{"title":"Forward physics at LHC: Intersections with astrophysics","authors":"Aldo Penzo","doi":"10.1016/j.nuclphysbps.2024.11.006","DOIUrl":"10.1016/j.nuclphysbps.2024.11.006","url":null,"abstract":"<div><div>LHC pp collisions at <span><math><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>14</mn><mspace></mspace><mrow><mi>TeV</mi></mrow></math></span> correspond to <span><math><msup><mrow><mn>10</mn></mrow><mrow><mn>17</mn></mrow></msup><mspace></mspace><mrow><mi>eV</mi></mrow></math></span> in the cosmic ray spectrum, reaching regions (f.i. the “knee”) whose interpretation is still debated, and whose models may be strongly influenced by LHC results on forward hadronic production, for instance as measured with CMS forward calorimeters. Other astrophysics problems that may receive a decisive input from LHC, and in particular HL-LHC, concern the interpretation of dark matter and dark energy in the universe, in correspondence with BSM (Beyond Standard Model) particles that may be detected as LLP (Long-Lived Particles). LLP searches have been generally done up to now at low pseudorapidity <em>η</em>, as exemplified by some CMS recent results. There may be however reasons why detectors in the forward direction of LHC experiments, could be better suited for these searches, at least for some lifetime ranges, due to large relativistic boosts of the produced particles at LHC energies in the forward region. Considering the CMS forward detectors, their role for some of these searches and corresponding signatures are discussed. Additional possibilities of instrumenting specific regions of the LHC tunnel near the interaction point IP5, where CMS is installed, are discussed.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 116-125"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"QCD aspects in W and Z production with ATLAS","authors":"Alberto Lorenzo Rescia , ATLAS Collaboration","doi":"10.1016/j.nuclphysbps.2024.11.005","DOIUrl":"10.1016/j.nuclphysbps.2024.11.005","url":null,"abstract":"<div><div>The ATLAS collaboration has used the <em>W</em>- and <em>Z</em>-boson production processes to perform a range of precision measurements providing important tests of perturbative QCD and information about the parton distribution functions for quarks within the proton. This contribution presents recent differential <em>Z</em>+heavy flavour jets results, measurements of inclusive, differential cross sections for the production of missing transverse momentum plus jets, measurements of the Drell-Yan cross section as a function of transverse momentum based on low pileup data, total <em>W</em>- and <em>Z</em>-boson cross section measurements at 13.6 TeV.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 98-104"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"aμ|l.ohvp, QCD power corrections and αs from e+e− → Hadrons","authors":"Stephan Narison","doi":"10.1016/j.nuclphysbps.2024.11.007","DOIUrl":"10.1016/j.nuclphysbps.2024.11.007","url":null,"abstract":"<div><div>In this talk, I review the results obtained recently in Ref. <span><span>[1]</span></span>. <em>First,</em> we estimate the LO hadronic vacuum polarization contribution to the muon and <em>τ</em> anomalous magnetic moments to be: <span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow></msub><msubsup><mrow><mo>|</mo></mrow><mrow><mi>l</mi><mo>.</mo><mi>o</mi></mrow><mrow><mi>h</mi><mi>v</mi><mi>p</mi></mrow></msubsup><mo>=</mo><mo>(</mo><mn>7036.5</mn><mo>±</mo><mn>38.9</mn><mo>)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>11</mn></mrow></msup></math></span>, <span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>τ</mi></mrow></msub><msubsup><mrow><mo>|</mo></mrow><mrow><mi>l</mi><mo>.</mo><mi>o</mi></mrow><mrow><mi>h</mi><mi>v</mi><mi>p</mi></mrow></msubsup><mo>=</mo><mo>(</mo><mn>3494.8</mn><mo>±</mo><mn>24.7</mn><mo>)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>9</mn></mrow></msup></math></span> (see Table 1) leading to: <span><math><mi>Δ</mi><msub><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow></msub><mo>≡</mo><msubsup><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow><mrow><mi>e</mi><mi>x</mi><mi>p</mi></mrow></msubsup><mo>−</mo><msubsup><mrow><mi>a</mi></mrow><mrow><mi>μ</mi></mrow><mrow><mi>S</mi><mi>M</mi></mrow></msubsup><mo>=</mo><mo>(</mo><mn>143</mn><mo>±</mo><msub><mrow><mn>42</mn></mrow><mrow><mi>t</mi><mi>h</mi></mrow></msub><mo>±</mo><msub><mrow><mn>22</mn></mrow><mrow><mi>e</mi><mi>x</mi><mi>p</mi></mrow></msub><mo>)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>11</mn></mrow></msup></math></span> which is about 3<em>σ</em> discrepancy between the SM predictions and experiment. One also finds: <span><math><msup><mrow><mi>α</mi></mrow><mrow><mo>(</mo><mn>5</mn><mo>)</mo></mrow></msup><mo>(</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>Z</mi></mrow></msub><mo>)</mo><msub><mrow><mo>|</mo></mrow><mrow><mi>h</mi><mi>a</mi><mi>d</mi></mrow></msub><mo>=</mo><mo>(</mo><mn>2766.3</mn><mo>±</mo><mn>4.5</mn><mo>)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></math></span>. <em>Second,</em> we estimate the QCD power corrections up to dimension 20 from the ratio of Laplace sum rule and from <em>τ</em>-like decay high moments (see Table 3). We do not observe any exponential growth of their size which may not favour a duality violation of the spectral function. We obtain <span><math><mo>〈</mo><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub><msup><mrow><mi>G</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>〉</mo><mo>=</mo><mo>(</mo><mn>7.8</mn><mo>±</mo><mn>3.5</mn><mo>)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><mspace></mspace><msup><mrow><mtext>GeV</mtext></mrow><mrow><mn>4</mn></mrow></msup></math></span> in agreement with the more precise one from heavy quark sum rules, while <span><math><mi>ρ</mi><msub><mrow><mi>α</mi></mrow><mrow><mi>s</mi></mrow></msub><msup><mrow><mo>〈</mo><mover><mrow><","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 105-115"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Recent results on hadron spectroscopy at LHCb","authors":"Liming Zhang","doi":"10.1016/j.nuclphysbps.2024.11.001","DOIUrl":"10.1016/j.nuclphysbps.2024.11.001","url":null,"abstract":"<div><div>The most recent LHCb results related to heavy hadron spectroscopy, encompassing both conventional and exotic states, have been reported. These results include the first observation the radiative decay <span><math><msub><mrow><mi>χ</mi></mrow><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo>(</mo><mn>3872</mn><mo>)</mo><mo>→</mo><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo><mi>γ</mi></math></span>, the observation of <span><math><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>ϕ</mi></math></span> resonances in a new production environment, observation of new charmonium(-like) states in <span><math><msup><mrow><mi>D</mi></mrow><mrow><mo>⁎</mo><mo>±</mo></mrow></msup><msup><mrow><mi>D</mi></mrow><mrow><mo>∓</mo></mrow></msup></math></span> systems, and several pentaquark-related searches.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 90-93"},"PeriodicalIF":0.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A gauge-invariant measure for gauge fields on CP2","authors":"Antonina Maj","doi":"10.1016/j.nuclphysbps.2024.10.006","DOIUrl":"10.1016/j.nuclphysbps.2024.10.006","url":null,"abstract":"<div><div>We consider four-dimensional non-Abelian gauge theory living on a complex projective space <span><math><msup><mrow><mi>CP</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> as a way of gaining insights into (3+1)-dimensional QCD. In particular, we use a complex parametrization of gauge fields on which gauge transformations act homogeneously. This allows us to factor out the gauge degrees of freedom from the volume element leading to a manifestly gauge-invariant measure for the gauge-orbit space (the space of all gauge potentials modulo gauge transformations). The terms appearing in the measure that are of particular interest are mass-like terms for the gauge-invariant modes of the gauge fields. Since these mass terms come with dimensional parameters they are significant in the context of dimensional transmutation. Moreover, the existence of local gauge-invariant mass terms on <span><math><msup><mrow><mi>CP</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> could be related to Schwinger-Dyson calculations of the soft gluon mass. Finally, we argue that there is a kinematic regime in which the theory can be approximated by a 4d Wess-Zumino-Witten (WZW) theory. This result can be used to draw similarities between the mechanism of confinement in four and (2+1) dimensions.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 62-67"},"PeriodicalIF":0.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Recent results and upgrade of the ALICE muon spectrometer","authors":"Luca Quaglia, ALICE collaboration","doi":"10.1016/j.nuclphysbps.2024.10.008","DOIUrl":"10.1016/j.nuclphysbps.2024.10.008","url":null,"abstract":"<div><div>The ALICE experiment at the CERN Large Hadron Collider (LHC) is a multi-purpose particle detector, mainly focused on the study of quark-gluon plasma (QGP) in heavy-ion collisions. In the forward rapidity region, 2.5 < y < 4, ALICE is equipped with a muon spectrometer (MS), which allows to study quarkonia and open heavy-flavor particles, both key probes to investigate QGP properties.</div><div>Although in LHC Run 1 and 2 many important results were achieved, the front absorber of the MS represented a limit to the physics program, due to the multiple scattering and energy loss in the material. To assess this limitation, a new forward vertex tracker (Muon Forward Tracker, MFT) was installed between the inner tracking system (ITS) and the front absorber. This has enhanced the MS physics performance, enabling the separation of prompt/non-prompt charmonium production at forward rapidity. It will also allow one to reduce the combinatorial background from semi-leptonic decays of kaons and pions. Finally, it will greatly improve the invariant-mass resolution of the low-mass dimuon pairs.</div><div>Moreover, during the ongoing LHC Run 3, the rate of Pb–Pb collisions has been increased from 10 kHz (in Run 2) up to 50 kHz, allowing to collect a data sample about 5 times larger than the one recorded in Run 2.</div><div>This contribution will provide a brief overview of the MS upgrades and it will focus on the expected physics performance during the LHC Run 3. Some of the preliminary results already obtained will also be shown.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 75-81"},"PeriodicalIF":0.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"QCD chemistry: Remarks on diquarks","authors":"Mikhail Shifman","doi":"10.1016/j.nuclphysbps.2024.10.007","DOIUrl":"10.1016/j.nuclphysbps.2024.10.007","url":null,"abstract":"<div><div>I review the status of “good diquarks” in light-quark hadronic structure and argue that the heavy-light diquarks play no role in the structure of <em>b</em>-containing hadrons (including exotics), and their role in <em>c</em>-containing hadrons is likely to be minimal if at all. I explain that a crucial phenomenological proof can be obtained from weak decays of <em>b</em>-containing hadrons, such <span><math><msub><mrow><mi>Λ</mi></mrow><mrow><mi>b</mi></mrow></msub></math></span>.</div></div>","PeriodicalId":37968,"journal":{"name":"Nuclear and Particle Physics Proceedings","volume":"347 ","pages":"Pages 86-89"},"PeriodicalIF":0.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}