Shohei Nishida

Belle in recovering (2)

Finally, Belle resumed the operation last Friday. Now the luminosity is around 1.2 x 10^{34} cm-2/s, so it's still below what we achieved before summer, but  not so  bad. I think we can
accumulate 500 /fb soon.

Belle in recovering

Finally, we have replaced the connectors of the Silicon detector.
Today we are closing the endcap. Hope we can start the operation soon.

The reason the connectors were burned was not completely understood.
Some guesses that this is due to the radiation, but there is no evidence.

Belle in trouble

Though Belle started operation in September, it's not working now. Last week, some problems happened in the Silicon detector, which is in the innermost part of the Belle detector.
We decided to open the detector to check what was happening, and found that some connectors were burnt. Maybe some deterioration due to radiation?

We need a few more days to fix the problem.

先週あたりから

Belle 実験再開されています。いまのところ順調に運転しています。夏前までの性能が出るにはしばらく時間がかかると思いますが。

ところで、ITmedia にKEKの記事が取り上げられてますね。 Belleとは関係ないですが。

KEK一般公開

明日は一般公開です。台風が近づいて来ているようですが、なんとか晴れそうです。あわせて、ＫＥＫコミュニケーションプラザ も新たに開場するそうです。

しかし、「展示室」だと思っていたのに、横文字のよくわからん名前がついたんですね。単なる常設展示以外にもなんかするんでしょうか？

Belle in maintainance

In summer, Belle is in maintaince. We opened the Belle detector so that we can access to the SVD (Silicon Vertex Detector). This time, we have an upgrade of DAQ, so DAQ people are now working hard.

The detector was already closed a few days ago. KEKB accelerator will start the operation on Sep 15th, but before that we have KEK Open House on Sep 4th. It will be a good chance to look at various experiments in KEK as well as the Belle detector.

つくばエクスプレス（つづき）

こないだ、路線バスの時刻は変わってないと書きましたが、KEK-つくばセンター間の路線バスはつくばエクスプレスの開通にあわせて半減してしまいました。

つくばエクスプレス

本日、つくばエクスプレスが開通しました。これで、つくば市にもようやく鉄道がやってきました。KEK への行き来も、いままでよりは便利になるのではと思います。尤も、KEK とつくばセンターまでの間のバスがもう少し改善されるのが重要ですが。いまのところ、路線バスや高速バスの時刻表が変わったという話は聞いてないですが。

９月４日には、KEK の一般公開があります。つくばエクスプレスに乗って、KEK 見学はいかがでしょうか？

I'm off now

Now, I'm back in my home town, Kyoto. This time, a friend of mine (Belle collaborator from India) visited Kyoto for sightseeing. The picture was taken in the Imperial Palace (need reservation to enter). Actually, this was my first time to enter.

I'm going to stay in Kyoto a few more days, but I have to go back to KEK, because we have a power down soon. I have to shut down many computers.

Upsilon(5S)

Sorry for not writing for long time. I was busy for the analysis for summer conferences. Maybe I should look back what happened.

KEKB accelerator stopped its operation in the end of June for summer shutdown. Actually, we have to stop the accelerator during summer, in order to save electric power. In Japan, summer is the season when people use a large amount of the electricity. We will resume the experiment on September.

Before we stop the operation, we took some data at Upsilon(5S) resonance. Usually, the energy of KEKB is adjusted to Upsilon(4S) to produce B mesons (e+e- -> Upsilon(4S) -> BB). But this time, some collaborators requested to take at Upsilon(5S) for feasibility study for Bs mesons.
The study of Bs (Bs mixing, rare Bs decays ...) is now ongoing at Tevatron, and will be planned at LHC. But, KEKB/Belle can also provide some interesting physics if it runs at Upsilon(5S). The problem is that Upsilon(5S) does not necessarily produce Bs mesons (B* etc. are also produced), so I don't know how difficult the analysis is.

The Upsilon(5S) data is still under process, but will be available soon, so we might see some results in near future.