Black Holes at the LHC can Determine the Spin of Higgs Bosons

Black Holes at the LHC can Determine the Spin of Higgs Bosons
Black Holes at the LHC can Determine the Spin of Higgs Bosons

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UT-02-28Black Holes at the LHC can Determine the Spin of Higgs bosons Yosuke Uehara Department of Physics,University of Tokyo,Tokyo 113-0033,Japan Abstract We propose a new method to determine the spin of Higgs bosons at the LHC by using the decay products of black holes.Black holes may be produced if TeV-scale gravity theories are correct,and black holes decay into several particles.This decay results in the emission of high energy particles,including Higgs bosons.The di?erence of the degree of freedom between spin 0and spin 1Higgs bosons leads to a di?erence of the number of reconstructed Higgs bosons.From this fact,we can determine the spin of Higgs bosons with 5σsigni?cance by using the integrated luminosity L ~2.4fb ?1,which can be accumulated in only one month operation.

The theories of TeV-scale gravity have the possibility that we can operate the experiments which directly access Planckian and transPlanckian region.The most exciting phenomenon in these theories may be the production of black holes at the LHC[1–3],Tevatron[4]and future linear colliders[5].Once black holes are produced,black holes decay by emitting the Hawking radiation.Since we do not know the fundamental theory of the quantum gravity,we can calculate only the decay of transPlanckian black holes and in the following we neglect the decay processes in the Planckian region.

TransPlanckian black holes have masses M BH,which is beyond the fundamental scale O(TeV).The temperature of such black holes T BH is typically a few hundred GeV[1,2].Thus the decay products of black holes have energies beyond100GeV and black holes have the possibility to produce the particles which are not discov-ered yet,like Higgs bosons.In fact,[6]claimed that the black holes produced at the LHC decay into Higgs bosons,leading to the5σdiscovery on the?rst day of its operation.(If the fundamental scale is1TeV.)

In this letter,we show that the spin of Higgs bosons can also be determined by the decay of black holes.

It was di?cult to determine the spin of the Higgs bosons at the LHC Most channels su?er from too large backgrounds or too few events,and hence detailed studies of angular distributions are not easy.But in this letter,we propose a completely di?erent method to determine the spin,not relying on the angular distributions.

As a beginning we brie?y review the mechanism of black hole production and decay.

The black hole decay occurs in several stages:balding phase,spin-down phase, Schwarzshild phase and Planck phase[1].Through the balding phase,black holes will settle down to a symmetrical rotating black holes by emitting gauge and grav-itational radiation.In the spin-down phase,by emitting the Hawking radiation they lose their spin and enter Schwarzshild phase.Schwarzshild black holes emit quanta and lose their energies.After this phase,their properties are very di?cult to analyse because of the quantum gravity e?ects.

In this letter we concentrate on the non-spinning Schwarzshild black hole.Since the production cross section of spinning black holes is~2?3times higher than that of Schwarzshild black holes[7],and in the spin-down phase the spin-1Higgs boson emittion is preferred Sto the Schwarzschild phase because spin-1Higgs bosons can carry angular momentum by themselves,making the spin of the Higgs boson easy to detect.So our approximation is conservative.

The parton level non-spinning black hole production cross section is given by[2]:

σ(M BH)~πR2S=1

M D

(

8Γ(n+3

n+2

) 2/(n+1),(1)

where n is the number of extra dimensions,R S is the Schwarzshild radius of(n+4)-

dimensional black holes and M D is the fundamental scale of TeV-scale gravity theories,which is often given by:

M n+2

D

V n=M2pl,(2) where V n is the n-dimensional volume of compacti?ed extra dimensions.

But in order to validate the supossition that the produced object is truly a black hole,the entropy of the object must be large enough.[1,8]concluded that the necessary condition is

M BH>~5M D(3) We have to integrate equation(1)in order to obtain the total cross section.In

that process we convolute the parton distribution function of protons with energies √

4πR S

.(4) The energy spectrum of decay products is obtained by averaging Planck formula, and it is roughly:

E ~2T BH.(5)

So now we can obtain the number of particles emitted from black holes N.

N=M BH

M D

)(n+2)/(n+1).(6)

Black holes do not discriminate the Standard Model(SM)particles,and thus the probability of a certain particle being emitted from them depends on the degree of freedom of the particle.That of the SM is about120,and that of spin0Higgs bosons is1.

Here we end the brief review,and from now we consider how to determine the spin of Higgs bosons by using black holes produced at the LHC.

First we must pay attention to the current bounds on n and M D.According to the review[10],the cases of n=2,3are already rejected as the candidates of the TeV-scale gravity.Then the left possibility is4≤n≤7,but since superstring theory or M-theory predict10-or11-dimensional spacetime,we choose n=6and n=7as candidates.In these cases,the constraints on M D are very weak[11],and we can roughly set M D=1TeV.

Now we have determined n,M D and M min

BH

.So we can calculate the total cross section of black holes at the LHC.It becomes[2]:

σ~106fb.(7) Here we assume the integrated luminosity L=100fb?1.So~108black holes are produced.

As stated above,the degree of freedom of the SM is about120and that of Higgs bosons is1.So as N increases,the probability that black holes decay into Higgs bosons drastically decreases.From the?gure1(d)of[2]and our setup,we observe N≥4.(In the case M BH=5TeV.)Since as we increase the mass of produced black hole,the production cross section decreases exponentially,we concentrate on the case of N=4,namely a black hole decay into four particles,including one Higgs boson.We trigger the event by the observation of one reconstructed Higgs boson and that of very high energy(E T>~a few TeV)three particles or jets. Three particles except one Higgs boson must satisfy the following conditions:

?The possible particle candidates are gluon,quarks except top,electron,muon and photon.Top,tau,Z and W±decay before they are detected,and neutri-nos and gravitons(including their Kaluza-Klein excitations)escape from the detection.

?The total electric charge of three particles Q must satisfy|Q|<4/3.

The degree of freedom which satis?es these requirements becomes roughly110000 d.o.f.Thus P,which denotes the probability that the decay of black holes are triggered becomes:

P~5.1×10?4.(8) So from the108black holes,51000possible candidates are left.

We assume that the masses of Higgs bosons are m h=120GeV.By using a program HDECAY[12],the branching ratios of such Higgs bosons are calculated to be:

BR(h→bˉb)~0.66,(9a)

BR(h→W W?)~0.14,(9b)

BR(h→g g)~0.076,(9c)

BR(h→τˉτ)~0.074.(9d) The trigger conditions stated above are so stringent that the processes(9a-9d)are almost background free.

We assume that in analyzing this process,Higgs boson is already discovered. then we do not have to b-quaarks to be b-tagged,and gluons can also be used for the reconstruction.W W andττcan be reconstructed when they decay hadronically or semileptonically.So the reconstruction e?ciency becomes0.92.So if we operate the LHC with the integrated luminosity100fb?1and under the above trigger assumption,we can observe51000×0.92=47000Higgs bosons.

Now,let us assume that Higgs bosons have spin1.Such situations can be realized in strongly electroweak symmetry breaking models.If the spin of Higgs bosons is1,the degree of freedom becomes three,leading to the enhancement factor

3of produced Higgs bosons in the decay of black holes.So in that case we expect 140000spin1Higgs bosons will be produced.

Strongly electroweak symmetry breaking models have extra vector bosons which break electroweak symmetry and become the alternative of the Higgs bosons in the SM.Since we are considering120GeV Higgs bosons,the decay of spin1Higgs bosons into W W is highly suppressed,and they mainly decay into fermions.We use electrons,muons and quarks except top for the reconstruction.Then we obtain 92000reconstructed spin1Higgs bosons.

Now let us?nalize our discussion.if the spin of Higgs bosons is truly0,we can con?rm the hypothesis with:

|47000?92000|

~210σ.(10)

42000

For the5σdiscovery,only L=2.4fb?1is needed.Low luminosity run of the LHC is designed to be1033cm?2s?1,namely10?6fb?1s?1.Thus only the one month operation is enough to announce the5σdiscovery of the spin0nature of Higgs bosons.

So black holes produced at the LHC or other colliders have the potential not only to discover new physics[1,5–8],but also to measure the properties of the SM particles more precisely[5,14].One example of the precision measurement is just the determination of the spin of Higgs bosons.

To summarize,in this letter we propose a new method to determine the spin of Higgs bosons at the LHC by the decay of black holes.The method relies on the fact that the probability a black hole decays into a particular particle depends on the degree of freedom of the particle.Spin1Higgs bosons have the freedom which is three times larger than that of spin0Higgs bosons.This fact results in the di?erence of the number of reconstructed Higgs bosons.We can reject the hy-pothesis that Higgs bosons have spin1with5σsigni?cance by using the integrated luminosity L=2.4fb?1,which can be accumulated in one month operation.

Acknowledgment

Y.U.thank Japan Society for the Promotion of Science for?nancial support.

References

[1]S.B.Giddings and S.Thomas,Phys.Rev.D65,056010(2002)[arXiv:hep-

ph/0106219].

[2]S.Dimopoulos and https://www.360docs.net/doc/d39860261.html,ndsberg,Phys.Rev.Lett.87,161602(2001)

[arXiv:hep-ph/0106295].

[3]P.C.Argyres,S.Dimopoulos and J.March-Russell,Phys.Lett.B441,96

(1998)[arXiv:hep-th/9808138].S.Dimopoulos and R.Emparan,Phys.Lett.B 526,393(2002)[arXiv:hep-ph/0108060].S.Hossenfelder,S.Hofmann,M.Ble-icher and H.Stocker,arXiv:hep-ph/0109085.G.F.Giudice,R.Rattazzi and J.D.Wells,Nucl.Phys.B630,293(2002)[arXiv:hep-ph/0112161].P.Kanti and J.March-Russell,arXiv:hep-ph/0203223.L.A.Anchordoqui,H.Goldberg and A.D.Shapere,arXiv:hep-ph/0204228.K.Cheung,arXiv:hep-ph/0205033.

K.Cheung and C.H.Chou,arXiv:hep-ph/0205284.

[4]M.Bleicher,S.Hofmann,S.Hossenfelder and H.Stocker,arXiv:hep-

ph/0112186.

[5]Y.Uehara,arXiv:hep-ph/0205068.

[6]https://www.360docs.net/doc/d39860261.html,ndsberg,Phys.Rev.Lett.88,181801(2002)[arXiv:hep-ph/0112061].

[7]S.C.Park and H.S.Song,arXiv:hep-ph/0111069.

[8]K.m.Cheung,arXiv:hep-ph/0110163.

[9]R.C.Myers and M.J.Perry,Annals Phys.172,304(1986).

[10]Y.Uehara,arXiv:hep-ph/0203244.

[11]L.A.Anchordoqui,J.L.Feng,H.Goldberg and A.D.Shapere,arXiv:hep-

ph/0112247.

[12]A.Djouadi,J.Kalinowski and M.Spira,https://www.360docs.net/doc/d39860261.html,mun.108,56

(1998)[arXiv:hep-ph/9704448].

[13]ATLAS Detector and Physics Performance Technical Design Report,CERN-

LHCC99-14.

[14]Y.Uehara,arXiv:hep-ph/0205199.

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