Highlights of my Day One at ICHEP

With great excitements I arrived at Palais des Congres this morning for Day One at ICHEP. Most of the talks today were outside of my area of research. This is a good thing in a sense as it means that I may get to learn new things from the talks. And yes, it was indeed the case. On the experimental side, I have enjoyed the well attended Tevatron Higgs session this afternoon on updated limits in both the high and low mass regions from CDF and D0. On the theory side, the highlight was the talk on Emergent Gravity by Erik Verlinde based on the paper (arXiv:1001.0785) he wrote earlier this year claiming that

"Gravity is not a fundamental force"

but it emerges as an entropic force caused by changed in the information associated with the positions of material bodies. Given that this claim changes fundamentally how we think about gravity, there were many very critical questions from the audience as you can imagine, such as the scale at which the entropic interpretation breaks down, the role of graviton in this scenario, the equivalence of the entropic scenario and other known theories in which gravity is a fundamental force.

As pointed out by my fellow bloggers as well that the most important thing being at conferences probably is to interact with other physicists face to face. Besides the coffee breaks, poster sessions also provide such an opportunity to informally discuss and learn new results and ideas from one another.

So what did I learn during the poster session today??

"Is there LSND anomaly?"

According to Poster # 588 from Harp - CDP, which presents the new results they just released a few weeks ago on the low energy pion backgrounds, the answer is NO. What they found is that there is a significant asymmetry in producing pi+ and pi-. The effects of this was not taken into account by LSND, according to the poster. More specifically, LSND underestimated the backgrounds by a factor of 2 and it underestimated the systematic errors by at least by a factor of 2, according to Poster #588. If the analysis stands, the still unanswered question then is, could the excess seen by MiniBoone in both the neutrino and antineutrino modes similarly due to the low energy pion backgrounds?

Tomorrow will be an exciting day as well. It will start out with presentations on first physics results from the LHC. Very much looking forward to it!

Two Days to Go!

Two days before the ICHEP meeting, and I am now sitting at LAX waiting to board my flight for Frankfurt en route to Paris. Finally! It has been really hectic for the past few weeks as the pressures of getting ready for ICHEP were building up.

Like the experimentalists, theorists also have to make the last minute fine-tuning on slides, making the plots looking pretty, you name it, albeit being an operation at a much smaller scale when compared to the experimentalists. For these, my graduate student has been working extremely hard during the past month or so with some days apparently skipping lunch and sleep, for a project that we are collaborating... This is also what another collaborator of mine and I have been doing for another project that he will be presenting at ICHEP.

Unlike the experimentalists, though, theorists do not have the luxury of generating the excitements associated with the anticipation of new experimental results. Of course everyone is eagerly awaiting to hear the status updates on LHC and on Tevatron Higgs searches. On the flavor physics front, MEG will be presenting its first summer talk on its current status on mu to e + gamma searches at ICHEP. With the anomalies in MiniBoone and Minos that were presented at Neutrino 2010, there have been several theoretical speculations on the sources of these anomalies (assuming they are not due to low statistics or low energy backgrounds). I am sure we will hear about these speculations at ICHEP too.

Now it's time for boarding. Look forward to an exciting meeting in Paris!

Hello World from Athens, Greece!

Greetings from Athens where I have been for the Neutrino 2010 Conference! As this is my first post, let me just briefly introduce myself. I am a particle theorist working on beyond the standard model physics. Particularly I have been interested in the origin of fermion masses and mixing (including the neutrinos, of course!) and have been trying to gain some insights into this problem by constructing models utilizing a variety kinds of new physics (grand unification, extra dimensions, Z'...).

Getting back to the Neutrino 2010 Conference. Some of the highlights of the conference were the new results from MINOS and MiniBoone. The MINOS Collaboration updated their results on the neutrino mode with more than double the data from their previous update in 2008. Updated results on the antineutrino mode were also presented. What is puzzling is the fact that the best fit value for the mass square difference extracted from the antineutrino mode is 3.36 x 10(-3) eV^2, which is far higher than the value determined using the neutrino mode data, 2.35 x 10^(-3) eV^2. One should note that the result for the neutrino mode was based on 7 x 10^(20) POT while the antineutrino mode result was based on significantly low statistics of 1.71 x 10^(20) POT. If the results turn out to be correct, it could mean CPT violation or the existence of new neutrino interaction. Clearly these data are still very preliminary and we should wait and see how this discrepancy disolve when more data becomes available.

MiniBoone also presented the results for both the neutrino and antineutrino modes. For both modes, an excess in the electron-like events was found in the low energy region. For the neutrino mode, there is an unexplained 3 sigma electron-like excess in the region of energy > 475 MeV, while in the region below 475 MeV the fit does not agree with LSND. For the anti-neutrino mode, there is a small excess above 475 MeV and the fit below 475 MeV agree with LSND result. It would be interesting to see if the low energy excess is still present when more statistics have been accumulated and when we have a better understanding of the background in the low energy region.

For the Neutrino Conference series, it has been the case that there are plenary sessions only. One thing that has been started since Neutrino 2008 in Christ Church, New Zealand, is the poster session. This is not uncommon in physics conferences, but what is special is the 3 min talks that enable the poster presenters to advertise their posters. Given that there are more than one hundred of them, the execution of the "3 min talk sessions" was quite an operation! Fortunately, the sessions went very smoothly, and since the talks were only for 3 min duration each, the speakers really had to get to the point right away making it an efficient way to learn numerous new results.

In addition to the exciting physics, life in Athens has been quite an experience. As you all know, there have been several protests and riots in Athens due to the economic crisis. Today is the third day since the Metro has gone on strike. This has posted a big problem for conference participants as most of us are staying quite far from the Megaron conference center and the Metro is the best way to get there from the hotels especially given that it is extrememly hard to get a taxis in central Athens. Hopefully the strike will end soon, or at the very least that it will not be extended to the airport in the next few days when everyone will be flying out of Athens.

This is it for this post. In the next one, I will report on the theoretical developments and additional experimental updates that I have learned at the conference as well as my overall impressions. So stay tuned.