{"product_id":"diphantom-pixel-hoodie","title":"Diphantom – The 750 GeV Diphoton Excess Pixel Hoodie","description":"\u003cp\u003eDiphantom, a spectral knight made of two crossing beams of light, carries a small flickering bump at his heart while a skyline of histogram bars falls away behind him.\u003c\/p\u003e\u003ch3\u003eThe Physics\u003c\/h3\u003e\u003cp\u003eOn 15 December 2015 the ATLAS and CMS collaborations each showed a small excess of photon pairs with invariant mass near 750 GeV in the first 13 TeV LHC data. A new heavy boson decaying to two photons would show up as exactly such a bump above the smoothly falling background. Hundreds of theory papers followed. With roughly four to five times more data (ATLAS 15.4 fb⁻¹ in 2016 against 3.2 fb⁻¹ in 2015; CMS 12.9 fb⁻¹ against 3.3 fb⁻¹), both experiments reported at ICHEP on 5 August 2016 that the excess had gone. It was a statistical fluctuation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003em\u003csub\u003eγγ\u003c\/sub\u003e² c⁴ = 2 E₁ E₂ (1 − cos θ)\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003em\u003csub\u003eγγ\u003c\/sub\u003e: invariant mass of the photon pair (GeV\/c²)\u003c\/li\u003e\n\u003cli\u003eE₁, E₂: measured photon energies (GeV)\u003c\/li\u003e\n\u003cli\u003eθ: opening angle between the two photons in the lab frame\u003c\/li\u003e\n\u003cli\u003ec: speed of light\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhen many mass bins are searched, an excess somewhere is likely by chance (the look-elsewhere effect), so its local significance overstates the global one. Sources: ATLAS briefing, “High-mass di-photon resonances: the first 2016 ATLAS results” (Aug 2016); CMS ICHEP 2016 public results; Physics World, Aug 2016.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eHonest caveat:\u003c\/em\u003e Nothing was wrong with the detectors or analyses; small samples fluctuate. The data rule out this particular bump, not every heavy diphoton resonance.\u003c\/p\u003e\u003ch3\u003eIn character\u003c\/h3\u003e\u003cp\u003e\u003cem\u003eFor eight months I wore a crown of a thousand papers. Then the data grew, and I was what I always was: noise, standing a little too tall.\u003c\/em\u003e\u003c\/p\u003e\u003ch3\u003eOn the hoodie\u003c\/h3\u003e\u003cp\u003eFront: two crossing photon lines with a hollow dot at the crossing. Front label: “750 GeV DIPHOTON · FADED 2016”. Back: Diphantom in full pixel art with “BORN 15 DEC 2015 - DIED 5 AUG 2016” and “A FLUCTUATION WEARING A CROWN.” Gildan 18500 Heavy Blend hoodie, Black, S to 5XL.\u003c\/p\u003e\u003cp\u003ePart of the \u003cstrong\u003eGhost Particles That Were Wrong\u003c\/strong\u003e set with \u003ca href=\"\/nl\/products\/sir-aetheron-pixel-hoodie\"\u003eSir Aetheron\u003c\/a\u003e, \u003ca href=\"\/nl\/products\/enrayne-pixel-hoodie\"\u003eEnrayne\u003c\/a\u003e, \u003ca href=\"\/nl\/products\/calorus-pixel-hoodie\"\u003eCalorus\u003c\/a\u003e, \u003ca href=\"\/nl\/products\/prematura-pixel-hoodie\"\u003ePrematura\u003c\/a\u003e, \u003ca href=\"\/nl\/products\/thetarch-pixel-hoodie\"\u003eThetarch\u003c\/a\u003e. Browse all \u003ca href=\"\/nl\/collections\/hoodies\"\u003ephysics hoodies\u003c\/a\u003e, more \u003ca href=\"\/nl\/collections\/particle-physics\"\u003eparticle \u0026amp; nuclear physics designs\u003c\/a\u003e, or the \u003ca href=\"\/nl\/collections\/deep-cuts\"\u003eDeep Cuts\u003c\/a\u003e.\u003c\/p\u003e","brand":"Printify","offers":[{"title":"Black \/ S","offer_id":50964468367463,"sku":"10237940436925301286","price":64.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ M","offer_id":50964468400231,"sku":"20341608686246934641","price":64.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ L","offer_id":50964468432999,"sku":"25462335692149801443","price":64.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ XL","offer_id":50964468465767,"sku":"19100754457203331811","price":64.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 2XL","offer_id":50964468498535,"sku":"33619771665418655161","price":64.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 3XL","offer_id":50964468531303,"sku":"16636946075454964806","price":64.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 4XL","offer_id":50964468564071,"sku":"30942987810949317717","price":64.99,"currency_code":"USD","in_stock":true},{"title":"Black \/ 5XL","offer_id":50964468596839,"sku":"18847333557252584756","price":64.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0596\/8746\/9159\/files\/03_H15_d3152f2e-bdfd-4579-a005-7d7d6d4fad72.png?v=1793678447","url":"https:\/\/pixelatedphysics.com\/nl\/products\/diphantom-pixel-hoodie","provider":"Pixelated Physics","version":"1.0","type":"link"}