Friday, December 21, 2012

First In-House Symposium at Physics Department, TU

It was a great day for Physics department of Tezpur University. On the last day of Mayan calender, we organized our first ever in-house symposium. The aim of this symposium was to get familiarize with the works being done in the department by various groups, both experimental as well as theoretical. Since, it was a one day program, we had to stick to just one talk from one group (either by a faculty member or by a research scholar). The program was  co-funded by Intellectual Property Rights cell at TU and the inaugural speech was delivered on IPR by an invited speaker. Rest of the day was all about four different sessions (3-4 talks each) followed by poster session by all the research scholars. The event was pretty smooth and we all had a great day for sure. I got reminded of SYMPHY, the in-house symposium we used to organize at IIT Bombay every year. One generic issue which I observed in SYMPHY as well as in today's event is that people get too technical in their talks showing too many plots, technical details and all. That's encouraging for those who are familiar with that particular field, but could yawning for others. May be we should come up with a guideline from next time requesting the speakers to give an overview of the field highlighting the basics as well as theoretical/practical importance so that swallowing it becomes easier for all. Otherwise only few people in the audience will be listening. Good thing about our initiative is that the administration has decided to make such in-house symposium mandatory in all TU departments. Such a practice is very common in well established institutes like IIT Bombay, its really good that a relatively younger department is following those footsteps. Hope this continues every year in future and bring in more collaboration and ideas.

Another Milestone for the SM!

The standard model (SM) of particle physics has crossed another milestone as reported by LHCb collaboration at the recent hadron collider physics symposium held in Kyoto. They have done an incredible measurement of B meson decaying into muon anti-muon pairs. However, people started using this SM milestone as a bullet in SUSY's chest. BBC reported LHCb UK spokesperson saying, "SUSY might not be dead yet, but these results have certainly put her into hospital". And this statement was enough to spark off a debate in the blogosphere followed by couple of arXiv pre-prints. Well, its true that no sign of new physics in this measurement is disappointing, but it amazes me that SUSY has suffered the most whereas there are plenty of other beyond standard model frameworks in the market. I could see three different types of reactions : SUSY is dead or in hospital, SUSY is less natural than thought and SUSY is still alive or in good health. The first reaction is of course a bit harsh and extreme but probably was good for many others who have come up with pre-prints showing available parameter space (natural parameter space probably, I am confused though what to call natural nowadays) which exactly fit these observations. Even if we collect as much data as we want, they will probably never justify the first reaction and at the worst case will leave us with a situation which is a linear combination of the second two reactions.

Sunday, November 11, 2012

Should have written a paper on it already ;-)

Like most of the experimental anomalies and surprises, the Fermi 130 GeV line has also come under dark shadows recently (http://www.newscientist.com/article/dn22466-doubt-cast-on-fermis-dark-matter-smoking-gun.html). It's not that I believed the dark matter interpretation of this line too much, but I still thought this would survive at least for a year ;) This so called game of town in particle astrophysics was initiated by Weniger in April 2012 with a detailed analysis of the publicly available Fermi-LAT data. This was followed by a series of papers from theorists with many well motivated models explaining the origin of this 130 GeV monochromatic line which apparently does not seem to have any obvious astrophysical origin. As the above link to the article in New Scientist says, the Fermi collaboration hasn't denied the presence of this peak in their data, but the dark matter origin of this line is in doubt as the same line is present even when the Fermi detector is pointed towards earth rather than the galactic center (where dark matter is more abundant). Hope Fermi collaboration would soon come up with an official publication telling us more about it. It won't be too much of a surprise if this goes away like B meson anomalies at DO/CDF went away in the wake of LHC results or the phantom of OPERA disappeared after the loose cable connection was found. Nevertheless, one obvious and immediate advantage of these anomalies is that theorists get a chance to write couple of more papers trying to fit their favorite theory or model with the data. Anyways, as someone pointed out correctly at the BENE workshop at ICTP, Trieste two months back, models don't get killed, they sometimes die out of starvation ;-)  So even if future Fermi-LAT analysis kills the dark matter interpretation of this interesting gamma ray line, all the models used to explain it already are still in safe heaven. Vive Le Model-Building! 

PS: For more information on this doubt cast on Fermi gamma ray line, see RESONANCE blog post!

Monday, November 5, 2012

Looking for a common theme of work!

Pursuing research in an academic institute or university in India is not easy with so much teaching load as well as other administrative works. And probably that's the reason why most of the good research in India are carried out in special research institutes or laboratories where the teaching load is almost zero. This is quite a different picture compared to universities/institutes in other countries (developed ones, in particular) where most of the research output comes from universities. I don't know whom to blame for the poor research conditions of Indian universities, but hopefully the situation will change slowly with the central government authorities seem to be taking a series of initiatives. Anyways, without going further into the blame game, the best way is to make maximum use of the existing system and produce maximum possible quality output. In the physics department of Tezpur University (http://www.tezu.ernet.in/dphy/) where I work, there are around 16 faculty members working in different areas like nano-physics, astrophysics, high energy physics etc. The experimental people are comparatively more active in research as they have a large number of research students under their supervision as well as good number of equipments. Whereas, the members of the theory people do not have many students under them and so is the number of publications. Recently, we have decided to choose a common theme for the theory people so that the theory people can work together on it with a long run perspective. That should hopefully take some load of an individual faculty who do not have the "eligibility" yet to take students under him/her. Here "eligibility" doesn't refer to intellectual eligibility of course, but the "eligibility" criteria defined by the system here which I neither try to justify nor ridicule. But, choosing a common theme of work is not as easy as it may sound, since almost all of us had worked on quite different things during doctoral research. But looking at the fact that the present era is the era of inter-disciplinary research with people explaining condensed matter problems using theory of gravity (just an example), the possible options for such a theme should not be a scarcity.

The expertise the theory people here have are mainly neutrino physics, hadron physics, cosmology, astrophysics/astronomy and plasma physics. As a first trial, we are thinking of considering the problem of dark matter as a common theme (yet to be decided though). Since this is a huge research area, the general feeling is that it should touch upon the field of expertise of each one of us to some extent at least. To go ahead with this theme, it was necessary to highlight some of the interesting and recent things happening in this area to the members since not all of us are actively working on it. I gave an overview seminar on dark matter starting with astrophysical hints like galaxy rotation curve, bullet cluster, structure formation and then going into some details of particle characteristics of dark matter, direct/indirect experimental evidence highlighting many recent anomalies (130 GeV Fermi-LAT line for example) which indirectly point towards the existence of dark matter. Of course, in my ways of looking at this problem, the knowledge of particle physics would be very important to find out the dark matter abundance, its cross section with nuclei in direct detection experiments, the cross section for producing gamma rays or other stuff which we treat as indirect evidence of dark matter etc. One of my colleague here (who specializes in UV astronomy, high energy astrophysics) gave a follow up seminar bringing up an astrophysics problem which could be linked to dark matter in some ways which I do not understand yet. It's about the Missing Baryon problem. This is about the fraction of baryons predicted by big bang nucleosynthesis (BBN) which remain unobserved (about 30% if I am not wrong). Initially I thought this is similar to the Missing Satellite problem which is generic in cold dark matter scenarios which predict more number of satellite galaxies in the clusters which are not observed. Missing Satellite problem can be fixed in scenarios of warm dark matter or non-thermal production of dark matter scenarios well studied in the literature. But this missing baryon problem seems to be different as my colleague says. Its independent of cold or warm dark matter scenarios. Its hard to understand from theory point of view, where those baryons could have gone. Certainly they cant decay into something else, may be BBN scenario has to be modified, but that's also tricky as BBN is one of the very successful predictions of big bang cosmology. I got a Nature news today (http://www.nature.com/nature/journal/v490/n7418/full/490008b.html?WT.ec_id=NATURE-20121004) which talks about a paper claiming that the missing baryons have been spotted in the X-ray data. If confirmed, it would imply that the missing baryons are not exactly missing but just were not being detected somehow. Anyways, it might be too early to settle this mystery and more future data analysis like this group would be needed.

Tuesday, October 30, 2012

Upcoming Conferences Dec-Jan 2012-13

There are couple of nice conferences coming up in next 2-3 months in India which most of the researchers working in the field of high energy physics (HEP) must be waiting for. The first one is TeV particle astrophysics (TeVPA) 2012 (https://grapes-3.tifr.res.in/indico/conferenceDisplay.py?confId=0) to he held at Tata Institute, Bombay during December 10-14, 2012. Looking at the amount of experimental as well as theoretical activities going all around the world on particle astrophysics (dark matter, in particular), this conference would be really exciting. Among other things, I would probably look forward to talks or discussions on 130 GeV gamma ray  line claimed to be present in the Fermi-LAT data ( analyzed by C. Weniger first, who is coming to this conference as a panel speaker). No matter this line is real or not, but the excitement it has created for last couple of months is truly amazing. One another conference (symposium) which almost all Indian HEP people keep looking for is the DAE-BRNS symposium on high energy physics that happens every alternate years. I was there in the last symposium of this series and the experience was amazing probably because of the time and place of the event. It was in the month of December at Jaipur two years back. This time it is being organized at Shantiniketan by Visva Bharati University. The organizers have finally come up with a website and extended the registration deadline also by around 17 days (from October 31 to November 17). The details can be found here http://www.visva-bharati.ac.in/news/DAE-2013/index.html.

Thursday, October 18, 2012

Impact Factors, citations bla bla...

As the competition in academics is getting tougher and tougher due to recession, fund cuts or whatever, it seems to me that certain things like "journal impact factor", "number of citations" etc have become very very important and grabbing more attention than ever. Though I am just a beginner in this field, I feel as if I have started hearing more about these keywords nowadays than I did say, four five years back. Anyways, I guess independent of any personal experiences, it is the overall trend these days. Earlier, if someone has a paper in a journal like Physical Review D, nobody would care about the present impact factor of this prestigious journal. But, with the journal market growing bigger and bigger (and flooded with many open access journals whose sole target is just to publish articles based on the money author gives, rather than the quality of the work), the race towards high impact factor has become more and more visible. Like my PhD supervisor, I never paid much attention to these things as long as we get one or two papers per year in a reputed journal like Physical Review D. I was also unaware of the mechanism which governs the impact factor. But as expected, things like impact factor plays non-trivial role in getting you a job. And that's when I had to search for the impact factors of the journals where I got some papers published. In my job applications I had to write clearly the impact factors of all the journals. I don't know how much that did help me getting a job, but I always hope that my favorite journals like Physical Review among a few others  will maintain their quality always and people wont be caring much about their impact factors, their very names would carry their impact rather than some real numbers known as impact factor which results from some data analysis. Recently, I saw the list of journal impact factors for the year 2011. And I saw some tables showing the number of citations each journal has got in that year and depending on that, the impact factors were ordered (roughly speaking). There were couple of surprises in that table (I hope I dint look at a fake one). For example Physics Letters B impact factor has decreased substantially from around 5 to around 3.5. To a less extent Physical Review D and JHEP impact factor also decreased. Journals like IJMPA, EPJC has somewhat maintained the same impact factor as before, but MPLA impact factor seems to have decreased. Anyways, to conclude the last few lines, all the familiar journals to hep-ph community (at least) have lost their impact factors to some extent. That's heartbreaking indeed. However,  I saw one journal whose impact factor seems to have increased a lot, that's journal of physics G. It's current impact factor is around 4.something. I am sure it was lower than this earlier. Obviously, it has got enormous number of citations as well. That made me think how come a journal in which  I hardly see any paper related to hep-ph can get such a huge number of citations. I had no clue, and I dint even bother to find out. But while reordering the bibliography of a paper I am writing, suddenly I saw one paper in this journal which I am citing. And yes, as expected that's the particle data group (PDG) paper published in 2010 which has around 4000 citations now. So, that's how it works. Even if a journal does not have a significant number of articles important to myself or hep-ph in general compared to other popular journals, even a paper with such huge citations in a year or so can make a big difference. Anyways, I hope I won't get driven into such a race of impact factors and would be ignoring these issues consistently throughout my life and hope my present favorite journals will always remain favorite to me :)

Tuesday, October 2, 2012

A few Updates!

Well, quite a few updates to be precise. That's natural when one is away from the blogosphere for a long time. Lots of things happened since my last post, not all of them worth mentioning of course. The most important of them perhaps is my new affiliation and job. Yes, as I mentioned earlier, my PhD life ended on June 30, 2012 as scheduled without taking any extensions. And thankfully, I dint have to roam around jobless for a long time. I got an offer from a central government university in Tezpur, a small town in the Indian state Assam. Though I was supposed to join HRI, Allahabad sometime in July as a postdoctoral fellow, this offer from Tezpur University came as a big surprise. Being a fresh graduate, I applied there with zero expectation but with a good reason (as the University is just 30 km away from my Home). Also, I did know that its the best University in the North Eastern region of India and the education system is not too different from the IIT's. I am not much sure how different life would have been if I had gone to HRI rather than coming to Tezpur. But one difference is for sure: in Allahabad I would been crossing the river Ganges everyday whereas here I am crossing the Brahmaputra everyday ;-)

Anyways, life is quite enjoyable here in Tezpur specially after I got a campus residence few days back. I hardly feel like being away from my alma mater IIT Bombay. But of course the difference is severe if one goes outside the Tezpur University campus and that of IIT Bombay which for me is not of any concern as I never got addicted to typical city life in Bombay or any other cities. I have been teaching Electromagnetic Theory to MSc first year and General Theory of Relativity to MSc second year. Plus I have to take BTech Physics tutorials sometimes and have to guide an MSc second year project student. Yes, its quite hectic for a beginner as it sounds! But, same load will be on a postdoctoral fellow also in any good research institute. So, I have nothing to complain either to my employer or to myself. It's true (obviously) that teaching load slows down individual research quite a lot. That's the only thing which concerns me most here. I hope I will be able to complement this by visiting some good places whenever my university allows me. Recently, I visited ICTP for the workshop on BEhind NEutrino mass and mixing (BENE) which turned out to be a really good experience with almost all the big shots in this field from all around the world delivering some enlightening talks.I listened to so many talks on discrete flavor symmetries there that I have started liking some of them now, though discrete symmetries always looked very unnatural and ugly to me while I was a PhD student. I am planning to visit Aizawl, Mizoram next month for another conference and perhaps DAE symposium also which will be in January at Shantiniketan, West Bengal.

Hope to post some more updates soon, Cheers!

Wednesday, March 7, 2012

Last few days of PhD life!

The very title of this post is enough to explain my disappearance from the blogosphere for more than four months or so. PhD life has always been fun until recently. I don't even remember now how many trips I made during last four years for attending schools, workshops, conference as well as for picnic, trekking, wildlife etc. May be the distance I have traveled will be close to the one from Earth to Moon ;-) But finally, the fun-time was over and it was time to do some serious work to finish PhD. With just a few months at hand, it was really scary. The most hectic thing was applying for postdocs, arranging recommendation letters, writing thesis etc which often took me away from the research works I had been involved. And, at the end of the day all these efforts went in vain except for an offer in India. Although there are good people in India to work with, the salary of a postdoc is just four thousand rupees ($80) more than the monthly scholarship of a PhD student and with a bonus of more than double the workload. If I had enough time at hand, I would have probably chosen another PhD life than the poor life of a postdoc in India. Anyways, my time in Montreal is almost over, I have many things to update about life and work in Montreal, hopefully I will do that after returning to India next week!