We are the lattice gauge theory group at the Eotvos University in Budapest, part of the Department of Theoretical Physics at the Faculty of Science. Since 2011 we are an NVIDIA GPU Research Center.

Currently there are nine members and we are seeking new ones. Positions are available for PhD students and postdocs for 2 - 4 years appointments. If you are interested please email Sandor Katz at katz {at} bodri {dot} elte {dot} hu or Daniel Nogradi at nogradi {at} bodri {dot} elte {dot} hu.

Our activities are and were funded by various funding agencies for which we are grateful, these include the Lendulet grant of the Hungarian Academy of Sciences, the OTKA-NF-104034 grant of OTKA and the EU Framework Programme 7 grant (FP7/2007-2013)/ERC No 208740.

Our primary interests are:

• Chiral symmetry restoration and deconfinement in QCD with Wilson fermions
• Finite chemical potential
• QCD hadron spectrum
• Eigenvalue distributions of the overlap Dirac operator
• Strongly interacting Higgs sector - strong dynamics
• Conformal gauge theories

Weekly seminars of the Department of Theoretical Physics

Location: 2nd floor, 2.54, Novobatzky room

Time: Wednesdays at 14:15

See the archive for seminars in past years.

• 12 September 2018, Zsolt Frei (ELTE)

  The road to the detection of gravitational waves, and ELTE's contribution to the quest

  I will briefly summarise what we all know by now about gravitational waves (GW) as a prediction of general relativity, the history of searching for the waves, and some technical details of the Laser Interferometer Gravitational-wave Observatory (LIGO), where the group I formed participated since 2007.

  I will tell you about our contribution to the data search: we have been an active member of the so-called "burst" group, where we are searching for transient-type signals in the noisy data stream of the detector. We have came up with two new search methods, the "Locust" and "Hough" algorithms. We also contributed to the experiment by developing, making and installing infrasound detectors at both the Hanford and Livingston sites. These detectors are increasingly important to measure the srength of gravity gradient noise, so I will spend some time to elaborate on this topic. Lately, we are also contributing to the identification of possible electromagnetic (EM) counterparts of the newly detected GW sources: binary neutron stars. We have developed a new galaxy catalog for LIGO, containing 2.5 million galaxies (compared to the 50.000 galaxies in the catalog LIGO used before). Some of our partners actually found the EM counterparts of the 2018 August event using our data.

  I will conclude with our current work and plans for the future: launching 9 small satellites to low-Earth orbit within the next 5 years to detect gamma-rays originating from binary neutron star merges and using these detections to precisely and promptly locate (triangulate) the position of the sources of the emerging GWs on the sky for subsequent EM observations.

• 19 September 2018, Ankita Mehta (ELTE)

  Study of double-parton scattering processes using same-sign WW events at the CMS experiment

  Double-parton scattering (DPS) processes include the simultaneous occurrence of two distinct hard parton-parton interactions within in a single proton-proton collision. These interesting physics processes could provide valuable information on the distribution of partons inside the proton in the transverse direction and act as a background for SM and new physics searches at the LHC. This presentation is based on the results obtained from the first search for same-sign WW production via DPS processes, based on proton-proton collision data at a center-of-mass energy of 8 TeV. The decay of two W bosons is considered in dimuon and electron-muon final states. A multivariate analysis is used to discriminate the single from different background processes. Obtained results on the production cross section for same-sign WW via DPS and effective cross section parameter for DPS processes are compared with existing measurements and predictions from MC event generators.

• 26 September 2018, Attila Pasztor (ELTE)

  TBA

• 3 October 2018, Keming Shen (Wigner-MTA)

  TBA

  TBA

• 10 October 2018, Zoltan Kokenyesi (ELTE)

  TBA

  TBA

• 17 October 2018, Zoltan Trocsanyi (ELTE)

  TBA

  TBA

• 31 October 2018, Dezso Horvath (Wigner-MTA, Atomki Debrecen)

  Recent results in Higgs studies and BSM searches at the LHC

  The almost half-century old theory of particle physics, the standard model (SM) seems to describe most of the experimental data very well. All of its elementary particles were identified and studied, and the discovery of the Higgs boson by ATLAS and CMS at the LHC with the mass m(H) = 125.09 +/- 0.21 (stat.) +/- 0.11 (syst.) GeV proved the validity of the Brout-Englert-Higgs mechanism of spontaneous symmetry breaking. In spite of the general quantitative agreement of its predictions with experiment the SM has serious theoretical shortcomings. It cannot account for neutrino oscillations, cannot solve the hierarchy problem (the unnaturally high corrections to the mass of the Higgs boson), there is no place in it for the particles of dark matter, and it cannot explain the lack of antimatter galaxies in the universe. Its gauge couplings are converging but not to the same point at high energies and it cannot include gravity as a gauge interaction. Most of these problems are solved within the frameworks of SM extensions, the most popular of them being supersymmetry. The latter predicts several deviations from the SM, especially in the Higgs sector, where it expects 5 Higgs bosons, three neutral and two charged ones.

  Studying the observed Higgs boson may uncover new physics beyond the SM, and thus it is one of the most important programs for the experiments of the Large Hadron Collider. We summarize the activity of CMS and also ATLAS to measure the mass and couplings of the 125 GeV Higgs boson, its decay properties as compared to the SM predictions, and also attempts to check for other Higgs bosons at different masses. Thus far all data collected by ATLAS and CMS agree with the SM, no deviation is found. Great effort is invested by both experiments to study extensions of the standard model and possibly uncover physics beyond it. We shall describe the history of an aborted discovery: a new boson at 750 GeV. Thus the question what new physics is beyond the SM is open yet.

  The talk is based on a plenary given on behalf of CMS at the QCD at LHC 2018 Workshop, 27-31 August 2018, Dresden (Germany).

• 7 November 2018, Vladimir Korobov (Dubna)

  TBA

  TBA

• 14 November 2018

  No seminar because of CERN25 event of the Academy

• 21 November 2018, Stefan Teufel (Tubingen)

  TBA

  TBA

• 28 November 2018, Peter Posfay (Wigner-MTA)

  TBA

  TBA

• 5 December 2018

  No seminar because of Zimanyi School

• 12 December 2018, Gabor Biro (Wigner-MTA)

  TBA

  TBA

Our group offers TDK, diploma and PhD topics in Lattice Field Theory.

Please contact Sandor: katz {at} bodri {dot} elte {dot} hu
or Daniel: nogradi {at} bodri {dot} elte {dot} hu
in case you are interested.

Current topics include:

• QCD thermodynamics
• SU(N) gauge theory with topological lattice action
• O(3) non-linear sigma model with topological term
• Beyond Standard Model - technicolor

Since it is tricky to locate all papers by a large number of people whose names are not unique on inspire, you can try various search queries:

• Papers by Sandor Katz and Zoltan Fodor
• Papers by Sandor Katz and Gergely Endrodi
• Papers by Sandor Katz and Matteo Giordano
• Papers by Daniel Nogradi

Our group has access to a number of high performance computer installations in Europe and also maintains several PC and GPU clusters on site in Budapest.

Our primary resource is a 128 node cluster with two NVIDIA GTX 275 cards in each node, hosted in Budapest. There is also a 60 node cluster with one NVIDIA GTX 8800 card per node.

In addition we also have access to the Juropa cluster and the BlueGene/P installation in Forschungszentrum Juelich, Germany.

Our collaboriation with the University of Wuppertal, Germany also allows us to use several PC and GPU clusters there.

You will most likely stay at the Peregrinus hotel in the downtown area of Pest.

The simplest way to get to/from your hotel from/to the airport is by taxi. The fare should be around 30 euros. Uber also works in Budapest :)

Our department is on the Buda side of the Danube very close to the Petofi Bridge and it is about a 30-35 minutes walk from the hotel:

You exit your hotel, walk past the Great Market Hall (definitely worth a closer look if you have about half an hour or an hour!) and the Corvinus University, cross the Danube on the Szabadsag Bridge and walk South. You will pass the Budapest University of Technology and the Petofi Bridge and our building will be a redish seven-story building on the right. The Department of Theoretical Physics is on the first floor on the Danube facing side of the building: