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Edgar Carrera | USLHC | USA

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Immediate rediscovery of physics

Tuesday, March 30th, 2010

The CMS Collaboration has made public the preliminary plot that shows the di-photon resonance (pi0). Enjoy!!

Edgar Carrera (BU)

run_132440_pi0

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CMS first 7 TeV collision events!!!!

Tuesday, March 30th, 2010

CMS one of the 1st collision events at 7 TeV

CMS one of the 1st collision events at 7 TeV

After years of hard work by many people, after several weeks of intense work for preparation, and after several hours of holding our breaths, we finally got stable colliding beams at the record center-of-mass energy of 7 TeV.  Today, Tuesday 30th of March of 2010, CMS captured these beautiful collision candidate events!!!

You will see them appearing  here soon!!!

A new era of exciting physics (hopefully discoveries) has just started, a renaissance of science, which will most certainly change the way we perceive our universe and trigger an enhancement of our own humanism.

Cheers for particle physics and for humankind!!

Edgar Carrera (Boston University)

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Where will the collisions be at CMS?

Tuesday, March 30th, 2010

These are plots of the horizontal and vertical positions at CMS where collisions will be expected to happen.  They were measured from “beam gas” events by experts from the CMS Collaboration.  There is a small offset of about 100 microns in one of the directions.  This information is being passed to the LHC operators.   The moment of truth approaches, stay tuned….

Edgar Carrera (BU)

BeamGasXposBeamGasYpos

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Stable non-colliding beams at 3.5 TeV!!

Monday, March 29th, 2010

We will enjoy about one hour of stable non-colliding beams at 3.5 TeV.  When was the last time we saw all those indicators “true” and “green”?  It looks beautiful; congratulations LHC, and thanks!!….. we can’t wait for collisions!!

Edgar Carrera(BU)

lhc stable non-colliding beams at 3.5 TeV per beam

lhc stable non-colliding beams at 3.5 TeV per beam

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Collisions at 7 Tera Electronvolts!!! ……

Tuesday, March 23rd, 2010

….. is what we are hoping  to have next Tuesday 🙂  The LHC made it official, and so they will attempt to collide the two proton beams at 3.5 TeV each, on Tuesday March 30.

It’s 01:15am and I just got home after a quite long day of work (although shorter than I expected).  Everything needs to be ready before we get collisions, so the efforts have to double.  As part of the high level trigger team in CMS, my work this week consists in making sure that we are able to accept all the good collision events (data).  After a few days of intensive testing from different groups and people, we hope we will deploy the final version of the trigger “menu” tomorrow, or on Thursday the latest.  The high level trigger is a key component of being able to accept data.  It is basically a collection of code that runs online, live, to discriminate what information is put into tape and what is not.

It is very likely that  we will have lower energy collisions (900 GeV) during the weekend as a preamble for the historic 7 TeV smashings. We also need the trigger to catch beam gas events from 3.5 TeV circulating stable beams (no collisions), maybe on Sunday.

The adrenaline is starting to flow here at CERN.  It is somehow difficult to sleep, thinking about all this, for people like me who are on-call.  Most of the improvements, fixes, upgrades, etc, that we made after the learning experience of last year’s collisions are now in place, and ready for prime time.   We will do just fine.  I am sure.

Edgar F. Carrera (Boston University)

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The IEEE month’s question on the LHC

Tuesday, March 9th, 2010

One of our kind readers has sent us the last issue of  “the institute” magazine from the IEEE.  Its month’s question on page 9 has to do with the LHC and it reads:

Do you think the LHC is a worthwhile scientific endeavor? Will it help answer important questions about the nature of our universe?

Of course, my simple answers would be: yes and yes!  However, since  the IEEE is one of the most important (if not the most important) association related to technology and engineering,  it might be worthwhile elaborating on the answer.  Apparently anyone can make a comment to the address indicated in the magazine.

Enjoy!

Edgar Carrera (Boston University)

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Happy International Women’s day!!

Monday, March 8th, 2010

If you had walked into the CMS control room (P5) today 8th of March of 2010, you would have seen an almost only-women crew at the controls.  It was my last day on-call for the CMS high level trigger system, so I had to attend the daily meeting at CMS P5.  It was fun to see an overwhelming number of women.

I haven’t been paying much attention, and I don’t know the statistics, but I have the feeling that there’s usually a good mix of women and man in the control room. As a matter of fact, this past week (when I was on-call and I had to go to P5 every day) both run field managers were women and I guess they continue for this week.

The fun part of today was that they managed to schedule women for 32 out of the 34 shift positions required to run the CMS experiment; or at least that’s what I was told.  I am sure those two other spots were not filled in with women because the women that can cover them are very busy.  Like my boss, for example, who were supposed to be here for this day but couldn’t make it because she is rather busy with some other CMS responsibilities in the US.

Now, I am curious if they could manage to do the inverse though, i.e., have mostly man scheduled for shifts.  That would be an interesting exercise; it won’t be easy for sure, as many women in CMS have essential expertise in many areas.

All in all it was a good day,  it definitely felt like a special day, and that’s always a lot of fun.  It smelled very nice too!

Hope all women had a good day !!

Edgar Carrera (Boston University)

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Learning at CMS

Sunday, March 7th, 2010

Humans are very curious by nature; we just love to learn.  Maybe that’s what makes us the most successful mammals on earth.  This need to learn is a common factor among all of us, with no exceptions.  Physicist (scientist), however, are particularly curious and avid of knowledge, and maybe that is why we like what we do. A big plus of our job is that we rarely do the same thing every day.  There is always something new to learn, a new idea to develop, new code to implement, etc. We are constantly doing things that no one has ever done before!

I took a block of 4  day data acquisition (DAQ) shifts during the last weekend (Thu-Sat) at CMS point 5 (where all the action happens).  I was lucky to have a trainee who is also a good friend of mine.  My mission was to prepare him to take DAQ shifts by himself and be able to run the whole CMS experiment (that’s what DAQ shifters do, and that’s why it is so much fun).

My friend, as all of us, had to read and study the documentation about how to run the different applications that are used to run the experiment.  Being able to comprehend the data flow, understand how the sub-detectors interconnect , and quickly identify potential problems are tasks that require some training and practice.  The good side is that we do love to do this; every day is a learning experience.

As the LHC has been playing with the beams (injection, tuning, dumping, beta beats, optics, etc, etc) in order to prepare for energy ramp-up, there were many occasions for my friend to learn and adapt to being a DAQ shifter.  He quickly picked up the basics on how to incorporate or drop sub-detectors in/from the CMS run; how to read and understand the no-less-than 7 monitors (3 keyboards) used for the DAQ system; how to interpret the big screens that announce the current LHC and CMS conditions; how to start, end, pause a CMS run; how to load the appropiate conditions to run a cosmic run, splash events, circulating beams (and eventually collisions); how to issue resynch signals to the different components; how to debug more complicated problems like loss of synch and back-pressure (data flow stuck); and most importantly, become confident and comfortable to know that a 2+ billion dollars experiment like CMS is, in great part, in his hands while driving the DAQ.

Despite him being an experienced professional physicist, I can’t avoid being impressed of how, in general, we humans learn.  It is a marvelous thing, an amazing skill to have.  It propels great things like this experiment, it is so much fun, but it also comes with a great deal of responsibility.

Edgar F. Carrera (Boston University)

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APS Meeting as Higgsless as the Standard Model???

Friday, February 19th, 2010

I came back from Washington D.C. a couple of days ago.  I was attending the APS “April” Meeting (yes it took place on February), which was held at the Marriot Wardman Park hotel.  It was fun, and I got to give a quick presentation about the analysis that I was working on earlier last year, in preparation for physics analysis at CMS. It was based on simulation and was about exploring electroweak symmetry breaking (EWSB) scenarios beyond the Standard Model. In particular, “Higgsless” scenarios like Technicolor models or the Minimal Higgsless Model.

It was scheduled that professor Peter Higgs (one of the proponents of the Standard Model EWSB mechanism) would recieve the prestigious Sakurai Prize for theoretical physics along with many other great theorists that were involved in developing such formalism.  I was really looking forward to see professor Higgs giving one of the acceptance talks, but unfortunately he did not make it to the APS meeting on Monday: it was a Higgsless APS meeting!!! As Higgsless as the models we are trying to study, isn’t that neat??

There are many physical and even philosophical reasons (well, let me say more like aesthetic reasons) for which many of us believe that we will not find the “Higgs” particle per se, i.e., not as a fundamental scalar particle but maybe as composite or none at all (although something must be there).  One of these reasons is, for example, that we have never seen a fundamental scalar particle in nature before.  I dislike the idea of the Higgs boson being a special component, why would that be?  …. Well, I guess we are at the brink of finding out… stay tuned as the LHC will resume very soon!!!!

Edgar Carrera (Boston University)

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Getting fired up again!

Sunday, January 31st, 2010

As the time approaches for the reinitiation of LHC operations, we are starting to feel the excitement  of this grandiose experiment again.

With the Tevatron’s first direct constraint on the mass of the Higgs boson beyond good-old LEP’s this past week, physicists in all LHC experiments are getting ready and more excited to re-start operations and finally gather some data that allow them to search for new physics and hopefully complement or surpass very quickly the astonishing Tevatron results.  Meanwhile, LHC physicists and engineers are finalizing the improvements in the quench protection systems that will allow us to run at the energy of 3.5 TeV/beam, starting middle February.

My two cents, as always, consists of collaborating in putting the CMS trigger system in the best condition possible to start taking good data.  This time though, we are using “real” data from last year’s operations as opposed to using “simulated” data.  No more relying entirely on Monte Carlo, no more tweaking and tuning and speculating about our computer simulations.  This is the real deal guys!!

What we do with the data is to skim it off-line into a collection of good and interesting events, then we feed them into our on-line system and run the trigger menu to check its performance.  These data has all the information, event by event, that the detector collected (in the form of electronic signals) from those proton-proton collisions we had last year.  For these past month or so, we have been capable of touching nature’s primary constituents over and over in order to adapt our detectors and tune them to be able to better sense the most fantastic petals of life: particles!

Edgar Carrera (Boston University)

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