It is indeed sad to know that our friend and colleague is no longer with us. Janet and I have enjoyed the company of Sandip and Heide for over 16 years of visits to Hawaii for periods of a month or more. I learned a lot of physics from him and always enjoyed my opportunities to talk science with him, often with John and others. We also enjoyed the social occasions as you can see from the picture attached that was taken at a restaurant in Honolulu in 2019 with John and Colleen, Heide and Sandip. There were many other enjoyable opportunities like that in Venice, Paris and other conferences.

Sandip was a remarkable intellect and a great physicist. He made many contributions to our field theoretically and was a great advisor and colleague to experimentalists as well. His clarity of thought and description of complex physics was very valuable to those of us developing an experimental path. I enjoyed his friendship and collegiality for many years at Manoa and will miss him very much.

Our sincere sympathy to Heide and to Sandip’s many friends and colleagues. Art and Janet McDonald

I first met Sandip in the 80’s, at Madison WI. He invited me to U. Hawaii. He later invited me to apply to be the Sabbatical replacement for Ernie Ma. In the intervening decades, I have stayed at his and Heide’s house many nights (also at John Learned and Colleen’s house).

I love Sandip. In 1996 I threw a two-day mini-confrence/party for Sandip at my home institution, Vanderbilt Universtty, entitled “Topics in the Electroweak Interaction”. Many of Sandips friends atteneded and presented.

Sandip is famous for his humility and humanity. Many of Sandip’s eulogy-writers have attested to this fact. I miss Sandip.

I have Parkinson’s Disease (PD) which limits my balance and travel. I have probably been to U Hawaii for my last time, Sandip too had developed balance issues. which precluded his travel to the mainland, precluding his travel to Vanderbilt. He could not make it to my retirement party August 2019 (organized as a mini-conference by Heinrich Pas and Sergio Palomares-Ruiz). Now I will never see him again. It. hurts. He had been to Vanderbilt many times, including as a special lecturer.

My first publication with Sandip (and John) scooped the world, It was a phenomenological treatment of neutrino oscillations,
performed in Hawaii while I was a visitor there. It was based upon John’s data on the depletion of atmospheric muon neutrinos.
Sandip, in his mentoring mode, had saved the issue for my arrival in Hawaii.
Many papers followed, and Sandip became my most frequent co-author.
His retirement inevitably curtailed his research productivity, and Sandip “slipped” to number two in my list of co-authors (just behind Luis Anchordoqui).

Tom

Physics will never be as much fun as when doing it with Sandip. Not even to mention going to the restaurants.

I came to Hawaii in 2004 as a postdoc, and actually I was somewhat hesitant to go: I had been in the US before and although I liked it a lot I was happy to be back in Germany with my family and friends. Now I was way above 30, and I worried what moving around the world would do to my private life. I went anyway, and I had the best two years of my life in physics. Sandip was the perfect match to me, we could talk about anything, Lorentz violation, time travel, whatever, and he would listen and come up with crucial information and helpful remarks. Countless times we would settle in the comfy leather chairs in his office after lunch, watch the funny pictures on his walls and talk physics. Or other things…

I remember a discussion not too long ago with Sandip and Danny Marfatia about cryonics and the possibility about getting resurrected in the future. Danny was very excited about it. Sandip just said:”This life was a good one. Why try it again?“

I think Sandip had the right attitude – as he had about so many other things in life and in physics.
But he leaves a very big void. I will miss him a lot.

ps: The picture is on John’s patio, on February 17, 2013.

Where to start… I knew Sandip as a close friend since about 1980, and we worked together and shared many a meal and travels to meetings. As everyone knows he was the remarkable combination of being a world class physicist given to precision in his thinking and analysis, and a real gentle man. He got along with everyone. But in physics he was my mentor in many areas of theory, mostly having to do with weak interactions. Many is the time I would propose some crazy idea, and he would respond, “ah but you forgot about….”. He was my guru about theory. Some of our ideas came to fruition whilst at the Tokkuri Tei sushi bar which we frequented (with Heide and Coleen), with Sandip and I drawing on napkins. Two of our most cited papers in fact hang on the wall there, given that we gave an acknowledgment to our sushi master Kazu-san.
Life at UH without my old friend, and certainly that of the Department as well, is much the poorer. Sandip touched many lives as these memorials testify, and I already miss him greatly. I would just say truly a life well lived… yet we would have enjoyed a few more years with him.

It was shocked to know Sandip Pakvasa can not be with us anymore. I still remember his smiling, the way he talks. He is a very nice person, great advisor and well known scientist. Rest In Peace.

A collaboration by Sandip and my thesis advisor Oliver Overseth (Michigan) on a paper had much to do with my joining the University of Hawaii. (Also relevant was that Joan decided Hawaii sounded much more like her home state of Florida and would be a big improvement over Michigan.)

Sandip and Heide were very welcoming when I first visited Hawaii, and we have been good friends ever since. We will miss him very much. Fred and Joan Harris

It is difficult to believe that Sandip Pakvasa is not with us anymore. I had an honour and privilege to work and communicate with him for the last ten years since I was a member (post-doctorate researcher) of the UH High Energy Physics Group (2009-2013). Sandip was great scientist, wonderful person and good friend. I still remember our exciting and truly enjoyable discussions regarding physics, history, politics, etc. Will miss him a lot. Rest In Peace, Sandip. Thanks for everything!!

Sandip Pakvasa
——————

I knew Sandip from early 1960’s. I was in Chicago University and he was in Purdue, but we did not know each other. Raju Raghavan whom I knew was also in Purdue. PP Divakaran who was also in Chicago and myself went to meet Raghavan and there we met Sandip. This may be in 1962 or 63.

Controversy with Dalitz
—————————–
Unfortunately I got into a controversy with R H Dalitz, my Professor. Soon after I returned to Bombay, I deviced an empirical test to find out whether a particular hadron was a composite of quarks or a composite of other hadrons. This test was based on K matrix and applying it on Lambda (1405), I showed that it cannot be a composite of quarks. I did not publish it, but talked  about it in the HEP Symposium at Aligarh (1967) and also at a Matsience Symposium. So Lambda (1405) is the first example of what are now called “Molecular Hadrons”.

Sandip wrote to me that Dalitz was angry with me. Earlier Dalitz, T C Wong and myself had worked on the same hadron Lambda (1405) and so perhaps Dalitz  felt that he should have been a coauthor in my K matrix paper. It was very good that Sandip gave me a timely warning. Immediately I wrote to Dalitz explaining that it was not a full-fledged paper. In the full paper I acknowledged Dalitz properly. I think he was quite satisfied and we became friends again.

Sandip staying in my flat
——————————
As a consequence of a fight with TIFR in 1970 (I will not go into details of that now), I decided to understake a pilgrimage to the South. I sent my family to our home town and visited the temple towns Kanchipuram, Thanjavur,  Srirangam, Kumbakonam, Thiruvannamalai, Thruvananthapuram and Madurai. I was  very much impressed by the famous temples and the magnificence of South Indian  culture.

During this time Sandip visited TIFR and stayed at my flat in the Baskara building. I think he stayed with A P Balachandran. He did not know where I had gone and infact nobody in TIFR knew that. Sandip said that only recently that mystery was solved when he read about my trip in my Autobiography.

Hawaiian trip
—————–
In 1974, Sandip invited me to visit him at Hawaii. I hesitated since I felt it would be difficult to travel with my family (wife and two children). It was CS Warke who said it would be a good opportunity for the family to see USA.

I spent 2 months with Sandip. We worked very hard and completed a paper on the weak neutral current. We analyzed the consequences of the most general form of the neutral current with S,P,V,A and T Lorentz structure. It is this paper that finally led to the integrally charged quark model on which I worked  Probir Roy.

After that I had planned to take my family around for sight-seeing. But hell broke lose one fine October morning. An exceedingly narrow peak was seen in elecron-positron collision. Every day San Fu Tuan was at the phone trying to pump out information on this discovery from Stanford and other centres. San Fu, Sandip and myself wrote a paper on about a dozen inter- -pretations of this peak, which became known as the psi particle. Fortunately our paper did include the correct interpretation, namely a ccbar bound state.

After Hawaii, I took my family to many places where I gave seminars. JJ Sakurai at UCLA, ECG Sudarshan at Austin, RN Mohaptra at Maryland, VS Mathur at Rochester
and AP Balachandran at Syracuse were my hosts.

Myself and my family were very thankful to Sandip for this extensive trip which enabled our visit to so many places and meeting so many physicists.

Visit to Japan
—————–
I visited KEK in Japan for two years 1980-82. This too happened because of  Sandip. When Hirotaka Sugawara was looking for a Gaijin (Foreign Visitor) for the newly formed KEK, Sandip suggested my name.

My family was with me only for one year. This was a very enjoyable visit. I was very much impressed by the devotion of the Japanese Professors and Research Scholars to work. Some of the very senior Professors (in their 80’s) stayed in their offices or in the laboratory working even at 10 PM!

I got an oportunity to work with experimental physicists too. Yasumi San wanted to measure the mass of the antineutrino using internal bremstrahlung in elecron capture of Ho^169 and he wanted me to help.I calculated the atomic  transition rates needed to study this process. Yasumi San included me as the first author in the paper! This is my only experimental paper.

At KEK i learnt three things: Karate, Japanese language and car driving. It was Sandip’s wife Heide who taught me driving. I bought a old car from a friend. Altho’ i could drive, i could not get a driving licence since that needed Japanese language in which i had not become proficient. So I drove round and round the one-mile long photon factory in KEK. All the three things that i learnt in Japan evaporated after my return to India.

Second visit to Hawaii
—————————
I made a second visit to Hawaii in 1989. I gave a series of lectures on String Theory there. One day we saw in Physics Today a letter by Glashow and Ginsparg who had criticized String Theory as Theology. I answered that criticism in my lectures. San Fu Tuan said i must publish my reply. So San Fu and myself published a polemic in Physics Today in reply to Glashow and Ginsparg.

Sandip, his student Xiao-Gang He, and myself wrote two papers on integrally charged quark (ICQ) model on which i had been working with Lakshmi Bala and Saurabh Rindani. Radiation zeroes in YM theory had been discovered by Sahdev and Samuel. We showed how the presence or absence of these zeroes could be used to distinguigh ICQ from the fractionally charged quarks (FCQ). For, the position of the radiation zero depends on the quark charge. In the ICQ the charge of the quark depends onits colour and so gets washed away.

Sandip and the Nobel Prize
———————————
Sandip played a very important role in Kobayashi and Maskawa winning the Nobel Prize. It was his paper with Sugawara that made the Kobayashi-Maskawa work known to others. Sandip and Heide were invited to attend the Nobel Ceremony. Sandip was very happy about it. He said this was the nearest he could get to the Nobel Prize!

INO
——
Sandip was an early supporter of INO. In fact he was involved in it from the beginning of our planning for INO. He contacted Nobel Laureates Sheldon Glashow, Mc Donald, Kajita and other top neutrino physicists such as Halzen  and they wrote letters to the PM. Later when the project got bogged down by opposition from politicians and “activists”, Jogesh Pati led a campaign collecting the support of many NRI physicists. Sandip served in the core committee of that campaign.

Sandip Pakvasa passed away. I am shocked! I have had the privilege of having Sandip Pakvasa as a long-term visitor, as a collaborator but, above all, as a friend. He was a great phenomenologist and, above all, a great human being. RIP José

Sandip, Heide and me