Search for physics beyond the standard model in high-mass diphoton events from proton-proton collisions at $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$

Open Access

Search for physics beyond the standard model in high-mass diphoton events from proton-proton collisions at $\sqrt{s} = 13 TeV$

A. M. Sirunyan et al. (CMS Collaboration)

Phys. Rev. D 98, 092001 – Published 2 November 2018

Abstract

A search for physics beyond the standard model is performed using a sample of high-mass diphoton events produced in proton-proton collisions at $\sqrt{s} = 13 TeV$ . The data sample was collected in 2016 with the CMS detector at the LHC and corresponds to an integrated luminosity of $35.9 {fb}^{- 1}$ . The search is performed for both resonant and nonresonant new physics signatures. At 95% confidence level, lower limits on the mass of the first Kaluza-Klein excitation of the graviton in the Randall-Sundrum warped extra-dimensional model are determined to be in the range of 2.3 to 4.6 TeV, for values of the associated coupling parameter between 0.01 and 0.2. Lower limits on the production of scalar resonances and model-independent cross section upper limits are also provided. For the large extra-dimensional model of Arkani-Hamed, Dimopoulos, and Dvali, lower limits are set on the string mass scale $M_{S}$ ranging from 5.6 to 9.7 TeV, depending on the model parameters. The first exclusion limits are set in the two-dimensional parameter space of a continuum clockwork model.

Received 1 September 2018

DOI:https://doi.org/10.1103/PhysRevD.98.092001

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

Physics Subject Headings (PhySH)

Gravitons

Hadron colliders

Particles & Fields

Authors & Affiliations

Click to Expand

Article Text

Click to Expand

References

Click to Expand

Issue

Vol. 98, Iss. 9 — 1 November 2018

Reuse & Permissions

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
The product of the event selection efficiency ( $ϵ$ ) and the detector acceptance (A) is shown as a function of signal resonance mass $m_{X}$ for the $Γ_{X} / m_{X} = 1.4 \times 10^{- 4}$ signal width hypothesis. The total (black), EBEB (red), and EBEE (blue) curves are shown for the spin (J) hypotheses $J = 0$ (solid line) and $J = 2$ (dashed line).
Reuse & Permissions
Figure 2
Observed diphoton invariant mass spectra for the EBEB (left) and EBEE (right) categories. Also shown are the results of a likelihood fit to the background-only hypothesis. The shaded region shows the one standard deviation uncertainty band associated with the fit, reflecting the statistical uncertainty of the data. The lower panels show the difference between the data and fit, divided by the statistical uncertainty in the data points.
Reuse & Permissions
Figure 3
Expected and observed 95% CL upper limits on the production cross section for RS gravitons of mass $m_{G}$ and three values of $\tilde{k}$ (left) and for spin-0 resonances of mass $m_{S}$ produced via gluon fusion for the three width hypotheses (right). The shaded bands represent the 1 and 2 standard deviation uncertainty in the expected limit.
Reuse & Permissions
Figure 4
Expected and observed 95% CL upper limits on the fiducial cross section for the resonant $p p \to γ γ$ process. Shown are the results in the EBEB (left) and EBEE (right) categories for the three width hypotheses. The shaded bands represent the 1 and 2 standard deviation uncertainty in the expected limit.
Reuse & Permissions
Figure 5
The diphoton invariant mass distributions in the EBEB (left) and EBEE (right) categories for the SM diphoton background prediction and the fake background measurement compared to the data. The last bin includes the overflow. The error bars on the points indicate the statistical uncertainty. The upper (lower) plots show the prefit (postfit) background estimates. The hatched bands indicate the total prefit or postfit systematic uncertainties. Invariant mass distributions from two signal scenarios are superimposed on the lower plots. The bottom panels show the pull distributions, indicating the difference between the data and background prediction, divided by the uncertainty in the background, with error bars representing the statistical uncertainty and shaded bands showing the one standard deviation systematic uncertainty, normalized by the statistical uncertainty.
Reuse & Permissions
Figure 6
The 95% CL exclusion limits for the continuous graviton model in the clockwork framework over the $k - M_{5}$ parameter space. The shaded bands represent the 1 and 2 standard deviation uncertainty in the expected limit. The shaded region with $k > M_{5}$ denotes the area where the theory becomes nonperturbative.
Reuse & Permissions

Physical Review D

covering particles, fields, gravitation, and cosmology

Search for physics beyond the standard model in high-mass diphoton events from proton-proton collisions at $\sqrt{s} = 13 TeV$

A. M. Sirunyan et al. (CMS Collaboration)

Phys. Rev. D 98, 092001 – Published 2 November 2018

Abstract

Physics Subject Headings (PhySH)

Authors & Affiliations

Article Text

References

Issue

Physical Review D

covering particles, fields, gravitation, and cosmology

Search for physics beyond the standard model in high-mass diphoton events from proton-proton collisions at s=13 TeV

A. M. Sirunyan et al. (CMS Collaboration)

Phys. Rev. D 98, 092001 – Published 2 November 2018

Abstract

Physics Subject Headings (PhySH)

Authors & Affiliations

Article Text

References

Issue

Authorization Required

Other Options

Download & Share

Images

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Reuse & Permissions

Log In

Search

Article Lookup

Paste a citation or DOI

Enter a citation

Search for physics beyond the standard model in high-mass diphoton events from proton-proton collisions at $\sqrt{s} = 13 TeV$