JHEP12(2009)012 c Colliders December 2, 2009 November 3, 2009 September 2, 2009 : : : region of the parameter show that these contribu- Received Accepted Published 10.1088/1126-6708/2009/12/012 e investigated at the Tevatron doi: titut, Published by IOP Publishing for SISSA ) corrections to the process of gluino pair produc- α 2 s α ( O 0908.3318v1 Supersymmetric Standard Model, NLO Computations, Hadroni We calculate the full [email protected] SISSA 2009 Max-Planck-Institut Physik, f¨ur Werner-Heisenberg-Ins RingF¨ohringer 6, D-80805 Germany M¨unchen, E-mail: c tions can be neglectedspace. at the The LHC impact of performing theseis a corrections small. scan in over the a parameter rang wide Keywords: tion at hadron colliders in the framework of the real MSSM. We

Abstract: E. Mirabella NLO electroweak contributions toproduction gluino at pair hadron colliders ArXiv ePrint: JHEP12(2009)012 4 5 6 6 8 9 1 2 4 7 16 18 13 15 ]. 9 , 8 can explain the big aking of electroweak studies have shown the ture years. In particular, 2 of the muon [ a guideline for its extension. ak precision observables pro- zed by Supersymmetry itself. − hysics is affected by theoretical g of integrated luminosity in the inclusive ], is one of the most promising scenarios 5 1 – − 3 ], and in particular the Minimal Supersymmet- 2 – 1 – , ], provided that the masses of squarks and gluinos 1 11 , 10 ] which is at least as good as that obtained using the SM, 7 , 2 TeV). Interestingly, the 95 % confidence level area of the 6 < channel [ T E fusion ¯ q γ and annihilation with electroweak loops annihilation with real photon emission ) corrections to the hadronic process ¯ ¯ q q α q q qγ 2 s α ( These features render SUSY an appealing framework, and they O 4.1 Dependence4.2 on the SUSY scenario Dependence on the MSSM parameters 3.1 3.2 3.3 3.4 Factorization of initial collinear singularities and phenomenological problems whose solution canIn be this respect used as Supersymmetry (SUSY) [ B Input parameters 1 Introduction Despite of its success, the Standard Model (SM) of particle p 5 Numerical results, Tevatron 6 Conclusions A Feynman diagrams 4 Numerical results, LHC 3 Contents 1 Introduction 2 Gluino pair production in lowest order are not too heavy (e.g. for physics beyond thesymmetry is Standard obtained Model. radiativelyMoreover, at the In comparison a of SUSY scale MSSM modelsvides predictions which and an is the electrowe overall stabili bre fit ofand data even better [ in the case of specific observables such as ric extension of the Standard Model (MSSM) [ effort in the hunting forthis SUSY search not is only in onepossibility the of of past early the but discovery also major of in SUSY goals fu with of 1 the fb LHC. Experimental multijet plus missing JHEP12(2009)012 ) ) 2 s α α 2 s = 2 ( (2.1) (1.1) α ( O , /N ] would O ) 8% of the 15 ], and the τS = 1 – ( − summarizes ). At lowest ˜ g 24 2 s ˜ g 13 6 N gion that will , α → ( 0 , 23 2 gg O ino pair production dσ ]. These corrections ) (1 TeV). In this mass τ 21 ( (600 GeV). Moreover, O O gg such as the of the squarks and of the re dτ ted at Born level long time e measure of the spin of a ]. ost efficiently. This implies dL p to 5%. The computation d Model scenarios, but also ction of squarks and gluinos. pendix. 29 p computing the full ion of colored SUSY particles. vatron. Section – dτ LL) accuracy [ are of the order of 2 EW and NLO EW contributions ection can be written as follows, 1 25 0 we briefly summarize the τ le dependence. They are included 2 is devoted to a brief discussion on Z 5 )+ ]. Their inclusion further stabilizes the ) are of QCD origin, of 24 ), to the process of hadronic production τS ( α ˜ g X, ˜ g 1.1 2 s ˜ g we describe the partonic processes contribut- ˜ g α → ( ]. More recent is the resummation of the QCD 0 3 , q 2 q → O – 2 – 22 [ dσ ]. ) 7 , while section τ P P ( 4 q (10 pb) if the gluino mass is q O dτ dL ). In section Prospino ) in the framework of the real MSSM. Our computation is dτ 1.1 ] and the confirmation of its Majorana nature [ at 14 TeV [ 1.1 1 0 τ 1 12 Z − q X ]. ) = S 16 ( ˜ g ). Numerical results for the electroweak corrections to glu ˜ g α → 2 s ]. NLO SUSY-QCD contributions were computed in ref. [ ) plane of the Constrained MSSM (CMSSM) lies largely in the re α 2 ( QCD, LO 20 PP / – 1 O dσ 17 The total cross section for gluino pair production was compu The plan of the paper is the following. In section At hadron colliders, colored particles can be searched for m ,m 0 m corrections to the process ( is one of the most importantIndeed, processes its leading cross to the section product is large, the gluino plays a(supposed key role to in be) characterizing gluino SUSY [ models. Th range the contribution ofof the NLO Coulomb electroweak corrections (EW) amounts corrections, u of of a gluino pair is still missing. In this paper, we fill this ga NLO QCD predictions, provided the squark and gluino masses a order in the perturbative expansion the differential cross s ago [ ( be investigated with 1 fb hybrid scheme [ at the LHC are presented in section ing at the numerical value of theour electroweak results. corrections A at list the of Te Feynman diagrams is2 collected in the ap Gluino pair productionThe leading in order lowest contributions order to the process ( part of an ongoing project aiming to evaluate the tree-level that Supersymmetry could be discoveredAmong looking the at others, the the produ process of gluino pair production, Sudakov logarithms at theresummation next-to-leading-logarithmic of the (N leading Coulombprediction corrections [ against scale variation. The NLL contributions to the production of colored SUSY particles at the LHC [ allow not only toamong distinguish MSSM among and others different SUSY beyond models Standar involving Dirac gauginos, are positive and large (fromgluino), and 5 they to reduce 90%, appreciably the dependinginto factorization the on sca publicly the available code masses contributions to the process ( JHEP12(2009)012 . β a,b X , is (2.2) (2.6) (2.5) (2.3) (2.4) dσ /S ˜ g 2  ) can be m . 2 ˜ q, , t 2.4 1 2 = 4 ˜ q, . . The squared !# ) ) in the strong 0 ! ) u b τ ˜ g . The sum runs s X 2 ˜ α g 2 , i u ˜ 2 q, 1 + a s H ˜ g ! τ τ x m t ss u ) and ( 2 α 1 are the lowest order  ( 1 ˜ 2 q, ˜ q, − t + ˜ g t P 2.3 O ˜ | 1 g 1 x. We retain the mass 1 i 1 ˜ + q, f → ˜ 2 q, 0 1

) , u 1 es ( u nhancement due to tan 2 gg ˜ x g s 1 ˜ . The cross sections can be 2 q, (  f the initial (final) particles ˜ g 2 u t

dσ A P ˜ s g , , | r the spins and the colors of ˜ 2 g m t o ˜ 2 g

j 2 2 r. We use the convention u

f

˜ g 2 consider the five light quarks as m ˜ g ˜ t g , , ˜ g ˜ g ) ) + and 2 2 → → 2 + 4 + 4 0 0 + 16 k k  ˜ g ¯ , , q inside the hadron ( ( ˜ g 1 1 q gg + 16
x τ − g g  i ˜ g 2 → at a given order 0  2 ¯ ,  ˜ g q ) ˜ ) ˜ u M M 2 q ˜ 2 1 q, 1

1 2 u P | X s of appendix k k ˜ g 1 u + ˜ q, j ( ( t t dσ ˜ f 2 g 9 ˜ ˜ g g t " ) X X + + x 1 2 2  ( + 1 ˜ ˜ q, g 1 → → P – 3 – s 1 ˜ | q, 2 πs πs u u i ˜ g dt 2 dt t ) ) s ˜ g f 2 2 t  16 16 m h  p p 2 ) ( ( ) − ˜ 2 g q g ˜ x g 2 = = dx t u 1 2 ) ) ˜ ˜ g g 1 s 1 72 1 ˜ ˜ g g  + + τ . The lower limit on the integral over p p Z ( ( ( → → s s s 0 0 ( s ¯ , q , 2 q ˜ ˜ g 2 g 2 g 2 2 q 2 gg π π ij m m 2 s δ dσ 2 s dσ 1 α α 36( 36( 8 1+ 27 + + = 18 = u, d, c, s, b )= 2 2 τ

= ( ˜ ˜ g g ˜ ˜ g g ij q → → 0 0 dτ ¯ , q , dL 1 q 1 gg is the tree-level contribution to the amplitude of the proce ] 0 M M ,

1 X 21 – M ) is the momentum distribution of the parton X X 17 x In lowest order, the partonic cross sections for the process ( H | i amplitudes averaged (summed) over theread spins [ and the colors o related to the threshold for the production of the gluino pai f with the help of the parton luminosities, defined according t over the quarks where to denote the cross section for a partonic process obtained from the Feynman diagramswritten in as figure respectively. The crossthe sections incoming are (outgoing) averaged particles. (summed)massless In ove this and analysis we we approximate will of the the CKM bottom matrix in by the the Yukawa unity couplings, matri owing to the possible e We perform our computation in Feynman gauge. and electroweak coupling constants. Therefore, differential cross sections for the partonic processes JHEP12(2009)012 (2.7) (3.2) (3.1) ), from 2 α (  . ) , O , ˜ 2 g ˜ 2 g ). Besides the τS les in the final #) m m ( ) ]. The reduction − 2.2 ˜ ], while the scalar gγ − ˜ ), we consider the g τS ). Renormalization t u 31 ( 33 α → α q 1 , 2 s , q ( ˜ , g = = 2 q ˜ g f the quark–anti-quark α . 30 ˜ O ˜ g g ( 32 [ → er to cure the UV diver- [ 1 dσ o q , O ˜ g 2 γ at ˜ g to the first two generations, . Infrared (IR) and collinear )+ → dσ 1 her produced at , q ) 1 q s at τ ino pair together with an (anti- ntribution are displayed in fig- τS ( ( q M ˜ g γ ˜ g ˜ g FeynArts giving a small mass to the photon ˜ g FormCalc dτ → 1 ∗ , dL → q , u 0 ] production, EW contributions enter , t 2 , q q 1 q ˜ LoopTools 2 q,a 29 ˜ 2 q,a dσ )+ M m m  n ) τS − τ − ( ) are the electroweak one-loop corrections to ( t u Re q ˜ gq ). The NLO EW contributions to the hadronic q ˜ g 2 – 4 – 3.1 α = = ) are built according to eq. ( dτ 2 s → 1 dL , α 2 X ˜ qγ ˜ 3.1 q,a q,a ( " 2 O dσ dτ ) πs dt 1 0 τ τ ( 16 Z qγ ) via photon-induced processes. Therefore, in contrast to = ( dτ ] and squark-gluino [ α ˜ g dL s ˜ g q 28 α X + ( → , 1 , t , u , , q 2 2 2 2 q O 27 ) ) ) 2 2 2 , ) = dσ p k k . S . 25 ( t A + − − 1 2 1 ), yielding the following partonic cross section, ˜ gX − p p p ˜ g luminosities entering ( s → 2.3 ¯ q − = ( = ( = ( γ ) corrections to the hadronic process EW NLO PP ˜ t 2 g 2 has been taken into account because of the identical partic s u α / m 2 s annihilation with electroweak loops dσ is the one-loop electroweak contribution to the amplitude o and α ¯ q ˜ g of appendix ( = 2 ˜ g q qγ → u We treat UV divergences using dimensional reduction. In ord O 1 12 , q initial states, nor at q 1 ¯ q The first class of corrections entering eq. ( singularities are treated usingand mass to regularization, the i.e. five light quarks. 3.1 differential cross section reads as follows, states. The Mandelstam variables are defined as squark–anti-squark [ q A factor 1 M virtual corrections and the real photon radiation processe of the one-loop integrals is performed with the help of only at NLO, and they are at least of one-loop integrals are numerically evaluated using the processes ( The of mass and wavefunction of the quarks and squarks belonging and photon-induced processes leading to the)quark. production of Diagrams a glu and amplitudes are generated with Gluinos do not interact weakly, thus a pair of gluinos is neit gences we have to renormalize the quark and the squark sector annihilation process. Theure diagrams responsible for this co 3 JHEP12(2009)012 ). 0, m s α (3.3) (3.4) (3.6) (3.5) ( → shows 3 O k β gian that bb ¯ 0 tan h ! s 2 1  α 2 b, 2 b, ˜ ˜ β m m . This parameters

b tan µ DR”) scheme defined ∆ α ln b 2 have to be considered as ) within the Rs2 scheme 2 b, ˜ m ounting in tan α A virtues and drawbacks, we m ( ), can be accounted for by 1 nman diagrams depicted in − O β 2 b, ˜ receives radiative corrections , 1 arameter ], and several renormalization n schemes. The first (second) . n ) m b  3 xtra-couplings is OS” (” " y 38 k hen the tree-level contribution of β ( – α tan ) b !# ˜ 2 g γ 1 n s ˜ 2 g b m 34 2 b, ˜ ) m α sin cos 2 ( m regime, the tree-level relation between Rs b m . k − + O ( # m β

1 g b 1+∆ 2 b, bb ˜ ¯ 5 of the appendix ) ˜ ln 0 1 m 1 = k H biγ 12 ¯ coupling is dynamically generated at 2 b, ˜ ( )( 0 ˜ 2 g ˜ g Rs b  β 0 u m A – 5 – is the bottom mass in a given renormalization ˜ 2 g h m is large and it is worth to include such effects α m  β → m tan − Rs b − β β → ) b 2 tan ¯ b + 2 2 m µ boson, has been performed according to the proce- 2 b, b ˜ tan p Rs b ∆ − ˜ g ( ! . ∆ m b q m tan 2 b W ˜ m 2 g y )( 2 b, ˜ ) 2 1 − m m 2 b, ˜ 1+ p 1 ( 

m and q  ] that, in the large tan we keep the mass of the b-quark that appears in the couplings. β α b ln β − 44 ]. The renormalization of mass and wavefunction of the botto ˜ ˜ 2 g g 1 m – ˜ DR scheme. g . The integral over the phase space is IR divergent when 2 b, ˜ cos cos enhanced contributions, of m 28 tan 39 A 2 and the bottom Yukawa couplings m − Higgs Yukawa couplings. In particular, the effective Lagran " → 2 b, β ˜ ( b − b ¯ s Rs b m b b ¯ π v m α 3 m 2 + is defined as − b b = = b ∆ of appendix annihilation with real photon emission eff. Higgs ]. The renormalization of the stop-sbottom sector at and of the mass of the L ¯ q 38 β 10 q In the case of has been defined in the scheme, Rs. ∆ in the relation between requires the renormalization of the supersymmetric Higgs p of tan Concerning the Higgs sector, the is included. This contributionfigure can be computed using the Fey in ref. [ well. It is well known [ dure described in ref.and [ top quarks andschemes squarks have has been been proposed. widely Eachperform studied of our these [ schemes computation has using itsscheme, two own referred different in renormalizatio the following as Rs1 (Rs2), is the ” the bottom mass IR singularities in the virtualthe corrections partonic are process cancelled of w real photon radiation, 3.2 modifying the correctly takes into account these dynamically generated e This coupling can be enhanced if tan In this case, the last twelve diagrams in figure that can be strongly enhanced and have to be resummed. Power c that the leading tan means of the substitution JHEP12(2009)012 ) – a of α 2 s 45 been (3.7) (3.8) (3.9) α 11 ( O . ], respectively. 3.4 50 become singular. , 11 49 trinsically suppressed arios we consider, the g to the suppression of ]. As already mentioned, ent of the whole ms depicted in figure ntegration uncertainty. 28 ¯ q, , . tion and the subsequent decay ) ) of the on-shell squarks into the ¯ q e space slicing and dipole sub- q. 3 3 obtained squaring the resonant on are again absorbed into the nd the virtual contributions are ted in figure k k Fs), c.f. section ) are the tree-level contributions ing both, phase space slicing [ ˜ 0. IR and collinear divergences g ˜ g q, es related to the collinear splittings ( ( → q q ] and in refs. [ 1.1 , since this PDF is originated from ) ) → → → 2 2 45 α i k k ∗ p ( ( q q g g · ) ˜ ) ˜ 3 1 1 k ¯ qγ, γ k k ( ( ˜ ˜ g g and ˜ and ˜ → – 6 – ¯ q → → ∗ ˜ ) ) ˜ q q 2 2 ˜ g ˜ g p p ( ( ]. The two methods are in good numerical agreement, q γ → → q γ, ) ) 49 1 1 ¯ q , p p ( → ( ). Collinear singularities remain and have to be absorbed vi q γ γ 48 γ q q , the quark in the final state can be the decay product of an on- 3.1 ], the extraction of the Breit-Wigner pole contribution has ˜ g ) contributions to the process ( 29 α , 2 s >m α ˜ 21 q ( fusion m O ¯ q γ . A and qγ Note that, if Collinear singularities arising from initial state emissi The contribution of this channel is expected to be small owin ] and dipole subtraction [ correction. 3.4 Factorization of initialAs already collinear mentioned, the singularities universal logarithmic divergenc appearing in the phase space integration are regularized us These contributions can be computed from the Feynman diagra the emission of acontribution photon of from this a partonic (anti-)quark. process amounts In up the SUSY to scen few perc 47 while collinear singularities appear whenever shell squark. If this is the case the last four diagrams depic IR singularities cancel when theadded together, real as radiation in processes eq.the a ( factorization of the parton distribution functions3.3 (PD appendix performed in the narrow width approximation. The results obtained using the two methods agree within the i as found also in the case of squark-anti–squark production [ of the partonic processes The related poles have to becorresponding regularized propagator. inserting the Furthermore, width thediagrams contribution has to be subtractedof since it an arises (anti-)squark from through the (anti-)quark–photon produc fusion, PDFs. These singularities aretraction. regularized The using formulae both, needed phas can be found in ref. [ the photon PDF insidewith the respect proton. to the Indeed, valence quark the PDF photon by PDF a is factor in The last class of According to refs. [ JHEP12(2009)012 ]. he 52 . ]. We (3.11) (3.10) (3.12) ) 38  ) ) zτS ( zτS . ˜ ( ) g ˜ ˜ g g , x ]. We obtain the suggested by the ˜ g ( → 0 ′ ], starting from the , q 54 → 0 2 , q q + 3 expressed in units of 2 q 55 [ z tribution functions at dx f q dσ dσ .  a eters quoted in ref. [ 2 SPS1a + 2 + 0 ) corrections. ) i Z in ref. [ (2) q z α z , equal to the factorization ( H (1) q R ation. We factorize the (anti- 1 e initial scale. MRST2004qed − SPheno − O ,  µ (1) H 2 1 g h z 2 3 8 dz + (1 − dz 1 0 − − 2  z 1 0 z . z  Z z ˜ g 1 Z (1)  ) g m ) − )= τ ] project. The second one, called SPS2, τ ( z − 1 + 8 ( = (  q ) q 53 q ) F γ − x qγ z dτ ( µ dτ dL  g MS mass factorization scheme. As discussed in dL − – 7 – 1  2 q z = ) e is the charge of the quark x (1 z R − π α ( q , P z )+ DR scheme is computed according to ref. [ µ e 1 2 . τ 2 q z − 2 F ( z 2 q B 2 F µ m  . The low-energy input parameters for these scenarios − dx f µ qγ m 1  ( 1 dτ 1 1+  distribution is defined as a dL ln q ]. This fit takes into account QED-effects into the DGLAP Z +  ), while  X ] read as follows, ) ln ) )= 2 q 51 z z e z ), τS ( ( )= dτ ( · · · ( (2) q π α x / qγ qq 1 qq 2 0 3 ( 3.1 ˜ g H τ of appendix P P g P Z − m + 5 ) in the DIS scheme. The effect of this factorization is to add t = = )] α and ( x = 4 ) = ( (2) (1) q q O 0 f S (1) q [ z H ( H H ˜ gX dx ˜ g 1 → a , and to the gluino mass, i.e. Z Fact. PP F ], the DIS scheme is used for the factorization of the µ dσ 50 In our computation we set the renormalization scale, is defined as 0 following term into eq. ( are absorbed into the definition of the PDFs via mass factoriz )quark PDFs at where the splitting functions are z Supersymmetry Parameters Analyses (SPA) [ The value of the bottom mass in the input parameters shown inare table collected in table evolution equations and the parametrization of the PDF at th ref. [ PDFs are defined at NLO QCD within the choose two different SUSY scenarios. Thebelongs first to scenario the is set the parameters of of Snowmass the two Points scenarios and with Slopes, the help introduced of the program the positron charge. The [ The functions In the actualNLO computation, QED we and use NLO QCD the [ MRST2004qed parton dis scale, 4 Numerical results, LHC For our numerical discussion we use the Standard Model param JHEP12(2009)012 ′ . The ut they 2 ]. We do 56 [ = 14 TeV). In 1 S − √ 1 ons amount up to QCD, LO 13% 29% f the two scenarios . . σ · 0 0 L √ is defined as = 100 fb collected in table mn shows the sum of the the LHC ( δ L s as small as few percent of relevant. In the case of the affecting the measurement of 07% 31% scheme, the finite part of the ed the Rs1 scheme turns out δ . . . The numbers in parentheses are 0 0 such as the uncertainty on the 1 is within the integration error. 0 − − − 10 elative to the LO + NLO EW result . n schemes since they agree within , is comparable with the value of al error affecting the measurement of 2 )) contribution for the points SPS1a ” + ” SPS2 fin b α 300 GeV 1450 GeV 2 s the electroweak corrections are much α δA ′ + EW, NLO = 100 fb 2 s ′ σ EW, NLO L α σ ( 1, and the perturbative expansion is spoiled. + 37 . O + EW, NLO ∼ σ ” + ” – 8 – 10 ) ( b 300 GeV SPS1a 70 GeV 2 s 250 GeV 1822(6) pb 2089(1) pb − . . α /A ( 6 1 QCD, LO fin b O σ QCD, LO ) σ Z ) δA ≡ 2 µ M δ / 0 0 ( 1 ) contributions. In the fourth column the contribution of A m β m α 2 s sign( are defined at the GUT scale. α parameter tan ( 0 itself, i.e. O A QCD, LO b ) corrections are of the same order of the statistical error b σ 1865(6) pb 2127(1) pb α . . A 2 s 6 1 and α 0 ( ′ m O annihilation channel cross section. The latter contributi , b ¯ 2 / b 1 point SPS2 SPS1a m ) corrections relative to the total result is given, i.e. α 2 s . MSSM input parameters for the computation of the spectrum o . Total hadronic cross section for gluino pair production at α ( As one can see, in the case of the point SPS1a O and SPS2. In theare fourth given. column The the last electroweakthe corrections column total r shows cross an section estimate for of an the integrated statistic luminosity In the last entrythe we give total an cross estimate section of based the statistical on error an integrated luminosity of 4.1 Dependence onWe the compute SUSY the scenario total hadronic cross section, the results are the numerical uncertainties on the last digit. Table 2 Table 1 second column shows thelowest lowest order order and results. of the The third colu not distinguish the results inthe the integration different renormalizatio error.to A be priori unreliable this in isrenormalization the not constant scenarios guaranteed. of we are the Inde considering. trilinear coupling, In this the second (third) column we show the the trilinear coupling are smaller than the theoretical systematic uncertainties the point SPS2, the smaller than the statistical uncertainty and so they are not However, the difference amongthe the tree-level renormalization schemes i several fb, therefore the variation of the results in table considered. JHEP12(2009)012 1500 GeV. . The EW & 1 T 4% of the total p . ntum of the two bution. The two lines n figure [GeV] [GeV] ontribution relative to inv inv M M the LHC. In the left panels region, for meter space of the MSSM. meters in the second renor- T 2000 2500 3000 ass parameters are equal and p the order of 0 . With these assumptions there ributions. In the right panels the he shape of the distribution. τ 1500 2000 2500 3000 nsverse momentum distribution”. A ) corrections to gluino pair produc- α = 0 0 -1 -1 2 s n.

t

. The physical masses of the sfermions

-0.5 -0.5 α

[%] [%] ( A δ δ O ′ Susy M – 9 – SPS2 SPS1a ] and the factorization scale dependence (from 3 to 5% LO distribution NLO distribution LO distribution NLO distribution 21 diagonalizing the mass matrices. Moreover, we consider the [GeV] [GeV] 10%) [ Susy inv inv . M M M 2000 2500 3000 ]. 24 we consider the distribution of the largest transverse mome 1500 2000 2500 3000 2 ) corrections are rather small, the absolute value of their c -4 -3 -4 -3 -2 α . Invariant mass distribution for gluino pair production at

2 s

1 TeV) [ 10 10 10 10 10

inv inv

[pb/GeV] /dM d /dM d [pb/GeV] α σ σ ( ≤ O In figure The invariant mass distribution of the two gluinos is shown i ˜ g m 4.2 Dependence on theIn MSSM this parameters subsection we investigate the size of the tion in a more systematicThe way, parameters performing involved a in scan themalization over scan scheme. the are We para the suppose that independentwe all para indicate the their sfermionic value soft in m the Rs2 scheme as we show theare LO indistinguishable, (black owing line)electroweak to correction and the relative the to smallness the LO of total + the result is NLO EW show cont EW (redPDF line) parametrization distri ( can be obtained from the total result is at most 1%, reaching this value in the high Figure 1 contribution. Moreover, these corrections do not distort t if corrections are small, their absolute value being at most of gluinos, for brevity we will referThe to this observable as ”tra surfaces of the parameter space characterized by JHEP12(2009)012 ρ or re is more . As expected, 3 ameters and we study [GeV] [GeV] . T T 0 p p A e exclusion limits arising boson has been computed air of parameters, while the ly, contributions. . ], and the bound on the mass β, m 58 100 tan · 0 500 1000 0 500 1000 , 0 0 -1 -1

b

-0.5 -1.5 -0.5 -1.5

[%] [%] δ δ ′ , A EW, NLO t σ which enters in the virtual correction of the t + , A SPS2 A values. Here there is a brief discussion on the – 10 – EW, NLO SPS1a 2 ′ σ QCD, LO σ LO distribution NLO distribution LO distribution NLO distribution ] and at the Tevatron [ , µ, M ≡ ˜ g , but considering the transverse momentum distribution. ]. Moreover, each point in the selected regions fulfills the 57 1 ∆ being the dominant SUSY corrections to the electroweak 61 – , m ρ The results of this scan are displayed in figure 59 [GeV] [GeV] [ T T Susy . p p values. ∆ varies only by an amount of the order of few percent f b M A β 025, ∆ . 0 and in the definition of the mass of the top squarks. This featu and . Same as figure ˜ g t | ≤ ˜ g ρ A ∆ 0 500 1000 1500 0 500 1000 1500 → | -5 -4 -3 -4 -2 -3 b

10 10 10 10 10 10 b T T

[pb/GeV] /dp d [pb/GeV] /dp d σ σ Figure 2 FeynHiggs 2.5.1 We perform four different scans. In each scan we select two par evident for large tan results of these scans. Scan over We repeat each of theseremaining scans four for are different values fixed of to another p their SPS1a The subregions of thefrom parameter SUSY space searches are at LEP chosen imposing [ th ∆ is quite independent on the parameter condition are eight independent parameters involved in the scan, name of the light Higgsusing boson. The physical mass of the light Higgs parameter, corrections arising from top and bottom squarks the dependence of the quantity ∆, process JHEP12(2009)012 for 65. . and is at 0 µ ˜ g | − 45 m ∆ 1000 | 40 for different for different 500 35 0 b A

30 β A

0 [GeV]

m

tan tan b

25 A and 20 −500 and t endence of the lowest 15 values. β A 1). . ′ −1000 values. is more important and 10 (0 ′ is almost independent on . As a general result the 2 , the dependence of ∆ on 5 O 4 −1500 reaching the value of M f iation of ∆ as a function of Susy 2 −1500 600 M 1500 to 1500 GeV ). Note that M −1000 800 − = 730 GeV. In the case of the last −500 =1250 GeV ~ g 0

[GeV] 0 and ). In all cases the value of =730 GeV [GeV] t 1000 A A m Susy ˜ g 500 , ∆ is almost independent on Susy 1200 5 Susy m M 1000 1400 =730 GeV, m =40, M −0.69

1, while in the first plot, characterized by 100 as a function of

−0.101 β

, M −0.686 −0.687 −0.688 −0.689 −0.102

.

−0.1005 −0.1015 −0.1025 ∆ ∆ · Susy ˜ g 0 100 as a function of tan M tan ) · m − neutralinos are much lighter than the gluino. ) / – 11 – 45 3 to . 1000 varies, growing as the value of this parameter grows. EW, NLO 0 40 σ 2 EW, NLO − 500 35 σ + M ) while the dependence on = 1250 GeV and +

30 β 0

˜

g

[GeV]

tan tan As can be inferred from figure b

25 A Susy In this scan we investigate the dependence of ∆ on m . 20 −500 QCD, LO 0 As displayed in figure . , M σ QCD, LO ˜ ˜ g g A 15 ( σ over a quite broad range (from . / m −1000 ( m m t 10 2 / . The other parameters are fixed to their SPS1a 7. A . 5 . The other parameters are fixed to their SPS1a M −1500 Susy and and −1500 Susy M EW, NLO 600 and σ EW, NLO β M −1000 b and 800 σ Susy −500 =750 GeV A ~ g and but varies strongly as 0 , the value of ∆ is enhanced for small values of

[GeV] µ 0 =730 GeV [GeV] 1000 and M t β

A µ A m ) strongly varies for different values of ˜ 500 g Susy 0 Susy 1200 . ∆= A . ∆= m M 1000 · =730 GeV, m 1400 =15, M

−0.111

2 −0.101 β

−0.1112

−0.1114 −0.1116 −0.1118 , which is expected to be the most important because of the dep −0.1108 −0.1008 −0.1012 −0.1014 −0.1016 ∆ ∆ Susy β,m Notice that the mass of the lightest neutralino and chargino M tan ∼ Susy ˜ g M So this enhancement occurs when charginos Scan over order cross section on these parameters. We consider the var the value of three plots the value of ∆ is of order m particularly pronounced when each value of the pair ( Figure 4 Figure 3 Scan over tan (tan in the whole subregion considered the absolute value of ∆ is o values of tan overall dependence is mild for each value of ( most of the order of 0 Scan over a variation of values of JHEP12(2009)012 ∆ for ˜ g m ≡ − 400 ξ 600 1600 GeV, and 1500 1500 800 ≥

Susy [GeV]

˜ g decreases. The

[GeV] [GeV] being enhanced values.

1000

2 2

Susy

M

M M ′

for different values m M 2 1000 1000 1200 2 Susy M asing importance of M M 1400 500 500 1600 and µ . Note that we plot 600 values. 6 ′ 800 1000 1000 =1250 GeV ~ g =750 GeV 3 in the region 1000 ~ g 1200 1500 1500

[GeV] 100 as a function of ∼ [GeV] [GeV] ~ g

µ µ 1400 m · =1100 GeV 2 increases and as ξ ) 1600 2000 2000 1 3 2 0 ˜ g 1800 2.5 1.5 0.5 −0.1 −0.3 = 1350 GeV, m = 730 GeV, m

=15, M

−0.26 −0.28 −0.32 −0.34 −0.06 −0.08

m

β

ξ , see figure

∆ ∆ Susy Susy β M M tan 100 as a function of EW, NLO is affected by the value of · ) σ ˜ g – 12 – + m 400 500 and tan 600 1500 and 2 EW, NLO increases as σ 800 ξ QCD, LO M + σ

Susy [GeV]

1000

[GeV] [GeV] (

1000

2

2

Susy

M M /

M M 1000 1200 . The other parameters are fixed to their SPS1a β QCD, LO 1400 1500 σ ( EW, NLO 500 1600 / σ − and tan 2 600 M 800 EW, NLO ∆ = 1000 2000 =750 GeV . The other parameters are fixed to their SPS1a σ ~ g as a function of =1250 GeV 1000 ~ g ξ 1200 1500 1500 [GeV] ≡ − Susy [GeV] [GeV] ~ g

µ 1400 µ m =600 GeV ξ ) for different values of 2 M 1600 2000 1000 . . ∆= 1 500 GeV. 3 2 0 1800 3.5 2.5 1.5 0.5 Susy −0.2 −0.4 −0.6 = 1350 GeV, m = 730 GeV, m

=15, M

−0.24 −0.26 −0.27 −0.28

−0.25

≤

and β

ξ

∆ ∆ Susy Susy The enhancement of the EW corrections is related to the incre ˜ g M M , M tan ˜ g m Susy m M behaviour of for smaller values of this parameter. In particular Figure 6 instead of ∆. As a general feature Figure 5 different values of of ( JHEP12(2009)012 ]. 64 (5.2) (5.1) . B , starting channel, c.f. sidered. We is small owing . u i ) SPheno x f Susy ( and P M of appendix t | i s higher. Indeed, the 5 f the scenarios TP1 and DF and D0 collabora- the MSSM parameter f  . These points are com- gluino mass rises. Since k–anti-quark annihilation 3 τ x 550 GeV). The low-energy able  belong to the region of the to be more important at the h the gluino is heavier than ass of the gluino grows. The s the momentum fraction of P ∼ e, it is worth to estimate the | ced when he Tevatron, i.e. to the process ed in the j e by the D0 collaboration [ ˜ t f ” 6= ˜ q + 0 3 − TP2 m  ” τ x ), provided that the definition of the 120 GeV 500 GeV  5.1 P | j ˜ g X. ” f ) ˜ g 0 3 − x ( TP1 ” → P | – 13 – 200 GeV 130 GeV i P f 340 GeV, and h ) P 460 GeV), while the second one describes a scenario ∼ Z ) x dx 2 µ ˜ g ∼ M 0 / 0 1 ( 1 ˜ t τ m A m β 6= Z m ˜ q sign( m ij parameter tan δ 1 1+ )= 500 GeV, ), is replaced by τ ( ∼ 2.2 ij ˜ g we show the total hadronic cross section in the two points con dτ dL m 4 ]. We obtain the parameters in these scenarios with the help o 64 – . MSSM input parameters for the computation of the spectrum o , which are enhanced when the squark masses decrease. annihilation channel when the production threshold become 9 62 ¯ q For numerical evaluation, we focus on two different points of In table q The previous analysis can be easily extended to ( figure from the input parameters at the GUT scale described in table Table 3 to the presence of tree-level diagrams with squarks exchang space, referred to asparameter TP1 space and of TP2 the respectively.tions MSSM These [ used points in the data analysis made by C input parameters for the scenarios TP1 and TP2 are listed in t In particular, the firstthe one squarks corresponds ( to a scenario in whic luminosity, eq. ( patible with the experimental limits set by the analysis mad characterized by a light gluino ( Tevatron than at the LHC, owingchannels to with the enhancement respect of to theimpact quar the of the gluon EW fusion contributions to channel. gluino pair Therefor production at t 5 Numerical results, Tevatron The EW contributions to gluino pair production are expected minimal value of thethe parton’s relative momentum importance fraction ofthe rises the (anti-)quark increases, as (anti-)quark the PDF the EWrelative increases importance corrections of a grow the as EW the contributions is m more pronoun the TP2. JHEP12(2009)012 F µ 1%). estimate − on, while the e. the process 3 to − . In both cases 7 1 6 % QCD, LO . and do not change σ 61 % · 3 L ] claims that the [GeV] [GeV] √ 64 inv inv 2 to 5% ( M M n figure the Tevatron via the process − he point TP1 (TP2) EW ref. [ o 20%. ties affecting SUSY searches he electroweak contributions. 14% 26% δ . . 800 1000 1200 0 1 at the expected final integrated − − der of al cross section based on an integrated

0 6 4 2 0 1000 1200 1400 -1

-2 -3 -4 -2 own in the right panels.

[%] [%] δ δ EW, NLO σ + TP2 TP1 – 14 – 16691(1) fb . 048256(4) pb . 0 0 QCD, LO . In the case of the point TP1, the size of the elec- σ 2 LO distribution NLO distribution LO distribution NLO distribution . In the case of the point TP2 we obtain a relative statistical [GeV] [GeV] 1 inv inv − . , but considering gluino pair production at the Tevatron, i. QCD, LO M M 1 2 σ 96 TeV, and different SUSY scenarios. The last column shows an − 16714(1) fb . . 048864(3) pb 8 fb . 0 0 8 fb × =1 800 1000 1200 × S √ = 2 =2 at L TP1 TP2 . In the left panels we show the LO and the EW+NLO EW contributi point ) corrections are small compared to the lowest order results L 1000 1200 1400 -6 -6 -4 -5 -3 -4 -5 α . Invariant mass distribution of the two gluinos produced at

2 s ˜ 10 10 10 10 10 10 10

gX

˜ . Same as table inv gX inv

[pb/GeV] /dM d /dM d [fb/GeV] ˜ σ σ g α ˜ g ( The invariant mass distribution for the two points is shown i → O → P P electroweak corrections relative to the total result are sh use the same notation as in table P the shape ofcorrections the relative distribution. to the total In contribution particular, are of in the the or case of t Figure 7 Table 4 dependence of the total cross section gives an error from 15 t troweak corrections is so smallluminosity that they will not be visible the P Moreover it is worthat to the notice Tevatron that are the typically systematic greater uncertain than 1%. For instance, error of order 4% which is three times bigger than the size of t of the statistical errorluminosity affecting the measurement of the tot JHEP12(2009)012 n 1% − 5 to . 2 − n of the electroweak [GeV] [GeV] T T uction at the Tevatron p p schemes were used. The contributions do not enter Compared to squark–anti- was performed within two ions of the parameter space. mentum distribution, shown er. eter space investigated by the lative to the total contribution oduction channel in a wide part ) contributions at the LHC in two α 2 s 0 200 400 0 100 200 300 400 500 6 4 2 0 0 α -1 -2 -2 -3 -4 (

) corrections to gluino pair production

[%]

[%] O δ δ α 2 s ) contributions are small and negligible. α α ( 2 s O α TP1 TP2 ( – 15 – O ] production, the EW contributions to gluino pair 29 LO distribution NLO distribution LO distribution NLO distribution , but considering the transverse momentum distribution. 7 ) contribution is rather independent on the renormalizatio α 2 s α [GeV] [GeV] ( T T p p 5% in the case of the TP1 point and of the order of O . 2 to 4 . Same as figure − ] and squark-gluino [ 28 0 100 200 300 400 500 0 200 400 600 , . The shape of the distribution is not affected by the insertio -6 -5 -6 -4 -5 -3 -4

8

25

10 10 10 10 10 10 10 T T

[pb/GeV] /dp d [fb/GeV] /dp d σ σ Figure 8 We have also provided numerical results for gluino pair prod Similar considerations hold in the case of the transverse mo We have studied the numerical impact of the in the TP2 scenario. 6 Conclusions In this paper, we have computed the full different scenarios and we have performedThe scans EW over corrections many are reg squark negative and [ can be safely neglected. production are less important. Thethe main gluon reason fusion is channel, that whichof the is the EW the region leading of tree-level the pr parameter space investigated in this pap in figure corrections in both points.are of The order electroweak corrections of re selecting two scenarios belonging toD0 the and region CDF of collaborations. the Again, param the at the LHC and at the Tevatron. Two different renormalization numerical value of the scheme. The treatmentdifferent of methods. the IR and collinear singularities JHEP12(2009)012 q S q ˜ g ˜ g ˜ g ˜ g γ ˜ g ˜ g s → ˜ q ˜ g q q s q ˜ ˜ g q γ q q . γ q ˜ gγ ˜ ˜ g g . ˜ g . g g ˜ g → q ˜ g → q q ˜ g ˜ γ, Z g ˜ g γ gg = s ˜ 0 g ˜ g ˜ q q s q ˜ q V and q q nkel for useful discussions γ ˜ g ˜ g n the following the label acknowledged for countless q ˜ g g g → q ˜ g q ˜ g ˜ g ˜ g q ˜ g γ ˜ g s g ˜ q q . The diagrams for the process q g ˜ gq q ˜ g γ q q g → g qγ ˜ g – 16 – ˜ g ˜ g ˜ ˜ g ˜ g g q γ s ˜ q s s s q q ˜ ˜ ˜ q q q q q q q γ ˜ g ˜ g q q γ ˜ g ˜ ˜ g g ˜ ˜ g g ˜ g s ˜ g ˜ q γ s q q ˜ . Tree-level diagrams for the processes q ˜ g g s q s q ˜ ˜ q q q q q γ s q . Tree-level diagrams for the real photon emission process ˜ q q q q γ ˜ g ˜ g Figure 9 g ˜ g . Tree-level diagrams for the process ˜ ˜ g g ˜ ˜ ˜ g g g q γ ˜ q ˜ g g γ Figure 10 q s g g ˜ q q q q s s s ˜ ˜ ˜ q q q ) is used to denote charged (neutral) Higgs bosons. Moreover γ q q q γ 0 q q q S Acknowledgments We are indebted to Jan Germer, Wolfgang Hollik, and Maike Tre and for reading thesuggestions manuscript. in the Michael early Rauch stages is of gratefully this work. A Feynman diagrams In this appendix we( collect the relevant Feynman diagrams. I Figure 11 can be obtained inverting the arrows. JHEP12(2009)012 s 0 ′ ˜ q q ˜ ˜ ˜ ˜ g g g g ′ V ˜ g ˜ ˜ g g 0 t q ˜ ˜ ˜ ˜ ˜ g g g g g ′ V ˜ q s s ′ ′ t ˜ ˜ s q q t s ′ q ˜ q ˜ q q ′ ′ q ˜ ˜ q q t t 0 s 0 ˜ ˜ ˜ q q q S u V q q q q q W ˜ ˜ q χ q q b q q b q ˜ ˜ g s g ˜ t s ′ t t u ˜ q q ˜ ˜ ˜ ˜ g g g g ˜ f ˜ g ˜ ˜ g g u q ′ ˜ ˜ ˜ ˜ ˜ g g g g g t ˜ q ˜ s s q S ′ ′ t b b ˜ ˜ s q q q ˜ q t s ˜ q q q ˜ ˜ q q t t 0 s 0 ˜ ˜ q q ˜ q 0 S V S q q q q q 0 V q q b q q ˜ χ s ˜ ˜ g g b q b ˜ ˜ g ˜ g s ˜ q b b t ˜ ˜ s g q ˜ q ˜ ˜ g g q . Diagrams with crossed final states 0 q S ˜ ˜ ˜ g g g b b t ˜ g u S ˜ ˜ ˜ ˜ ˜ ˜ g g g g g g ′ ′ ˜ q ˜ g ˜ q s s g ˜ ˜ q q q q t ′ s s ′ ′ ′ q ˜ q → t t s s q q 0 ˜ ˜ ˜ g q q ˜ ˜ q q ˜ 0 χ q S q ˜ g q q q q q q ˜ W g S q ˜ g b t q q q q ˜ t ˜ χ b t g s b ˜ S b q b ˜ s g – 17 – 0 ˜ q q ˜ ˜ g g ˜ ˜ ˜ g g g S ˜ ˜ ˜ ˜ ˜ ˜ g g g g g g t ˜ χ ˜ q q s s g ˜ ˜ q q q q t q ˜ s s q ˜ g t t s s q q 0 ˜ g ˜ ˜ g g t ˜ ˜ ˜ ˜ q q 0 q q ′ 0 b S ˜ ˜ q q q q q q q χ V b q q b q q 0 s s b ˜ χ ˜ b 0 ˜ q b q q S b ˜ ˜ g g ′ q s ˜ ˜ g g ′ ˜ ˜ ˜ g g g ˜ ˜ g g ˜ 0 q ˜ ˜ ˜ g g g ′ ˜ χ q s ˜ g g g t ˜ s q ˜ g t ˜ ′ ˜ g g ′ ′ ′ t ′ ˜ ˜ q ˜ t q ′ ′ q q s ˜ q t 0 s b t t q q ˜ ˜ q ˜ q ˜ t χ q V q q q s q q q q ˜ q W b b q q S S q b q q W b ˜ ˜ ′ g g q ˜ ˜ g g . One-loop EW diagrams for the process s W ˜ ˜ ˜ ˜ g g g g ˜ ˜ g g ˜ q ˜ ˜ ˜ ˜ ˜ ˜ g g g g g g t W q b s ˜ s g g t ˜ s q b ˜ ′ ′ t b q q ˜ q ˜ ˜ q q t t s s 0 b b q q ˜ ˜ q ˜ ˜ q 0 0 q q u V ˜ b q q q q q χ ′ S 0 ˜ q q b q q q b b q q V 0 0 q S Figure 12 are not shown. V JHEP12(2009)012 (1973) B46 3 91 48 -77 503 500 506 628 337 562 561 562 492 365 562 500 -323 -362 TP2 0.987 ]. 38 , 3 82 155 179 193 153 386 499 475 463 463 485 371 463 179 -318 -580 -127 TP1 0.874 Phys. Lett. , set of low-energy input nsidered, more details can 10 125 232 403 784 971 -806 -181 1453 1450 1453 1494 1562 1557 1557 1306 1545 1456 0.993 SPS2 rations are mass degenerate. ′ 10 , is fixed as in ref. [ 125 171 195 103 193 396 426 608 565 548 547 586 366 546 173 -945 -446 ˜ t 0.823 ˜ θ SPS1a ]. Since light quark masses are neglected, ˜ c,R ˜ ˜ ˜ s,R c,L µ,R µ 38 ˜ ν m m m m m , , , , ˜ t (GeV) (GeV) , – 18 – β (GeV) 1 θ 0 (GeV) 2 1 2 τ e , ˜ 1 2 (GeV) ˜ ˜ ˜ ˜ ˜ ˜ ˜ ˜ ˜ A u,L u,R t, t b, g d,R ν τ, ν e,R ˜ b τ ]. m m m cos tan M M µ A A m m m m m m m m m : ˜ g . Squarks belonging to the third generation have been Is the Neutrino a Goldstone Particle? 5 m SPIRES [ = R Supergauge Transformations in Four-Dimensions µ = (1974) 39 F µ B 70 Mixing angle, stop sector: On-shell masses (GeV): DR parameters evaluated at the scale Parameters . Low-energy input parameters for the four SUSY scenarios co 109. Nucl. Phys. [1] J. Wess and B. Zumino, [2] D.V. Volkov and V.P. Akulov, B Input parameters For the four SUSY scenarios considered in this work we use the be found in the text. parameters introduced in table Table 5 The angle describing the mixing in the stop sector, labelled according to thesame-charge conventions and of same-chirality ref. squarks [ of the first two gene References JHEP12(2009)012 ng , , , ] , (1984) 1 Riv. Nuovo , ]. on 110 arXiv:0802.3672 , SPIRES The Supersymmetric ] [ ]. ]. collider energies arXiv:0707.3447 (2006) 095010 [ Phys. Rept. ¯ p (2002) 101804 p , (2004) 161802 eiglein, SPIRES ]. 89 ]. D 74 92 ] [ SPIRES [ (2007) 87 ]. SPIRES SPIRES ]. Testing the Majorana Nature of Gluinos arXiv:0808.2410 ]. [ ] [ [ ]. Measurement of the Positive Muon Measurement of the negative muon Phys. Rev. B 657 , (1982) 227 Discovering supersymmetry with like sign SPIRES [ Phys. Rev. Lett. SPIRES CMS technical design report, volume II: Physics SPIRES Hadroproduction of Supersymmetric Particles Phys. Rev. Lett. , [ hep-ph/9306204 SPIRES – 19 – [ , ] [ [ ]. B 112 Expected Performance of the ATLAS Experiment. Search for Supersymmetric Particles in Hadron-Hadron ]. Phys. Lett. (2008) 095007 (1985) 75 , It’s a gluino physics Observables and Electroweak Precision Data hep-ph/0512284 [ SPIRES arXiv:0901.0512 [ − , SPIRES (1993) 349 117 Experimental Constraints on Gluino Masses and [ B (1985) 1581 (2007) 995 D 78 The Search for Supersymmetry: Probing Physics Beyond the Same-sign top quarks as signature of light stops at the LHC ]. ]. ]. Phys. Lett. , Supersymmetric particle production at Prediction for the Lightest Higgs Boson Mass in the CMSSM usi D 31 G 34 arXiv:0706.0652 B 315 [ (1983) 223 SPIRES SPIRES SPIRES Physics Beyond the Standard Model: Supersymmetry (1985) 645 (2006) 075002 ] [ ] [ ] [ Phys. Rev. Phys. Rept. , , J. Phys. Looking Beyond the Standard Model: The Supersymmetric Opti (1988) 1. B 213 , Supersymmetry, Supergravity and Particle Physics collaboration, G.W. Bennett et al., collaboration, G.W. Bennett et al., D 32 D 73 Phys. Rev. (2007) 083 Phys. Lett. , collaboration, G. Aad et al., ]. ]. ]. , 08 collaboration, G.L. Bayatian et al., 11N4 SPIRES hep-ph/0605067 hep-ex/0401008 hep-ex/0208001 SPIRES SPIRES Anomalous Magnetic Moment to 0.7 ppm Detector, Trigger and Physics Indirect Experimental Constraints CMS Phys. Rev. Collisions Supersymmetric Theories Nucl. Phys. Phys. Rev. [ [ [ anomalous magnetic moment to[ 0.7 ppm ATLAS dileptons and Neutralinos [ JHEP Muon g-2 [ performance Muon g-2 Cim. Parameter Space in Light of Standard Model [8] [3] H.P. Nilles, [4] H.E. Haber and G.L. Kane, [5] R. Barbieri, [7] O. Buchmueller et al., [9] [6] J.R. Ellis, S. Heinemeyer, K.A. Olive, A.M. Weber and G. W [11] [19] E. Reya and D.P. Roy, [20] S. Dawson, E. Eichten and C. Quigg, [12] A. Alves, O. Eboli and T. Plehn, [17] G.L. Kane and J.P. Leveille, [10] [13] R.M. Barnett, J.F. Gunion and H.E. Haber, [14] S. Kraml and A.R. Raklev, [15] S.Y. Choi, M. Drees, A. Freitas and P.M. Zerwas, [16] M.M. Nojiri et al., [18] P.R. Harrison and C.H. Llewellyn Smith, JHEP12(2009)012 , ]. ]. , ]. eak ] and air ]. ] SPIRES SPIRES ]. ]. ] [ SPIRES ] [ ] [ SPIRES [ ]. ]. SPIRES SPIRES , ] [ Stop-antistop and ] [ ]. arXiv:0905.4749 [ ]. hep-ph/0304006 (2001) 115013 ]. [ SPIRES SPIRES (2002) 79 (2002) 54 hep-ph/0411114 ] [ [ ] [ ]. arXiv:0709.2544 [ SPIRES , 143 D 64 arXiv:0807.2405 SPIRES [ or model parameters dependence ] [ Verzegnassi, ]. B 643 ] [ SPIRES hep-ph/9611232 , ] [ SPIRES High-precision predictions for the (2003) 563 hep-ph/9807565 Squark and gluino production at [ (2009) 095004 Electroweak Contributions to Squark arXiv:0712.0287 ] [ [ (2005) 465 On the two-loop sbottom corrections to One-loop corrections to the chargino and SPIRES Analysis of the chargino and neutralino Phys. Rev. C 29 ] [ D 80 , hep-ph/9610490 (2007) 095020 [ C 39 Nucl. Phys. arXiv:0810.1044 [ (2009) 111802 , Electroweak contributions to squark-gluino (1999) 153 hep-ph/0012260 (2008) 018 [ hep-ph/0601248 [ PROSPINO: A program for the Production of D 76 Hadronic production of top-squark pairs with 102 – 20 – 02 118 arXiv:0804.1252 [ (1997) 51 Phys. Rev. arXiv:0806.1433 , [ Eur. Phys. J. Comput. Phys. Commun. (2009) 002 , , Automatized one-loop calculations in four and D Eur. Phys. J. hep-ph/0305328 JHEP [ , 02 (2001) 418 The implementation of the minimal supersymmetric standard , ) (2006) 236 Phys. Rev. B 492 s Squark anti-squark pair production at the LHC: the electrow , α Threshold resummation for squark-antisquark and gluino- p Soft gluon resummation for the production of gluino-gluino ]. ]. ]. b The sfermion mass spectrum of the MSSM at the one-loop level 140 α (2008) 4779 157 News from FormCalc and LoopTools JHEP Phys. Rev. Lett. (2008) 087 , , 12 (2003) 127 SPIRES SPIRES SPIRES A 23 ] [ ] [ ] [ Nucl. Phys. , C 32 JHEP Comput. Phys. Commun. , , Generating Feynman diagrams and amplitudes with FeynArts 3 ]. ]. SPIRES hep-ph/0206101 hep-ph/0104109 hep-ph/0105349 SPIRES MSSM Higgs sector at O( model in FeynArts and FormCalc mass parameters at one-loop level Eur. Phys. J. [ production at the LHC dimensions Nucl. Phys. Proc. Suppl. [ [ production at the LHC squark-antisquark pairs at the[ LHC Pair Production at the LHC contribution Comput. Phys. Commun. neutralino mass matrices in the on-shell scheme the neutral Higgs boson masses in the MSSM [ Int. J. Mod. Phys. Supersymmetric Particles In Next-to-leading Order QCD electroweak NLO contributions hadron colliders sbottom-antisbottom production at LHC: a one-loop search f [31] T. Hahn and C. Schappacher, [36] W. Oller, H. Eberl, W. Majerotto and C. Weber, [37] W. Hollik and H. Rzehak, [38] S. Heinemeyer, W. Hollik, H. Rzehak and G. Weiglein, [32] T. Hahn and M. P´erez-Victoria, [35] A. Brignole, G. Degrassi, P. Slavich and F. Zwirner, [23] A. Kulesza and L. Motyka, [24] A. Kulesza and L. Motyka, [26] M. Beccaria, G. Macorini, L. Panizzi, F.M. Renard and C. [27] S. Bornhauser, M. Drees, H.K. Dreiner and J.S.[28] Kim, W. Hollik and E. Mirabella, [29] W. Hollik, E. Mirabella and M.K. Trenkel, [30] T. Hahn, [33] T. Hahn and M. Rauch, [34] H. Eberl, M. Kincel, W. Majerotto and Y. Yamada, [25] W. Hollik, M. Kollar and M.K. Trenkel, [22] W. Beenakker, R. Hopker and M. Spira, [21] W. Beenakker, R. Hopker, M. Spira and P.M. Zerwas, JHEP12(2009)012 ]. + , s ¯ tbH , SPIRES ] , ] [ (2000) 88 (2003) 275 (2000) 055006 (1988) 172 153 corrections B 577 SUSY particle decays D 62 ]. (2005) 093002 B 303 ctions at the one loop hep-ph/0411040 ]. , [ , (1994) 269 (1993) 307 arXiv:0707.2553 Improved SUSY QCD Electroweak symmetry [ D 72 , SPIRES Nucl. Phys. 41 Parton distributions er, ]. , ] [ ]. Phys. Rev. SPIRES e, , ]. Review of particle physics Effective Lagrangian for the B 426 servables ] [ Nucl. Phys. , (2005) 155 (2008) 138 SPIRES SPIRES Phys. Rev. ] [ , SPIRES ] [ Comput. Phys. Commun. Polarized QED splittings of massive C 39 , ] [ Nucl. Phys. Fortschr. Phys. B 790 Electroweak higher-order effects and theoretical , , hep-ph/9306309 [ Electroweak corrections to W-boson hadroproduction Quasireal electron method in high-energy quantum – 21 – colliders hep-ph/0511344 ]. [ − The Top quark mass in supersymmetric SO(10) e (1973) 381. + Eur. Phys. J. e ]. , hep-ph/0202233 Nucl. Phys. [ arXiv:0802.1405 [ SPIRES , hep-ph/9904440 [ [ (1994) 7048 Supersymmetry parameter analysis: SPA convention and B65 ]. (2006) 43 ]. ]. ]. ]. ]. collaboration, W.M. Yao et al., SPIRES [ D 50 C 46 The Snowmass points and slopes: Benchmarks for SUSY searche SPIRES (2002) 113 (2000) 69 (2008) 146 SPIRES SPIRES SPIRES SPIRES SPIRES ] [ (1994) 6168 ] [ ] [ ] [ ] [ ] [ Nucl. Phys. , (2006) 1 Yukawa coupling unification with supersymmetric threshold C 25 A general approach to photon radiation off fermions B 565 B 800 Phys. Rev. Techniques for calculation of electroweak radiative corre D 49 SPheno, a program for calculating supersymmetric spectra, Supersymmetry and the Quark Mass Matrix , G 33 ]. ]. Eur. Phys. J. , hep-ph/0301101 SPIRES hep-ph/0509084 arXiv:0709.1075 hep-ph/9912463 hep-ph/9402253 hep-ph/9912516 SPIRES [ level and results for W physics at LEP-200 incorporating QED contributions breaking and bottom-top Yukawa unification [ Eur. Phys. J. [ J. Phys. project uncertainties in deep-inelastic neutrino[ scattering Particle Data Group Nucl. Phys. Nucl. Phys. at finite transverse momentum [ [ [ electrodynamics fermions and dipole subtraction for non-collinear-safe ob [ Phys. Rev. corrections to Higgs boson decays into quarks and squarks and SUSY particle production at unification interaction in the MSSM and charged Higgs phenomenology [50] K.P.O. Diener, S. Dittmaier and W. Hollik, [47] W. Hollik, T. Kasprzik and B.A. Kniehl, [51] A.D. Martin, R.G. Roberts, W.J. Stirling and R.S. Thorn [52] [53] J.A. Aguilar-Saavedra et al., [45] V.N. Baier, V.S. Fadin and V.A. Khoze, [48] S. Dittmaier, [49] S. Dittmaier, A. Kabelschacht and T. Kasprzik, [54] B.C. Allanach et al., [55] W. Porod, [43] M.S. Carena, D. Garcia, U. Nierste and C.E.M. Wagner, [44] H. Eberl, K. Hidaka, S. Kraml, W. Majerotto and Y. Yamada [40] L.J. Hall, R. Rattazzi and U. Sarid, [41] R. Hempfling, [42] M.S. Carena, M. Olechowski, S. Pokorski and C.E.M. Wagn [46] A. Denner, [39] T. Banks, JHEP12(2009)012 ] , collisions ]. ¯ p production p (2006) 119 , Zγ SPIRES ] [ B 638 and hep-ph/0212020 ]. [ ]. = 1.96 TeV Wγ Towards high-precision s , √ (1999) 4937 SPIRES ]. ] [ Phys. Lett. 83 SPIRES (2003) 133 , ]. ]. ] [ Weiglein, , hep-ph/0611326 [ SPIRES C 28 ] [ SPIRES SPIRES ] [ ] [ = 1.96 TeV collision data at s ¯ p hep-ph/0509234 √ (2007) 047 p [ Phys. Rev. Lett. FeynHiggs: a program for the calculation of the , of hep-ph/9812320 Electroweak corrections to 02 Search for gluinos and scalar quarks in [ – 22 – Search for neutral MSSM Higgs bosons at LEP 1 Eur. Phys. J. Search for squarks and gluinos in events with jets and Search for squarks and gluinos in events with jets and − , fb Search for squarks and gluinos in events containing jets hep-ex/0106001 [ JHEP (2006) 125 , hep-ex/0602042 collisions at [ arXiv:0712.3805 (2000) 76 ¯ [ p p ]. ]. C 47 124 (2006) 547 (2002) 041801 SPIRES SPIRES (2008) 449 ] [ ] [ 88 The Higgs boson masses and mixings of the complex MSSM in the C 47 Eur. Phys. J. TeV using the missing energy plus multijets signature B 660 , 8 . collaboration, S. Schael et al., ]. =1 collaboration, A.A. Affolder et al., s collaboration, V.M. Abazov et al., collaboration, B. Abbott et al., collaboration, V.M. Abazov et al., √ hep-ex/9902013 SPIRES hep-ex/0604029 missing transverse energy using 2.1 and a large imbalance in transverse energy missing transverse energy in at D0 Phys. Lett. [ D0 [ CDF Phys. Rev. Lett. Comput. Phys. Commun. Eur. Phys. J. [ Feynman-diagrammatic approach ALEPH D0 masses of the neutral CP-even Higgs bosons in the MSSM predictions for the MSSM Higgs sector at the LHC [64] [62] [63] [59] S. Heinemeyer, W. Hollik and G. Weiglein, [57] [58] [60] M. Frank et al., [61] G. Degrassi, S. Heinemeyer, W. Hollik, P. Slavich and G. [56] E. Accomando, A. Denner and C. Meier,