Update on 750 GeV diphotons from closed string states

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• 作者：Luis A. Anchordoqui^a ; ^b ; ^c ; ^{laa410@nyu.edu" class="auth_mail" title="E-mail the corresponding author} ; Ignatios Antoniadis^d ; ^e ; Haim Goldberg^f ; Xing Huang^g ; Dieter Lü ; st^h ; ⁱ ; Tomasz R. Taylor^f
• 刊名：Physics Letters B
• 出版年：2016
• 出版时间：10 August 2016
• 年：2016
• 卷：759
• 期：Complete
• 页码：223-228
• 全文大小：1972 K

文摘

Motivated by the recent update on LHC searches for narrow and broad resonances decaying into diphotons we reconsider the possibility that the observed peak in the invariant mass spectrum at ve&_eid=1-s2.0-S0370269316302106&_mathId=si1.gif&_user=111111111&_pii=S0370269316302106&_rdoc=1&_issn=03702693&md5=7587572a9e5188a76f188007b24f7857" title="Click to view the MathML source">M_γγ=750 GeV originates from a closed string (possibly axionic) excitation φ (associated with low mass scale string theory) that has a coupling with gauge kinetic terms. We reevaluate the production of φ by photon fusion to accommodate recent developments on additional contributions to relativistic light–light scattering. We also study the production of φ   via gluon fusion. We show that for both a narrow and a broad resonance these two initial topologies can accommodate the excess of events, spanning a wide range of string mass scales ve&_eid=1-s2.0-S0370269316302106&_mathId=si2.gif&_user=111111111&_pii=S0370269316302106&_rdoc=1&_issn=03702693&md5=22dba413627af269a3316d0c0ae511b3" title="Click to view the MathML source">7≲M_s/TeV≲30 that are consistent with the experimental lower bound: ve&_eid=1-s2.0-S0370269316302106&_mathId=si3.gif&_user=111111111&_pii=S0370269316302106&_rdoc=1&_issn=03702693&md5=7b70c9b62c29e026fd418e1bbbb8602d" title="Click to view the MathML source">M_s>7 TeV, at 95% CL. We demonstrate that for the two production processes the LHC13 data is compatible with the lack of a diphoton excess in LHC8 data within ve&_eid=1-s2.0-S0370269316302106&_mathId=si4.gif&_user=111111111&_pii=S0370269316302106&_rdoc=1&_issn=03702693&md5=2df7161a72ae814ea61ba1c0f62ed6f6" title="Click to view the MathML source">∼1σ. We also show that if the resonance production is dominated by gluon fusion the null results on dijet searches at LHC8 further constrain the coupling strengths of φ, but without altering the range of possible string mass scales.