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Novell trigger strategies for HL-LHC in ATLAS
No full textThe ATLAS experiment at CERN is constructing upgraded system for the "High Luminosity LHC", with collisions due to start in 2029. In order to deliver an order of magnitude more data than previous LHC runs, 14 TeV protons will collide with an instantaneous luminosity of up to 7.5 x 10e34 cm^-2s^-1, resulting in much higher pileup and data rates than the current experiment was designed to handle. While this is essential to realise the physics programme, it presents a huge challenge for the detector, trigger, data acquisition and computing. The detector upgrades themselves also present new requirements and opportunities for the trigger and data acquisition system. The design of the TDAQ upgrade comprises: a hardware-based low-latency real-time Trigger operating at 40 MHz, Data Acquisition which combines custom readout with commodity hardware and networking to deal with 4.6 TB/s input, and an Event Filter running at 1 MHz which combines offline-like algorithms on a large commodity compute service with the potential to be augmented by commercial accelerators . Commodity servers and networks are used as far as possible, with custom ATCA boards, high speed links and powerful FPGAs deployed in the low-latency parts of the system. Offline-style clustering and jet-finding in FPGAs, and accelerated track reconstruction are designed to combat pileup in the Trigger and Event Filter respectively. This contribution will report recent progress on the design, technology and construction of the system. Highlighting novel trigger signatures which this system will be able to exploi
Thermal design of an ejector-supported cycle using krypton for cooling of particle detector accelerators
No full textAccording to the High-Luminosity plan (HL-LHC) the Large Hadron Collider will be upgraded to further extend physics discoveries (2033–2034). The increase of the luminosity is followed by an increase of the radiation damage on the silicon sensors used to detect those particles, which they must be preserved from the thermal runaway after which the sensors reach electrical breakdown. The future upgrade will require to the cooling system temperature levels ranging from -60 to -80 °C, currently unattainable by the CO2 cooling technology (2PACL). From a previous study the noble gas krypton was selected for the thermal management of future detectors as working medium. To meet the requirements of the new generation of particle accelerators, a new ejector-supported cooling system was proposed.
In this work, thermal design of the innovative ejector cycle was carried out starting from the detector. The semi-passive detector loop was first designed to ensure optimal working conditions of the detector. Liquid krypton is supplied to the detector by the ejector, maintaining a constant pressure lift independently of the operating temperature, with a flow variation not exceeding 4.3 % of the design value. The boundary conditions expressed by pressure, density and flow rates will serve as inputs for the design of the adjustable geometry ejector. To verify the thermal stability along the detectors, development of a control strategy to handle setpoint changes and sudden change in the cooling power is also addressed. The off-design case with fluctuating heat loads shows an offset in the evaporating temperature below 0.3 K
Probing flavor effects in QCD showers with heavy-flavor jets
No full textMeasurements of jet substructure provide precise tests of Quantum Chromodynamics (QCD) and offer a distinct way to study hadronization mechanisms, compared to measurements of hadrons alone. QCD predicts that jet radiation patterns depend on the mass and color charge of the initiating parton. Parton showers, in particular, are sensitive to the Casimir factors of quarks and gluons, as well as the parton mass due to the dead-cone effect. Three key charm-tagged jet measurements from the ALICE experiment are discussed
BSM: Extended Scalar Sectors
No full textIn particle physics the world is described by a function, the Lagrangian. Each of its sectors characterizes the interactions between the particles of the Standard Model (SM). The addition of hypothetical new particles is done by including new terms in the Lagrangian. The scalar or Higgs sector of the SM is built with only one scalar complex field and it is extended by including new spin zero fields. This can help to solve questions that cannot be answered by the SM alone, like introducing dark matter candidates or new sources of CP-violation required to explain the matter-antimatter asymmetry of the universe. The corresponding theories have to be probed experimentally. For the high energy region, the standard tools are collider experiments such as the Large Hadron Collider, or other possible future facilities. Dark matter experiments scrutinize the connection between the visible and the dark world
Visit by Mr Juozas Olekas, First Deputy Speaker of the Parliament, Lithuania
No full textVisit by Mr Juozas Olekas, First Deputy Speaker of the Parliament, Republic of Lithuani
Centre for Dark Matter IdeaSquare Planet programme
No full textCentre for Dark Matter and Swinburne University of Technology participants had the chance to observe and interact with other student teams and attend different masterclasses: from value proposition design to prototyping and science communication. In their second week, they embarked on a thought-experiment, lifting their lenses from Earth and travelling to an Earth-like exoplanet to envision how a society might function there. They focused on the survival phase at landing. By making order-of-magnitude calculations and systemic impact assessments, they were able to look at societal systems in a holistic and comprehensive manner. This perspective allowed them to consider possible ripple effects or unintended consequences of their actions and ideas. They also visited CERN facilities such as the AMS, a CERN experiment looking for dark matter, antimatter and missing matter from a module on the International Space Station
