aspects of the BICEP/Keck instrument design which maximize polarization sensitivity and reduce systematics at large angular scales\, including the ability to measure beams in the far field with high precision.  Finally\, I will discuss the prospects for dealing with temperature-to-polarization leakage in future experiments\, and how the beams systematics levels we achieve with current instrument and analysis technology will scale with detector count. URL:https://rpm.physics.lbl.gov/event/reserved-27/ END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20170124T160000 DTEND;TZID=America/Los_Angeles:20170124T170000 DTSTAMP:20260423T135309 CREATED:20160922T160019Z LAST-MODIFIED:20160922T160019Z UID:331-1485273600-1485277200@rpm.physics.lbl.gov SUMMARY:Reserved DESCRIPTION: URL:https://rpm.physics.lbl.gov/event/reserved-28/ LOCATION:Zoom Talk\, 50A-5132\, Berkeley\, ca\, 94720 END:VEVENT BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20170126T160000 DTEND;TZID=America/Los_Angeles:20170126T170000 DTSTAMP:20260423T135309 CREATED:20160922T160109Z LAST-MODIFIED:20160922T160109Z UID:333-1485446400-1485450000@rpm.physics.lbl.gov SUMMARY:Reserved DESCRIPTION: URL:https://rpm.physics.lbl.gov/event/reserved-29/ LOCATION:Zoom Talk\, 50A-5132\, Berkeley\, ca\, 94720 END:VEVENT END:VCALENDAR