Friday, 21 August 2015

Friday wrap-up: 3/fb, ATLAS on Higgs LFV decays...

Wherein I list some (mostly) recent happenings, ramble a bit, and provide links, in an order roughly determined by importance and relevance to particle physics. Views are my own. Content very definitely skewed by my own leanings and by papers getting coverage, and it may not even be correct. It is a blog after all...

FYI, I've posted a list of recommended (active) high energy physics news and blog links in the sidebar, also here for those using a reader: A Perfectly Formed Puddle, A Quantum Diaries Survivor, ATLAS Blog, ATLAS Briefings, ATLAS News, Backreaction, CERN Press ReleasesCERN Updates, CMS Blog: Cylindrical Onion, CMS Physics News, Collider Blog, Ellipsix, Interactions.org, Life and Physics, Life on the Lattice, Looking Inside the SM, Nautilus: Particle Physics, Neutrino Blog, Not Even Wrong, Of Particular Significance, PhysicsMatt, Preposterous Universe, Quanta Magazine: Physics, Quantum Diaries, RWTH Aachen, Resonaances, Tim Head, Transcyberphysix, symmetry magazine, the reference frame.

• The XXVII International Symposium on Lepton Photon Interactions at High Energies (Lepton Photon 2015) has been going this week (indico/twitter). We heard from Mike Lamont about LHC performance; multiple commissioning issues (electron cloud, UFOs, ULO, ...), none of which are expected to be long term, mean that predicted integrated luminosity for ATLAS/CMS in 2015 is now at ~3/fb. [See also a brief story at New Scientist].
• Following up the CMS 2.4σ excess from February, ATLAS on Monday placed their search for LFV Higgs decays in the $\mu\tau_{had}$ channel on the arXiv. Their result is consistent with zero, but also consistent with CMS. Their best fit is a $\mathcal{B}=(0.77\pm 0.62)\%$, compared to $\mathcal{B}=(0.84^{+0.39}_{-0.30})\%$ from CMS. One can see that the CMS search is more sensitive; this is likely driven by the fact that CMS also included the $\mu\tau_e$ channel. Do ATLAS have plans to look at this channel soon as well?
• A few weeks ago we mentioned that LHCb announced preliminary results in a search for displaced light scalar bosons. The preprint is on the arXiv now, which allowed me to scrape their data points and reinterpret their branching limits for the real singlet scalar portal. For interest, the result is below in orange, quite similar to the approximate plot from that previous blog post (more information there). Anyway, LHCb have done a great job excluding parameter space!

• The Dark Energy Survey (DES) has discovered eight new dwarf galaxy candidates (arXiv/press release), to add to the nine they discovered earlier this year. The sky is filling with satellites...

Now taking bets on which one has an excess of gamma rays consistent with dark matter annihilation...
• On that note, the first paper pointing out the gamma ray excess in Reticulum II (on the day of the first DES dwarf galaxy candidates announcement) was published in Physical Review Letters this week. Tracy Slatyer has a Viewpoint here.
• Mary K. Gaillard has a book out: A Singularly Unfeminine Profession: One Woman's Journey in Physics. There's a review on nature.com from Val Gibson.