The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton-proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon-nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction.

Search for supersymmetry in a final state containing two photons and missing transverse momentum in [Formula: see text] = 13 TeV [Formula: see text] collisions at the LHC using the ATLAS detector

A search has been made for supersymmetry in a final state containing two photons and missing transverse momentum using the ATLAS detector at the Large Hadron Collider. The search makes use of [Formula: see text] of proton-proton collision data collected at a centre-of-mass energy of 13 TeV in 2015. Using a combination of data-driven and Monte-Carlo-based approaches, the Standard Model background is estimated to be [Formula: see text] events. No events are observed in the signal region; considering the expected background and its uncertainty, this observation implies a model-independent 95 % CL upper limit of 0.93 fb (3.0 events) on the visible cross section due to physics beyond the Standard Model. In the context of a generalized model of gauge-mediated supersymmetry breaking with a bino-like next-to-lightest supersymmetric particle, this leads to a lower limit of 1650 GeV on the mass of a degenerate octet of gluino states, independent of the mass of the lighter bino-like neutralino.

Study of the rare decays of [Formula: see text] and [Formula: see text] into muon pairs from data collected during the LHC Run 1 with the ATLAS detector

A study of the decays [Formula: see text] and [Formula: see text] has been performed using data corresponding to an integrated luminosity of 25 fb[Formula: see text] of 7 and 8 TeV proton-proton collisions collected with the ATLAS detector during the LHC Run 1. For the [Formula: see text] dimuon decay, an upper limit on the branching fraction is set at [Formula: see text] at 95 % confidence level. For [Formula: see text], the branching fraction [Formula: see text] is measured. The results are consistent with the Standard Model expectation with a p value of 4.8 %, corresponding to 2.0 standard deviations.

Charged-particle distributions at low transverse momentum in [Formula: see text] TeV pp interactions measured with the ATLAS detector at the LHC

Measurements of distributions of charged particles produced in proton-proton collisions with a centre-of-mass energy of 13 TeV are presented. The data were recorded by the ATLAS detector at the LHC and correspond to an integrated luminosity of 151 [Formula: see text]. The particles are required to have a transverse momentum greater than 100 MeV and an absolute pseudorapidity less than 2.5. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the dependence of the mean transverse momentum on multiplicity are measured in events containing at least two charged particles satisfying the above kinematic criteria. The results are corrected for detector effects and compared to the predictions from several Monte Carlo event generators.

Search for Higgs and Z Boson Decays to ϕγ with the ATLAS Detector

A search for the decays of the Higgs and Z bosons to a ϕ meson and a photon is performed with a pp collision data sample corresponding to an integrated luminosity of 2.7  fb^{-1} collected at sqrt[s]=13  TeV with the ATLAS detector at the LHC. No significant excess of events is observed above the background, and 95% confidence level upper limits on the branching fractions of the Higgs and Z boson decays to ϕγ of 1.4×10^{-3} and 8.3×10^{-6}, respectively, are obtained.

Search for single production of vector-like quarks decaying into Wb in pp collisions at [Formula: see text] TeV with the ATLAS detector

A search for singly produced vector-like Q quarks, where Q can be either a T quark with charge [Formula: see text] or a Y quark with charge [Formula: see text], is performed in proton-proton collisions recorded with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 20.3 fb[Formula: see text] and was produced with a centre-of-mass energy of [Formula: see text] TeV. This analysis targets [Formula: see text] decays where the W boson decays leptonically. A veto on massive large-radius jets is used to reject the dominant [Formula: see text] background. The reconstructed Q-candidate mass, ranging from 0.4 to 1.2 TeV, is used in the search to discriminate signal from background processes. No significant deviation from the Standard Model expectation is observed, and limits are set on the [Formula: see text] cross-section times branching ratio. The results are also interpreted as limits on the QWb coupling and the mixing with the Standard Model sector for a singlet T quark or a Y quark from a doublet. T quarks with masses below 0.95 TeV are excluded at 95 % confidence level, assuming a unit coupling and a BR[Formula: see text], whereas the expected limit is 1.10 TeV.

Charged-particle distributions in pp interactions at [Formula: see text] measured with the ATLAS detector

This paper presents measurements of distributions of charged particles which are produced in proton-proton collisions at a centre-of-mass energy of [Formula: see text] and recorded by the ATLAS detector at the LHC. A special dataset recorded in 2012 with a small number of interactions per beam crossing (below 0.004) and corresponding to an integrated luminosity of 160 [Formula: see text] was used. A minimum-bias trigger was utilised to select a data sample of more than 9 million collision events. The multiplicity, pseudorapidity, and transverse momentum distributions of charged particles are shown in different regions of kinematics and charged-particle multiplicity, including measurements of final states at high multiplicity. The results are corrected for detector effects and are compared to the predictions of various Monte Carlo event generator models which simulate the full hadronic final state.

Search for squarks and gluinos in final states with jets and missing transverse momentum at [Formula: see text] =13 [Formula: see text]with the ATLAS detector

A search for squarks and gluinos in final states containing hadronic jets, missing transverse momentum but no electrons or muons is presented. The data were recorded in 2015 by the ATLAS experiment in [Formula: see text] proton-proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 3.2 [Formula: see text] of analyzed data. Results are interpreted within simplified models that assume R-parity is conserved and the neutralino is the lightest supersymmetric particle. An exclusion limit at the 95 % confidence level on the mass of the gluino is set at 1.51 [Formula: see text] for a simplified model incorporating only a gluino octet and the lightest neutralino, assuming the lightest neutralino is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.03 [Formula: see text] are excluded for a massless lightest neutralino. These limits substantially extend the region of supersymmetric parameter space excluded by previous measurements with the ATLAS detector.

Denis RD, Stabile A, Staerz S, Stahlman J, Stamen R, Stamm S, Stanecka E, Stanek RW, Stanescu C, Stanescu-Bellu M, Stanitzki MM, Stapnes S, Starchenko EA, Stark GH, Stark J, Staroba P, Starovoitov P, Staszewski R, Steinberg P, Stelzer B, Stelzer HJ, Stelzer-Chilton O, Stenzel H, Stewart GA, Stillings JA, Stockton MC, Stoebe M, Stoicea G, Stolte P, Stonjek S, Stradling AR, Straessner A, Stramaglia ME, Strandberg J, Strandberg S, Strandlie A, Strauss M, Strizenec P, Ströhmer R, Strom DM, Stroynowski R, Strubig A, Stucci SA, Stugu B, Styles NA, Su D, Su J, Subramaniam R, Suchek S, Sugaya Y, Suk M, Sulin VV, Sultansoy S, Sumida T, Sun S, Sun X, Sundermann JE, Suruliz K, Susinno G, Sutton MR, Suzuki S, Svatos M, Swiatlowski M, Sykora I, Sykora T, Ta D, Taccini C, Tackmann K, Taenzer J, Taffard A, Tafirout R, Taiblum N, Takai H, Takashima R, Takeda H, Takeshita T, Takubo Y, Talby M, Talyshev AA, Tam JYC, Tan KG, Tanaka J, Tanaka R, Tanaka S, Tannenwald BB, Tapia Araya S, Tapprogge S, Tarem S, Tartarelli GF, Tas P, Tasevsky M, Tashiro T, Tassi E, Tavares Delgado A, Tayalati Y, Taylor AC, Taylor GN, Taylor PTE, Taylor W, Teischinger FA, Teixeira-Dias P, Temming KK, Temple D, Ten Kate H, Teng PK, Teoh JJ, Tepel F, Terada S, Terashi K, Terron J, Terzo S, Testa M, Teuscher RJ, Theveneaux-Pelzer T, Thomas JP, Thomas-Wilsker J, Thompson EN, Thompson PD, Thompson RJ, Thompson AS, Thomsen LA, Thomson E, Thomson M, Tibbetts MJ, Ticse Torres RE, Tikhomirov VO, Tikhonov YA, Timoshenko S, Tipton P, Tisserant S, Todome K, Todorov T, Todorova-Nova S, Tojo J, Tokár S, Tokushuku K, Tolley E, Tomlinson L, Tomoto M, Tompkins L, Toms K, Tong B, Torrence E, Torres H, Torró Pastor E, Toth J, Touchard F, Tovey DR, Trefzger T, Tremblet L, Tricoli A, Trigger IM, Trincaz-Duvoid S, Tripiana MF, Trischuk W, Trocmé B, Trofymov A, Troncon C, Trottier-McDonald M, Trovatelli M, Truong L, Trzebinski M, Trzupek A, Tseng JCL, Tsiareshka PV, Tsipolitis G, Tsirintanis N, Tsiskaridze S, Tsiskaridze V, Tskhadadze EG, Tsui KM, Tsukerman II, Tsulaia V, Tsuno S, Tsybychev D, Tudorache A, Tudorache V, Tuna AN, Tupputi SA, Turchikhin S, Turecek D, Turgeman D, Turra R, Turvey AJ, Tuts PM, Tyndel M, Ucchielli G, Ueda I, Ueno R, Ughetto M, Ukegawa F, Unal G, Undrus A, Unel G, Ungaro FC, Unno Y, Unverdorben C, Urban J, Urquijo P, Urrejola P, Usai G, Usanova A, Vacavant L, Vacek V, Vachon B, Valderanis C, Valdes Santurio E, Valencic N, Valentinetti S, Valero A, Valery L, Valkar S, Vallecorsa S, Valls Ferrer JA, Van Den Wollenberg W, Van Der Deijl PC, van der Geer R, van der Graaf H, van Eldik N, van Gemmeren P, Van Nieuwkoop J, van Vulpen I, van Woerden MC, Vanadia M, Vandelli W, Vanguri R, Vaniachine A, Vankov P, Vardanyan G, Vari R, Varnes EW, Varol T, Varouchas D, Vartapetian A, Varvell KE, Vasquez JG, Vazeille F, Vazquez Schroeder T, Veatch J, Veloce LM, Veloso F, Veneziano S, Ventura A, Venturi M, Venturi N, Venturini A, Vercesi V, Verducci M, Verkerke W, Vermeulen JC, Vest A, Vetterli MC, Viazlo O, Vichou I, Vickey T, Vickey Boeriu OE, Viehhauser GHA, Viel S, Vigani L, Vigne R, Villa M, Villaplana Perez M, Vilucchi E, Vincter MG, Vinogradov VB, Vittori C, Vivarelli I, Vlachos S, Vlasak M, Vogel M, Vokac P, Volpi G, Volpi M, von der Schmitt H, von Toerne E, Vorobel V, Vorobev K, Vos M, Voss R, Vossebeld JH, Vranjes N, Vranjes Milosavljevic M, Vrba V, Vreeswijk M, Vuillermet R, Vukotic I, Vykydal Z, Wagner P, Wagner W, Wahlberg H, Wahrmund S, Wakabayashi J, Walder J, Walker R, Walkowiak W, Wallangen V, Wang C, Wang C, Wang F, Wang H, Wang H, Wang J, Wang J, Wang K, Wang R, Wang SM, Wang T, Wang T, Wang X, Wanotayaroj C, Warburton A, Ward CP, Wardrope DR, Washbrook A, Watkins PM, Watson AT, Watson IJ, Watson MF, Watts G, Watts S, Waugh BM, Webb S, Weber MS, Weber SW, Webster JS, Weidberg AR, Weinert B, Weingarten J, Weiser C, Weits H, Wells PS, Wenaus T, Wengler T, Wenig S, Wermes N, Werner M, Werner P, Wessels M, Wetter J, Whalen K, Whallon NL, Wharton AM, White A, White MJ, White R, White S, Whiteson D, Wickens FJ, Wiedenmann W, Wielers M, Wienemann P, Wiglesworth C, Wiik-Fuchs LAM, Wildauer A, Wilk F, Wilkens HG, Williams HH, Williams S, Willis C, Willocq S, Wilson JA, Wingerter-Seez I, Winklmeier F, Winston OJ, Winter BT, Wittgen M, Wittkowski J, Wollstadt SJ, Wolter MW, Wolters H, Wosiek BK, Wotschack J, Woudstra MJ, Wozniak KW, Wu M, Wu M, Wu SL, Wu X, Wu Y, Wyatt TR, Wynne BM, Xella S, Xu D, Xu L, Yabsley B, Yacoob S, Yakabe R, Yamaguchi D, Yamaguchi Y, Yamamoto A, Yamamoto S, Yamanaka T, Yamauchi K, Yamazaki Y, Yan Z, Yang H, Yang H, Yang Y, Yang Z, Yao WM, Yap YC, Yasu Y, Yatsenko E, Yau Wong KH, Ye J, Ye S, Yeletskikh I, Yen AL, Yildirim E, Yorita K, Yoshida R, Yoshihara K, Young C, Young CJS, Youssef S, Yu DR, Yu J, Yu JM, Yu J, Yuan L, Yuen SPY, Yusuff I, Zabinski B, Zaidan R, Zaitsev AM, Zakharchuk N, Zalieckas J, Zaman A, Zambito S, Zanello L, Zanzi D, Zeitnitz C, Zeman M, Zemla A, Zeng JC, Zeng Q, Zengel K, Zenin O, Ženiš T, Zerwas D, Zhang D, Zhang F, Zhang G, Zhang H, Zhang J, Zhang L, Zhang R, Zhang R, Zhang X, Zhang Z, Zhao X, Zhao Y, Zhao Z, Zhemchugov A, Zhong J, Zhou B, Zhou C, Zhou L, Zhou L, Zhou M, Zhou N, Zhu CG, Zhu H, Zhu J, Zhu Y, Zhuang X, Zhukov K, Zibell A, Zieminska D, Zimine NI, Zimmermann C, Zimmermann S, Zinonos Z, Zinser M, Ziolkowski M, Živković L, Zobernig G, Zoccoli A, zur Nedden M, Zurzolo G, Zwalinski L. Measurement of event-shape observables in [Formula: see text] events in pp collisions at [Formula: see text] [Formula: see text] with the ATLAS detector at the LHC

Event-shape observables measured using charged particles in inclusive Z-boson events are presented, using the electron and muon decay modes of the Z bosons. The measurements are based on an integrated luminosity of [Formula: see text] of proton-proton collisions recorded by the ATLAS detector at the LHC at a centre-of-mass energy [Formula: see text] [Formula: see text]. Charged-particle distributions, excluding the lepton-antilepton pair from the Z-boson decay, are measured in different ranges of transverse momentum of the Z boson. Distributions include multiplicity, scalar sum of transverse momenta, beam thrust, transverse thrust, spherocity, and [Formula: see text]-parameter, which are in particular sensitive to properties of the underlying event at small values of the Z-boson transverse momentum. The measured observables are compared with predictions from Pythia 8, Sherpa, and Herwig 7. Typically, all three Monte Carlo generators provide predictions that are in better agreement with the data at high Z-boson transverse momenta than at low Z-boson transverse momenta, and for the observables that are less sensitive to the number of charged particles in the event.

Panagiotopoulou E, Pandini CE, Panduro Vazquez JG, Pani P, Panitkin S, Pantea D, Paolozzi L, Papadopoulou TD, Papageorgiou K, Paramonov A, Paredes Hernandez D, Parker AJ, Parker MA, Parker KA, Parodi F, Parsons JA, Parzefall U, Pascuzzi V, Pasqualucci E, Passaggio S, Pastore F, Pastore F, Pásztor G, Pataraia S, Patel ND, Pater JR, Pauly T, Pearce J, Pearson B, Pedersen LE, Pedersen M, Pedraza Lopez S, Pedro R, Peleganchuk SV, Pelikan D, Penc O, Peng C, Peng H, Penwell J, Peralva BS, Perego MM, Perepelitsa DV, Perez Codina E, Perini L, Pernegger H, Perrella S, Peschke R, Peshekhonov VD, Peters K, Peters RFY, Petersen BA, Petersen TC, Petit E, Petridis A, Petridou C, Petroff P, Petrolo E, Petrov M, Petrucci F, Pettersson NE, Peyaud A, Pezoa R, Phillips PW, Piacquadio G, Pianori E, Picazio A, Piccaro E, Piccinini M, Pickering MA, Piegaia R, Pilcher JE, Pilkington AD, Pin AWJ, Pina J, Pinamonti M, Pinfold JL, Pingel A, Pires S, Pirumov H, Pitt M, Plazak L, Pleier MA, Pleskot V, Plotnikova E, Plucinski P, Pluth D, Poettgen R, Poggioli L, Pohl D, Polesello G, Poley A, Policicchio A, Polifka R, Polini A, Pollard CS, Polychronakos V, Pommès K, Pontecorvo L, Pope BG, Popeneciu GA, Popovic DS, Poppleton A, Pospisil S, Potamianos K, Potrap IN, Potter CJ, Potter CT, Poulard G, Poveda J, Pozdnyakov V, Pozo Astigarraga ME, Pralavorio P, Pranko A, Prell S, Price D, Price LE, Primavera M, Prince S, Proissl M, Prokofiev K, Prokoshin F, Protopopescu S, Proudfoot J, Przybycien M, Puddu D, Puldon D, Purohit M, Puzo P, Qian J, Qin G, Qin Y, Quadt A, Quayle WB, Queitsch-Maitland M, Quilty D, Raddum S, Radeka V, Radescu V, Radhakrishnan SK, Radloff P, Rados P, Ragusa F, Rahal G, Raine JA, Rajagopalan S, Rammensee M, Rangel-Smith C, Ratti MG, Rauscher F, Rave S, Ravenscroft T, Raymond M, Read AL, Readioff NP, Rebuzzi DM, Redelbach A, Redlinger G, Reece R, Reeves K, Rehnisch L, Reichert J, Reisin H, Rembser C, Ren H, Rescigno M, Resconi S, Rezanova OL, Reznicek P, Rezvani R, Richter R, Richter S, Richter-Was E, Ricken O, Ridel M, Rieck P, Riegel CJ, Rieger J, Rifki O, Rijssenbeek M, Rimoldi A, Rinaldi L, Ristić B, Ritsch E, Riu I, Rizatdinova F, Rizvi E, Rizzi C, Robertson SH, Robichaud-Veronneau A, Robinson D, Robinson JEM, Robson A, Roda C, Rodina Y, Rodriguez Perez A, Rodriguez Rodriguez D, Roe S, Rogan CS, Røhne O, Romaniouk A, Romano M, Romano Saez SM, Romero Adam E, Rompotis N, Ronzani M, Roos L, Ros E, Rosati S, Rosbach K, Rose P, Rosenthal O, Rossetti V, Rossi E, Rossi LP, Rosten JHN, Rosten R, Rotaru M, Roth I, Rothberg J, Rousseau D, Royon CR, Rozanov A, Rozen Y, Ruan X, Rubbo F, Rubinskiy I, Rud VI, Rudolph MS, Rühr F, Ruiz-Martinez A, Rurikova Z, Rusakovich NA, Ruschke A, Russell HL, Rutherfoord JP, Ruthmann N, Ryabov YF, Rybar M, Rybkin G, Ryu S, Ryzhov A, Saavedra AF, Sabato G, Sacerdoti S, Sadrozinski HFW, Sadykov R, Safai Tehrani F, Saha P, Sahinsoy M, Saimpert M, Saito T, Sakamoto H, Sakurai Y, Salamanna G, Salamon A, Salazar Loyola JE, Salek D, Sales De Bruin PH, Salihagic D, Salnikov A, Salt J, Salvatore D, Salvatore F, Salvucci A, Salzburger A, Sammel D, Sampsonidis D, Sanchez A, Sánchez J, Sanchez Martinez V, Sandaker H, Sandbach RL, Sander HG, Sanders MP, Sandhoff M, Sandoval C, Sandstroem R, Sankey DPC, Sannino M, Sansoni A, Santoni C, Santonico R, Santos H, Santoyo Castillo I, Sapp K, Sapronov A, Saraiva JG, Sarrazin B, Sasaki O, Sasaki Y, Sato K, Sauvage G, Sauvan E, Savage G, Savard P, Sawyer C, Sawyer L, Saxon J, Sbarra C, Sbrizzi A, Scanlon T, Scannicchio DA, Scarcella M, Scarfone V, Schaarschmidt J, Schacht P, Schaefer D, Schaefer R, Schaeffer J, Schaepe S, Schaetzel S, Schäfer U, Schaffer AC, Schaile D, Schamberger RD, Scharf V, Schegelsky VA, Scheirich D, Schernau M, Schiavi C, Schillo C, Schioppa M, Schlenker S, Schmieden K, Schmitt C, Schmitt S, Schmitz S, Schneider B, Schnellbach YJ, Schnoor U, Schoeffel L, Schoening A, Schoenrock BD, Schopf E, Schorlemmer ALS, Schott M, Schovancova J, Schramm S, Schreyer M, Schuh N, Schultens MJ, Schultz-Coulon HC, Schulz H, Schumacher M, Schumm BA, Schune P, Schwanenberger C, Schwartzman A, Schwarz TA, Schwegler P, Schweiger H, Schwemling P, Schwienhorst R, Schwindling J, Schwindt T, Sciolla G, Scuri F, Scutti F, Searcy J, Seema P, Seidel SC, Seiden A, Seifert F, Seixas JM, Sekhniaidze G, Sekhon K, Sekula SJ, Seliverstov DM, Semprini-Cesari N, Serfon C, Serin L, Serkin L, Sessa M, Seuster R, Severini H, Sfiligoj T, Sforza F, Sfyrla A, Shabalina E, Shaikh NW, Shan LY, Shang R, Shank JT, Shapiro M, Shatalov PB, Shaw K, Shaw SM, Shcherbakova A, Shehu CY, Sherwood P, Shi L, Shimizu S, Shimmin CO, Shimojima M, Shiyakova M, Shmeleva A, Shoaleh Saadi D, Shochet MJ, Shojaii S, Shrestha S, Shulga E, Shupe MA, Sicho P, Sidebo PE, Sidiropoulou O, Sidorov D, Sidoti A, Siegert F, Sijacki D, Silva J, Silverstein SB, Simak V, Simard O, Simic L, Simion S, Simioni E, Simmons B, Simon D, Simon M, Sinervo P, Sinev NB, Sioli M, Siragusa G, Sivoklokov SY, Sjölin J, Sjursen TB, Skinner MB, Skottowe HP, Skubic P, Slater M, Slavicek T, Slawinska M, Sliwa K, Slovak R, Smakhtin V, Smart BH, Smestad L, Smirnov SY, Smirnov Y, Smirnova LN, Smirnova O, Smith MNK, Smith RW, Smizanska M, Smolek K, Snesarev AA, Snidero G, Snyder S, Sobie R, Socher F, Soffer A, Soh DA, Sokhrannyi G, Solans Sanchez CA, Solar M, Soldatov EY, Soldevila U, Solodkov AA, Soloshenko A, Solovyanov OV, Solovyev V, Sommer P, Son H, Song HY, Sood A, Sopczak A, Sopko V, Sorin V, Sosa D, Sotiropoulou CL, Soualah R, Soukharev AM, South D, Sowden BC, Spagnolo S, Spalla M, Spangenberg M, Spanò F, Sperlich D, Spettel F, Spighi R, Spigo G, Spiller LA, Spousta M, St. Denis RD, Stabile A, Staerz S, Stahlman J, Stamen R, Stamm S, Stanecka E, Stanek RW, Stanescu C, Stanescu-Bellu M, Stanitzki MM, Stapnes S, Starchenko EA, Stark GH, Stark J, Staroba P, Starovoitov P, Staszewski R, Steinberg P, Stelzer B, Stelzer HJ, Stelzer-Chilton O, Stenzel H, Stewart GA, Stillings JA, Stockton MC, Stoebe M, Stoicea G, Stolte P, Stonjek S, Stradling AR, Straessner A, Stramaglia ME, Strandberg J, Strandberg S, Strandlie A, Strauss M, Strizenec P, Ströhmer R, Strom DM, Stroynowski R, Strubig A, Stucci SA, Stugu B, Styles NA, Su D, Su J, Subramaniam R, Suchek S, Sugaya Y, Suk M, Sulin VV, Sultansoy S, Sumida T, Sun S, Sun X, Sundermann JE, Suruliz K, Susinno G, Sutton MR, Suzuki S, Svatos M, Swiatlowski M, Sykora I, Sykora T, Ta D, Taccini C, Tackmann K, Taenzer J, Taffard A, Tafirout R, Taiblum N, Takai H, Takashima R, Takeda H, Takeshita T, Takubo Y, Talby M, Talyshev AA, Tam JYC, Tan KG, Tanaka J, Tanaka R, Tanaka S, Tannenwald BB, Tapia Araya S, Tapprogge S, Tarem S, Tartarelli GF, Tas P, Tasevsky M, Tashiro T, Tassi E, Tavares Delgado A, Tayalati Y, Taylor AC, Taylor GN, Taylor PTE, Taylor W, Teischinger FA, Teixeira-Dias P, Temming KK, Temple D, Ten Kate H, Teng PK, Teoh JJ, Tepel F, Terada S, Terashi K, Terron J, Terzo S, Testa M, Teuscher RJ, Theveneaux-Pelzer T, Thomas JP, Thomas-Wilsker J, Thompson EN, Thompson PD, Thompson RJ, Thompson AS, Thomsen LA, Thomson E, Thomson M, Tibbetts MJ, Ticse Torres RE, Tikhomirov VO, Tikhonov YA, Timoshenko S, Tipton P, Tisserant S, Todome K, Todorov T, Todorova-Nova S, Tojo J, Tokár S, Tokushuku K, Tolley E, Tomlinson L, Tomoto M, Tompkins L, Toms K, Tong B, Torrence E, Torres H, Torró Pastor E, Toth J, Touchard F, Tovey DR, Trefzger T, Tremblet L, Tricoli A, Trigger IM, Trincaz-Duvoid S, Tripiana MF, Trischuk W, Trocmé B, Trofymov A, Troncon C, Trottier-McDonald M, Trovatelli M, Truong L, Trzebinski M, Trzupek A, Tseng JCL, Tsiareshka PV, Tsipolitis G, Tsirintanis N, Tsiskaridze S, Tsiskaridze V, Tskhadadze EG, Tsui KM, Tsukerman II, Tsulaia V, Tsuno S, Tsybychev D, Tudorache A, Tudorache V, Tuna AN, Tupputi SA, Turchikhin S, Turecek D, Turgeman D, Turra R, Turvey AJ, Tuts PM, Tyndel M, Ucchielli G, Ueda I, Ueno R, Ughetto M, Ukegawa F, Unal G, Undrus A, Unel G, Ungaro FC, Unno Y, Unverdorben C, Urban J, Urquijo P, Urrejola P, Usai G, Usanova A, Vacavant L, Vacek V, Vachon B, Valderanis C, Valdes Santurio E, Valencic N, Valentinetti S, Valero A, Valery L, Valkar S, Vallecorsa S, Valls Ferrer JA, Van Den Wollenberg W, Van Der Deijl PC, van der Geer R, van der Graaf H, van Eldik N, van Gemmeren P, Van Nieuwkoop J, van Vulpen I, van Woerden MC, Vanadia M, Vandelli W, Vanguri R, Vaniachine A, Vankov P, Vardanyan G, Vari R, Varnes EW, Varol T, Varouchas D, Vartapetian A, Varvell KE, Vasquez JG, Vazeille F, Vazquez Schroeder T, Veatch J, Veloce LM, Veloso F, Veneziano S, Ventura A, Venturi M, Venturi N, Venturini A, Vercesi V, Verducci M, Verkerke W, Vermeulen JC, Vest A, Vetterli MC, Viazlo O, Vichou I, Vickey T, Vickey Boeriu OE, Viehhauser GHA, Viel S, Vigani L, Vigne R, Villa M, Villaplana Perez M, Vilucchi E, Vincter MG, Vinogradov VB, Vittori C, Vivarelli I, Vlachos S, Vlasak M, Vogel M, Vokac P, Volpi G, Volpi M, von der Schmitt H, von Toerne E, Vorobel V, Vorobev K, Vos M, Voss R, Vossebeld JH, Vranjes N, Vranjes Milosavljevic M, Vrba V, Vreeswijk M, Vuillermet R, Vukotic I, Vykydal Z, Wagner P, Wagner W, Wahlberg H, Wahrmund S, Wakabayashi J, Walder J, Walker R, Walkowiak W, Wallangen V, Wang C, Wang C, Wang F, Wang H, Wang H, Wang J, Wang J, Wang K, Wang R, Wang SM, Wang T, Wang T, Wang X, Wanotayaroj C, Warburton A, Ward CP, Wardrope DR, Washbrook A, Watkins PM, Watson AT, Watson IJ, Watson MF, Watts G, Watts S, Waugh BM, Webb S, Weber MS, Weber SW, Webster JS, Weidberg AR, Weinert B, Weingarten J, Weiser C, Weits H, Wells PS, Wenaus T, Wengler T, Wenig S, Wermes N, Werner M, Werner P, Wessels M, Wetter J, Whalen K, Whallon NL, Wharton AM, White A, White MJ, White R, White S, Whiteson D, Wickens FJ, Wiedenmann W, Wielers M, Wienemann P, Wiglesworth C, Wiik-Fuchs LAM, Wildauer A, Wilk F, Wilkens HG, Williams HH, Williams S, Willis C, Willocq S, Wilson JA, Wingerter-Seez I, Winklmeier F, Winston OJ, Winter BT, Wittgen M, Wittkowski J, Wollstadt SJ, Wolter MW, Wolters H, Wosiek BK, Wotschack J, Woudstra MJ, Wozniak KW, Wu M, Wu M, Wu SL, Wu X, Wu Y, Wyatt TR, Wynne BM, Xella S, Xu D, Xu L, Yabsley B, Yacoob S, Yakabe R, Yamaguchi D, Yamaguchi Y, Yamamoto A, Yamamoto S, Yamanaka T, Yamauchi K, Yamazaki Y, Yan Z, Yang H, Yang H, Yang Y, Yang Z, Yao WM, Yap YC, Yasu Y, Yatsenko E, Yau Wong KH, Ye J, Ye S, Yeletskikh I, Yen AL, Yildirim E, Yorita K, Yoshida R, Yoshihara K, Young C, Young CJS, Youssef S, Yu DR, Yu J, Yu JM, Yu J, Yuan L, Yuen SPY, Yusuff I, Zabinski B, Zaidan R, Zaitsev AM, Zakharchuk N, Zalieckas J, Zaman A, Zambito S, Zanello L, Zanzi D, Zeitnitz C, Zeman M, Zemla A, Zeng JC, Zeng Q, Zengel K, Zenin O, Ženiš T, Zerwas D, Zhang D, Zhang F, Zhang G, Zhang H, Zhang J, Zhang L, Zhang R, Zhang R, Zhang X, Zhang Z, Zhao X, Zhao Y, Zhao Z, Zhemchugov A, Zhong J, Zhou B, Zhou C, Zhou L, Zhou L, Zhou M, Zhou N, Zhu CG, Zhu H, Zhu J, Zhu Y, Zhuang X, Zhukov K, Zibell A, Zieminska D, Zimine NI, Zimmermann C, Zimmermann S, Zinonos Z, Zinser M, Ziolkowski M, Živković L, Zobernig G, Zoccoli A, zur Nedden M, Zurzolo G, Zwalinski L. Measurement of the charged-particle multiplicity inside jets from [Formula: see text][Formula: see text] pp collisions with the ATLAS detector

The number of charged particles inside jets is a widely used discriminant for identifying the quark or gluon nature of the initiating parton and is sensitive to both the perturbative and non-perturbative components of fragmentation. This paper presents a measurement of the average number of charged particles with [Formula: see text] [Formula: see text] inside high-momentum jets in dijet events using 20.3 fb[Formula: see text] of data recorded with the ATLAS detector in pp collisions at [Formula: see text] [Formula: see text] collisions at the LHC. The jets considered have transverse momenta from 50 [Formula: see text] up to and beyond 1.5 [Formula: see text]. The reconstructed charged-particle track multiplicity distribution is unfolded to remove distortions from detector effects and the resulting charged-particle multiplicity is compared to several models. Furthermore, quark and gluon jet fractions are used to extract the average charged-particle multiplicity for quark and gluon jets separately.

Denis RD, Stabile A, Stamen R, Stamm S, Stanecka E, Stanek RW, Stanescu C, Stanescu-Bellu M, Stanitzki MM, Stapnes S, Starchenko EA, Stark GH, Stark J, Staroba P, Starovoitov P, Stärz S, Staszewski R, Steinberg P, Stelzer B, Stelzer HJ, Stelzer-Chilton O, Stenzel H, Stewart GA, Stillings JA, Stockton MC, Stoebe M, Stoicea G, Stolte P, Stonjek S, Stradling AR, Straessner A, Stramaglia ME, Strandberg J, Strandberg S, Strandlie A, Strauss M, Strizenec P, Ströhmer R, Strom DM, Stroynowski R, Strubig A, Stucci SA, Stugu B, Styles NA, Su D, Su J, Subramaniam R, Suchek S, Sugaya Y, Suk M, Sulin VV, Sultansoy S, Sumida T, Sun S, Sun X, Sundermann JE, Suruliz K, Susinno G, Sutton MR, Suzuki S, Svatos M, Swiatlowski M, Sykora I, Sykora T, Ta D, Taccini C, Tackmann K, Taenzer J, Taffard A, Tafirout R, Taiblum N, Takai H, Takashima R, Takeshita T, Takubo Y, Talby M, Talyshev AA, Tam JYC, Tan KG, Tanaka J, Tanaka R, Tanaka S, Tannenwald BB, Tapia Araya S, Tapprogge S, Tarem S, Tartarelli GF, Tas P, Tasevsky M, Tashiro T, Tassi E, Tavares Delgado A, Tayalati Y, Taylor AC, Taylor GN, Taylor PTE, Taylor W, Teischinger FA, Teixeira-Dias P, Temming KK, Temple D, Ten Kate H, Teng PK, Teoh JJ, Tepel F, Terada S, Terashi K, Terron J, Terzo S, Testa M, Teuscher RJ, Theveneaux-Pelzer T, Thomas JP, Thomas-Wilsker J, Thompson EN, Thompson PD, Thompson AS, Thomsen LA, Thomson E, Thomson M, Tibbetts MJ, Ticse Torres RE, Tikhomirov VO, Tikhonov YA, Timoshenko S, Tipton P, Tisserant S, Todome K, Todorov T, Todorova-Nova S, Tojo J, Tokár S, Tokushuku K, Tolley E, Tomlinson L, Tomoto M, Tompkins L, Toms K, Tong B, Torrence E, Torres H, Torró Pastor E, Toth J, Touchard F, Tovey DR, Trefzger T, Tricoli A, Trigger IM, Trincaz-Duvoid S, Tripiana MF, Trischuk W, Trocmé B, Trofymov A, Troncon C, Trottier-McDonald M, Trovatelli M, Truong L, Trzebinski M, Trzupek A, Tseng JCL, Tsiareshka PV, Tsipolitis G, Tsirintanis N, Tsiskaridze S, Tsiskaridze V, Tskhadadze EG, Tsui KM, Tsukerman II, Tsulaia V, Tsuno S, Tsybychev D, Tudorache A, Tudorache V, Tuna AN, Tupputi SA, Turchikhin S, Turecek D, Turgeman D, Turra R, Turvey AJ, Tuts PM, Tyndel M, Ucchielli G, Ueda I, Ueno R, Ughetto M, Ukegawa F, Unal G, Undrus A, Unel G, Ungaro FC, Unno Y, Unverdorben C, Urban J, Urquijo P, Urrejola P, Usai G, Usanova A, Vacavant L, Vacek V, Vachon B, Valderanis C, Valdes Santurio E, Valencic N, Valentinetti S, Valero A, Valery L, Valkar S, Vallecorsa S, Valls Ferrer JA, Van Den Wollenberg W, Van Der Deijl PC, van der Geer R, van der Graaf H, van Eldik N, van Gemmeren P, Van Nieuwkoop J, van Vulpen I, van Woerden MC, Vanadia M, Vandelli W, Vanguri R, Vaniachine A, Vankov P, Vardanyan G, Vari R, Varnes EW, Varol T, Varouchas D, Vartapetian A, Varvell KE, Vasquez JG, Vazeille F, Vazquez Schroeder T, Veatch J, Veloce LM, Veloso F, Veneziano S, Ventura A, Venturi M, Venturi N, Venturini A, Vercesi V, Verducci M, Verkerke W, Vermeulen JC, Vest A, Vetterli MC, Viazlo O, Vichou I, Vickey T, Vickey Boeriu OE, Viehhauser GHA, Viel S, Vigani L, Vigne R, Villa M, Villaplana Perez M, Vilucchi E, Vincter MG, Vinogradov VB, Vittori C, Vivarelli I, Vlachos S, Vlasak M, Vogel M, Vokac P, Volpi G, Volpi M, von der Schmitt H, von Toerne E, Vorobel V, Vorobev K, Vos M, Voss R, Vossebeld JH, Vranjes N, Vranjes Milosavljevic M, Vrba V, Vreeswijk M, Vuillermet R, Vukotic I, Vykydal Z, Wagner P, Wagner W, Wahlberg H, Wahrmund S, Wakabayashi J, Walder J, Walker R, Walkowiak W, Wallangen V, Wang C, Wang C, Wang F, Wang H, Wang H, Wang J, Wang J, Wang K, Wang R, Wang SM, Wang T, Wang T, Wang X, Wanotayaroj C, Warburton A, Ward CP, Wardrope DR, Washbrook A, Watkins PM, Watson AT, Watson MF, Watts G, Watts S, Waugh BM, Webb S, Weber MS, Weber SW, Webster JS, Weidberg AR, Weinert B, Weingarten J, Weiser C, Weits H, Wells PS, Wenaus T, Wengler T, Wenig S, Wermes N, Werner M, Werner P, Wessels M, Wetter J, Whalen K, Whallon NL, Wharton AM, White A, White MJ, White R, White S, Whiteson D, Wickens FJ, Wiedenmann W, Wielers M, Wienemann P, Wiglesworth C, Wiik-Fuchs LAM, Wildauer A, Wilk F, Wilkens HG, Williams HH, Williams S, Willis C, Willocq S, Wilson JA, Wingerter-Seez I, Winklmeier F, Winston OJ, Winter BT, Wittgen M, Wittkowski J, Wollstadt SJ, Wolter MW, Wolters H, Wosiek BK, Wotschack J, Woudstra MJ, Wozniak KW, Wu M, Wu M, Wu SL, Wu X, Wu Y, Wyatt TR, Wynne BM, Xella S, Xu D, Xu L, Yabsley B, Yacoob S, Yakabe R, Yamaguchi D, Yamaguchi Y, Yamamoto A, Yamamoto S, Yamanaka T, Yamauchi K, Yamazaki Y, Yan Z, Yang H, Yang H, Yang Y, Yang Z, Yao WM, Yap YC, Yasu Y, Yatsenko E, Yau Wong KH, Ye J, Ye S, Yeletskikh I, Yen AL, Yildirim E, Yorita K, Yoshida R, Yoshihara K, Young C, Young CJS, Youssef S, Yu DR, Yu J, Yu JM, Yu J, Yuan L, Yuen SPY, Yusuff I, Zabinski B, Zaidan R, Zaitsev AM, Zakharchuk N, Zalieckas J, Zaman A, Zambito S, Zanello L, Zanzi D, Zeitnitz C, Zeman M, Zemla A, Zeng JC, Zeng Q, Zengel K, Zenin O, Ženiš T, Zerwas D, Zhang D, Zhang F, Zhang G, Zhang H, Zhang J, Zhang L, Zhang R, Zhang R, Zhang X, Zhang Z, Zhao X, Zhao Y, Zhao Z, Zhemchugov A, Zhong J, Zhou B, Zhou C, Zhou L, Zhou L, Zhou M, Zhou N, Zhu CG, Zhu H, Zhu J, Zhu Y, Zhuang X, Zhukov K, Zibell A, Zieminska D, Zimine NI, Zimmermann C, Zimmermann S, Zinonos Z, Zinser M, Ziolkowski M, Živković L, Zobernig G, Zoccoli A, zur Nedden M, Zurzolo G, Zwalinski L. Muon reconstruction performance of the ATLAS detector in proton-proton collision data at [Formula: see text]=13 TeV

This article documents the performance of the ATLAS muon identification and reconstruction using the LHC dataset recorded at [Formula: see text] TeV in 2015. Using a large sample of [Formula: see text] and [Formula: see text] decays from 3.2 fb[Formula: see text] of pp collision data, measurements of the reconstruction efficiency, as well as of the momentum scale and resolution, are presented and compared to Monte Carlo simulations. The reconstruction efficiency is measured to be close to [Formula: see text] over most of the covered phase space ([Formula: see text] and [Formula: see text] GeV). The isolation efficiency varies between 93 and [Formula: see text] depending on the selection applied and on the momentum of the muon. Both efficiencies are well reproduced in simulation. In the central region of the detector, the momentum resolution is measured to be [Formula: see text] ([Formula: see text]) for muons from [Formula: see text] ([Formula: see text]) decays, and the momentum scale is known with an uncertainty of [Formula: see text]. In the region [Formula: see text], the [Formula: see text] resolution for muons from [Formula: see text] decays is [Formula: see text] while the precision of the momentum scale for low-[Formula: see text] muons from [Formula: see text] decays is about [Formula: see text].