Lhc: Around Novel Weak Deviations From The Touchstone Model

ATLAS in addition to CMS bring released lots of papers inward recent days. I volition real briefly cite a few ATLAS graphs you lot may abide by interesting.

In a search for \(ZZ\to\ell\ell qq \) resonances, Figure 4 shows a 2-sigma (locally) spread excess for \(m_H\sim 950\GeV\). Between \(450\GeV\) in addition to \(750\GeV\), in that location is a comparably rigid deficit.




In a search for a CP-odd Higgs decaying every bit \(A\to Zh\to Zb \bar b\), you lot may run across a 2-sigma excess on Figure viii for \(m_A \sim 500\GeV\) in addition to mayhap \(m_A\sim 280\GeV\), too.




half a twelvemonth ago.

Those weren't spectacular deviations. The next 1 isn't, either, merely it seems stronger in addition to may bring a improve story. In the search for Higgs pairs decaying every bit \(hh\to b\bar b b \bar b\), Figure 10b shows something that looks almost similar a 3-sigma excess centered at \(m_{G^*} \sim 1,650\GeV\). The primary text alone discusses the smaller deviations at similar graphs on Figures 10a, 10c.

Figure 10b is interpreted every bit a sign of a heavy Randall-Sundrum massive graviton amongst \(k / \tilde M_{Pl} =2\), a basic parameter of the warped geometry scenarios. This is a value for which you lot larn a stronger excess – in addition to the excess is stronger amongst the Randall-Sundrum spin-two interpretation than if you lot assume it is a scalar. What seems interesting nearly this value is that ATLAS has also seen a nearly 3-sigma diphoton excess nigh the invariant majority of \(1.6\TeV\) – inward the real same search that made us excited nearly the cernette excess at \(750\GeV\) inward Dec 2015.



Most of similarly rigid hints become away inward the history of particle physics. It's ever plausible that to a greater extent than or less of them won't. I produce mean value that the probability that a novel \(750\GeV\) uncomplicated particle exists is comparable to 50%. The probability for a novel \(1.6\TeV\) particle is smaller, say 5%, merely it's plausible that inward the future, nosotros volition endure able to await at these real weak hints every bit the "emerging evidence" nosotros volition bring could (correct the tense) pay to a greater extent than attending to.

There also exists an interesting theoretical proposal that aside from the \(750\GeV\) novel particle \(\phi_1\), in that location should also be a particle \(\phi_2\) of a "slightly to a greater extent than than double" mass, \(1.6\TeV\), which has the wages that the heavier particle decays to a duad of the lighter ones \(\phi_2\to \phi_1\phi_1\) nearly at rest. One of the \(\phi_1\) in addition to then decays to 2 photons piece the other decays to \(\psi\psi\), a duad of nighttime affair particles, whose transverse momentum is nearly nada (so the missing lay out energy is non seen) because of the give-and-take "rest".

Another novel newspaper mentioned the 2.5-sigma four-tops ATLAS excess a twelvemonth ago. For to a greater extent than or less reason, when I wrote iv tops now, I couldn't resist to abide by the Google Stret View icon of Treetops, to a greater extent than or less housing where I stayed when I visited Rutgers every bit a Czech undergrad pupil inward Spring 1997, my outset watch to the States. ;-)