HIP NEWS June 13th 2016
==============================

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 14 June 2016 at 10.15 in A315
Carl Carlson (College of William and Mary, Virginia)
The proton charge radius puzzle

Abstract: There is a proton charge radius puzzle because the proton charge radius appears different when measured with electrons than when measured with muons. Explanations broadly fit into two categories. “Ordinary” explanations include problems with the extrapolations or theoretical corrections involved in the measurements, and “exotic” explanations include such beyond the standard model ideas as a breakdown of electron-muon universality. We will discuss something of how the measurements are done, and discuss possible explanations in both the “ordinary” and “exotic” categories.

COSMO-seminar
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Wednesday 15 June 2016 at 14:15 in A315
Eemeli Tomberg (Helsinki)
Decoherence in Inflation

Abstract: During inflation, cosmological scalar perturbations can be described by the Sasaki-Mukhanov variable. Quantizing this variable, we get a highly quantum mechanical, `squeezed’ vacuum state. However, it is common in cosmology to use classical perturbation theory to describe the perturbations after their birth. In this talk I will discuss some properties of the squeezed vacuum state, and show how decoherence can be used to understand the transition from the quantum mechanical initial conditions to the classical treatment. In decoherence, the system gets entangled with its environment, so that its reduced density matrix becomes an ensemble of classically observable states.

Visitors
————–
P. Dendooven 6.6.-9.6. ; 20.6.-8.7.
B.S. DiNunno 1.6. – 3.7. (NJ)
C. Carlson 31.5.-15.6. (MS)
A. Lopez 29.4. – 13.6. (MH, KR)

HIP NEWS June 6th 2016
==============================

HIP Staff News
———————-
Dr. Antti Väihkönen will start as HIP Research Coordinator on August 1st. He is moving to HIP from the Academy of Finland.

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Monday 6 June 2016 at 10.15 in A315
Juan Pedraza (Amsterdam) (Note day!)
Spread of entanglement in holographic theories

Abstract: In this talk I will present recent results of the propagation of entanglement entropy after a global quench in the context of AdS/CFT. I will start by reviewing the heuristic picture for entanglement propagation dubbed as ‘entanglement tsunami’, and explain why this interpretation fails for general theories and entangling regions. In the second part of the talk I will present an analytic perturbative calculation for small subregions and show that in this regime the spread of entanglement exhibit some distinct features: i) the instantaneous rate of growth is not constrained by causality, but rather its time average, and ii) the saturation is always continuous, regardless the shape of the entangling region. I will also comment on the generalization of these results for non-relativistic scale invariant theories in some generic examples (1602.05934).

Tuesday 7 June 2016 at 10.15 in A315
Ilpo Vattulainen (Helsinki)
Cholesterol, tiny but tough! How membranes sense changes in cholesterol structure.

Abstract: Cholesterol is one of the vital components in regulating the physical properties of animal cell membranes. Further, there are membrane proteins whose function is dependent on cholesterol, however the mechanisms and physical principles used by cholesterol to modulate protein function remain unknown. What makes cholesterol exceptionally intriguing is the fact that other sterols are not able to replace cholesterol, thus its structure is unique in a manner that is not yet understood. In this talk, we discuss how cell membranes sense cholesterol and changes in its structure. We consider synthetic sterols non-existent in nature to elucidate the roles of cholesterol’s individual structural elements. This brings out the critical components in cholesterol structure that are critical to its function. To clarify how reactive oxygen species affect cholesterol and its role in cell function, we also discuss how oxysterols based on oxidation of cholesterol affect membrane properties that turn out to be distinct from those induced by cholesterol. We further discuss how cholesterol is able to govern cellular signaling by modulating the structure and dynamics of membrane receptors that manage the signaling between the outside and the inside of cells. The data emerged from molecular simulations as well as experiments provide a basis to better understand why cholesterol is indeed unique in modulating membrane properties and membrane protein function, and the insight found by simulations can possibly be used to predict new synthetic sterols with applications in biotechnology.

Thursday 9 June 2016 at 14.15 in A315
Kai Schmidt-Hoberg (Desy) (Note time!)
The case for dark matter self interactions – evidence in Abell 3827?

Abstract: I will review motivations for the existence of self interacting dark matter and discuss possible astrophysical observables. Self-interactions of dark matter particles can potentially lead to an observable separation between the dark matter halo and the stars of a galaxy moving through a region of large dark matter density. Such a separation has recently been observed in a galaxy falling into the core of the galaxy cluster Abell 3827. I discuss the DM self-interaction cross section needed to reproduce the observed effects.

Upcoming Events: Nuclear Science and Technology Symposium – NST2016
————————————————————————————————————
The Finnish Nuclear Society (FNS) organizes the Nuclear Science and
Technology Symposium – NST2016 on November 2-3, 2016 in Helsinki. The
symposium gathers together research, industry and authority
representatives from Finland and abroad for scientific talks and
industry presentations. The FNS 50-year anniversary dinner and lectures
for the general public are held in connection with the symposium. For
details see the webpage http://www.ats-fns.fi/en/nst2016.

Visitors
————–
P. Dendooven 6.6.-9.6. ; 20.6.-8.7.
B.S. DiNunno 1.6. – 3.7. (NJ)
C. Carlson 31.5.-15.6. (MS)
M. Hindmarsh 29.4. – 12.6. (KR)
A. Lopez 29.4. – 13.6. (MH, KR)
J. Pedraza 1.6. – 7.6. (NJ)

HIP NEWS May 30th 2016
==============================

Deadline for registration is on May 30th: CERN School of Computing 2016 in Mol, Belgium
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A few places available for the upcoming CERN School of Computing 2016 (http://indico.cern.ch/event/502875/). This school is for two weeks and takes place from 28 August to 10 September 2016 in Mol, Belgium. It is organized in collaboration with the Vrije Universiteit Brussel (www.vub.ac.be ) and hosted in the Belgian Nuclear Research Centre ( www.sckcen.be ).
Register http://indico.cern.ch/event/502875/registrations/28213/
Schedule https://indico.cern.ch/event/502875/other-view?view=indico-weeks-view
General information https://indico.cern.ch/event/502875/other-view?view=indico-weeks-view

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 31 May 2016 at 10.15 in A315
Santosh Kumar Rai (Allahabad)
Revisiting compressed SUSY at LHC

Abstract: Recently a compressed mass spectrum has been thought as an explanation for the elusiveness of low-energy supersymmetry (SUSY). Some characteristic signals at the Large Hadron Collider, such as mono-jet + missing transverse energy (MET), had been propounded as its trademark signals. However, later investigations suggested that lower limits on the supersym- metric particle masses would be quite stringent in spite of compression. Also, most compressed SUSY scenarios studied so far are only partially compressed. By keeping the level of compression in the entire spectrum as high as possible we study a broad class of benchmark spectra, ensuring consistency with the observed Higgs mass as well as the dark matter constraints. We show that of both the multi-jet +MET and mono-jet + MET final states, the former is still more efficient to reveal a compressed SUSY spectrum first, while the latter can serve as a useful confirmatory channel.

Thursday 2 June 2016 at 14.15 in A315
Ritva Kinnunen (HIP)
My Experiences in Large Experiments

Abstract: I have worked in two large high energy physics experiments, UA1 and CMS. I will talk about some personal experiences, indicating also important milestones of particle physics achieved in these experiments.

Upcoming Events: Nuclear Science and Technology Symposium – NST2016
————————————————————————————————————
The Finnish Nuclear Society (FNS) organizes the Nuclear Science and
Technology Symposium – NST2016 on November 2-3, 2016 in Helsinki. The
symposium gathers together research, industry and authority
representatives from Finland and abroad for scientific talks and
industry presentations. The FNS 50-year anniversary dinner and lectures
for the general public are held in connection with the symposium. For
details see the webpage http://www.ats-fns.fi/en/nst2016.

Visitors
————–
B.S. DiNunno 1.6. – 3.7. (NJ)
C. Carlson 31.5.-15.6. (MS)
M. Hindmarsh 29.4. – 12.6. (KR)
A. Lopez 29.4. – 13.6. (MH, KR)
J. Pedraza 1.6. – 7.6. (NJ)
M. Taylor 1.6. – 3.6. (ML)

HIP NEWS May 23rd 2016
==============================

COSMO-seminar
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Wednesday 25 May 2016 at 14.15 in room A315
Enea Di Dio (OATS Trieste)
Relativistic effects on LSS spectrum and bispectrum

Abstract: I will discuss the Large Scale Structure spectrum and bispectrum in a relativistic framework. To first order, a relativistic description includes terms beyond the Kaiser approximation (doppler effects and galaxy evolution), gravitational potentials and integrated terms (cosmic magnification, integrated Sachs-Wolfe and Shapiro time-delay). These terms are currently neglected, but they might play a role in future surveys which probe larger scales. I will show how they can be isolated by correlating different probes, or by using the so-called multi-tracer technique. Moreover, some relativistic effects could give a non-negligible contribution to the LSS observables, hence, by neglecting them, the analysis may lead to biased cosmological parameters.

Finnish for international personnel, summer 2016
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The summer 2016 course programme is available at helsinki.fi/finnishcourses
https://flamma.helsinki.fi/en/notifications/finnishsummer2016

Upcoming Events: Nuclear Science and Technology Symposium – NST2016
————————————————————————————————————
The Finnish Nuclear Society (FNS) organizes the Nuclear Science and
Technology Symposium – NST2016 on November 2-3, 2016 in Helsinki. The
symposium gathers together research, industry and authority
representatives from Finland and abroad for scientific talks and
industry presentations. The FNS 50-year anniversary dinner and lectures
for the general public are held in connection with the symposium. For
details see the webpage http://www.ats-fns.fi/en/nst2016.

Visitors
————–
E. Di Dio 22.5. – 27.5. (FM)
B.S. DiNunno 1.6. – 3.7. (NJ)
M. Hindmarsh 29.4. – 12.6. (KR)
A. Lopez 29.4. – 13.6. (MH, KR)
J. Mohr 26.5. (H.K-S)
J. Pedraza 1.6. – 7.6. (NJ)

HIP NEWS May 16th 2016
==============================

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 17 May 2016 at 10.15 in A315
Mads Frandsen (Odense)
Electroweak symmetry breaking, dark matter and the diphoton excess

Abstract: I will discuss some interpretations of the putative LHC diphoton excess at 750 GeV in the light of models of dynamical electroweak symmetry breaking and models of dark matter.

COSMO-seminar
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Wednesday 18 May 2016 at 14.15 in room E205 (!)
Stefano Foffa (University of Geneva)
Binary parameters measurement from coalescence event(s) in LIGO

Abstract: After a brief introduction about gravitational waves (GW), binary systems and data analysis, I will discuss the informations that can be extracted from the study of a GW signal produced during a coalescence. I will take as a case study the recently announced GW detection at LIGO, and discuss what can be expected from other coalescence events and/or when other detectors will join the network.

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Thursday 19 May 2016 at 10.15 in A315
Tobias Zingg (HIP)
How I learned to stop worrying and love fractional spin: A systematic approach to holographic anyonization
Abstract: Anyons are a special type of particle in 2+1 dimensions that can have fractional spin quantum number and have garnered substantial interest theoretically as well as experimentally. However, they have a highly non-trivial configuration space of multiparticle states, compared to bosons or fermions, which often impedes a direct approach via quantum statistics, even in the most simple cases.

Holography provides a way to evade some of these issues. Within this framework, I will formulate a general method to obtain an effective physical description of strongly correlated anyonic systems via an alternative quantization of asymptotic electromagnetic degrees of freedom in a gravitational dual, and demonstrate how this prescription can be employed to compute the equation of state and various transport coefficients.

Finnish for international personnel, summer 2016
————————————————————
The summer 2016 course programme is available at helsinki.fi/finnishcourses
https://flamma.helsinki.fi/en/notifications/finnishsummer2016

Upcoming Events: Nuclear Science and Technology Symposium – NST2016
————————————————————————
The Finnish Nuclear Society (FNS) organizes the Nuclear Science and
Technology Symposium – NST2016 on November 2-3, 2016 in Helsinki. The
symposium gathers together research, industry and authority
representatives from Finland and abroad for scientific talks and
industry presentations. The FNS 50-year anniversary dinner and lectures
for the general public are held in connection with the symposium. For
details see the webpage http://www.ats-fns.fi/en/nst2016.

Visitors
————–
B.S. DiNunno 1.6. – 3.7. (NJ)
S. Foffa 17.5. – 19.5.(FM)
M. Frandsen 16.5. – 19.5. (KT)
M. Hindmarsh 29.4. – 12.6. (KR)
M. Karciauskas 16.5. – 20.5. (OL)
A. Lopez 29.4. – 13.6. (MH, KR)
J. Pedraza 1.6. – 7.6. (NJ)
M. Raidal 20.5. (KT)
T. Takahashi 15.5. – 20.5. (KE)

HIP NEWS May 9th 2016
==============================

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 10 May 2016 at 10.15 in A315
Kai Schmidt-Hoberg (Desy)
The case for dark matter self interactions – evidence in Abell 3827?

Abstract: I will review motivations for the existence of self interacting dark matter and discuss possible astrophysical observables. Self-interactions of dark matter particles can potentially lead to an observable separation between the dark matter halo and the stars of a galaxy moving through a region of large dark matter density. Such a separation has recently been observed in a galaxy falling into the core of the galaxy cluster Abell 3827. I discuss the DM self-interaction cross section needed to reproduce the observed effects.

COSMO-seminar
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Wednesday 11 May 2016 at 14.15 in A315
David Wiltshire (Canterbury University)
Models of inhomogeneity and backreaction in cosmology: A status report

Abstract: The possibility of backreaction – that inhomogeneous structures on small (< 100/h Mpc) scales change average cosmic evolution relative to a homogeneous isotropic FLRW cosmology – can be tested in different ways. 1. In our own < 100/h Mpc environment the assumption of a FLRW geometry can be tested model-independently. We present very strong Bayesian evidence that the standard CMB rest frame is not the frame in which the spherically averaged variation of the Hubble expansion is minimized. Using large ray tracing simulations in exact solutions of Einstein’s equations we further show that observations are consistent with a 0.5% differential expansion of space on 100/h Mpc scales detailed models of backreaction are required for cosmological tests. The Timescape Cosmology provides such a phenomenology, without dark energy. We report on the status of observational tests of this model, including fits of the acoustic peaks in the CMB anisotropy spectrum. The Timescape Cosmology passes current tests, and can be distinguished from the FLRW cosmology with future Euclid satellite data. In terms of the CMB we find that the effects of backreaction in the primordial plasma still need to accounted for to deal with systematic uncertainties of 8-13% in particular cosmological parameters.

Deadline for registration May 15th 2016: The Helsinki Workshop on Quantum Gravity
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A workshop on quantum gravity will be held in the Physics department the 1st to 3rd of June 2016. The idea of the workshop is to introduce the subject of quantum gravity in Finland. In particular to the interested student.
Homepage: www.hip.fi/qg_helsinki
Deadline for registration: 15th of May 2016
Further information: miklos.langvik[AT]helsinki.fi
The organizing committee
(Esko Keski-Vakkuri, Antti Kupiainen, Miklos Långvik, Kari Rummukainen, Aleksi Vuorinen)

Finnish for international personnel, summer 2016
———————————————————–
The summer 2016 course programme is available at helsinki.fi/finnishcourses
https://flamma.helsinki.fi/en/notifications/finnishsummer2016

Upcoming Events: Nuclear Science and Technology Symposium – NST2016
————————————————————————–
The Finnish Nuclear Society (FNS) organizes the Nuclear Science and
Technology Symposium – NST2016 on November 2-3, 2016 in Helsinki. The
symposium gathers together research, industry and authority
representatives from Finland and abroad for scientific talks and
industry presentations. The FNS 50-year anniversary dinner and lectures
for the general public are held in connection with the symposium. For
details see the webpage http://www.ats-fns.fi/en/nst2016.

Visitors
————–
B.S. DiNunno 1.6. – 3.7. (NJ)
M. Hindmarsh 29.4. – 12.6. (KR)
A. Lopez 29.4. – 13.6. (MH, KR)
J. Pedraza 1.6. – 7.6. (NJ)
D. Wiltshire 10.5. – 12.5. (FM)

HIP NEWS May 2nd 2016
==============================

HIP Staff News
——————–
The Finnish Society of Sciences and Letters has awarded HIP Director, professor Paula Eerola, the 2016 Professor E.J. Nyström prize for significant contribution in her field of research.

COSMO-seminar
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Wednesday 4 May 2016 at 14.15 in A315
Francesca Day (University of Oxford)
Astrophysical signatures of axions

Abstract: Many extensions of the Standard Model include axions or axion-like particles. Such axions are potentially observable via their interaction with electromagnetism, leading to axion-photon conversion in an external magnetic field. I will discuss potential observational signatures of axions in galaxies and galaxy clusters. In particular, I will present predictions from a cosmic axion background propagating in galaxies. I will also describe a scenario in which the recently observed 3.5 keV photon line is caused by dark matter decay to axions, which then mix with the photon in astrophysical magnetic fields. I will motivate this scenario in terms of the observed morphology of the line, and present predictions unique to this model.

Deadline for registration May 15th 2016: The Helsinki Workshop on Quantum Gravity
—————————————————————————————
A workshop on quantum gravity will be held in the Physics department the 1st to 3rd of June 2016. The idea of the workshop is to introduce the subject of quantum gravity in Finland. In particular to the interested student.
Homepage: www.hip.fi/qg_helsinki
Deadline for registration: 15th of May 2016
Further information: miklos.langvik[AT]helsinki.fi
The organizing committee
(Esko Keski-Vakkuri, Antti Kupiainen, Miklos Långvik, Kari Rummukainen, Aleksi Vuorinen)

Finnish for international personnel, summer 2016
——————————————————
The summer 2016 course programme is available at helsinki.fi/finnishcourses
https://flamma.helsinki.fi/en/notifications/finnishsummer2016

Upcoming Events: Nuclear Science and Technology Symposium – NST2016
————————————————————————————————————
The Finnish Nuclear Society (FNS) organizes the Nuclear Science and
Technology Symposium – NST2016 on November 2-3, 2016 in Helsinki. The
symposium gathers together research, industry and authority
representatives from Finland and abroad for scientific talks and
industry presentations. The FNS 50-year anniversary dinner and lectures
for the general public are held in connection with the symposium. For
details see the webpage http://www.ats-fns.fi/en/nst2016.

Visitors
————–
F. Day 3.5. – 6.5. (FM)
M. Hindmarsh 29.4. – 12.6. (KR)
A. Lopez 29.4. – 13.6. (MH, KR)
D. Weir 2.5. – 4.5. (KR)
D. Wiltshire 10.5. – 12.5. (FM)

HIP NEWS April 25th 2016
==============================

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 26 April 2016 at 10.15 in A315
Thomas Konstandin (Desy)
Effective actions in particle physics and cosmology

Abstract: Effective actions are an invaluable tool in particle physics and cosmology. For example, they are used to determine properties of the Higgs or the stability of the vacuum. Other applications include the sphaleron rate in the early universe or the characteristics of the electroweak phase transition. In this talk, I will give an extensive introduction to the topic and finally touch on some advanced questions as infrared problems or gauge-dependence.

COSMO-seminar
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Wednesday 27 April 2016 at 14.15 in A315
Steen Hansen (DARK, Copenhagen)
Pancakes in space

Abstract: The cosmological web consists of equilibrated galaxies and clusters of galaxies, one dimensional filaments, two dimensional sheets (also called Zeldovich pancakes) and three dimensional voids.

I will discuss the first detection of two Zeldovich pancakes near the Coma cluster. These sheets/pancakes, which are few Mpc wide and about 10 Mpc long, are very cold structures with velocity dispersion about 100 km/sec. In comparison, groups of galaxies have dispersions around 300 km/sec.

By measuring the departure from a pure Hubble flow of the galaxies belonging to the sheets/pancakes, one can determine the virial mass of the nearby galaxy cluster, and I will discuss how this method complements other methods.

Finnish for international personnel, summer 2016
—————————————————————————————————
The summer 2016 course programme is available at helsinki.fi/finnishcourses
https://flamma.helsinki.fi/en/notifications/finnishsummer2016

Visitors
————–
S. Hansen 27.4. – 29.4. (FM)
L. Boldizsar 13.4. – 26.4. (EB)
M. Hindmarsh 29.4. – 12.6. (KR)
T. Konstandin 26.4. – 27.4. (OL)
A. Lopez 29.4. – 13.6. (MH, KR)

HIP NEWS April 18th 2016
==============================

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
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Tuesday 19 April 2016 at 10.15 in A315
Aurora Meroni (Odense)
Neutrino physics: status and quests for the future

Abstract: Neutrino physics has entered the precision era. Nevertheless many questions still remain without an answer. We know that the SM cannot be the ultimate theory, since a so-called “elusive” sector is completely missing: neutrinos are not properly included since we cannot describe their mass. Moroever, the nature, Dirac or Majorana, of the three light active neutrinos nuj (j = 1,2,3) with definite mass mj is unknown. I will review unknown properties of neutrinos and how possibly detect some of them. In particular I will define a theoretical framework and deduce the conditions under which multi-messenger astronomy can constrain neutrino masses and unveil their ordering. The framework uses time differences between the arrival of neutrinos and the other two light messengers, i.e. light and gravitational waves, emitted by astrophysical catastrophes.

COSMO-seminar
———————–
Wednesday 20 April 2016 at 14.15 in A315
Adam Amara (ETH Zurich)
Cosmology and the Dark Energy Survey

Abstract: The Dark Energy Survey (DES) is a 5000 square degree survey targeting dark matter and dark energy science. This year sees the release of the first science results from the DES collaboration using data taken during science verification. I plan to present these new results, which include dark matter maps, cosmology constraints and new discoveries such as the new strong lens systems being found. I will also give an update on the progress of the main science survey, which is still ongoing.

Finnish for international personnel, summer 2016
—————————————————————————————————
The summer 2016 course programme is available at helsinki.fi/finnishcourses
During the summers months the courses are intensive courses, with meetings four times a week. The first courses begin on 30 May. Courses are filled on a first-come first-served basis.
https://flamma.helsinki.fi/en/notifications/finnishsummer2016

Visitors
————–
A. Amara 19.4. – 21.4. (FM)
L. Boldizsar 13.4. – 26.4. (EB)
A. Meroni 18.4. – 20.4. (AV)
F. Sannino 18.4. – 19.4. (KT)

HIP NEWS April 11th 2016
==============================

DEPARTMENT OF PHYSICS / HIP JOINT COLLOQUIA / SEMINARS
——————————————————————————————
Tuesday 12 April 2016 at 10.15 in A315
Louis Lyons (Imperial College)
Statistical Issues in Searches for New Physics

Abstract: Given the cost, both financial and even more importantly in terms of human effort, in building High Energy Physics accelerators and detectors and running them, it is important to use good statistical techniques in analysing data. This talk covers some of the statistical issues that arise in searches for New Physics. They include topics such as: Blind Analysis. How should we deal with the `Look Elsewhere Effect’? Should we insist on the 5 sigma criterion for discovery claims? Significance P(A|B) is not the same as P(B|A). The meaning of p-values. What is Wilks’ Theorem and when does it not apply? Dealing with systematics such as background parametrisation. Coverage: What is it and does my method have the correct coverage? Upper Limits. The use of p_0 vs p_1 plots. Higgs search: Discovery and Spin.

Thursday 14 April 2016 at 10.15 in A315: Guy Moore (Darmstadt)
Relating the Axion Mass and Dark Matter Density

Abstract: QCD appears to allow for large parity and time-reversal violating effects, which are in fact unmeasurably small. The simplest dynamical model to explain this predicts a new particle, the Axion, which is also an excellent dark matter candidate. Under reasonable assumptions it should be possible to predict the relation between the axion’s mass and its dark matter abundance. I will discuss the interesting physics we need to make this prediction concrete — axionic string networks and topological susceptibility.

COSMO-seminar
———————–
Wednesday 13 April 2016 at 14.15 in A315
Matti Herranen (Jyväskylä)
Nonequilibrium QFT approach to leptogenesis
Abstract: he observed baryon asymmetry of the Universe may have been produced dynamically in the very early Universe by a baryogenesis via leptogenesis process from the CP- and lepton number violating decays of heavy right-handed neutrinos. For reliable calculations of the baryon asymmetry generated in leptogenesis first principle methods of nonequilibrium quantum field theory are required.

We construct a transport theory of leptogenesis based on the Schwinger-Keldysh or Closed Time Path (CTP) formalism of nonequilibrium QFT. The resulting kinetic equations incorporate finite density medium effects and quantum coherence effects and therefore provide a generalization to standard (quantum) Boltzmann equations. We find that the finite density corrections from loop integrals typically lead to an enhancement of the asymmetry. In the resonant regime with nearly degenerate right-handed neutrino masses, our results confirm the well-known resonant enhancement of CP-violation, however, novel effects from the flavour oscillations can be important in the dynamics.

Wednesday 13 April 2016, Upcoming events for international staff
———————————————————————–
Sign up in http://www.helsinki.fi/trainingcalendar ( Staff Training Calendar HENKKA) or via https://elomake.helsinki.fi/lomakkeet/48601/lomake.html

Last sign-up date: 17.04.2016: Completing Your Tax Return Form – Veroilmoitus in English
————————————————————————————————
Sign up in http://www.helsinki.fi/trainingcalendar ( Staff Training Calendar HENKKA)

Visitors
————–
L. Boldizsar 13.4. – 26.4. (EB)
M. Herranen 12.4. – 13.4. (FM)
A. Meroni 18.4. – 20.4. (AV)
G. Moore 13.4. – 15.4. (AV)
D. Varga 13.4. – 15.4. (EB)
M. Vargyas 11.4. – 15.4. (EB)