Particle Physics Seminar: Recasting LHC data for new BSM model constraints
LHC measurements and searches are usually conducted with a particular theory model in mind, but can also have unexpected implications for alternative scenarios. Especially in the absence so far of smoking gun signals of new physics at the LHC, reinterpreting combinations of many “preserved” data analyses in this way, applied to more general models of beyond-SM physics has become a big business. I will show uses of the Rivet & Professor MC toolkits for reinterpretation of electroweak, top quark, and BSM search data in this way, particularly in first results from the TopFitter, Contur, and Gambit fitting groups, and how these studies can also inform future experimental measurements.
Grainne Wilkinson
Journal club on experimental condensed matter physics (Monday at 10 a.m.)
The next speaker is Josh Chawner and he will be presenting a paper titled
Extracting work from quantum measurement in Maxwell demon engines
The next session of the Journal club on experimental condensed matter physics is on Monday 27/02/2017 at 10:00 in C36.
Everyone is welcome!
Dima Zmeev
Physics Colloquium – “Reconfiguring the Fields of Astrophysical Objects: Magnetic Reconnection, Parallel Electric FIelds, and Turbulence”
Date: 07 March 2017, 3pm-4pm
Venue: Marcus Merriman LT
Speaker: Prof. Bob Ergun, University of Colorado
Abstract: Magnetic reconnection is a fundamental process that enables a change of magnetic topology in plasmas, which can result in a sudden, sometimes violent, release of energy. For example, magnetic reconnection initiates solar flares and coronal mass ejections. At magnetized planets, reconnection allows the for a robust energy exchange between the solar wind and the planet’s magnetosphere and can result in magnetic storms, magnetic sub-storms, and intense auroral displays. In astrophysical plasmas, reconnection can drive disk instabilities, energize jets, and result in strong particle acceleration. In laboratory plasmas, it is the root of “saw tooth” events in tokomaks. Because of its widespread importance, magnetic reconnection has been investigated for over one half of a century. However, a full understanding of the process has eluded us. As of now, it is best understood on ion scales in two dimensions. The electron-scale physics and the three-dimensional nature of magnetic reconnection are a topic vigorous investigation with laboratory experiments, space experiments, and numerical simulations.
The Magnetospheric Multiscale (MMS) mission, which has four spacecraft in a close tetrahedron, is designed to study the three-dimensional structure of magnetic reconnection focusing on the electron diffusion region. MMS has two phases, the first phase, which examines reconnection near the Earth’s sub-solar magnetopause, is now complete. The initial results have verified some of the electron-scale physics that was predicted by simulation in two dimensions. Deeper examination, however, shows that magnetic reconnection may be inherently a turbulent process in three dimensions as evidenced by strong magnetic field fluctuations, drift waves, and intense parallel electric fields. I discuss recent advances in our understanding of magnetic reconnection that have been enabled by MMS observations.
Grainne Wilkinson
Astrophysics Seminar – Star Formation – Tues 28th Feb
Title: Massive stars formed in atomic hydrogen reservoirs
Speaker: Michal Michalowski (University of Edinburgh)
Time: 11:30am on Tuesday 28th February 2017
Venue: Physics C36
Abstract:
I will discuss the process of gas inflow on galaxies and subsequent fuelling of star-formation. Using recent ATCA HI observations I will show that galaxies with anomalous local metallicity decrements (gamma-ray burst host galaxies) have substantial atomic gas reservoirs, and are deficient in molecular gas. This suggests that star formation in these galaxies may be fuelled by recent inflow of metal-poor atomic gas.
This is controversial, but can happen in low-metallicity gas near the onset of star formation because cooling of gas (necessary for star
formation) is faster than the HI-to-H2 conversion.
Grainne Wilkinson
Works by Facilities in the Physic building next week.
We have been informed by Facilities that the emergency lights and the water hygiene of the Physics building will be checked next week.
Fire door interface inspections will take place in the Physics Building on 1st March from 9am daily. These are the doors that are operated by the evacuation alarm.
AEC contractors are undertaking internal management surveys in University buildings in order to update Facilities records and to ensure compliance is maintained to the highest standard. They are expected to be in Physics on 2nd and 3rd of March, we will accompany them into any labs they require access to.
All the above are short tests/inspections and shouldn’t cause any inconvenience but let me now if you foresee any issues.
Shonah Ion
March Safety Induction
The March safety induction will take place on Thursday 2nd March in C29 at 2:30 pm. Any new members of staff or those wanting a reminder please come along.
Shonah Ion
Astrophysics Seminar – Soft X-ray sources/novae – 24th Feb
Title: High-resolution X-ray spectra of Super Soft X-ray Sources
Speaker: Jan-Uwe Ness (European Space Astronomy Centre, Madrid)
Time: 1100hrs Friday 24th February 2017
Venue: Bowland North SR 23
Abstract:
Super-Soft X-ray Sources (SSS) are a small class of X-ray sources characterised by a blackbody-like spectrum of effective temperature
30-100 eV (several 10^5 K) and luminosities above 10^36 erg/s. Owing to their softness, galactic SSS are more difficult to observe and interpret because of high galactic extinction and uncertain distances, respectively. While a small number of permanent SSS are known since the 80s, novae have been predicted to pass through a phase of SSS emission that has indeed been observed with, e.g., ROSAT, BeppoSAX, or ASCA.
Attempts of spectral modeling of nova SSS spectra ranged from blackbody fits to most refined local thermodynamic equilibrium (LTE) and non-LTE atmosphere modeling, but the low resolution of CCD spectra allows no unique constraint of spectral parameters of complex models. The X-ray grating spectrometers on board XMM-Newton and Chandra allow much more detailed analysis of SSS spectra and, as always in nature, the truth is much more complicated than believed. I will first present historic observations and attempts of interpretation, and then show the grating spectra with the details. A large variety in grating spectra of canonical SSS spectra and those of novae emerged, and I will show approaches how to find trends and to explain some commonalities.
Spectral modeling is currently not possible, but I will present and discuss some approaches.
Grainne Wilkinson
Do you fancy acting as a judge at the IOP’s North West undergraduate Physics Challenge this year?
Derek Ward-Thompson at UCLan has asked me to circulate the invitation to staff here at Lancaster. It’s at Salford University on Wednesday 29th March from 10.30am till 3pm.
If interested, please contact Derek directly (dward-thompson@uclan.ac.uk)
Gráinne Wilkinson & Jim Wild