Measurement of exclusive pion pair production in proton–proton collisions at $$\sqrt{s}={7}\,\text {TeV}$$ with the ATLAS detector


Aad, G ORCID: 0000-0002-6665-4934, Abbott, B ORCID: 0000-0002-5888-2734, Abbott, DC ORCID: 0000-0002-7248-3203, Abeling, K ORCID: 0000-0002-1002-1652, Abidi, SH ORCID: 0000-0002-8496-9294, Aboulhorma, A ORCID: 0000-0002-9987-2292, Abramowicz, H ORCID: 0000-0001-5329-6640, Abreu, H ORCID: 0000-0002-1599-2896, Abulaiti, Y ORCID: 0000-0003-0403-3697, Hoffman, AC Abusleme ORCID: 0000-0003-0762-7204 et al (show 2920 more authors) (2023) Measurement of exclusive pion pair production in proton–proton collisions at $$\sqrt{s}={7}\,\text {TeV}$$ with the ATLAS detector. The European Physical Journal C, 83 (7). 627-.

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Abstract

<jats:title>Abstract</jats:title><jats:p>The exclusive production of pion pairs in the process <jats:inline-formula><jats:alternatives><jats:tex-math>$$pp\rightarrow pp\pi ^+\pi ^-$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>p</mml:mi> <mml:mi>p</mml:mi> <mml:mo>→</mml:mo> <mml:mi>p</mml:mi> <mml:mi>p</mml:mi> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>-</mml:mo> </mml:msup> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> has been measured at <jats:inline-formula><jats:alternatives><jats:tex-math>$$\sqrt{s}={7}\,\text {TeV}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>7</mml:mn> <mml:mspace /> <mml:mtext>TeV</mml:mtext> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> with the ATLAS detector at the LHC, using <jats:inline-formula><jats:alternatives><jats:tex-math>$${80}\,{\upmu \textrm{b}}^{-1}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>80</mml:mn> <mml:mspace /> <mml:msup> <mml:mrow> <mml:mi>μ</mml:mi> <mml:mtext>b</mml:mtext> </mml:mrow> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> of low-luminosity data. The pion pairs were detected in the ATLAS central detector while outgoing protons were measured in the forward ATLAS ALFA detector system. This represents the first use of proton tagging to measure an exclusive hadronic final state at the LHC. A cross-section measurement is performed in two kinematic regions defined by the proton momenta, the pion rapidities and transverse momenta, and the pion–pion invariant mass. Cross-section values of <jats:inline-formula><jats:alternatives><jats:tex-math>$$4.8 \pm 1.0 \mathrm {\ (stat)} {~}^{+0.3}_{-0.2} \mathrm {\ (syst)}\ {\upmu \textrm{b}}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>4.8</mml:mn> <mml:mo>±</mml:mo> <mml:mn>1.0</mml:mn> <mml:mrow> <mml:mspace /> <mml:mo>(</mml:mo> <mml:mi>stat</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <mml:msubsup> <mml:mrow> <mml:mspace /> </mml:mrow> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>0.2</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.3</mml:mn> </mml:mrow> </mml:msubsup> <mml:mrow> <mml:mspace /> <mml:mo>(</mml:mo> <mml:mi>syst</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:mrow> <mml:mi>μ</mml:mi> <mml:mtext>b</mml:mtext> </mml:mrow> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> and <jats:inline-formula><jats:alternatives><jats:tex-math>$$9 \pm 6 \mathrm {\ (stat)} {~}^{+2}_{-2} \mathrm {\ (syst)}\ {\upmu \textrm{b}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>9</mml:mn> <mml:mo>±</mml:mo> <mml:mn>6</mml:mn> <mml:mrow> <mml:mspace /> <mml:mo>(</mml:mo> <mml:mi>stat</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <mml:msubsup> <mml:mrow> <mml:mspace /> </mml:mrow> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msubsup> <mml:mrow> <mml:mspace /> <mml:mo>(</mml:mo> <mml:mi>syst</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:mrow> <mml:mi>μ</mml:mi> <mml:mtext>b</mml:mtext> </mml:mrow> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> are obtained in the two regions; they are compared with theoretical models and provide a demonstration of the feasibility of measurements of this type.</jats:p>

Item Type: Article
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 25 Jul 2023 14:39
Last Modified: 18 Mar 2024 03:58
DOI: 10.1140/epjc/s10052-023-11700-x
Open Access URL: https://link.springer.com/article/10.1140/epjc/s10...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3171895
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