Navigation auf



Experimental Particle and Astro-Particle Physics Seminar

Monday 14:30

UZH Y16 G05 - Irchel Campus, CERN 42-R-407


Join via Vidyo: Join via phone: Join by H.323:
Connect to room and PIN 8057. Use these phone numbers with meeting extension 10501582 and PIN 8057. Use the gateway at, meeting extension 112757289656, PIN 8057.

Current Program - Spring 2016






22 February Pasquale Musella - ETH The diphoton excess at 750 GeV
The search for diphoton resonances in proton-proton collisions provides a very clean probe of physics beyond the Standard Model. In this seminar, the recent results on the search for high mass diphoton resonances from the CMS and ATLAS experiments at the CERN LHC will be presented. The appearance of a moderate excess of events consistent with a new resonance with a mass of roughly 750GeV in the results of both collaborations recently attracted the attention of the high energy physics community. The experimental techniques used in the analyses will be discussed in details and all the available information will be reviewed.
Talk F. Canelli
29 February Antonio Augusto Alves - University of Cincinnati Mulitquark States in LHCb
The quarkonia spectroscopy has recently got a renewed interest due to the discovery of several missing states and numerous unexpected quarkonium-like resonances. These studies were performed at Charm and Beauty factories, at Tevatron and more recently at the LHC experiments. While the conventional q anti-q states are well described by phenomenological potential models, many of the newly discovered quarkonium-like mesons do not seem to fit into the q anti-q conventional spectrum. There is an increasing evidence that some of these new states are "exotic", that means new forms of hadronic matter such as mesonic molecules, tetraquarks or pentaquarks, hybrid mesons and also hadroquarkonium. In this seminar the recent activities of the LHCb experiment in this field are described together with the outlook for Run II of the LHC. The very recent results on Pc(4450) and Pc(4380) pentaquarks and Z(4430) tetraquark will be discussed in details.
Talk B. Mangano
7 March Heather Gray - CERN Track reconstruction in the ATLAS experiment
During a typical crossing of protons beams at the LHC, up to 40 proton-proton collisions produce hundreds to thousands of charged particles traversing the inner part of the ATLAS detector. The formation of the trajectories of these charged particles plays a crucial role in extracting the physics from these collisions and is one of the main building blocks in the reconstruction of more complex objects. I will briefly review the algorithms used to reconstruct charged particles in the inner part of the ATLAS detector and their performance including early results using the recent sqrt(s)=13 TeV collision data collected during the first year of Run-2 of the LHC. I will describe some of the main challenges faced in data-taking conditions and the developments made to address them. I will discuss how tracking has come to play an increasingly central role in reconstruction, particularly in its use to mitigate effects from pile up and in extracting details of structure within reconstructed objects — for example studies of sub-structure within jets. I will also highlight selected key physics results that depend critically on the performance of track reconstruction algorithms. I will finally provide some comments towards the future upgrade of the inner tracking detector for run-3 of the LHC, with an expected ~200 proton-proton collisions per bunch crossing.
Talk F. Canelli
9 March
Y36 K52
Bernhard Schwingenheuer - MPIK Heidelberg Neutrinoless double beta decay searches with 76-Ge
The search for neutrinoless double beta decay might be the only window to observe lepton number violation and to establish the nature of neutrinos. Historically, the isotope 76Ge has played an important role in this search and currently the ongoing GERDA experiment has the lowest background if normalized to the region of interest. The status of the field and the prospects of a new initiative for a future Ge-76 experiment is presented.
Talk L. Baudis
14 March Michael Williams - MIT Proton Structure and Searches for Low-Mass BSM at LHCb
The LHCb experiment located at the LHC at CERN is the world's premier flavor-physics laboratory. Beyond this, its unique kinematic coverage and detector capabilities also make LHCb an excellent lab for studying proton structure, and for searching for low-mass beyond the Standard Model (BSM) particles. This talk will present proton-structure studies with a focus on final states involving charm and beauty jets (including top). Searches for low-mass BSM particles, e.g., hidden-sector bosons that mix with the Higgs sector and dark photons, will also be covered. In each case, Run 1 results will be shown and future potential discussed.
Talk N. Serra
16 March
Y36 K52
Marco Drewes - Technische University Munich Heavy neutrinos in particle physics and cosmology
Neutrinos are the only particles that appear only with left handed chirality in the Standard Model of particle physics. If right handed neutrinos exist, they would not only explain the observed neutrino oscillations, but could also be responsible for several phenomena in cosmology, including the baryon asymmetry of the universe, dark matter and dark radiation. A crucial parameter in this context is their Majorana mass, which in principle could have any value between the eV scale and the scale of grand unification. The implications for experiments and cosmology strongly depend on the choice of this mass scale. We discuss recent progress in the phenomenology of heavy neutrinos with different masses, focusing on scenarios in which the mass is within reach of existing or planned collider experiments.
Talk N. Serra
21 March Simon Eidelmann - Budker Institute and Novosibirsk State University Recent results on e+e- -> hadrons and their implications for muon g-2
Two detectors, CMD-3 and SND, collected about 60/pb each running in 2011-2013 in the center-of-mass energy range 320-2000 MeV at the VEPP-2000 collider in Novosibirsk. We report their results on e+e- annihilation into various hadronic final states as well as recent low-energy e+e- results from other colliders and discuss their physical implications for muon g-2
Talk G. Isidori/N. Serra
4 April Annapaola de Cosa - UZH Dark Matter at the LHC Talk F. Canelli
11 April Antonello Polosa - University of Rome "La Sapienza" Multiquark Hadron Spectroscopy
I will introduce the topic of exotic hadron spectroscopy through experimental facts and theoretical interpretations. The proliferation of X, Y, Z resonances, the very recent discovery of pentaquark states and the existence of seemingly contradictory pictures to explain their nature, reflect the ignorance about the exact solutions of non-perturbative QCD. I will mostly concentrate on theoretical open questions and solutions proposed.
Talk G. Isidori
13 April
Y36 J33
Rahul Sinha - Institute of Mathematical Science - Taramani (India) Signal of right-handed currents using $B\to K^*\ell^+\ell^-$ observables at the kinematic endpoint
The decay mode $B\to K^*\ell^+\ell^-$ is one of the most promising modes to probe physics beyond the standard model (SM), since the angula\ r distribution of the decay products enable measurement of several constraining observables. LHCb has recently measured these observables \ using $3fb^{-1}$ of data. We show that LHCb data implies a signal for new physics and provides unambiguous evidence for right-handed currents.
Talk N. Serra/G. Isidori
25 April Christopher Betancourt - UZH Radiation Damage in Silicon Detectors
Silicon detectors are essential components of many high energy physics experiments. They provide the primary means of momentum measurements of charged particles in experiments such as ATLAS and CMS. A main concern of such sensors is signal loss due to radiation damage, stemming from the high particle fluxes near the collision point. We discuss the mechanisms of radiation damage in silicon, and then move towards different detector designs aimed at mitigating the effect of radiation damage on silicon sensors.
Talk N. Serra
2 May   tbd Talk  
9 May Florian Bernlochner - Universitaet Bonn Flavour anomalies and Belle II's impact on the physics landscape Particle physics research is carried out at several complementary frontiers: the intensity frontier uses intense particle beams to search for signs of new physics beyond the Standard Model of particle physics in deviations from high precision observables. The precision study of decays of bound states involving heavy third generation b-quark probes an integral part of the Standard Model. In recent years a range of persistent anomalies showed up, which produced speculations if such are the first sign of emergence of new physics: for example semi-tauonic B-meson decay rates into ground state charmed mesons seem enhanced over the SM expectation and angular distributions in electroweak penguins show an unexpected behaviour. I review a range of ongoing analyses in Bonn that address some of these questions using data from the Belle experiment and discuss some of the challenges these measurements face. In addition I will try to review the status of the Belle II experiment and close up with a review the Belle II physics program in light of the success of LHCb. Talk D. van Dyk/N. Serra
23 May Michael Kramer - RWTH Aachen A global fit of the gamma-ray galactic center excess within the scalar singlet Higgs portal model We analyse the excess in the gamma-ray emission from the center of our galaxy observed by Fermi-LAT in terms of dark matter annihilation within the scalar Higgs portal model. We demonstrate through a detailed numerical fit that the strength and shape of the gamma-ray spectrum can indeed be described by the model in various regions of dark matter masses and couplings. Constraints from invisible Higgs decays, direct dark matter searches, indirect searches in dwarf galaxies and for gamma-ray lines, and constraints from the dark matter relic density reduce the parameter space to dark matter masses near the Higgs resonance. Unfortunately, this parameter region is hard to probe in future direct detection and collider experiments. Talk L. Baudis
30 May Andrzej Buras The Renaissance of Kaon Flavour Physics
Recent anomalies in B Decays identified in the last years by Belle, BaBar, LHCb, CMS and ATLAS indicate the presence of new physics beyond the Standard Model but none of them points towards new sources of CP-violation. On the contrary the recently improved estimates of CP-violation in $K_L\to \pi \pi$ decays ($\epsilon'/\epsilon$) give a strong indication for the presence of new sources of CP violation beyond the Cabibbo-Kobayashi-Maskawa framework. Moreover, some tensions between $B_{s,d}⁻0-\bar B_{s,d}^0$ mixing and CP-violation in $K^0-\bar K^0$ mixing ($\epsilon_K$) seem to emerge. The talk discusses these new anomalies and their implications for the rare decays $K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$ as well as correlations of with some of the anomalies hinted by B-decays.
Talk N. Serra/G. Isidori
6 June Yonit Hochberg - UC Berkeley The Simplest Miracle

Talk G. Isidori/N. Serra