Thursday, June 25, 2015

quantum gravity - What's the recent released 750GeV particle's spin?


I was told that it has recently been confirmed to be spin-2 particle, and potentially to be graviton. I'm pretty interested in how this has been examined.


Edit: During the Moriond 2016 conference, CMS clearly stated it is a spin-2 rather than spin-0 particle (spin-1 has already been ruled out by Landau-Yang theorem [1-2]). For a review, see [3].


The yesterday report on ATLAS claims new analysis and new methods gave promising result, which is what I'm looking forward to know. Also I would like some experts to give an introduction to the physics picture how to examine the spin, and what's the theoretical model [4] means.


Edit2: on Aug 5th, ICHEP conference, the new result is gonna to be published.


Edit3: ICHEP conference released ATLAS & CMS results [5-6]. ATLAS doesn't contain newest spin-2 selection results (which could be something), while CMS gives disappointing results.





[1] C.-N. Yang, Selection Rules for the Dematerialization of a Particle Into Two Photons, Phys. Rev. 77 (1950) 242–245. http://dx.doi.org/10.1103/PhysRev.77.242;


[2] L. D. Landau, On the angular momentum of a system of two photons, Dokl. Akad. Nauk Ser. Fiz. 60 (2) (1948) 207–209. http://dx.doi.org/10.1016/B978-0-08-010586-4.50070-5.


[3] Strumia, Alessandro. "Interpreting the 750 GeV digamma excess: a review." arXiv preprint arXiv:1605.09401 (2016).


[4] Dillon, Barry M., and Veronica Sanz. "A little KK graviton at 750 GeV." arXiv preprint arXiv:1603.09550 (2016).


[5] http://indico.cern.ch/event/432527/contributions/1072336/attachments/1321033/1981068/BL_ATLAS_HighMassDiphotons_ICHEP2016.pdf


[6] http://indico.cern.ch/event/432527/contributions/1072431/attachments/1320985/1980991/chiara_ichep.pdf




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