scholarly journals Production of dileptons via photon-photon fusion in proton-proton collisions with one forward proton measurement

2021 ◽  
Author(s):  
Marta Luszczak
2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
C. Baldenegro ◽  
G. Biagi ◽  
G. Legras ◽  
C. Royon

Abstract We present a phenomenology study on central exclusive production of W+W− boson pairs in proton-proton collisions at the Large Hadron Collider at 14 TeV using the forward proton detectors, such as the ATLAS Forward Proton or the CMS-TOTEM Precision Proton Spectrometer detectors. Final states where at least one of the W bosons decay hadronically in a large-radius jet are considered. The latter extends previous efforts that consider solely leptonic final states. A measurement of exclusive W+W− also allows us to further constrain anomalous quartic gauge boson interactions between photons and W bosons. Expected limits on anomalous quartic gauge couplings $$ {a}_{0,C}^W $$ a 0 , C W associated to dimension-six effective operators are derived for the hadronic, semi-leptonic, and leptonic final states. It is found that the couplings can be probed down to one-dimensional values of $$ {a}_0^W=3.7\times {10}^{-7}{\mathrm{GeV}}^{-2} $$ a 0 W = 3.7 × 10 − 7 GeV − 2 and $$ {a}_C^W=9.2\times {10}^{-7}{\mathrm{GeV}}^{-7} $$ a C W = 9.2 × 10 − 7 GeV − 7 at 95% CL at an integrated luminosity of 300 fb−1 by combining all final states, compared to values of about $$ {a}_0^W=4\times {10}^{-6}{\mathrm{GeV}}^{-2} $$ a 0 W = 4 × 10 − 6 GeV − 2 and $$ {a}_C^W=1\times {10}^{-5}{\mathrm{GeV}}^{-2} $$ a C W = 1 × 10 − 5 GeV − 2 at 95% CL expected for the leptonic channel alone.


Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
S. P. Adhya ◽  
A. Adler ◽  
...  

Abstract The production rates and the transverse momentum distribution of strange hadrons at mid-rapidity ($$\left| y\right| < 0.5$$y<0.5) are measured in proton-proton collisions at $$\sqrt{s}$$s = 13 TeV as a function of the charged particle multiplicity, using the ALICE detector at the LHC. The production rates of $$\mathrm{K}^{0}_{S}$$KS0, $$\Lambda $$Λ, $$\Xi $$Ξ, and $$\Omega $$Ω increase with the multiplicity faster than what is reported for inclusive charged particles. The increase is found to be more pronounced for hadrons with a larger strangeness content. Possible auto-correlations between the charged particles and the strange hadrons are evaluated by measuring the event-activity with charged particle multiplicity estimators covering different pseudorapidity regions. When comparing to lower energy results, the yields of strange hadrons are found to depend only on the mid-rapidity charged particle multiplicity. Several features of the data are reproduced qualitatively by general purpose QCD Monte Carlo models that take into account the effect of densely-packed QCD strings in high multiplicity collisions. However, none of the tested models reproduce the data quantitatively. This work corroborates and extends the ALICE findings on strangeness production in proton-proton collisions at 7 TeV.


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