scholarly journals Semiexclusive production of vector mesons in proton-proton collisions with electromagnetic dissociation of protons

2019 ◽  
Vol 199 ◽  
pp. 05010
Author(s):  
Anna Cisek ◽  
Wolfgang Schäfer ◽  
Antoni Szczurek
Keyword(s):  
Structure Function ◽  
Cross Sections ◽  
Single Particle ◽  
Center Of Mass ◽  
Vector Mesons ◽  
Differential Distribution ◽  
Proton Proton ◽  
Proton Collisions ◽  
Electromagnetic Structure ◽  
Proton Proton Collisions

We discuss the semiexclusive production of vector mesons in protonproton collisions with electromagnetic dissociation of one of the protons. Several differential distribution in missing mass (MX), or single-particle variables related exclusively to the produced vector meson are calculated for pp center-of-mass energies 7 and 13 TeV. The cross sections and some differential distributions are compared to their counterparts for purely exclusive reaction $pp \to pV{\rm{ }}p$. For electromagnetic dissociation the important property is that the $p\gamma^{\bigstar} \to Xp$ transitions are given by the electromagnetic structure function of proton. In our calculations we use different parametrizations of the structure function and discuss how it is constrained by the data on virtual photoabsorption on a proton.

scholarly journals Study of central exclusive "Equation missing" No EquationSource Format="TEX", only image production in proton-proton collisions at $$\sqrt{s} = 5.02$$ and 13TeV

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Cross Sections ◽  
Production Cross ◽  
Center Of Mass ◽  
Momentum Equation ◽  
Theoretical Description ◽  
Proton Proton ◽  
Proton Collisions ◽  
Image Production ◽  
Proton Proton Collisions

Abstract Central exclusive and semiexclusive production of "Equation missing" pairs is measured with the CMS detector in proton-proton collisions at the LHC at center-of-mass energies of 5.02 and 13TeV. The theoretical description of these nonperturbative processes, which have not yet been measured in detail at the LHC, poses a significant challenge to models. The two pions are measured and identified in the CMS silicon tracker based on specific energy loss, whereas the absence of other particles is ensured by calorimeter information. The total and differential cross sections of exclusive and semiexclusive central "Equation missing" production are measured as functions of invariant mass, transverse momentum, and rapidity of the "Equation missing" system in the fiducial region defined as transverse momentum "Equation missing" and pseudorapidity "Equation missing". The production cross sections for the four resonant channels "Image missing" , "Equation missing", "Image missing" , and "Image missing" are extracted using a simple model. These results represent the first measurement of this process at the LHC collision energies of 5.02 and 13TeV.

scholarly journals Search for physics beyond the standard model in events with jets and two same-sign or at least three charged leptons in proton-proton collisions at $$\sqrt{s}=13\,{\text {TeV}} $$

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
Center Of Mass ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Charged Leptons ◽  
Proton Proton Collisions

Abstract A data sample of events from proton-proton collisions with at least two jets, and two isolated same-sign or three or more charged leptons, is studied in a search for signatures of new physics phenomena. The data correspond to an integrated luminosity of $$137{\,{\text {fb}}^{-1}} $$137fb-1 at a center-of-mass energy of $$13\,{\text {TeV}} $$13TeV, collected in 2016–2018 by the CMS experiment at the LHC. The search is performed using a total of 168 signal regions defined using several kinematic variables. The properties of the events are found to be consistent with the expectations from standard model processes. Exclusion limits at 95% confidence level are set on cross sections for the pair production of gluinos or squarks for various decay scenarios in the context of supersymmetric models conserving or violating R parity. The observed lower mass limits are as large as $$2.1\,{\text {TeV}} $$2.1TeV for gluinos and $$0.9\,{\text {TeV}} $$0.9TeV for top and bottom squarks. To facilitate reinterpretations, model-independent limits are provided in a set of simplified signal regions.

Production of a light top-squark pair in association with a light non-SM Higgs boson within the NMSSM from proton–proton collisions at s = 13 TeV and 33 TeV

2019 ◽  
Vol 34 (22) ◽  
pp. 1950125
Author(s):  
Siba P. Das ◽  
Jorge F. Fraga ◽  
Carlos Avila
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Cross Sections ◽  
Center Of Mass ◽  
Top Squark ◽  
Proton Proton ◽  
Proton Collisions ◽  
Physical Constraints ◽  
Leptonic Decays ◽  
Proton Proton Collisions

We study the production of a light top-squark pair in association with the lightest Higgs boson [Formula: see text], as predicted by the Next-to-Minimal Supersymmetric Standard Model (NMSSM) in proton–proton collisions at center-of-mass energies of 13 TeV and 33 TeV. We scan randomly about 10 million points of the NMSSM parameter space, allowing all possible decays of the lightest top-squark and lightest Higgs boson, with no further assumptions, except for known physical constraints such as perturbative bounds, dark matter relic density consistent with recent Planck experiment measurements, Higgs mass bounds on the next to lightest Higgs boson, [Formula: see text], assuming it is consistent with LHC measurements for the Standard Model Higgs boson, LEP bounds for the chargino mass and [Formula: see text] invisible width, experimental bounds on [Formula: see text] meson rare decays and some LHC experimental bounds on SUSY particle spectra different to the particles involved in our analysis. We find that for low mass top-squark, the dominating decay mode is [Formula: see text] with [Formula: see text]. We use three benchmark points with the highest cross-sections, which naturally fall within the compressed spectra of the top-squark, and make a phenomenological analysis to determine the optimal event selection that maximizes the signal significance over backgrounds. We focus on the leptonic decays of both [Formula: see text]’s and the decay of the lightest Higgs boson into [Formula: see text]-quarks [Formula: see text]. Our results show that the high luminosity LHC will have limitations to observe the studied SUSY scenario and only a proton collider with a collision energy above 33 TeV will be able to observe this signal with more than three standard deviations over background, albeit for stop masses below 300 GeV.

scholarly journals Measurement of prompt open-charm production cross sections in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
T. Bergauer ◽  
...  
Keyword(s):  
Cross Sections ◽  
Theoretical Calculations ◽  
Production Cross ◽  
Center Of Mass ◽  
Open Charm ◽  
Charm Mesons ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Proton Proton Collisions

Abstract The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13 TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb−1. The differential production cross sections of the D∗±, D±, and D0$$ \left({\overline{\mathrm{D}}}^0\right) $$ D ¯ 0 mesons are presented in ranges of transverse momentum and pseudorapidity 4 < pT< 100 GeV and |η| < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.

scholarly journals Measurement of the Z boson differential production cross section using its invisible decay mode (Z → $$ \nu \overline{\nu} $$) in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
T. Bergauer ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Cross Section ◽  
Cross Sections ◽  
Z Boson ◽  
Production Cross ◽  
Center Of Mass ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Proton Proton Collisions

Abstract Measurements of the total and differential fiducial cross sections for the Z boson decaying into two neutrinos are presented at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were collected by the CMS detector in 2016 and correspond to an integrated luminosity of 35.9 fb−1. In these measurements, events are selected containing an imbalance in transverse momentum and one or more energetic jets. The fiducial differential cross section is measured as a function of the Z boson transverse momentum. The results are combined with a previous measurement of charged-lepton decays of the Z boson. The measured total fiducial cross section for events with Z boson transverse momentum greater than 200 GeV is $$ {3000}_{-170}^{+180} $$ 3000 − 170 + 180 fb.

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